RAC2

Gene Summary

Gene:RAC2; Rac family small GTPase 2
Aliases: Gx, EN-7, HSPC022, p21-Rac2
Location:22q13.1
Summary:This gene encodes a member of the Ras superfamily of small guanosine triphosphate (GTP)-metabolizing proteins. The encoded protein localizes to the plasma membrane, where it regulates diverse processes, such as secretion, phagocytosis, and cell polarization. Activity of this protein is also involved in the generation of reactive oxygen species. Mutations in this gene are associated with neutrophil immunodeficiency syndrome. There is a pseudogene for this gene on chromosome 6. [provided by RefSeq, Jul 2013]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:ras-related C3 botulinum toxin substrate 2
Source:NCBIAccessed: 29 August, 2019

Ontology:

What does this gene/protein do?
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Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 29 August 2019 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

Tag cloud generated 29 August, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (5)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: RAC2 (cancer-related)

Cao Y, Zhu W, Chen W, et al.
Prognostic Value of BIRC5 in Lung Adenocarcinoma Lacking EGFR, KRAS, and ALK Mutations by Integrated Bioinformatics Analysis.
Dis Markers. 2019; 2019:5451290 [PubMed] Free Access to Full Article Related Publications
Objective: This study was aimed at investigating the prognostic significance of Baculoviral IAP repeat containing 5 (BIRC5) in lung adenocarcinoma (LAD) lacking EGFR, KRAS, and ALK mutations (triple-negative (TN) adenocarcinomas).
Methods: The gene expression profiles were obtained from Gene Expression Omnibus (GEO). The identification of the differentially expressed genes (DEGs) was performed by GeneSpring GX. Gene set enrichment analysis (GSEA) was used to execute gene ontology function and pathway enrichment analysis. The protein interaction network was constructed by Cytoscape. The hub genes were extracted by MCODE and cytoHubba plugin from the network. Then, using BIRC5 as a candidate, the prognostic value in LAD and TN adenocarcinomas was verified by the Kaplan-Meier plotter and The Cancer Genome Atlas (TCGA) database, respectively. Finally, the mechanism of BIRC5 was predicted by a coexpressed network and enrichment analysis.
Results: A total of 38 upregulated genes and 121 downregulated genes were identified. 9 hub genes were extracted. Among them, the mRNA expression of 5 genes, namely, BIRC5, MCM4, CDC20, KIAA0101, and TRIP13, were significantly upregulated among TN adenocarcinomas (all
Conclusion: Overexpressed in tumors, BIRC5 is associated with unfavorable overall survival in TN adenocarcinomas. BIRC5 is a potential predictor and therapeutic target in TN adenocarcinomas.

Tang X, Huang X, Wang D, et al.
Identifying gene modules of thyroid cancer associated with pathological stage by weighted gene co-expression network analysis.
Gene. 2019; 704:142-148 [PubMed] Related Publications
Thyroid cancer is the most common type of endocrine tumor. The TNM classification remains a standard for treatment determination and predicting prognosis in thyroid cancer. The genes modules associated with the progression of papillary thyroid carcinoma (PTC) were not clear. We applied a weighted gene co-expression network analysis (WGCNA) and differential expression analysis to systematically identified co-expressed gene modules and hub genes associated with PTC progression based on The Cancer Genome Atlas (TCGA) PTC transcriptome sequencing data. An independent validation cohort, GSE27155, was used to evaluate the preservation of gene modules. We identified two co-expressed genes modules associated with progression of PTC. Enrichment analysis indicated that the two modules were enriched in angiogenesis and extracellular matrix organization. DCN, COL1A1, COL1A2, COL5A2 and COL3A1 were hub genes in the co-expressed network. We systematically identified co-expressed gene modules and hub genes associated with PTC progression for the first time, which provided insights into the mechanisms underlying PTC progression and some potential targets for the treatment of PTC.

Tang D, Wu Q, Yuan Z, et al.
Identification of key pathways and gene changes in primary pancreatic stellate cells after cross-talk with pancreatic cancer cells (BXPC-3) using bioinformatics analysis.
Neoplasma. 2019; 2019(3):446-458 [PubMed] Related Publications
It is well known that as the king of cancer, pancreatic ductal adenocarcinoma (PDAC) has relatively malignant biological behavior and poor prognosis. The interaction between pancreatic stellate cells and PDAC cells promotes the development of PDAC. The aim of this study was to describe gene characteristics in pancreatic stellate cell (PSCs) after cross-talked with BXPC-3 and unravel their underlying mechanisms. The expression profiling analysis of genes in PSCs was completed after co-cultured with primary BXPC-3 for 48h. The Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analysis and gene ontology (GO) analysis were performed, and the differentially expressed genes (DEGs) were identified by Agilent GeneSpring GX program. In total, 1804 DEGs were filtered out in PSCs, including 958 up-regulated genes and 846 downregulated genes. GO analysis showed that the up-regulated DEGs were significantly enriched in biological processes (BP) such as defense response, immune system process and immune response; the down-regulated DEGs were significantly enriched in biological regulation and cytoskeleton organization. KEGG pathway analysis showed that 28 pathways were upregulated and 5 were downregulated. By constructing PPI network, we selected out 10 key genes (IL6,IL8, IL1B, BCL2, CCL2, CSF2, KIT, ICAM1, PTPRC and IGF1) and significant enriched pathways. In conclusion, the current study suggests that the filtered DEGs contribute to our understanding of the molecular mechanisms underlying the interaction between PSCs and pancreatic cancer cells, and might be used as molecular targets to further the study the role of tumor microenvironment in the progression of PDAC.

Zhao X, Lei Y, Li G, et al.
Integrative analysis of cancer driver genes in prostate adenocarcinoma.
Mol Med Rep. 2019; 19(4):2707-2715 [PubMed] Free Access to Full Article Related Publications
Large‑scale genomics studies have identified recurrently mutated genes in the ETS gene family, including fusions and copy number variations (CNVs), which are involved in the development of prostate adenocarcinoma (PRAD). However, the aetiology of PRAD remains to be fully elucidated. In the present study, 333 driver genes were identified using four computational tools: OncodriveFM, OncodriveCLUST, iCAGES and DrGaP. In addition, 32 driver pathways were identified using DrGaP. SPOP, TP53, SPTA1, AHNAK, HMCN1, ATM, FOXA1, CSMD3, LRP1B and FREM2 were the 10 most recurrently mutated genes in PRAD. ITGAL, TAGAP, SIGLEC10, RAC2 and ITGA4 were the five hub genes in the yellow module that were associated with the number of positive lymph nodes. Hierarchical clustering analysis of the 20 driver genes with the most frequent CNVs revealed three clusters of patients with PRAD. Cluster 3 tumours exhibited significantly higher numbers of positive lymph nodes, higher Gleason scores, more advanced cancer stages and poorer prognosis than cluster 1 and 2 tumours. A total of 48 genes were significantly associated with the number of positive lymph nodes, Gleason scores and pathologic stage in patients with PRAD. The identified set of cancer genes and pathways sheds light on the tumorigenesis of PRAD and creates avenues for the development of prognostic biomarkers and driver gene‑targeted therapies in PRAD.

Aman NA, Doukoure B, Koffi KD, et al.
Immunohistochemical Evaluation of Ki-67 and Comparison with Clinicopathologic Factors in Breast Carcinomas
Asian Pac J Cancer Prev. 2019; 20(1):73-79 [PubMed] Free Access to Full Article Related Publications
Background: Patients primarily received tamoxifen based on their menopausal status due to the lack of immunohistochemistry. A recent study has shown that hormonal receptors were not correlated with menopausal status, and thus, indicating that they present limited therapeutic and prognostic significance in breast cancer management. This study aimed to evaluate Ki-67 value and analyze its association with clinicopathologic parameters in breast cancer patients. Methods: The formalin-fixed paraffin-embedded breast tissue blocks of 125 patients with primary breast carcinomas were subjected to immunohistochemical analysis using Ventana Benchmark® GX automated immunostainer. Analysis of variance and Chi-2 test were used to examine the relationship between Ki-67 and clinicopathologic variables. Results: The mean age of 125 patients included in the study was 47.7 years. The average score of Ki-67 was 56.0%. 84.8% of patients showed Ki-67 ≥ 14%. Mean scores of Ki-67 were correlated with grade (p = 0.006), PR (p = 0.026), histological type, ER, combined ER/RP, and molecular subtype (p < 0.001). Ki-67 was independent of HER2 (p = 0.402) and menopausal status (p = 0.471). The frequency of Ki-67 according to St Gallen 2011 was associated with histological type (p = 0.005), grade (p = 0.005), ER (p < 0.001), combined ER/PR (p = 0.004), and molecular subtype (p = 0.004). There was no significant relationship between the distribution of Ki-67 and the age of the patients (p = 0.859), menopausal status (p = 0.979), PR (p = 0.149), and HER2 (p = 0.597). Conclusion: Ki-67 is useful for treatment decisions in primary breast cancer patients. The high value of Ki-67 was associated with adverse clinicopathologic factors. The increased Ki-67 value should be carefully investigated in triple negative patients.

Gupta S, Mani NR, Carvajal-Hausdorf DE, et al.
Macrodissection prior to closed system RT-qPCR is not necessary for estrogen receptor and HER2 concordance with IHC/FISH in breast cancer.
Lab Invest. 2018; 98(8):1076-1083 [PubMed] Free Access to Full Article Related Publications
An on-demand, closed RT-qPCR, the GeneXpert (GX) system, has the potential to provide biomarker information in low-resourced settings and elsewhere. We used this system with a research use only version of the Breast Cancer STRAT4 cartridge that measures the mRNA expression levels of ERBB2, ESR1, PGR, and MKi67. Here we evaluated the impact of non-macrodissected (non m-d) versus macrodissected (m-d) samples using STRAT4 on formalin-fixed, paraffin-embedded (FFPE) core needle biopsies. Two cohorts were assessed: (1) 60 FFPE infiltrating ductal carcinoma (IDCA) cases and (2) 20 FFPE IDCA cases with ductal carcinoma in situ (DCIS) with a range of HER2 expression as determined by clinical immunohistochemistry and fluorescence in situ hybridization (IHC/FISH). We observed about half of the core needle biopsy area as invasive tumor in both IDCA (mean = 51.5%) and IDCA with DCIS (mean = 53.5%) cohorts, but also found the mRNA levels were independent of tumor area. We found excellent agreement of the mRNA transcript level between the paired samples, m-d versus non m-d, for ERBB2, ESR1, PGR, and MKi67 for both the IDCA and IDCA with DCIS cohorts. No significant difference (P > 0.99) was observed when we compared the mRNA transcript level between the paired samples m-d versus non m-d. In addition, we noted a significant concordance (P < 0.001) between RT-qPCR and IHC/FISH for HER2-positivity, ER-positivity, and PR-positivity, independent of specimen dissection. These data suggest that mRNA expression for ERBB2, ESR, and PGR is sufficiently low in surrounding tissue cells such that macrodissection is not required for assessment of key breast cancer mRNA markers and is independent of the amount of input tumor. This approach may be valuable in settings lacking pathology expertise or using specimen types, such as fine-needle aspirates, where it may be challenging to separate non-tumor from tumor tissue.

Shi Z, Zhou H, Pan B, et al.
Exploring the key genes and pathways of osteosarcoma with pulmonary metastasis using a gene expression microarray.
Mol Med Rep. 2017; 16(5):7423-7431 [PubMed] Free Access to Full Article Related Publications
Osteosarcoma is a common and highly malignant tumour in children and teenagers that is characterized by drug resistance and high metastatic potential. Patients often develop pulmonary metastasis and have a low survival rate. However, the mechanistic basis for pulmonary metastasis remains unclear. To identify key gene and pathways associated with pulmonary metastasis of osteosarcoma, the authors downloaded the gene expression dataset GSE85537 and obtained the differentially expressed genes (DEGs) by analyzing high‑throughput gene expression in primary tumours and lung metastases. Subsequently, the authors performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses and a protein‑protein interaction (PPI) network was constructed and analyzed by Cytoscape software. In total, 2,493 genes were identified as DEGs. Of these, 485 genes (19.45%) were upregulated, and the remaining 2,008 genes (80.55%) were downregulated. The authors identified the predominant GO categories and KEGG pathways that were significantly over‑represented in the metastatic OS samples compared with the non‑metastatic OS samples. A PPI network was constructed, and the results indicated that ALB, EGFR, INS, IL6, CDH1, FYN, ERBB2, IL8, CXCL12 and RAC2 were the top 10 core genes. The enrichment analyses of the genes involved in the top three significant modules demonstrated that the DEGs were principally related to neuroactive ligand‑receptor interaction, the Rap1 signaling pathway, and protein digestion and absorption. Together, these data elucidated the molecular mechanisms of OS patients with pulmonary metastasis and provide potential therapeutic targets. However, further experimental studies are needed to confirm these results.

Nolte E, Wach S, Silva IT, et al.
A new semisynthetic cardenolide analog 3β-[2-(1-amantadine)- 1-on-ethylamine]-digitoxigenin (AMANTADIG) affects G2/M cell cycle arrest and miRNA expression profiles and enhances proapoptotic survivin-2B expression in renal cell carcinoma cell lines.
Oncotarget. 2017; 8(7):11676-11691 [PubMed] Free Access to Full Article Related Publications
Cardiac glycosides are well known in the treatment of cardiovascular diseases; however, their application as treatment option for cancer patients is under discussion. We showed that the cardiac glycoside digitoxin and its analog AMANTADIG can inhibit the growth of renal cell carcinoma (RCC) cell lines and increase G2/M cell cycle arrest. To identify the signaling pathways and molecular basis of this G2/M arrest, microRNAs were profiled using microRNA arrays. Cardiac glycoside treatment significantly deregulated two microRNAs, miR-2278 and miR-670-5p. Pathway enrichment analysis showed that all cardiac glycoside treatments affected the MAPK and the axon guidance pathway. Within these pathways, three genes, MAPK1, NRAS and RAC2, were identified as in silico targets of the deregulated miRNAs. MAPK1 and NRAS are known regulators of G2/M cell cycle arrest. AMANTADIG treatment enhanced the expression of phosphorylated MAPK1 in 786-O cells. Secondly, we studied the expression of survivin known to be affected by cardiac glycosides and to regulate the G2/M cell phase. AMANTADIG treatment upregulated the expression of the pro-apoptotic survivin-2B variant in Caki-1 and 786-O cells. Moreover, treatment with AMANTADIG resulted in significantly lower survivin protein expression compared to 786-O control cells. Summarizing, treatment with all cardiac glycosides induced G2/M cell cycle arrest and downregulated the miR-2278 and miR-670-5p in microarray analysis. All cardiac glycosides affected the MAPK-pathway and survivin expression, both associated with the G2/M phase. Because cells in the G2/M phase are radio- and chemotherapy sensitive, cardiac glycosides like AMANTADIG could potentially improve the efficacy of radio- and/or chemotherapy in RCCs.

Chen G, Wang Y, Wang L, Xu W
Identifying prognostic biomarkers based on aberrant DNA methylation in kidney renal clear cell carcinoma.
Oncotarget. 2017; 8(3):5268-5280 [PubMed] Free Access to Full Article Related Publications
The outcome of kidney renal clear cell carcinoma (KIRC) differs even among individuals with similar clinical characteristics. DNA methylation is regarded as a regulator of gene expression in cancers, which may be a molecular marker of prognosis. In this study, we aimed to mine novel methylation markers of the prognosis of KIRC. We revealed a total of 2793 genes differentially methylated in their promoter regions (DMGs) and 2979 differentially expressed genes (DEGs) in KIRC tissues compared with normal tissues using The Cancer Genome Atlas datasets. Then, we detected 57 and 34 subpathways enriched among the DMGs and DEGs, respectively, using the R package iSubpathwayMiner. We retained 56 subpathways related to both aberrant methylation and expression based on a hypergeometric test for further analysis. An integrated gene regulatory network was constructed using the regulatory relationships between genes in the subpathways. Using the top 15% of the nodes from the network ranked by degree, survival analysis was performed. We validated four DNA methylation signatures (RAC2, PLCB2, VAV1, and PARVG) as being highly correlated with prognosis in KIRC. These findings suggest that DNA methylation might become a prognostic predictor in KIRC and could supplement histological prognostic prediction.

Nicoś M, Jarosz B, Krawczyk P, et al.
Screening for ALK abnormalities in central nervous system metastases of non-small-cell lung cancer.
Brain Pathol. 2018; 28(1):77-86 [PubMed] Related Publications
Anaplastic lymphoma kinase (ALK) gene rearrangement was reported in 3%-7% of primary non-small-cell lung cancer (NSCLC) and its presence is commonly associated with adenocarcinoma (AD) type and non-smoking history. ALK tyrosine kinase inhibitors (TKIs) such as crizotinib, alectinib and ceritinib showed efficiency in patients with primary NSCLC harboring ALK gene rearrangement. Moreover, response to ALK TKIs was observed in central nervous system (CNS) metastatic lesions of NSCLC. However, there are no reports concerning the frequency of ALK rearrangement in CNS metastases. We assessed the frequency of ALK abnormalities in 145 formalin fixed paraffin embedded (FFPE) tissue samples from CNS metastases of NSCLC using immunohistochemical (IHC) automated staining (BenchMark GX, Ventana, USA) and fluorescence in situ hybridization (FISH) technique (Abbot Molecular, USA). The studied group was heterogeneous in terms of histopathology and smoking status. ALK abnormalities were detected in 4.8% (7/145) of CNS metastases. ALK abnormalities were observed in six AD (7.5%; 6/80) and in single patients with adenosuqamous lung carcinoma. Analysis of clinical and demographic factors indicated that expression of abnormal ALK was significantly more frequently observed (P = 0.0002; χ

Frost HR, Shen L, Saykin AJ, et al.
Identifying significant gene-environment interactions using a combination of screening testing and hierarchical false discovery rate control.
Genet Epidemiol. 2016; 40(7):544-557 [PubMed] Free Access to Full Article Related Publications
Although gene-environment (G× E) interactions play an important role in many biological systems, detecting these interactions within genome-wide data can be challenging due to the loss in statistical power incurred by multiple hypothesis correction. To address the challenge of poor power and the limitations of existing multistage methods, we recently developed a screening-testing approach for G× E interaction detection that combines elastic net penalized regression with joint estimation to support a single omnibus test for the presence of G× E interactions. In our original work on this technique, however, we did not assess type I error control or power and evaluated the method using just a single, small bladder cancer data set. In this paper, we extend the original method in two important directions and provide a more rigorous performance evaluation. First, we introduce a hierarchical false discovery rate approach to formally assess the significance of individual G× E interactions. Second, to support the analysis of truly genome-wide data sets, we incorporate a score statistic-based prescreening step to reduce the number of single nucleotide polymorphisms prior to fitting the first stage penalized regression model. To assess the statistical properties of our method, we compare the type I error rate and statistical power of our approach with competing techniques using both simple simulation designs as well as designs based on real disease architectures. Finally, we demonstrate the ability of our approach to identify biologically plausible SNP-education interactions relative to Alzheimer's disease status using genome-wide association study data from the Alzheimer's Disease Neuroimaging Initiative (ADNI).

Wu X, Xia M, Chen D, et al.
Profiling of downregulated blood-circulating miR-150-5p as a novel tumor marker for cholangiocarcinoma.
Tumour Biol. 2016; 37(11):15019-15029 [PubMed] Related Publications
Altered microRNA (miRNA) expression plays a role in cholangiocarcinoma (CCA) development; thus, detection of blood-circulating miRNAs could be useful as CCA markers. This study profiled serum miRNA levels in patients with primary sclerosing cholangitis (PSC) and CCA and then assessed the role of miR-150-5p in CCA progression in vitro. Three samples were randomly selected from each of 50 sera of healthy controls, 30 PSC sera, and 28 CCA sera with matched bile samples for miRNA microarray profiling. The dysregulated miRNAs were confirmed using qRT-PCR, and miR-150-5p was selected for further in vitro and ex vivo studies. The miRNA microarray identified three dysregulated miRNAs in both CCA and PSC samples, while miR-150-5p level was consistently lower in CCA sera, bile, and tissues than in normal control and PSC sera (P < 0.05). Furthermore, levels of miR-150-5p were associated with serum carbohydrate antigen 19-9 (CA19-9) levels and CCA pathological grade. Bioinformatic Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses showed that miR-150-5p could regulate hand-full gene pathways, including cancer pathway (P < 0.01). However, overexpression of miR-150-5p inhibited proliferation, migration, and invasion capability of CCA cells (P < 0.05). Luciferase reporter assay showed that miR-150-5p bound to an oncogene Ets including gene-1 (ELK1), and Western blot data confirmed that miR-150-5p suppressed ELK1 expression in CCA cell lines. These results suggest that reduced miR-150-5p expression could contribute to CCA development and progression due to uncontrolled ELK1 expression. Thus, further study could evaluate miR-150-5p as a novel target and predictor for CCA prevention and treatment.

Walliser C, Hermkes E, Schade A, et al.
The Phospholipase Cγ2 Mutants R665W and L845F Identified in Ibrutinib-resistant Chronic Lymphocytic Leukemia Patients Are Hypersensitive to the Rho GTPase Rac2 Protein.
J Biol Chem. 2016; 291(42):22136-22148 [PubMed] Free Access to Full Article Related Publications
Mutations in the gene encoding phospholipase C-γ

Fokkelman M, Balcıoğlu HE, Klip JE, et al.
Cellular adhesome screen identifies critical modulators of focal adhesion dynamics, cellular traction forces and cell migration behaviour.
Sci Rep. 2016; 6:31707 [PubMed] Free Access to Full Article Related Publications
Cancer cells migrate from the primary tumour into surrounding tissue in order to form metastasis. Cell migration is a highly complex process, which requires continuous remodelling and re-organization of the cytoskeleton and cell-matrix adhesions. Here, we aimed to identify genes controlling aspects of tumour cell migration, including the dynamic organization of cell-matrix adhesions and cellular traction forces. In a siRNA screen targeting most cell adhesion-related genes we identified 200+ genes that regulate size and/or dynamics of cell-matrix adhesions in MCF7 breast cancer cells. In a subsequent secondary screen, the 64 most effective genes were evaluated for growth factor-induced cell migration and validated by tertiary RNAi pool deconvolution experiments. Four validated hits showed significantly enlarged adhesions accompanied by reduced cell migration upon siRNA-mediated knockdown. Furthermore, loss of PPP1R12B, HIPK3 or RAC2 caused cells to exert higher traction forces, as determined by traction force microscopy with elastomeric micropillar post arrays, and led to considerably reduced force turnover. Altogether, we identified genes that co-regulate cell-matrix adhesion dynamics and traction force turnover, thereby modulating overall motility behaviour.

Lai J, Zhou Z, Tang XJ, et al.
A Tumor-Specific Neo-Antigen Caused by a Frameshift Mutation in BAP1 Is a Potential Personalized Biomarker in Malignant Peritoneal Mesothelioma.
Int J Mol Sci. 2016; 17(5) [PubMed] Free Access to Full Article Related Publications
Malignant peritoneal mesothelioma (MPM) is an aggressive rare malignancy associated with asbestos exposure. A better understanding of the molecular pathogenesis of MPM will help develop a targeted therapy strategy. Oncogene targeted depth sequencing was performed on a tumor sample and paired peripheral blood DNA from a patient with malignant mesothelioma of the peritoneum. Four somatic base-substitutions in NOTCH2, NSD1, PDE4DIP, and ATP10B and 1 insert frameshift mutation in BAP1 were validated by the Sanger method at the transcriptional level. A 13-amino acids neo-peptide of the truncated Bap1 protein, which was produced as a result of this novel frameshift mutation, was predicted to be presented by this patient's HLA-B protein. The polyclonal antibody of the synthesized 13-mer neo-peptide was produced in rabbits. Western blotting results showed a good antibody-neoantigen specificity, and Immunohistochemistry (IHC) staining with the antibody of the neo-peptide clearly differentiated neoplastic cells from normal cells. A search of the Catalogue of Somatic Mutations in Cancer (COSMIC) database also revealed that 53.2% of mutations in BAP1 were frameshift indels with neo-peptide formation. An identified tumor-specific neo-antigen could be the potential molecular biomarker for personalized diagnosis to precisely subtype rare malignancies such as MPM.

Zhang JY, Weng MZ, Song FB, et al.
Long noncoding RNA AFAP1-AS1 indicates a poor prognosis of hepatocellular carcinoma and promotes cell proliferation and invasion via upregulation of the RhoA/Rac2 signaling.
Int J Oncol. 2016; 48(4):1590-8 [PubMed] Related Publications
It has been shown that long noncoding RNAs (lncRNAs) play a critical role in the regulation of cellular processes including cancer progression and metastasis. However, the biological functions and clinical significance of lncRNA AFAP1-AS1 in hepatocellular carcinoma (HCC) remain unclear. Expression of AFAP1-AS1 was analyzed in 78 HCC tissues by real-time PCR. The effect of AFAP1-AS1 on cell proliferation was examined by MTT assay, cell apoptosis was detected by flow cytometric analysis and cell invasion was determined by Transwell assay. RhoA/Rac2 signaling and downstream factors were verified by western blotting. HCC cells infected with si-AFAP1-AS1 were injected into nude mice to investigate the effect of AFAP1-AS1 on the tumorigenesis in vivo. We found that increased expression of AFAP1-AS1 was significantly correlated with pathological staging (P=0.024) and lymph-vascular space invasion (LVSI) in HCC patients (P=0.007). Multivariate analyses indicated that AFAP1-AS1 represented an independent predictor for overall survival of HCC (P=0.029). Further experiments showed that knockdown of AFAP1-AS1 by si-AFAP1-AS1 decreased the proliferation and invasion in vitro and in vivo, induced cell apoptosis and blocked cell cycle in S phase via inhibition of the RhoA/Rac2 signaling. Taken together, our findings indicate that AFAP1-AS1 may promote the HCC development through upregulation of RhoA/Rac2 signaling and provide a potential therapeutic target for HCC.

Caye A, Strullu M, Guidez F, et al.
Juvenile myelomonocytic leukemia displays mutations in components of the RAS pathway and the PRC2 network.
Nat Genet. 2015; 47(11):1334-40 [PubMed] Related Publications
Juvenile myelomonocytic leukemia (JMML) is a rare and severe myelodysplastic and myeloproliferative neoplasm of early childhood initiated by germline or somatic RAS-activating mutations. Genetic profiling and whole-exome sequencing of a large JMML cohort (118 and 30 cases, respectively) uncovered additional genetic abnormalities in 56 cases (47%). Somatic events were rare (0.38 events/Mb/case) and restricted to sporadic (49/78; 63%) or neurofibromatosis type 1 (NF1)-associated (8/8; 100%) JMML cases. Multiple concomitant genetic hits targeting the RAS pathway were identified in 13 of 78 cases (17%), disproving the concept of mutually exclusive RAS pathway mutations and defining new pathways activated in JMML involving phosphoinositide 3-kinase (PI3K) and the mTORC2 complex through RAC2 mutation. Furthermore, this study highlights PRC2 loss (26/78; 33% of sporadic JMML cases) that switches the methylation/acetylation status of lysine 27 of histone H3 in JMML cases with altered RAS and PRC2 pathways. Finally, the association between JMML outcome and mutational profile suggests a dose-dependent effect for RAS pathway activation, distinguishing very aggressive JMML rapidly progressing to acute myeloid leukemia.

Čokić VP, Mossuz P, Han J, et al.
Microarray and Proteomic Analyses of Myeloproliferative Neoplasms with a Highlight on the mTOR Signaling Pathway.
PLoS One. 2015; 10(8):e0135463 [PubMed] Free Access to Full Article Related Publications
The gene and protein expression profiles in myeloproliferative neoplasms (MPNs) may reveal gene and protein markers of a potential clinical relevance in diagnosis, treatment and prediction of response to therapy. Using cDNA microarray analysis of 25,100 unique genes, we studied the gene expression profile of CD34+ cells and granulocytes obtained from peripheral blood of subjects with essential thrombocythemia (ET), polycythemia vera (PV) and primary myelofibrosis (PMF). The microarray analyses of the CD34+ cells and granulocytes were performed from 20 de novo MPN subjects: JAK2 positive ET, PV, PMF subjects, and JAK2 negative ET/PMF subjects. The granulocytes for proteomic studies were pooled in 4 groups: PV with JAK2 mutant allele burden above 80%, ET with JAK2 mutation, PMF with JAK2 mutation and ET/PMF with no JAK2 mutation. The number of differentially regulated genes was about two fold larger in CD34+ cells compared to granulocytes. Thirty-six genes (including RUNX1, TNFRSF19) were persistently highly expressed, while 42 genes (including FOXD4, PDE4A) were underexpressed both in CD34+ cells and granulocytes. Using proteomic studies, significant up-regulation was observed for MAPK and PI3K/AKT signaling regulators that control myeloid cell apoptosis and proliferation: RAC2, MNDA, S100A8/9, CORO1A, and GNAI2. When the status of the mTOR signaling pathway related genes was analyzed, PI3K/AKT regulators were preferentially up-regulated in CD34+ cells of MPNs, with down-regulated major components of the protein complex EIF4F. Molecular profiling of CD34+ cells and granulocytes of MPN determined gene expression patterns beyond their recognized function in disease pathogenesis that included dominant up-regulation of PI3K/AKT signaling.

Fu J, Khaybullin R, Zhang Y, et al.
Gene expression profiling leads to discovery of correlation of matrix metalloproteinase 11 and heparanase 2 in breast cancer progression.
BMC Cancer. 2015; 15:473 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: In order to identify biomarkers involved in breast cancer, gene expression profiling was conducted using human breast cancer tissues.
METHODS: Total RNAs were extracted from 150 clinical patient tissues covering three breast cancer subtypes (Luminal A, Luminal B, and Triple negative) as well as normal tissues. The expression profiles of a total of 50,739 genes were established from a training set of 32 samples using the Agilent Sure Print G3 Human Gene Expression Microarray technology. Data were analyzed using Agilent Gene Spring GX 12.6 software. The expression of several genes was validated using real-time RT-qPCR.
RESULTS: Data analysis with Agilent GeneSpring GX 12.6 software showed distinct expression patterns between cancer and normal tissue samples. A group of 28 promising genes were identified with ≥ 10-fold changes of expression level and p-values < 0.05. In particular, MMP11 and HPSE2 were closely examined due to the important roles they play in cancer cell growth and migration. Real-time RT-qPCR analyses of both training and testing sets validated the gene expression profiles of MMP11 and HPSE2.
CONCLUSIONS: Our findings identified these 2 genes as a novel breast cancer biomarker gene set, which may facilitate the diagnosis and treatment in breast cancer clinical therapies.

Manukjan G, Ripperger T, Santer L, et al.
Expression of the ETS transcription factor GABPα is positively correlated to the BCR-ABL1/ABL1 ratio in CML patients and affects imatinib sensitivity in vitro.
Exp Hematol. 2015; 43(10):880-90 [PubMed] Related Publications
In Philadelphia-positive chronic myeloid leukemia (CML), imatinib resistance frequently emerges because of point mutations in the ABL1 kinase domain, but may also be the consequence of uncontrolled upstream signaling. Recently, the heteromeric transcription factor GA-binding protein (GABP) was found to promote CML-like myeloproliferative disease in mice. In a cohort of 70 CML patients, we found that expression of the GABP α subunit (GABPα) is positively correlated to the BCR-ABL1/ABL1 ratio. Moreover, significantly higher GABPα expression was detected in blast crisis than in chronic phase CML after performing data mining on 91 CML patients. In functional studies, imatinib sensitivity is enhanced after GABPα knockdown in tyrosine kinase inhibitors (TKI)-sensitive K-562, as well as by overexpression of a deletion mutant in TKI-resistant NALM-1 cells. Moreover, in K-562 cells, GABP-dependent expression variations of PRKD2 and RAC2, relevant signaling mediators in CML, were observed. Notably, protein kinase D2 (Prkd2) was reported to be a GABP target gene in mice. In line with this, we detected a positive correlation between GABPA and PRKD2 expression in primary human CML, indicating that the effects of GABP are mediated by PRKD2. These findings illustrate an important role for GABP in disease development and imatinib sensitivity in human CML.

Vulsteke C, Pfeil AM, Maggen C, et al.
Clinical and genetic risk factors for epirubicin-induced cardiac toxicity in early breast cancer patients.
Breast Cancer Res Treat. 2015; 152(1):67-76 [PubMed] Related Publications
Anthracycline-induced cardiotoxicity (ACT) is a well-known serious adverse drug reaction leading to substantial morbidity. The purpose of this study was to assess ACT occurrence and clinical and genetic risk factors in early breast cancer patients. In 6 genes of interest (ABCC1, ABCC2, CYBA, NCF4, RAC2, SLC28A3), 10 single nucleotide polymorphisms (SNPs) involved in ACT were selected based on a literature search. Eight hundred and seventy-seven patients treated between 2000 and 2010 with 3-6 cycles of (neo) adjuvant 5-fluorouracil, epirubicin and cyclophosphamide (FEC) were genotyped for these SNPs using Sequenom MassARRAY. Main outcome measures were asymptomatic decrease of left ventricular ejection fraction (LVEF) > 10 % and cardiac failure grade 3-5 (CTCAE 4.0). To evaluate the impact of these 10 SNPs as well as clinical factors (age, relative dose intensity of epirubicin, left-sided radiotherapy, occurrence of febrile neutropenia, and planned and received cycles of epirubicin) on decrease of LVEF and cardiac failure, we performed uni- and multivariable logistic regression analysis. Additionally, exploratory analyses including 11 additional SNPs related to the metabolism of anthracyclines were performed. After a median follow-up of 3.62 years (range 0.40-9.60), a LVEF decline of > 10 % occurred in 153 patients (17.5 %) and cardiac failure in 16 patients (1.8 %). In multivariable analysis, six cycles of FEC compared to three cycles received and heterozygous carriers of the rs246221 T-allele in ABCC1 relative to homozygous carriers of the T-allele were significantly associated with LVEF decline of > 10 % (OR 1.3, 95 % CI 1.1-1.4, p < 0.001 and OR 1.6, 95 % CI 1.1-2.3, p = 0.02). Radiotherapy for left-sided breast cancer was associated with cardiac failure (OR 3.7, 95 % CI 1.2-11.5, p 0.026). The other 9 SNPs and clinical factors tested were not significantly associated. In our exploratory analysis, no other SNPs related to anthracycline metabolism were retained in the multivariate model for prediction of LVEF decline. ACT in breast cancer patients is related to number of received cycles of epirubicin and left-sided radiotherapy. Additional studies should be performed to independently confirm the potential association between rs246221 in ABCC1 and LVEF.

Lee HJ, Lee JJ, Song IH, et al.
Prognostic and predictive value of NanoString-based immune-related gene signatures in a neoadjuvant setting of triple-negative breast cancer: relationship to tumor-infiltrating lymphocytes.
Breast Cancer Res Treat. 2015; 151(3):619-27 [PubMed] Related Publications
The prognostic significance of tumor-infiltrating lymphocytes and immune signals has been described previously in triple-negative breast cancer (TNBC). Furthermore, recent studies have shown that immunologic parameters are relevant for the response to neoadjuvant chemotherapy (NAC) in breast cancer as well as for outcomes after adjuvant chemotherapy. However, immune signals are variable, and which signals are important is largely unknown. We, therefore, evaluated the expression of immune-related genes in TNBC treated with NAC. We retrospectively evaluated biopsy tissue from 55 patients with primary TNBC treated with NAC (anthracycline, cyclophosphamide, and docetaxel) against the NanoString nCounter GX Human Immunology Panel (579 immune-related genes). Higher expression of cytotoxic molecules, T cell receptor signaling pathway components, cytokines related to T helper cell type 1 (Th1), and B cell markers was associated with a pathologic complete response (pCR). Higher expression of NFKB1, MAPK1, TRAF1, CXCL13, GZMK, and IL7R was significantly associated with pCR, higher Miller-Payne grade, and lower residual cancer burden class. Expression of NFKB1, TRAF1, and CXCL13genes, in particular, was significantly correlated with a longer disease-free survival rate. Conversely, patients those who failed to achieve a pCR showed increased expression of genes related to neutrophils. Higher expression of cytotoxic molecules, T cell receptor signaling pathway components, Th1-related cytokines, and B cell markers is correlated with pCR and survival in TNBC patients treated with NAC. Our results suggest that the activation status of neutrophils may provide additional predictive information for TNBC patients treated with NAC.

Reichwagen A, Ziepert M, Kreuz M, et al.
Association of NADPH oxidase polymorphisms with anthracycline-induced cardiotoxicity in the RICOVER-60 trial of patients with aggressive CD20(+) B-cell lymphoma.
Pharmacogenomics. 2015; 16(4):361-72 [PubMed] Related Publications
AIM: To identify gene variants responsible for anthracycline-induced cardiotoxicity.
PATIENTS & METHODS: Polymorphisms of the NADPH oxidase subunits and of the anthracycline transporters ABCC1, ABCC2 and SLC28A3 were genotyped in elderly patients (61-80 years) treated for aggressive CD20(+) B-cell lymphomas with CHOP-14 with or without rituximab and followed up for 3 years.
RESULTS: The accumulation of RAC2 subunit genotypes TA/AA among cases was statistically significant upon adjustment for gender, age and doxorubicin dose in a multivariate logistic regression analysis (OR: 2.3, p = 0.028; univariate: OR: 1.8, p = 0.077). RAC2 and CYBA genotypes were significantly associated with anthracycline-induced cardiotoxicity in a meta-analysis of this and a similar previous study.
CONCLUSION: Our results support the theory that NADPH oxidase is involved in anthracycline-induced cardiotoxicity. Original submitted 9 July 2014; Revision submitted 19 December 2014.

Zu M, Xu X, Zhou WX, et al.
Whole genome expression profiling of gastric high-grade intraepithelial neoplasia with or without cancer.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2015; 37(1):23-9 [PubMed] Related Publications
OBJECTIVE: To investigate the whole genome expression profiles between gastric high-grade intraepithelial neoplasia (HGIN) tissues with cancer and HGIN tissues without cancer.
METHODS: Gastric specimens from an upper magnifying chromoendoscopic targeted biopsy were collected at Peking Union Medical College Hospital from March 2010 to May 2013. Each of the forceps biopsies from the 21 patients was HGIN,but there were 10 HGIN and 11 HGIN with cancer after the endoscopic submucosal dissection. The whole genome expression profiling was performed on 10 HGIN samples and 11 HGIN with cancer samples using Agilent 4 × 44K Whole Human Genome microarrays. Differentially expressed genes between different types of lesions were identified using an unpaired t-test and corrected with the Benjamini and Hochberg false discovery rate algorithm. A gene ontology(GO)enrichment analysis was performed using the GeneSpring software GX 12.6.
RESULTS: The gene expression patterns were different between HGIN tissues with cancer and HGIN tissues without cancer. There were 470 significantly differentially expressed transcripts between them (P<0.05,Fold Change>2), with 180 up-regulated genes and 290 down-regulated genes in HGIN tissues with cancer. A GO enrichment analysis demonstrated that the most striking over-expressed transcripts in HGIN with cancer were in the category of triglyceride biosynthetic process,acylglycerol biosynthetic process,neutral lipid biosynthetic process,glycerol ether metabolic process,organic ether metabolic process,and glycerolipid metabolic process.
CONCLUSION: The change of lipid metabolism may contribute to the pathogenesis of gastric cancer at an early stage.

Xu X, Feng L, Liu Y, et al.
Differential gene expression profiling of gastric intraepithelial neoplasia and early-stage adenocarcinoma.
World J Gastroenterol. 2014; 20(47):17883-93 [PubMed] Free Access to Full Article Related Publications
AIM: To investigate the differentiated whole genome expression profiling of gastric high- and low-grade intraepithelial neoplasia and early-stage adenocarcinoma.
METHODS: Gastric specimens from an upper magnifying chromoendoscopic targeted biopsy were collected from March 2010 to May 2013. Whole genome expression profiling was performed on 19 low-grade intraepithelial neoplasia (LGIN), 20 high-grade intraepithelial neoplasia (HGIN), 19 early-stage adenocarcinoma (EGC), and 19 chronic gastritis tissue samples using Agilent 4 × 44K Whole Human Genome microarrays. Differentially expressed genes between different types of lesions were identified using an unpaired t-test and corrected with the Benjamini and Hochberg false discovery rate algorithm. A gene ontology (GO) enrichment analysis was performed using the GeneSpring software GX 12.6. The differentially expressed gene was verified using a real-time TaqMan® PCR assay with independent tissue samples, including 26 LGIN, 15 HGIN, 14 EGC, and 20 chronic gastritis. The expression of G0S2 were further validated by immunohistochemical staining (IHC) in 24 LGIN, 40 HGIN, 30 EGC and 61 chronic gastritis specimens.
RESULTS: The gene expression patterns of LGIN and HGIN tissues were distinct. There were 2521 significantly differentially expressed transcripts in HGIN, with 951 upregulated and 1570 downregulated. A GO enrichment analysis demonstrated that the most striking overexpressed transcripts in HGIN compared with LGIN were in the category of metabolism, defense response, and nuclear factor κB (NF-κB) cascade. While the vast majority of transcripts had barely altered expression in HGIN and EGC tissues, only 38 transcripts were upregulated in EGC. A GO enrichment analysis revealed that the alterations of the immune response were most prominent in the progression from HGIN to EGC. It is worth noting that, compared with LGIN, 289 transcripts were expressed at higher levels both in HGIN and EGC. A characteristic gene, G0/G1 switch 2 (G0S2) was one of the 289 transcripts and related to metabolism, the immune response, and the NF-κB cascade, and its expression was validated in independent samples through real-time TaqMan® PCR and immunohistochemical staining. In real-time PCR analysis, the expression of G0S2 was elevated both in HGIN and EGC compared with that in LGIN (P < 0.01 and P < 0.001, respectively). In IHC analysis, G0S2 immunoreactivity was detected in the cytoplasmic of neoplastic cells, but was undetectable in chronic gastritis cells. The G0S2 expression in HGIN was higher than that of LGIN (P = 0.012, χ (2) = 6.28) and EGC (P = 0.008, χ (2) = 6.94).
CONCLUSION: A clear biological distinction between gastric high- and low-grade intraepithelial neoplasia was identified, and provides molecular evidence for clinical application.

Suryawanshi S, Huang X, Elishaev E, et al.
Complement pathway is frequently altered in endometriosis and endometriosis-associated ovarian cancer.
Clin Cancer Res. 2014; 20(23):6163-74 [PubMed] Free Access to Full Article Related Publications
PURPOSE: Mechanisms of immune dysregulation associated with advanced tumors are relatively well understood. Much less is known about the role of immune effectors against cancer precursor lesions. Endometrioid and clear-cell ovarian tumors partly derive from endometriosis, a commonly diagnosed chronic inflammatory disease. We performed here a comprehensive immune gene expression analysis of pelvic inflammation in endometriosis and endometriosis-associated ovarian cancer (EAOC).
EXPERIMENTAL DESIGN: RNA was extracted from 120 paraffin tissue blocks comprising of normal endometrium (n = 32), benign endometriosis (n = 30), atypical endometriosis (n = 15), and EAOC (n = 43). Serous tumors (n = 15) were included as nonendometriosis-associated controls. The immune microenvironment was profiled using Nanostring and the nCounter GX Human Immunology Kit, comprising probes for a total of 511 immune genes.
RESULTS: One third of the patients with endometriosis revealed a tumor-like inflammation profile, suggesting that cancer-like immune signatures may develop earlier, in patients classified as clinically benign. Gene expression analyses revealed the complement pathway as most prominently involved in both endometriosis and EAOC. Complement proteins are abundantly present in epithelial cells in both benign and malignant lesions. Mechanistic studies in ovarian surface epithelial cells from mice with conditional (Cre-loxP) mutations show intrinsic production of complement in epithelia and demonstrate an early link between Kras- and Pten-driven pathways and complement upregulation. Downregulation of complement in these cells interferes with cell proliferation.
CONCLUSIONS: These findings reveal new characteristics of inflammation in precursor lesions and point to previously unknown roles of complement in endometriosis and EAOC.

Wan YJ, Yang Y, Leng QL, et al.
Vav1 increases Bcl-2 expression by selective activation of Rac2-Akt in leukemia T cells.
Cell Signal. 2014; 26(10):2202-9 [PubMed] Related Publications
Vav proteins are guanine nucleotide exchange factors (GEFs) that activate a group of small G proteins (GTPases). Vav1 is predominantly expressed in hematopoietic cells, whereas Vav2 and Vav3 are ubiquitously distributed in almost all human tissues. All three Vav proteins contain conserved structural motifs and associate with a variety of cellular activities including proliferation, migration, and survival. Previous observation with Jurkat leukemia T cells showed that Vav1 possessed anti-apoptotic activity by enhancing Bcl-2 transcription. However the mechanism has not been unveiled. Here, we explored the effectors of Vav1 in promoting Bcl-2 expression in Jurkat cells and revealed that Rac2-Akt was specifically evoked by the expression of Vav1, but not Vav2 or Vav3. Although all three Vav isoforms existed in Jurkat cells, Rac2 was distinguishably activated by Vav1 and that led to enhanced Bcl-2 expression and cell survival. Akt was modulated downstream of Vav1-Rac2, and the activation of Akt was indispensable in the enhanced transcription of Bcl-2. Intriguingly, neither Vav2 nor Vav3 was able to activate Rac2-Akt pathway as determined by gene silencing approach. Our data illustrated a unique role of Vav1 in T leukemia survival by selectively triggering Rac2-Akt axis and elevating the expression of anti-apoptotic Bcl-2.

López-Guerra M, Xargay-Torrent S, Rosich L, et al.
The γ-secretase inhibitor PF-03084014 combined with fludarabine antagonizes migration, invasion and angiogenesis in NOTCH1-mutated CLL cells.
Leukemia. 2015; 29(1):96-106 [PubMed] Related Publications
Targeting Notch signaling has emerged as a promising therapeutic strategy for chronic lymphocytic leukemia (CLL), especially for the poor prognostic subgroup of NOTCH1-mutated patients. Here, we report that the γ-secretase inhibitor PF-03084014 inhibits the constitutive Notch activation and induces selective apoptosis in CLL cells carrying NOTCH1 mutations. Combination of PF-03084014 with fludarabine has a synergistic antileukemic effect in primary NOTCH1-mutated CLL cells, even in the presence of the protective stroma. At transcriptional level, PF-03084014 plus fludarabine treatment induces the upregulation of the proapoptotic gene HRK and the downmodulation of MMP9, IL32 and RAC2 genes that are related to invasion and chemotaxis. PF-03084014 also overcomes fludarabine-mediated activation of nuclear factor-κB signaling. Moreover, this combination impairs angiogenesis and CXCL12-induced responses in NOTCH1-mutated CLL cells, in particular those related to tumoral migration and invasion. Importantly, all these collaborative effects are specific for NOTCH1 mutation and do not occur in unmutated cases. In conclusion, we provide evidence that Notch is a therapeutic target in CLL cases with NOTCH1-activating mutations, supporting the use of Notch pathway inhibitors in combination with chemotherapy as a promising approach for the treatment of these high-risk CLL patients.

Zwaenepoel K, Van Dongen A, Lambin S, et al.
Detection of ALK expression in non-small-cell lung cancer with ALK gene rearrangements--comparison of multiple immunohistochemical methods.
Histopathology. 2014; 65(4):539-48 [PubMed] Related Publications
AIM: Testing for ALK rearrangements in advanced, non-squamous non-small-cell lung cancers that are wild-type for activating EGFR mutation has become standard care. Fluorescence in-situ hybridization is considered the gold standard for this evaluation. Pre-screening with immunohistochemistry has been suggested, to reduce testing costs and to make testing more widely available. By analysing the sensitivity and specificity of different ALK immunohistochemical assays, we aimed to identify the most reliable assay to detect ALK rearrangement.
METHODS AND RESULTS: ALK screening performed by FISH analysis was compared with three different immunohistochemical assays, in which two ALK antibody clones (5A4 and D5F3) were used on two detection platforms (Dako AutostainerLink 48 and Ventana Benchmark GX). Data from 30 ALK FISH-positive cases show that the sensitivity of the immunohistochemical assays varies from 93.3% to 96.6%. Head-to-head comparison of the 5A4 and D5F3 ALK antibody clones demonstrates similar staining potency. In general, homogeneous, intermediate to strong staining of the ALK-positive samples was obtained.
CONCLUSIONS: ALK immunohistochemistry can be considered as a pre-screen method if one accepts a sensitivity of 93.3-96.6%. Because ALK immunohistochemical staining needs to be performed close to the detection limit of the assay, vigilant quality control monitoring is required to guarantee trustworthy results.

Gu DL, Chen YH, Shih JH, et al.
Target genes discovery through copy number alteration analysis in human hepatocellular carcinoma.
World J Gastroenterol. 2013; 19(47):8873-9 [PubMed] Free Access to Full Article Related Publications
High-throughput short-read sequencing of exomes and whole cancer genomes in multiple human hepatocellular carcinoma (HCC) cohorts confirmed previously identified frequently mutated somatic genes, such as TP53, CTNNB1 and AXIN1, and identified several novel genes with moderate mutation frequencies, including ARID1A, ARID2, MLL, MLL2, MLL3, MLL4, IRF2, ATM, CDKN2A, FGF19, PIK3CA, RPS6KA3, JAK1, KEAP1, NFE2L2, C16orf62, LEPR, RAC2, and IL6ST. Functional classification of these mutated genes suggested that alterations in pathways participating in chromatin remodeling, Wnt/β-catenin signaling, JAK/STAT signaling, and oxidative stress play critical roles in HCC tumorigenesis. Nevertheless, because there are few druggable genes used in HCC therapy, the identification of new therapeutic targets through integrated genomic approaches remains an important task. Because a large amount of HCC genomic data genotyped by high density single nucleotide polymorphism arrays is deposited in the public domain, copy number alteration (CNA) analyses of these arrays is a cost-effective way to reveal target genes through profiling of recurrent and overlapping amplicons, homozygous deletions and potentially unbalanced chromosomal translocations accumulated during HCC progression. Moreover, integration of CNAs with other high-throughput genomic data, such as aberrantly coding transcriptomes and non-coding gene expression in human HCC tissues and rodent HCC models, provides lines of evidence that can be used to facilitate the identification of novel HCC target genes with the potential of improving the survival of HCC patients.

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