HRAS

Gene Summary

Gene:HRAS; Harvey rat sarcoma viral oncogene homolog
Aliases: CTLO, HAMSV, HRAS1, RASH1, p21ras, C-H-RAS, H-RASIDX, C-BAS/HAS, C-HA-RAS1
Location:11p15.5
Summary:This gene belongs to the Ras oncogene family, whose members are related to the transforming genes of mammalian sarcoma retroviruses. The products encoded by these genes function in signal transduction pathways. These proteins can bind GTP and GDP, and they have intrinsic GTPase activity. This protein undergoes a continuous cycle of de- and re-palmitoylation, which regulates its rapid exchange between the plasma membrane and the Golgi apparatus. Mutations in this gene cause Costello syndrome, a disease characterized by increased growth at the prenatal stage, growth deficiency at the postnatal stage, predisposition to tumor formation, mental retardation, skin and musculoskeletal abnormalities, distinctive facial appearance and cardiovascular abnormalities. Defects in this gene are implicated in a variety of cancers, including bladder cancer, follicular thyroid cancer, and oral squamous cell carcinoma. Multiple transcript variants, which encode different isoforms, have been identified for this gene. [provided by RefSeq, Jul 2008]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Protein:GTPase HRas
HPRD
Source:NCBIAccessed: 27 August, 2015

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 (1990-2015)
Graph generated 27 August 2015 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 27 August, 2015 using data from PubMed, MeSH and CancerIndex

Specific Cancers (6)

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

Entity Topic PubMed Papers
Breast CancerHRAS and Breast Cancer View Publications68
Skin CancerHRAS and Skin Cancer View Publications69
Thyroid CancerHRAS and Thyroid Cancer View Publications67
MelanomaHRAS and Melanoma View Publications44
Costello SyndromeHRAS germline mutation in Costello Syndrome
Costello Syndrome is a rare congenital disorder with multiple anomalies; characterised by dysmorphic craniofacial features, musculoskeletal abnormalities, neurocognitive delay, and increased risk of cancers including rhabdomyosarcoma, neuroblastoma, childhood onset bladder carcinoma.
View Publications44
Eye CancerHRAS and Uveal Neoplasms View Publications2

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

Latest Publications: HRAS (cancer-related)

Ross JS, Badve S, Wang K, et al.
Genomic profiling of advanced-stage, metaplastic breast carcinoma by next-generation sequencing reveals frequent, targetable genomic abnormalities and potential new treatment options.
Arch Pathol Lab Med. 2015; 139(5):642-9 [PubMed] Related Publications
CONTEXT: Metastatic metaplastic breast carcinoma (MPBC) is an uncommon, but aggressive, tumor resistant to conventional chemotherapy.
OBJECTIVE: To learn whether next-generation sequencing could identify potential targets of therapy for patients with relapsed and metastatic MPBC.
DESIGN: Hybridization capture of 3769 exons from 236 cancer-related genes and 47 introns of 19 genes commonly rearranged in cancer was applied to a minimum of 50 ng of DNA extracted from 20 MPBC formalin-fixed, paraffin-embedded specimens and sequenced to high uniform coverage.
RESULTS: The 20 patients with MPBC had a median age of 62 years (range, 42-86 years). There were 9 squamous (45%), 9 chondroid (45%), and 2 spindle cell (10%) MPBCs, all of which were high grade. Ninety-three genomic alterations were identified, (range, 1-11) with 19 of the 20 cases (95%) harboring an alteration that could potentially lead to a targeted treatment option. The most-common alterations were in TP53 (n = 69; 75%), PIK3CA (n = 37; 40%), MYC (n = 28; 30%), MLL2 (n = 28; 30%), PTEN (n = 23; 25%), CDKN2A/B (n = 19; 20%), CCND3 (n = 14; 15%), CCNE1 (n = 9; 10%), EGFR (n = 9; 10%), and KDM6A (n = 9; 10%); AKT3, CCND1, CCND2, CDK4, FBXW7, FGFR1, HRAS, NF1, PIK3R1, and SRC were each altered in a single case. All 16 MPBCs (100%) that were negative for ERBB2 (HER2) overexpression by immunohistochemistry and/or ERBB2 (HER2) amplification by fluorescence in situ hybridization were also uniformly (100%) negative for ERBB2 amplification by next-generation sequencing-based copy-number assessment.
CONCLUSIONS: Our results indicate that genomic profiling using next-generation sequencing can identify clinically meaningful alterations that have the potential to guide targeted treatment decisions in most patients with metastatic MPBC.

He F, Melamed J, Tang MS, et al.
Oncogenic HRAS Activates Epithelial-to-Mesenchymal Transition and Confers Stemness to p53-Deficient Urothelial Cells to Drive Muscle Invasion of Basal Subtype Carcinomas.
Cancer Res. 2015; 75(10):2017-28 [PubMed] Article available free on PMC after 15/05/2016 Related Publications
Muscle-invasive urothelial carcinomas of the bladder (MIUCB) exhibit frequent receptor tyrosine kinase alterations, but the precise nature of their contributions to tumor pathophysiology is unclear. Using mutant HRAS (HRAS*) as an oncogenic prototype, we obtained evidence in transgenic mice that RTK/RAS pathway activation in urothelial cells causes hyperplasia that neither progresses to frank carcinoma nor regresses to normal urothelium through a period of one year. This persistent hyperplastic state appeared to result from an equilibrium between promitogenic factors and compensatory tumor barriers in the p19-MDM2-p53-p21 axis and a prolonged G2 arrest. Conditional inactivation of p53 in urothelial cells of transgenic mice expressing HRAS* resulted in carcinoma in situ and basal-subtype MIUCB with focal squamous differentiation resembling the human counterpart. The transcriptome of microdissected MIUCB was enriched in genes that drive epithelial-to-mesenchymal transition, the upregulation of which is associated with urothelial cells expressing multiple progenitor/stem cell markers. Taken together, our results provide evidence for RTK/RAS pathway activation and p53 deficiency as a combinatorial theranostic biomarker that may inform the progression and treatment of urothelial carcinoma.

Lopez-Chavez A, Thomas A, Rajan A, et al.
Molecular profiling and targeted therapy for advanced thoracic malignancies: a biomarker-derived, multiarm, multihistology phase II basket trial.
J Clin Oncol. 2015; 33(9):1000-7 [PubMed] Article available free on PMC after 20/03/2016 Related Publications
PURPOSE: We conducted a basket clinical trial to assess the feasibility of such a design strategy and to independently evaluate the effects of multiple targeted agents against specific molecular aberrations in multiple histologic subtypes concurrently.
PATIENTS AND METHODS: We enrolled patients with advanced non-small-cell lung cancer (NSCLC), small-cell lung cancer, and thymic malignancies who underwent genomic characterization of oncogenic drivers. Patients were enrolled onto a not-otherwise-specified arm and treated with standard-of-care therapies or one of the following five biomarker-matched treatment groups: erlotinib for EGFR mutations; selumetinib for KRAS, NRAS, HRAS, or BRAF mutations; MK2206 for PIK3CA, AKT, or PTEN mutations; lapatinib for ERBB2 mutations or amplifications; and sunitinib for KIT or PDGFRA mutations or amplification.
RESULTS: Six hundred forty-seven patients were enrolled, and 88% had their tumors tested for at least one gene. EGFR mutation frequency was 22.1% in NSCLC, and erlotinib achieved a response rate of 60% (95% CI, 32.3% to 83.7%). KRAS mutation frequency was 24.9% in NSCLC, and selumetinib failed to achieve its primary end point, with a response rate of 11% (95% CI, 0% to 48%). Completion of accrual to all other arms was not feasible. In NSCLC, patients with EGFR mutations had the longest median survival (3.51 years; 95% CI, 2.89 to 5.5 years), followed by those with ALK rearrangements (2.94 years; 95% CI, 1.66 to 4.61 years), those with KRAS mutations (2.3 years; 95% CI, 2.3 to 2.17 years), those with other genetic abnormalities (2.17 years; 95% CI, 1.3 to 2.74 years), and those without an actionable mutation (1.85 years; 95% CI, 1.61 to 2.13 years).
CONCLUSION: This basket trial design was not feasible for many of the arms with rare mutations, but it allowed the study of the genetics of less common malignancies.

Schechter RB, Nagilla M, Joseph L, et al.
Genetic profiling of advanced radioactive iodine-resistant differentiated thyroid cancer and correlation with axitinib efficacy.
Cancer Lett. 2015; 359(2):269-74 [PubMed] Related Publications
Biomarkers predicting which patients with advanced radioiodine-resistant differentiated thyroid cancer (DTC) may benefit from multi-kinase inhibitors are unavailable. We aimed to describe molecular markers in DTC that correlate with clinical outcome to axitinib. Pretreatment thyroid cancer blocks from 18 patients treated with axitinib were collected and genomic DNA was isolated. The OncoCarta™ Mutation Panel was used to test for 238 oncogenic mutations. Copy number of VEGFR1-3 and PIK3CA was determined using qPCR on enriched tumor samples. Genomic DNA was analyzed for all coding regions of VEGFR1-3 with custom primers. Protein expressions of VEGFR1-3, c-Met, and PIK3CA were evaluated with immunohistochemistry. Clinical response to axitinib, including best response (BR) and progression free survival (PFS), was ascertained from corresponding patients. Fisher's exact test and logistic regression models were used to correlate BR with molecular findings. Cox proportional hazards regression was used to correlate PFS with molecular defects. A total of 22 pathology samples (10 primary, 12 metastatic) were identified. In patients with 2 samples (n = 4), genetic results were concordant and only included once for analysis. Tumors from 4 patients (22%) harbored BRAF V600E mutations, 2 (11%) had KRAS mutations (G12A, G13D) and 2 (11%) had HRAS mutations (Q61R, Q61K). One metastatic sample with mutated KRAS also harbored a PIK3CA (H1047R) mutation. qPCR showed increased copy numbers of PIK3CA in 6 (33%) tumors, VEGFR1 in 0 (0%) tumors, VEGFR2 in 4 (22%) tumors, and VEGFR3 in 6 (33%) tumors. VEGFR sequencing was significant for a possibly damaging non-synonymous SNP in VEGFR2 (G539R) in 2 samples (11%), a possibly damaging SNP in VEGFR3 (E350V) in 1 sample (6%), and a potentially novel mutation in VEGFR2 (T439I) in 2 samples (11%). Immunohistochemistry (VEGFR1, -2, -3; c-MET; PIK3CA) revealed positive staining in the majority of samples. No significant relationship was seen between BR or PFS and the presence of molecular alterations. Molecular evaluation of DTC specimens did not predict clinical response to axitinib but our data were limited by sample size. We did identify molecular changes in VEGFR that should be further explored. While DTC is genetically heterogeneous, primary and metastatic lesions showed identical oncogenic alterations in four cases.


Comprehensive genomic characterization of head and neck squamous cell carcinomas.
Nature. 2015; 517(7536):576-82 [PubMed] Article available free on PMC after 20/03/2016 Related Publications
The Cancer Genome Atlas profiled 279 head and neck squamous cell carcinomas (HNSCCs) to provide a comprehensive landscape of somatic genomic alterations. Here we show that human-papillomavirus-associated tumours are dominated by helical domain mutations of the oncogene PIK3CA, novel alterations involving loss of TRAF3, and amplification of the cell cycle gene E2F1. Smoking-related HNSCCs demonstrate near universal loss-of-function TP53 mutations and CDKN2A inactivation with frequent copy number alterations including amplification of 3q26/28 and 11q13/22. A subgroup of oral cavity tumours with favourable clinical outcomes displayed infrequent copy number alterations in conjunction with activating mutations of HRAS or PIK3CA, coupled with inactivating mutations of CASP8, NOTCH1 and TP53. Other distinct subgroups contained loss-of-function alterations of the chromatin modifier NSD1, WNT pathway genes AJUBA and FAT1, and activation of oxidative stress factor NFE2L2, mainly in laryngeal tumours. Therapeutic candidate alterations were identified in most HNSCCs.

Wen YS, Cai L, Zhang XW, et al.
Concurrent oncogene mutation profile in Chinese patients with stage Ib lung adenocarcinoma.
Medicine (Baltimore). 2014; 93(29):e296 [PubMed] Related Publications
Molecular characteristics in lung cancer are associated with carcinogenesis, response to targeted therapies, and prognosis. With concurrent oncogene mutations being reported more often, the adjustment of treatment based on the driver gene mutations would improve therapy. We proposed to investigate the distribution of concurrent oncogene mutations in stage Ib lung adenocarcinoma in a Chinese population and find out the correlation between survival outcome and the most frequently mutated genes in EGFR and KRAS in Chinese population. Simultaneously, we tried to validate the Sequenom method by real time fluoresce qualification reverse transcription polymerase chain reaction (RT-PCR) in oncogene detection. One hundred fifty-six patients who underwent complete surgical resection in our hospital between 1999 and 2007 were retrospectively investigated. Using time-of-flight mass spectrometry, 238 mutation hotspots in 19 oncogenes were examined. Genetic mutations occurred in 86 of 156 patients (55.13%). EGFR was most frequently gene contained driver mutations, with a rate of 44.23%, followed by KRAS (8.33%), PIK3CA (3.84%), KIT (3.20%), BRAF (2.56%), AKT (1.28%), MET (0.64%), NRAS (0.64%), HRAS (0.64%), and ERBB2 (0.64%). No mutations were found in the RET, PDGFRA, FGFR1, FGFR3, FLT3, ABL, CDK, or JAK2 oncogenes. Thirteen patients (8.3%) were detected in multiple gene mutations. Six patients had PIK3CA mutations in addition to mutations in EGFR and KRAS. EGFR mutations can coexist with mutations in NRAS, KIT, ERBB2, and BRAF. Only one case was found to have a KRAS mutation coexisting with the EGFR T790M mutation. Otherwise, mutations in EGFR and KRAS seem to be mutually exclusive. There is no survival benefit in favor of EGFR/KRAS mutation. Several concomitant driver gene mutations were observed in our study. None of EFGR/KRAS mutation was demonstrated as a prognostic factor. Polygenic mutation testing by time-of-flight mass spectrometry was validated by RT-PCR, which can be an alternative option to test for multiple mutations and can be widely applied to clinical practice and help to guide treatment.

Park YH, Jung HH, Do IG, et al.
A seven-gene signature can predict distant recurrence in patients with triple-negative breast cancers who receive adjuvant chemotherapy following surgery.
Int J Cancer. 2015; 136(8):1976-84 [PubMed] Related Publications
The aim of this study was to investigate candidate genes that might function as biomarkers to differentiate triple negative breast cancers (TNBCs) among patients, who received adjuvant chemotherapy after curative surgery. We tested whether the results of a NanoString expression assay that targeted 250 prospectively selected genes and used mRNA extracted from formalin-fixed, paraffin-embedded would predict distant recurrence in patients with TNBC. The levels of expression of seven genes were used in a prospectively defined algorithm to allocate each patient to a risk group (low or high). NanoString expression profiles were obtained for 203 tumor tissue blocks. Increased expressions of the five genes (SMAD2, HRAS, KRT6A, TP63 and ETV6) and decreased expression of the two genes (NFKB1 and MDM4) were associated favorable prognosis and were validated with cross-validation. The Kaplan-Meier estimates of the rates of distant recurrence at 10 years in the low- and high-risk groups according to gene expression signature were 62% [95% confidence interval (CI), 48.6-78.9%] and 85% (95% CI, 79.2-90.7%), respectively. When adjusting for TNM stage, the distant recurrence-free survival (DRFS)s in the low-risk group was significantly longer than that in the high-risk group (p <0.001) for early stage (I and II) and advanced stage (III) tumors. In a multivariate Cox regression model, the gene expression signature provided significant predictive power jointly with the TNM staging system. A seven-gene signature could be used as a prognostic model to predict DRFS in patients with TNBC who received curative surgery followed by adjuvant chemotherapy.

Shen AS, Peterhof E, Kind P, et al.
Activating mutations in the RAS/mitogen-activated protein kinase signaling pathway in sporadic trichoblastoma and syringocystadenoma papilliferum.
Hum Pathol. 2015; 46(2):272-6 [PubMed] Related Publications
Trichoblastoma (TB) and syringocystadenoma papilliferum (SCAP) are both rare adnexal skin lesions occurring either sporadically or as secondary neoplasms in sebaceous nevi. TB and SCAP associated with sebaceous nevi have been shown to carry the same HRAS mutation as the underlying nevus. However, the genetic background of sporadic TB and SCAP has remained unknown. Therefore, we screened 18 sporadic TBs and 23 sporadic syringocystadenoma papillifera from 41 patients for the presence of activating mutations in RAS genes and other oncogenes. Using a RAS SNaPshot assay, HRAS mutations were detected in 2 (11%) of 18 sporadic TB and 6 (26%) of 23 sporadic syringocystadenoma papillifera. A KRAS mutation was identified in 1 sporadic SCAP. High-throughput oncogene mutation profiling furthermore identified BRAF V600E mutations in sporadic syringocystadenoma papillifera, which could be validated in 12 (52%) of 23 lesions using a BRAF SNaPshot assay. BRAF and RAS mutations were mutually exclusive in sporadic syringocystadenoma papillifera. No BRAF mutation could be detected in 3 syringocystadenoma papillifera secondarily arisen from a sebaceous nevus as well as in sporadic TB. In 14 lesions carrying an oncogenic mutation, nonlesional control tissue from the epidermal margin revealed a wild-type sequence, thus proving the somatic character of the mutation. Our results indicate that activation of the RAS-mitogen-activated protein kinase pathway by BRAF and RAS mutations contributes significantly to the tumorigenesis of sporadic SCAP and, less frequently, of sporadic TB.

Deb S, Wong SQ, Li J, et al.
Mutational profiling of familial male breast cancers reveals similarities with luminal A female breast cancer with rare TP53 mutations.
Br J Cancer. 2014; 111(12):2351-60 [PubMed] Article available free on PMC after 09/12/2015 Related Publications
BACKGROUND: Male breast cancer (MBC) is still poorly understood with a large proportion arising in families with a history of breast cancer. Genomic studies have focused on germline determinants of MBC risk, with minimal knowledge of somatic changes in these cancers.
METHODS: Using a TruSeq amplicon cancer panel, this study evaluated 48 familial MBCs (3 BRCA1 germline mutant, 17 BRCA2 germline mutant and 28 BRCAX) for hotspot somatic mutations and copy number changes in 48 common cancer genes.
RESULTS: Twelve missense mutations included nine PIK3CA mutations (seven in BRCAX patients), two TP53 mutations (both in BRCA2 patients) and one PTEN mutation. Common gains were seen in GNAS (34.1%) and losses were seen in GNAQ (36.4%), ABL1 (47.7%) and ATM (34.1%). Gains of HRAS (37.5% vs 3%, P=0.006), STK11 (25.0% vs 0%, P=0.01) and SMARCB1 (18.8% vs 0%, P=0.04) and the loss of RB1 (43.8% vs 13%, P=0.03) were specific to BRCA2 tumours.
CONCLUSIONS: This study is the first to perform high-throughput somatic sequencing on familial MBCs. Overall, PIK3CA mutations are most commonly seen, with fewer TP53 and PTEN mutations, similar to the profile seen in luminal A female breast cancers. Differences in mutation profiles and patterns of gene gains/losses are seen between BRCA2 (associated with TP53/PTEN mutations, loss of RB1 and gain of HRAS, STK11 and SMARCB1) and BRCAX (associated with PIK3CA mutations) tumours, suggesting that BRCA2 and BRCAX MBCs may be distinct and arise from different tumour pathways. This has implications on potential therapies, depending on the BRCA status of MBC patients.

Wu Y, Gu TT, Zheng PS
CIP2A cooperates with H-Ras to promote epithelial-mesenchymal transition in cervical-cancer progression.
Cancer Lett. 2015; 356(2 Pt B):646-55 [PubMed] Related Publications
The oncoprotein Cancerous Inhibitor of PP2A (CIP2A) has been reported to interact with Protein phosphatase 2 (PP2A) to stabilize c-Myc and prevent its degradation, and high expression levels of CIP2A have been proved to be related to poor clinical outcomes in multiple cancers. Here, we not only proved that the expression of CIP2A is positively correlated with lymph-node metastasis and cervical-cancer progression, but also revealed a close correlation between the protein's expression and the expression levels of two core epithelial-to-mesenchymal transition (EMT) markers, Vimentin and Snail. In addition, we manipulated CIP2A expression to regulate EMT conversion and employed a pull-down assay, mass-spectrometric (MS) peptide sequencing, as well as bilateral co-immunoprecipitation to identify potentially interacting proteins in cervical-cancer cells. In this study, we proposed and successfully proved, for the first time, that CIP2A physically associates with H-Ras, which leads to the activation of the MEK/ERK signaling pathway and promotes EMT and cervical-cancer progression. Based on our observations and prior findings that CIP2A participates in c-Myc regulation, we conjecture that CIP2A may be a potentially promising molecular target for the adoptive therapy of human cancer.

Frouin E, Guillot B, Larrieux M, et al.
Cutaneous epithelial tumors induced by vemurafenib involve the MAPK and Pi3KCA pathways but not HPV nor HPyV viral infection.
PLoS One. 2014; 9(10):e110478 [PubMed] Article available free on PMC after 09/12/2015 Related Publications
The inhibitors of mutant BRAF that are used to treat metastatic melanoma induce squamoproliferative lesions. We conducted a prospective histopathological and molecular study on 27 skin lesions from 12 patients treated with vemurafenib. Mutation hot spots in HRAS, NRAS, KRAS, BRAF, and Pi3KCA were screened. HPV and HPyV infection status were also determined. The lesions consisted of 19 verrucal papillomas, 1 keratoacanthoma and 7 squamous cell carcinomas. No mutations were found within BRAF and NRAS. KRAS, HRAS, and Pi3KCA oncogenic mutations were found in 10 (83.3%), 7 (58.3%), and 4 (33.3%) patients respectively; however, these mutations were not consistent within all tumors of a given patient. Pi3KCA mutation was always associated with a mutation in HRAS. Finally, no correlation was found between the mutated gene or type of mutation and the type of cutaneous tumor or clinical response to vemurafenib. P16 protein level was not indicative of HPV infection. HPV was detected in only two lesions. Two cases had MCPyV, and one had HPyV7. In conclusion, neither HPV nor HPyV seem to be involved in the development of squamoproliferative lesions induced by verumafenib. By contrast, HRAS and KRAS play a predominant role in the physiopathology of these tumors.

Martin D, Abba MC, Molinolo AA, et al.
The head and neck cancer cell oncogenome: a platform for the development of precision molecular therapies.
Oncotarget. 2014; 5(19):8906-23 [PubMed] Article available free on PMC after 09/12/2015 Related Publications
The recent elucidation of the genomic landscape of head and neck squamous cell carcinoma (HNSCC) has provided a unique opportunity to develop selective cancer treatment options. These efforts will require the establishment of relevant HNSCC models for preclinical testing. Here, we performed full exome and transcriptome sequencing of a large panel of HNSCC-derived cells from different anatomical locations and human papillomavirus (HPV) infection status. These cells exhibit typical mutations in TP53, FAT1, CDK2NA, CASP8, and NOTCH1, and copy number variations (CNVs) and mutations in PIK3CA, HRAS, and PTEN that reflect the widespread activation of the PI3K-mTOR pathway. SMAD4 alterations were observed that may explain the decreased tumor suppressive effect of TGF-β in HNSCC. Surprisingly, we identified HPV+ HNSCC cells harboring TP53 mutations, and documented aberrant TP53 expression in a subset of HPV+ HNSCC cases. This analysis also revealed that most HNSCC cells harbor multiple mutations and CNVs in epigenetic modifiers (e.g., EP300, CREBP, MLL1, MLL2, MLL3, KDM6A, and KDM6B) that may contribute to HNSCC initiation and progression. These genetically-defined experimental HNSCC cellular systems, together with the identification of novel actionable molecular targets, may now facilitate the pre-clinical evaluation of emerging therapeutic agents in tumors exhibiting each precise genomic alteration.

Dubruc E, Balme B, Dijoud F, et al.
Mutated and amplified NRAS in a subset of cutaneous melanocytic lesions with dermal spitzoid morphology: report of two pediatric cases located on the ear.
J Cutan Pathol. 2014; 41(11):866-72 [PubMed] Related Publications
Extensive cytogenetic testing is slowly unveiling the complexity of the genomics of melanocytic tumors. NRAS mutations have been the first genetic abnormality described in malignant melanomas. We report the cases of two children, presenting a melanocytic lesion located on the ear. One appeared as a combined dermal clone inside a congenital nevus and the other as a centimetric purely dermal tumor. Both tumors were composed of spindled spitzoid melanocytes with atypical histologic features. aCGH and FISH revealed an amplification of the NRAS gene. Sequencing showed an exon 3 NRAS mutation. In the combined case, the amplification was limited to the spitzoid component, underscoring a possible phenotypic shift induced by the alteration. Similarly an overexpression of CyclinD1 and elevation of ki-67 was found in the spitzoid component confirming a raise in proliferation. Such combination of mutation and copy number increase has been previously reported for the HRAS gene in a subset of Spitz nevi. Further studies must evaluate if mutated NRAS is also amplified in melanomas arising in this clinical setting. These combined alterations could represent an early event ultimately leading to malignancy.

Gailey MP, Stence AA, Jensen CS, Ma D
Multiplatform comparison of molecular oncology tests performed on cytology specimens and formalin-fixed, paraffin-embedded tissue.
Cancer Cytopathol. 2015; 123(1):30-9 [PubMed] Related Publications
BACKGROUND: Molecular oncology testing is important for patient management, and requests for the molecular analysis of cytology specimens are increasingly being made. Formalin-fixed, paraffin-embedded (FFPE) cell blocks of such specimens have been routinely used for molecular diagnosis. However, the inability to assess cellularity before cell block preparation is a pitfall of their use. In this study, various cytologic preparations were tested with several molecular test platforms, and the results were compared with paired FFPE tissue.
METHODS: Seventy-seven cytology cases, including fine-needle aspiration smears, touch preparations, and SurePath thin-layer preparations, were selected from the archives. Areas of interest were removed from the slide with a matrix capture solution. DNA extracted from the cells was evaluated by mutation analysis for BRAF, epidermal growth factor receptor (EGFR), RAS, and a 50-gene panel with various testing platforms (single-nucleotide primer extension assay, Sanger sequencing, and next-generation sequencing). Thirty-eight tumors with available FFPE tissue were tested in parallel.
RESULTS: The average DNA concentration was 299 ng/µL for the cytology specimens and 171 ng/µg for the paired FFPE tissue. Point mutations and large deletions were detected in BRAF, KRAS, NRAS, HRAS, and EGFR genes. In comparison with FFPE tissue, 5- to 8-fold less input DNA was needed when cytology preparations were used. The concordance between cytology specimens and FFPE tissue was 100%.
CONCLUSIONS: Cytologic preparations were found to be a reliable source for molecular oncology testing. DNA derived from cytology specimens performed well on multiple platforms, and 100% concordance was observed between cytology specimens and FFPE tissue.

Radkay LA, Chiosea SI, Seethala RR, et al.
Thyroid nodules with KRAS mutations are different from nodules with NRAS and HRAS mutations with regard to cytopathologic and histopathologic outcome characteristics.
Cancer Cytopathol. 2014; 122(12):873-82 [PubMed] Related Publications
BACKGROUND: Mutations in the RAS gene in the thyroid gland result in the activation of signaling pathways and are associated with a follicular growth pattern and the probability of a carcinoma outcome ranging from 74% to 87%. In the current study, the authors investigated the cytopathologic and histopathologic features of common RAS mutation subtypes.
METHODS: Malignant, indeterminate, and selected benign thyroid cytology cases were tested prospectively for the presence of NRAS61, HRAS61, and KRAS12/13 mutations. For each case, the Bethesda System for thyroid cytopathology diagnosis, additional cytologic descriptors, and surgical pathology outcomes were documented. The Fisher exact test and Wilcoxon 2-sample test were used for statistical comparison between the groups.
RESULTS: A total of 204 thyroid fine-needle aspiration cases with RAS mutations (93.6% of which were associated with indeterminate cytopathology diagnoses) and corresponding surgical pathology resection specimens were identified. The KRAS12/13 mutation was associated with a significantly lower carcinoma outcome (41.7%) when compared with HRAS61 (95.5%) and NRAS61 (86.8%) mutations (P<.0001). Furthermore, oncocytic change was observed in a significantly higher percentage of cytology and resection specimens with KRAS12/13 mutations (66.7% and 75.0%, respectively) in comparison with those with HRAS61 (4.5% and 4.5%, respectively) and NRAS61 (15.4% and 14.7%, respectively) mutations (P<.0001). RAS mutations also were identified in cases of poorly differentiated carcinoma (NRAS61), anaplastic carcinoma (HRAS61), and medullary thyroid carcinoma (HRAS61 and KRAS12/13).
CONCLUSIONS: Subclassification of RAS mutations in conjunction with cytopathologic evaluation improves presurgical risk stratification, provides better insight into lesional characteristics, and may influence patient management. In particular, KRAS12/13-mutated thyroid nodules were found to be different from HRAS61-mutated and NRAS61-mutated nodules with regard to cytopathologic and surgical outcome characteristics.

McDaniel AS, Zhai Y, Cho KR, et al.
HRAS mutations are frequent in inverted urothelial neoplasms.
Hum Pathol. 2014; 45(9):1957-65 [PubMed] Article available free on PMC after 09/12/2015 Related Publications
Inverted urothelial papilloma (IUP) is an uncommon neoplasm of the urinary bladder with distinct morphologic features. Studies regarding the role of human papillomavirus (HPV) in the etiology of IUP have provided conflicting evidence of HPV infection. In addition, little is known regarding the molecular alterations present in IUP or other urothelial neoplasms, which might demonstrate inverted growth pattern like low-grade or high-grade urothelial carcinoma (UCA). Here, we evaluated for the presence of common driving somatic mutations and HPV within a cohort of IUPs, (n = 7) noninvasive low-grade papillary UCAs with inverted growth pattern (n = 5), and noninvasive high-grade papillary UCAs with inverted growth pattern (n = 8). HPV was not detected in any case of IUP or inverted UCA by either in situ hybridization or by polymerase chain reaction. Next-generation sequencing identified recurrent mutations in HRAS (Q61R) in 3 of 5 IUPs, described for the first time in this neoplasm. Additional mutations of Ras pathway members were detected including HRAS, KRAS, and BRAF. The presence of Ras pathway member mutations at a relatively high rate suggests this pathway may contribute to pathogenesis of inverted urothelial neoplasms. In addition, we did not find any evidence supporting a role for HPV in the etiology of IUP.

Lee TH, Chennakrishnaiah S, Audemard E, et al.
Oncogenic ras-driven cancer cell vesiculation leads to emission of double-stranded DNA capable of interacting with target cells.
Biochem Biophys Res Commun. 2014; 451(2):295-301 [PubMed] Related Publications
Cell free DNA is often regarded as a source of genetic cancer biomarkers, but the related mechanisms of DNA release, composition and biological activity remain unclear. Here we show that rat epithelial cell transformation by the human H-ras oncogene leads to an increase in production of small, exosomal-like extracellular vesicles by viable cancer cells. These EVs contain chromatin-associated double-stranded DNA fragments covering the entire host genome, including full-length H-ras. Oncogenic N-ras and SV40LT sequences were also found in EVs emitted from spontaneous mouse brain tumor cells. Disruption of acidic sphingomyelinase and the p53/Rb pathway did not block emission of EV-related oncogenic DNA. Exposure of non-transformed RAT-1 cells to EVs containing mutant H-ras DNA led to the uptake and retention of this material for an extended (30days) but transient period of time, and stimulated cell proliferation. Thus, our study suggests that H-ras-mediated transformation stimulates vesicular emission of this histone-bound oncogene, which may interact with non-transformed cells.

Weng TY, Yen MC, Huang CT, et al.
DNA vaccine elicits an efficient antitumor response by targeting the mutant Kras in a transgenic mouse lung cancer model.
Gene Ther. 2014; 21(10):888-96 [PubMed] Related Publications
Mutant Kras (V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) is observed in more than 20% of non-small-cell lung cancers; however, no effective Kras target therapy is available at present. The Kras DNA vaccine may represent as a novel immunotherapeutic agent in lung cancer. In this study, we investigated the antitumor efficacy of the Kras DNA vaccine in a genetically engineered inducible mouse lung tumor model driven by Kras(G12D). Lung tumors were induced by doxycycline, and the therapeutic effects of Kras DNA vaccine were evaluated with delivery of Kras(G12D) plasmids. Mutant Kras(G12D) DNA vaccine significantly decreased the tumor nodules. A dominant-negative mutant Kras(G12D)N17, devoid of oncogenic activity, achieved similar therapeutic effects. The T-helper 1 immune response was enhanced in mice treated with Kras DNA vaccine. Splenocytes from mice receiving Kras DNA vaccine presented an antigen-specific response by treatment with peptides of Kras but not Hras or OVA. The number of tumor-infiltrating CD8(+) T cells increased after Kras vaccination. In contrast, Kras DNA vaccine was not effective in the lung tumor in transgenic mice, which was induced by mutant L858R epidermal growth factor receptor. Overall, these results indicate that Kras DNA vaccine produces an effective antitumor response in transgenic mice, and may be useful in treating lung cancer-carrying Ras mutation.

Trietsch MD, Spaans VM, ter Haar NT, et al.
CDKN2A(p16) and HRAS are frequently mutated in vulvar squamous cell carcinoma.
Gynecol Oncol. 2014; 135(1):149-55 [PubMed] Related Publications
BACKGROUND: Two etiologic pathways of vulvar cancer are known, a human papillomavirus (HPV)- and a TP53-associated route, respectively, but other genetic changes may also play a role. Studies on somatic mutations in vulvar cancer other than TP53 are limited in number and size. In this study, we investigated the prevalence of genetic mutations in 107 vulvar squamous cell carcinomas (VSCCs).
METHODS: A total of 107 paraffin-embedded tissue samples of primarily surgically treated VSCCs were tested for HPV infection and screened for mutations in 14 genes (BRAF, CDKN2A(p16), CTNNB1, FBXW7, FGFR2, FGFR3, FOXL2, HRAS, KRAS, NRAS, PIK3CA, PPP2R1A, PTEN, and TP53) using Sanger sequencing and mass spectrometry.
RESULTS: Mutations were detected in 7 genes. Of 107 VSCCs, 66 tumors (62%) contained at least one mutation (TP53=58, CDKN2A(p16)=14, HRAS=10, PIK3CA=7, PPP2R1A=3, KRAS=1, PTEN=1). Mutations occurred most frequently in HPV-negative samples. Five-year survival was significantly worse for patients with a mutation (47% vs 59%, P=.035), with a large effect from patients carrying HRAS-mutations.
CONCLUSION: Somatic mutations were detected in 62% of VSCCs. As expected, HPV infection and TP53-mutations play a key role in the development of VSCC, but CDKN2A(p16), HRAS, and PIK3CA-mutations were also frequently seen in HPV-negative patients. Patients with somatic mutations, especially HRAS-mutations, have a significantly worse prognosis than patients lacking these changes, which could be of importance for the development of targeted therapy.

Eszlinger M, Hegedüs L, Paschke R
Ruling in or ruling out thyroid malignancy by molecular diagnostics of thyroid nodules.
Best Pract Res Clin Endocrinol Metab. 2014; 28(4):545-57 [PubMed] Related Publications
Routine morphologic cytology is the basis for any kind of (integrated) molecular FNA diagnostics. The rule out (gene expression classifier) approach requires confirmation by independent studies, whereas the rule in approach (detection of BRAF, NRAS, HRAS, and KRAS and PAX8/PPARG- and RET/PTC rearrangements) has been investigated by several groups with overall reproducible results. Moreover, molecular screening for point mutations and rearrangements is feasible in routine air-dried FNA smears, offering several advantages over obtaining additional fresh FNA material. The current panel of somatic mutations (rule in approach) for indeterminate FNAs clarifies only a subgroup of indeterminate FNAs. Therefore, further markers are urgently needed that can reliably identify the malignant, but mutation negative and especially the many benign nodules, among the indeterminate FNAs. miRNA markers and the targeted next generation sequencing (NGS) technology do have the potential to identify those nodules that are mutation negative by current approaches.

Milinkovic VP, Skender Gazibara MK, Manojlovic Gacic EM, et al.
The impact of TP53 and RAS mutations on cerebellar glioblastomas.
Exp Mol Pathol. 2014; 97(2):202-7 [PubMed] Related Publications
Cerebellar glioblastoma (cGBM) is a rare, inadequately characterized disease, without detailed information on its molecular basis. This is the first report analyzing both TP53 and RAS alterations in cGBM. TP53 mutations were detected in more than half of the samples from our cohort, mainly in hotspot codons. There were no activating mutations in hotspot codons 12/13 and 61 of KRAS and HRAS genes in cGBM samples but we detected alterations in other parts of exons 2 and 3 of these genes, including premature induction of STOP codon. This mutation was present in 3 out of 5 patients. High incidence of RAS mutations, as well as significantly longer survival of cGBM patients compared to those with supratentorial GBM suggest that cGBM may have different mechanisms of occurrence. Our results suggest that inactivation of TP53 and RAS may play an important role in the progression of cerebellar GBM.

Malaguarnera R, Chen KY, Kim TY, et al.
Switch in signaling control of mTORC1 activity after oncoprotein expression in thyroid cancer cell lines.
J Clin Endocrinol Metab. 2014; 99(10):E1976-87 [PubMed] Article available free on PMC after 01/10/2015 Related Publications
CONTEXT: Thyroid growth is regulated by TSH and requires mammalian target of rapamycin (mTOR). Thyroid cancers frequently exhibit mutations in MAPK and/or phosphoinositol-3-kinase-related kinase effectors.
OBJECTIVE: The objective of the study was to explore the contribution of RET/PTC, RAS, and BRAF to mTOR regulation and response to mTOR inhibitors.
METHODS: PCCL3 cells conditionally expressing RET/PTC3, HRAS(G12V), or BRAF(V600E) and human thyroid cancer cells harboring mutations of these genes were used to test pathways controlling mTOR and its requirement for growth.
RESULTS: TSH/cAMP-induced growth of PCCL3 cells requires mTOR, which is stimulated via protein kinase A in a MAPK kinase (MEK)- and AKT-independent manner. Expression of RET/PTC3, HRAS(G12V), or BRAF(V600E) in PCCL3 cells induces mTOR but does not entirely abrogate the cAMP-mediated control of its activity. Acute oncoprotein-induced mTOR activity is regulated by MEK and AKT, albeit to differing degrees. By contrast, mTOR was not activated by TSH/cAMP in human thyroid cancer cells. Tumor genotype did not predict the effects of rapamycin or the mTOR kinase inhibitor AZD8055 on growth, with the exception of a PTEN-null cell line. Selective blockade of MEK did not influence mTOR activity of BRAF or RAS mutant cells. Combined MEK and mTOR kinase inhibition was synergistic on growth of BRAF- and RAS-mutant thyroid cancer cells in vitro and in vivo.
CONCLUSION: Thyroid cancer cells lose TSH/cAMP dependency of mTOR signaling and cell growth. mTOR activity is not decreased by the MEK or AKT inhibitors in the RAS or BRAF human thyroid cancer cell lines. This may account for the augmented effects of combining the mTOR inhibitors with selective antagonists of these oncogenic drivers.

Chen JJ, Bozza WP, Di X, et al.
H-Ras regulation of TRAIL death receptor mediated apoptosis.
Oncotarget. 2014; 5(13):5125-37 [PubMed] Article available free on PMC after 01/10/2015 Related Publications
TNF-related apoptosis-inducing ligand (TRAIL) induces apoptosis through the death receptors (DRs) 4 and/or 5 expressed on the cell surface. Multiple clinical trials are underway to evaluate the antitumor activity of recombinant human TRAIL and agonistic antibodies to DR4 or DR5. However, their therapeutic potential is limited by the high frequency of cancer resistance. Here we provide evidence demonstrating the role of H-Ras in TRAIL receptor mediated apoptosis. By analyzing the genome wide mRNA expression data of the NCI60 cancer cell lines, we found that H-Ras expression was consistently upregulated in TRAIL-resistant cell lines. By contrast, no correlation was found between TRAIL sensitivity and K-Ras expression levels or their mutational profiles. Notably, H-Ras upregulation associated with a surface deficiency of TRAIL death receptors. Selective inhibition of H-Ras activity in TRAIL-resistant cells restored the surface expression of both DR4 and DR5 without changing their total protein levels. The resulting cells became highly susceptible to both TRAIL and agonistic DR5 antibody, whereas K-Ras inhibition had little or no effect on TRAIL-induced apoptosis, indicating H-Ras plays a distinct role in the regulation of TRAIL death receptors. Further studies are warranted to determine the therapeutic potential of H-Ras-specific inhibitors in combination with TRAIL receptor agonists.

Cogoi S, Shchekotikhin AE, Xodo LE
HRAS is silenced by two neighboring G-quadruplexes and activated by MAZ, a zinc-finger transcription factor with DNA unfolding property.
Nucleic Acids Res. 2014; 42(13):8379-88 [PubMed] Article available free on PMC after 01/10/2015 Related Publications
The HRAS promoter contains immediately upstream of the transcription start site two neighboring G-elements, each capable of folding into a G-quadruplex structure. We have previously found that these G-quadruplexes bind to the zinc-finger transcription factors MAZ and Sp1. In the present study we have examined the interaction between the HRAS promoter and MAZ, demonstrating for the first time that the protein unfolds the G-quadruplex structures. We also demonstrate that MAZ-GST, in the presence of the complementary strands, promotes a rapid transformation of the two HRAS quadruplexes into duplexes. By a mutational analysis of the HRAS G-elements, we dissected the MAZ-binding sites from the quadruplex-forming motifs, finding that the two neighboring G-quadruplexes bring about a dramatic repression of transcription, in a synergistic manner. We also discovered that the two G-quadruplexes are strong targets for small anticancer molecules. We found that a cell-penetrating anthratiophenedione (ATPD-1), which binds tightly to the G-quadruplexes (ΔT > 15°C), promotes the total extinction of HRAS transcription. In contrast, when one of the two G-quadruplexes was abrogated by point mutations, ATPD-1 repressed transcription by only 50%. Our study provides relevant information for the rationale design of targeted therapy drugs specific for the HRAS oncogene.

Yadav DS, Chattopadhyay I, Verma A, et al.
A pilot study evaluating genetic alterations that drive tobacco- and betel quid-associated oral cancer in Northeast India.
Tumour Biol. 2014; 35(9):9317-30 [PubMed] Related Publications
The susceptibility of an individual to oral cancer is mediated by genetic factors and carcinogen-exposure behaviors such as betel quid chewing, tobacco use, and alcohol consumption. This pilot study was aimed to identify the genetic alteration in 100 bp upstream and downstream flanking regions in addition to the exonic regions of 169 cancer-associated genes by using Next Generation sequencing with aim to elucidate the molecular pathogenesis of tobacco- and betel quid-associated oral cancer of Northeast India. To understand the role of chemical compounds present in tobacco and betel quid associated with the progression of oral cancer, single nucleotide polymorphisms (SNPs) and insertion and deletion (Indels) found in this study were analyzed for their association with chemical compounds found in tobacco and betel quid using Comparative Toxogenomic Database. Genes (AR, BRCA1, IL8, and TP53) with novel SNP were found to be associated with arecoline which is the major component of areca nut. Genes (BARD1, BRCA2, CCND2, IGF1R, MSH6, and RASSF1) with novel deletion and genes (APC, BRMS1, CDK2AP1, CDKN2B, GAS1, IGF1R, and RB1) with novel insertion were found to be associated with aflatoxin B1 which is produced by fermented areca nut. Genes (ADH6, APC, AR, BARD1, BRMS1, CDKN1A, E2F1, FGFR4, FLNC, HRAS, IGF1R, IL12B, IL8, NBL1, STAT5B, and TP53) with novel SNP were found to be associated with aflatoxin B1. Genes (ATM, BRCA1, CDKN1A, EGFR, IL8, and TP53) with novel SNP were found to be associated with tobacco specific nitrosamines.

Chang YS, Hsu HT, Ko YC, et al.
Combined mutational analysis of RAS, BRAF, PIK3CA, and TP53 genes in Taiwanese patients with oral squamous cell carcinoma.
Oral Surg Oral Med Oral Pathol Oral Radiol. 2014; 118(1):110-116.e1 [PubMed] Related Publications
OBJECTIVE: Many genetic factors have been implicated in the development of oral squamous cell carcinoma (OSCC). Although mutations associated with OSCC have been well documented, the rate of these mutations is known to vary by location. The goal of this study was to determine the frequency of RAS, BRAF, PIK3CA, and TP53 mutations in OSCC within the Taiwanese population.
STUDY DESIGN: A total of 79 OSCC tissue specimens were screened for the presence of RAS, BRAF, PIK3CA, and TP53 mutations.
RESULTS: Missense mutations in HRAS were found in 10 of 79 cases (12.66%), and were significantly associated with tumor grade. PIK3CA mutations were observed in 11 of 79 cases (13.92%), including a rare mutation, Q546 P, that had not previously been reported in OSCC. TP53 mutations were observed in 26 of 79 patients (32.91%) and were significantly correlated with poor survival.
CONCLUSIONS: The results suggest that HRAS, PIK3CA, and TP53 may play a role in OSCC tumorigenesis.

Ambrosini G, Khanin R, Carvajal RD, Schwartz GK
Overexpression of DDX43 mediates MEK inhibitor resistance through RAS Upregulation in uveal melanoma cells.
Mol Cancer Ther. 2014; 13(8):2073-80 [PubMed] Related Publications
The majority of uveal melanomas carry oncogenic mutations in the G proteins GNAQ and GNA11, with consequent activation of the MAPK pathway. Selective MEK inhibitors, such as selumetinib, have shown clinical benefit in uveal melanoma. However, mechanisms of drug resistance limit their efficacy in some patients. Analysis of MEK inhibitor-resistant uveal melanoma cell lines revealed the induction of RAS protein expression and activity. This effect was mediated by the RNA helicase DDX43, which was remarkably overexpressed in these cells. Depletion of DDX43 in MEK inhibitor-resistant cells decreased RAS proteins and inhibited ERK and AKT pathways. On the contrary, ectopic expression of DDX43 in parental uveal melanoma cells induced RAS protein levels and rendered cells resistant to MEK inhibition. Similar to DDX43 depletion, downregulation of KRAS, HRAS, and NRAS inhibited downstream pathways in the resistant cells, overcoming mutant GNAQ signaling. We also analyzed the expression of DDX43 in liver metastases of patients with uveal melanoma by RT-PCR, and found a significant overexpression of DDX43 in patients who did not benefit from selumetinib therapy. In conclusion, DDX43 induces RAS protein expression and signaling, mediating a novel mechanism of MEK inhibitor resistance. The detection of DDX43 in patients with uveal melanoma could lead to more targeted therapies for this disease.

Tsai JH, Huang WC, Jhuang JY, et al.
Frequent activating HRAS mutations in trichilemmoma.
Br J Dermatol. 2014; 171(5):1073-7 [PubMed] Related Publications
BACKGROUND: Trichilemmoma is a benign follicular epithelial tumour exhibiting outer root sheath differentiation. It is associated with Cowden syndrome and naevus sebaceus (NS), but the pathogenesis of sporadic tumours is poorly understood. Recently, NS was found to be caused by postzygotic HRAS or KRAS mutations.
OBJECTIVES: We sought to determine whether NS-related and NS-unrelated trichilemmomas harbour RAS mutations.
METHODS: Formalin-fixed and paraffin-embedded blocks of 12 NS-related and 15 NS-unrelated trichilemmomas from 26 individuals were retrieved and analysed to determine the presence of mutations in exons 1 and 2 of the HRAS, KRAS and NRAS genes by polymerase chain reaction and direct sequencing. Mutational hotspots of the FGFR3 and PIK3CA genes were also analysed for NS-unrelated cases.
RESULTS: Among the 27 cases, mutually exclusive HRAS c.37G>C and c.182A>G mutations were observed in 17 and three tumours, respectively. Of the 12 NS-related tumours, 11 (92%) harboured the HRAS c.37G>C substitution. Of the 15 sporadic tumours, nine (60%) harboured HRAS mutations, including six c.37G>C and three c.182A>G. An HRAS c.182A>G mutation was observed only in sporadic tumours. No mutations were observed in the other genes that were tested.
CONCLUSIONS: The high frequency of HRAS activating mutations, including the c.182A>G substitution, which was rather rare in NS, suggests that most trichilemmomas are authentic neoplasms.

Fukumoto S
Anti-fibroblast growth factor 23 antibody therapy.
Curr Opin Nephrol Hypertens. 2014; 23(4):346-51 [PubMed] Related Publications
PURPOSE OF REVIEW: The review is intended to provide an update on the expanding knowledge regarding diseases caused by the excess actions of fibroblast growth factor 23 (FGF23) and also on the new therapeutic measures for these diseases, with an emphasis on the anti-FGF23 antibody.
RECENT FINDINGS: FGF23 decreases serum phosphate and 1,25-dihydroxyvitamin D levels. After the cloning of FGF23, several hypophosphatemic diseases, including tumor-induced osteomalacia and X-linked hypophosphatemic rickets (XLHR), were shown to be caused by excess actions of FGF23. In addition, recent studies indicated that mutations in the family with sequence similarity 20, member C (FAM20C), HRAS and NRAS genes, also caused FGF23-related hypophosphatemic diseases. The inhibition of FGF23 production or activity is, theoretically, an ideal treatment for these hypophosphatemic diseases. The C-terminal fragment of FGF23, inhibitors of FGF receptor and extracellular signal-regulated kinase, and anti-FGF23 antibody were shown to inhibit FGF23 actions both in vitro and in vivo. A phase I clinical trial of anti-FGF23 antibody has shown that this antibody increases serum phosphate in patients with XLHR.
SUMMARY: These recent findings confirm that FGF23 has a pivotal role in phosphate metabolism. The inhibition of FGF23 production or activity is promising as a new therapy for FGF23-related hypophosphatemic diseases. Further studies are clearly necessary to establish the clinical utility and long-term safety of these measures.

Giordano TJ, Beaudenon-Huibregtse S, Shinde R, et al.
Molecular testing for oncogenic gene mutations in thyroid lesions: a case-control validation study in 413 postsurgical specimens.
Hum Pathol. 2014; 45(7):1339-47 [PubMed] Related Publications
Molecular testing for oncogenic gene alterations provides clinically actionable information essential for the optimal management of follicular cell thyroid cancer. We aimed to establish the distribution and frequency of common oncogenic gene mutations and chromosomal rearrangements in a comprehensive set of benign and malignant thyroid lesions. A case-control study was conducted in 413 surgical cases comprising 17 distinct histopathologic categories, 244 malignant, 169 benign, and 304 double-blinded specimens. Seventeen alterations of BRAF, HRAS, KRAS, NRAS, PAX8, and RET genes were evaluated using a single validated technology platform. Following verification of analytical sensitivity, accuracy, and precision in model and surgical specimens, 152 molecular positive results were generated in lesions representing multiple stages of progression and epithelial differentiation as well as rare subtypes of primary, secondary, or recurring tumors. Single mutations were found in 58% of primary malignant lesions and 12% of benign (P < .001). In the blinded validation set, mutation distribution and frequency were distinct across variants of follicular and papillary carcinomas. BRAF or RET-PTC was detected exclusively in malignant lesions but not in follicular carcinomas (P < .001). RAS or PAX8-PPARG were present in 23% of adenomas, and NRAS was found in a single nonneoplastic lesion (P = .0014). These data substantiate the diagnostic utility of molecular testing for oncogenic mutations and validate its performance in a variety of surgical specimens. Standardized and validated multianalyte molecular panels can complement the preoperative and postoperative assessment of thyroid nodules and support a growing number of clinical and translational applications with potential diagnostic, prognostic, or theranostic utility.

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