ING3 is a potential candidate tumor-suppressor gene that has been implicated in the pathogenesis of various cancers, however the exact role and mechanism of ING3 in gastric cancer (GC) remains elusive. In this study, the low expression of ING3 was validated in GC tissues and various GC cell lines. Overexpression of ING3 by transfection with pEGFP-ING3 plasmids inhibited cell proliferation in SGC-7901 and BGC-825 cells, concomitant with the decrease in the expression of PCNA, a marker for cell proliferation. Furthermore, overexpression of ING3-induced cell cycle arrest at G

The effect of deregulation of nuclear export mediated by exportin-1, with consequent cellular mislocalization of p33ING1b, a member of the tumor suppressor gene family, has not been previously investigated in head and neck squamous cell cancer (HNSCC). We evaluated the effect of reversing cytoplasmic p33ING1b localization through inhibition of exportin-1 by leptomycin B (LMB) and the effect of nuclear entrapment of p33ING1b on molecular alterations in primary and metastatic HNSCC lines. The expression and location of exportin-1 and p33ING1b were analyzed by a quantitative real‑time reverse transcription polymerase chain reaction PCR (qRT-PCR), a Western blot, and immunostaining. Cell proliferation and migration assays were conducted to determine the effect of exportin-1 inhibition on the cell lines. Exportin-1 was overexpressed in metastatic HNSCC, whereas p33ING1b was poorly expressed. Exportin-1 inhibition induced nuclear entrapment and upregulation of p33ING1b, extensive apoptosis, and growth arrest. It also suppressed cell migration. Cytoplasmic p33ING1b-mediated regulation of cell growth and nuclear entrapment of p33ING1b via inhibition of exportin-1 may be a key mechanism for inducing HNSCC apoptosis.

BACKGROUND: Breast cancer is one of the most frequent malignancies and the second leading cause of cancer-related mortality in women. MicroRNAs play a key role in breast cancer development and progression. microRNA(miR)-8084 has been observed an aberrant expression in breast cancer. However, the functions and regulatory axes of miR-8084, particularly in breast cancer, were not entirely clear.
METHODS: miR-8084 expression in breast cancer were investigated in a GEO dataset by in silico analysis and in 42 paired tumor tissues by qPCR. The effects of deregulation of miR-8084 on breast cancer cell proliferation, migration and invasion in vitro and tumorigenicity in vivo were examined by colony-formation assay, wound healing assay, transwell assay and nude mouse subcutaneous tumor formation model. The target gene of miR-8084 were predicted by TargetScan and miRDB, and confirmed by luciferase reporter system. The roles of miR-8084 in the breast cancer cell proliferation, apoptosis and epithelial-mesenchymal transition (EMT) were investigated by MTS, FACS and associated-marker detection by western blot.
RESULTS: miR-8084 is significantly up-regulated in both serum and malignant tissues from the source of breast cancer patients. miR-8084 promotes the proliferation of breast cancer cells by activating ERK1/2 and AKT. Meanwhile miR-8084 inhibits apoptosis by decreasing p53-BAX related pathway. miR-8084 also enhances migration and invasion by inducing EMT. Moreover, the tumor suppressor ING2 is a potential target of miR-8084, and miR-8084 regulatory axes contribute to pro-tumor effect, at least partially through regulating ING2.
CONCLUSION: Our results strongly suggest that miR-8084 functions as an oncogene that promotes the development and progression of breast cancer, and miR-8084 is a potential new diagnostic marker and therapeutic target of breast cancer.

BACKGROUND: Although the founding members of the INhibitor of Growth (ING) family of histone mark readers, ING1 and ING2, were defined as tumour suppressors in animal models, the role of other ING proteins in cellular proliferation and cancer progression is unclear.
METHODS: We transduced ex vivo benign prostate hyperplasia tissues with inducible lentiviral particles to express ING proteins. Proliferation was assessed by H3S10
RESULTS: We found that ING3 stimulates cellular proliferation in ex vivo tissues, suggesting that ING3 could be oncogenic. Indeed, ING3 overexpression transformed normal human dermal fibroblasts. We observed elevated levels of ING3 in prostate cancer samples, which correlated with poorer patient survival. Consistent with an oncogenic role, gene-silencing experiments revealed that ING3 is required for the proliferation of breast, ovarian, and prostate cancer cells. Finally, ING3 controls the expression of an intricate network of cell cycle genes by associating with chromatin modifiers and the H3K4
CONCLUSIONS: Our investigations create a shift in the prevailing view that ING proteins are tumour suppressors and redefine ING3 as an oncoprotein.

BACKGROUND: The androgen receptor (AR) is a major driver of prostate cancer, and increased AR levels and co-activators of the receptor promote the development of prostate cancer. INhibitor of Growth (ING) proteins target lysine acetyltransferase or lysine deacetylase complexes to the histone H3K4Me3 mark of active transcription, to affect chromatin structure and gene expression. ING3 is a stoichiometric member of the TIP60 lysine acetyltransferase complex implicated in prostate cancer development.
METHODS: Biopsies of 265 patients with prostate cancer were stained for ING3, pan-cytokeratin, and DNA. LNCaP and C4-2 androgen-responsive cells were used for in vitro assays including immunoprecipitation, western blotting, Luciferase reporter assay and quantitative polymerase chain reaction. Cell viability and migration assays were performed in prostate cancer cell lines using scrambled siRNA or siRNA targeting ING3.
RESULTS: We find that ING3 levels and AR activity positively correlate in prostate cancer. ING3 potentiates androgen effects, increasing expression of androgen-regulated genes and androgen response element-driven reporters to promote growth and anchorage-independent growth. Conversely, ING3 knockdown inhibits prostate cancer cell growth and invasion. ING3 activates the AR by serving as a scaffold to increase interaction between TIP60 and the AR in the cytoplasm, enhancing receptor acetylation and translocation to the nucleus. Activation is independent of ING3's ability to target the TIP60 complex to H3K4Me3, identifying a previously unknown chromatin-independent cytoplasmic activity for ING3. In agreement with in vitro observations, analysis of The Cancer Genome Atlas (TCGA) data (n = 498) and a prostate cancer tissue microarray (n = 256) show that ING3 levels are higher in aggressive prostate cancers, with high levels of ING3 predicting shorter patient survival in a low AR subgroup. Including ING3 levels with currently used indicators such as the Gleason score provides more accurate prognosis in primary prostate cancer.
CONCLUSIONS: In contrast to the majority of previous reports suggesting tumor suppressive functions in other cancers, our observations identify a clear oncogenic role for ING3, which acts as a co-activator of AR in prostate cancer. Data from TCGA and our previous and current tissue microarrays suggest that ING3 levels correlate with AR levels and that in patients with low levels of the receptor, ING3 level could serve as a useful prognostic biomarker.

BACKGROUND: H3K27me3 histone marks shape the inhibition of gene transcription. In prostate cancer, the deregulation of H3K27me3 marks might play a role in prostate tumor progression.
METHODS: We investigated genome-wide H3K27me3 histone methylation profile using chromatin immunoprecipitation (ChIP) and 2X400K promoter microarrays to identify differentially-enriched regions in biopsy samples from prostate cancer patients. H3K27me3 marks were assessed in 34 prostate tumors: 11 with Gleason score > 7 (GS > 7), 10 with Gleason score ≤ 7 (GS ≤ 7), and 13 morphologically normal prostate samples.
RESULTS: Here, H3K27me3 profiling identified an average of 386 enriched-genes on promoter regions in healthy control group versus 545 genes in GS ≤ 7 and 748 genes in GS > 7 group. We then ran a factorial discriminant analysis (FDA) and compared the enriched genes in prostate-tumor biopsies and normal biopsies using ANOVA to identify significantly differentially-enriched genes. The analysis identified ALG5, EXOSC8, CBX1, GRID2, GRIN3B, ING3, MYO1D, NPHP3-AS1, MSH6, FBXO11, SND1, SPATS2, TENM4 and TRA2A genes. These genes are possibly associated with prostate cancer. Notably, the H3K27me3 histone mark emerged as a novel regulatory mechanism in poor-prognosis prostate cancer.
CONCLUSIONS: Our findings point to epigenetic mark H3K27me3 as an important event in prostate carcinogenesis and progression. The results reported here provide new molecular insights into the pathogenesis of prostate cancer.

Propofol is one of the most extensively used intravenous anesthetic agents and it can influence the biological behavior of gastric cancer. However, the underlying mechanism is poorly understood. In the present study, we found that propofol significantly inhibited cell proliferation, invasion and migration, and also promoted apoptosis in gastric carcinoma cell lines SGC-7901 and MGC-803, as detected using MTT, colony formation and flow cytometry assays, respectively. Moreover, propofol (10 and 20 µM) markedly upregulated the expression of inhibitor of growth 3 (ING3), which was lower in SGC-7901 and MGC-803 cells compared with that noted in normal human gastric epithelial cell lines GES-1 and HFE145. Furthermore, we transfected SGC-7901 and MGC-803 cells with ING3 overexpression vectors or ING3 small interference RNA (siING3), respectively, to assess the role of ING3 in propofol-induced antitumor activity. The siING3 transfection reversed the effects of propofol on the biological behavior of gastric cancer cells, while transfection of ING3 promoted the effects of propofol. In conclusion, our results indicate that propofol exerts an inhibitory effect on the growth and survival of gastric cancer cells by interfering with ING3 degradation.

PURPOSE: The inhibitor of growth (ING) family consists of ING1, ING2, ING3, ING4 and ING5, which function as the type II tumor suppressors. INGs regulate cell proliferation, senescence, apoptosis, differentiation, angiogenesis, DNA repair, metastasis, and invasion by multiple pathways. In addition, INGs increase cancer cell sensitivity for chemotherapy and radiotherapy, while clinical observations show that INGs are frequently lost in some types of cancers. The aim of the study was to summarize the recent progress regarding INGs regulating tumor progression.
METHODS: The literatures of INGs regulating tumor progression were searched and assayed.
RESULTS: The regulating signaling pathways of ING1, ING2, ING3 or ING4 on tumor progression were shown. The mechanisms of INGs on tumor suppression were also assayed.
CONCLUSIONS: This review better summarized the signaling mechanism of INGs on tumor suppression, which provides a candidate therapy strategy for cancers.

The androgen receptor (AR) is a transcriptional factor that has a pivotal role in the development of normal and also cancerous prostate. Therefore, analyzing AR signaling is essential to understand cancerogensis and proliferation of prostate cancer (PCa). Inhibitor of growth 1 (ING1) and ING2 are tumor suppressors with reduced expression in many cancer types. There are also indications of misregulation of ING1 and ING2 in PCa. However, the roles of ING1 and ING2 in PCa and AR signaling are poorly understood. Here, we show that surprisingly the ING1b knockdown (KD) represses AR-mediated transactivation on AR key target genes in the human LNCaP PCa cells. This is associated with growth reduction of LNCaP cells by ING1 KD. In line with this, using Ing1 knockout (KO) mice, we provide further evidence that ING1 deficiency downregulates prostate-specific AR target genes in vivo. Further analyses suggest that KD of ING1b results in induction of both cellular senescence and the cell cycle inhibitor p16
KEY MESSAGE: • The tumor suppressors ING1 and 2 are dysregulated in human prostate cancer. • ING1 deficiency reduces AR-mediated gene expression in vitro and in vivo. • ING2, like ING1, inhibits AR-mediated transactivation and prostate cancer cell growth. • ING1 regulates ING2. • ING1 and ING2 crosstalk with each other to inhibit AR signaling in prostate cancer.

The inhibitor of growth family member 3 (ING3) is a member of the ING tumor suppressor family. Although its expression has been reported in various types of cancers, the role of ING3 and its prognostic value in prostate cancer (PCa) has not been investigated. ING3 expression and prognostic value was assessed in a cohort of PCa patients (n = 312) treated with transurethral resection of prostate using immumoflourescent automated quantitative analysis (AQUA) system. In vitro studies were carried out in conjunction to investigate its expression in various PCa cell lines. ING3 knockdown was also carried out in DU145 cell lines to assess for any changes in invasion and migration. ING3 expression was highest in benign prostate tissues (mean 3.2 ± 0.54) compared to PCa (mean 2.5 ± 0.26) (p = 0.437), advanced prostate cancer (AdvPCa) (mean 1.5 ± 0.32) (p = 0.004), and castration-resistant prostate cancer (CRPC) (mean 2.28 ± 0.32) (p = 0.285). ING3 expression was inversely correlated to Gleason score (p = 0.039) and ETS-related gene (ERG) expression (p = 0.019). Higher ING3 expression was marginally associated with lethal disease (p = 0.052), and this was more pronounced in patients with ERG-negative status (p = 0.018). Inhibition of ING3 in DU145 PCa cells using small interfering RNA (siRNA) was associated with decreased cell invasion (p = 0.0016) and cell migration compared to control cells. ING3 is significantly associated with PCa disease progression and cancer-specific mortality. To our knowledge, this is the first report suggesting an oncogenic function of ING3, previously well known as a tumor suppressor protein. Further studies should investigate potential-related pathways in association to ING3.

In loss of heterozygosity (LOH) studies at the chromosome 4q22-35 region, it was shown that the amount of deletion was high in basal cell carcinoma (BCC). It has been proposed that genes located in this chromosomal region could be tumor suppressor genes in BCC. It has been thought that deletions in the ING2 gene located in the same region can play a role in the pathophysiology of BCC and that deletions occurring in this region may influence the level of ING2 expression in BCC. Tumoral and non-tumoral tissues from 75 patients with BCC (45 men and 30 women) were included to the study. Lesions were excised by a surgical margin of 0.5 cm. After excision, RNA was isolated from tumoral and non-tumoral tissue samples. ING2 messenger RNA (mRNA) expression level was determined in tumoral and non-tumoral tissues by the real-time polymerase chain reaction (RT-PCR). It was detected that ING2 mRNA expression level decreased in tumoral tissues when compared to non-tumoral tissues from BCC patients (p = 0.0001). It was found that expression levels of this gene were comparable among patients with primary, recurrent, or multiple BCC. It is thought that ING2 gene expression level could contribute to the development of BCC but not be associated with the stage and the prognosis of the tumor.

Osteosarcoma is a high-grade malignant bone tumor. Loss of inhibitor of growth 2 (ING2) expression has been demonstrated in numerous types of cancers. However, no study has shown the relationship between ING2 expression and osteosarcoma. In the present study, we confirmed that the levels of ING2 mRNA and protein were lower in cancer tissues than these levels in normal tissues. Loss of nuclear ING2 protein was significantly associated with a decreased survival time of patients. Osteosarcoma cells were transfected with ING2 protein without a nuclear localization signal or intact ING2 protein to examine the effects of exogenous expression of ING2 in vitro. Compared to the control cells, intact ING2-expressing cells exhibited increased apoptosis, G1 phase arrest and senescence. Taken together, these results suggest that ING2 acts as a tumor suppressor in osteosarcoma.

UNLABELLED: Prostate cancer has a proclivity to metastasize to bone. The mechanism by which prostate cancer cells are able to survive and progress in the bone microenvironment is not clear. Identification of molecules that play critical roles in the progression of prostate cancer in bone will provide essential targets for therapy. Ribosomal S6 protein kinases (RSK) have been shown to mediate many cellular functions critical for cancer progression. Whether RSK plays a role in the progression of prostate cancer in bone is unknown. IHC analysis of human prostate cancer specimens showed increased phosphorylation of RSK in the nucleus of prostate cancer cells in a significant fraction of human prostate cancer bone metastasis specimens, compared with the primary site or lymph node metastasis. Expression of constitutively active myristylated RSK in C4-2B4 cells (C4-2B4/RSK) increased their survival and anchorage-independent growth compared with C4-2B4/vector cells. Using an orthotopic bone injection model, it was determined that injecting C4-2B4/RSK cells into mouse femurs enhanced their progression in bone compared with control cells. In PC3-mm2 cells, knockdown of RSK1 (RPS6KA1), the predominant RSK isoform, but not RSK2 (RPS6KA2) alone, decreased anchorage-independent growth in vitro and reduced tumor progression in bone and tumor-induced bone remodeling in vivo. Mechanistic studies showed that RSK regulates anchorage-independent growth through transcriptional regulation of factors that modulate cell survival, including ING3, CKAP2, and PTK6. Together, these data provide strong evidence that RSK is an important driver in prostate cancer progression in bone.
IMPLICATIONS: RSK, an important driver in prostate cancer progression in bone, has promising potential as a therapeutic target for prostate cancer bone metastasis.

Histone deacetylases (HDACs) are targets for cancer therapy. Suberoylanilide hydroxamic acid (SAHA) is an HDAC inhibitor approved by the U.S. Food and Drug Administration for the treatment of cutaneous T-cell lymphoma. To obtain a better mechanistic understanding of the Sin3/HDAC complex in cancer, we extended its protein-protein interaction network and identified a mutually exclusive pair within the complex. We then assessed the effects of SAHA on the disruption of the complex network through six homologous baits. SAHA perturbs multiple protein interactions and therefore compromises the composition of large parts of the Sin3/HDAC network. A comparison of the effect of SAHA treatment on gene expression in breast cancer cells to a knockdown of the ING2 subunit indicated that a portion of the anticancer effects of SAHA may be attributed to the disruption of ING2's association with the complex. Our dynamic protein interaction network resource provides novel insights into the molecular mechanism of SAHA action and demonstrates the potential for drugs to rewire networks.

BACKGROUND & OBJECTIVES: ING3 (inhibitor of growth protein 3) overexpression decreased S-phase cell population and colony-forming efficiency, and induced apoptosis at a p53-mediated manner. The aim of this study was to investigate the clinicopathological and prognostic significance of ING3 expression in colorectal carcinogenesis and subsequent progression.
METHODS: ING3 expression was examined by immunohistochemistry on tissue microarray containing colorectal non-neoplastic mucosa (NNM), adenoma and adenocarcinoma. Colorectal carcinoma tissue and cell lines were studied for ING3 expression by Western blot or RT-PCR.
RESULTS: ING3 mRNA was differentially expressed in Colo201, Colo205, DLD-1, HCT-15, HCT-116, HT-29, KM-12, SW480, SW620 and WiDr cells. Carcinomas showed significantly lower ING3 expression than matched NNM at mRNA level (P< 0.05), but not at protein level. Immunohistochemically, ING3 expression was significantly decreased from NNM, adenoma to adenocarcinoma (P< 0.05). ING3 expression was not correlated with age, sex, tumour size, depth of invasion, lymphatic or venous invasion, lymph node metastasis, tumour- node- metastasis staging or differentiation. Kaplan-Meier analysis indicated that ING3 protein expression was not associated the prognosis of the patients with colorectal carcinoma (P< 0.05).
INTERPRETATION & CONCLUSIONS: Our study showed that downregulated ING3 expression might play an important role in colorectal adenoma-adenocarcinoma sequence. Further studies are required to understand the mechanism.

The inhibitor of growth 2 (ING2) is a member of lNG family, involved in cell cycle regulation, DNA repair, apoptosis and senescence, and participating in chromatin remodeling and transcriptional regulation by histone modification. Recent researches suggest ING2 plays roles in carcinogenesis both as tumor suppressor gene and ongocene depending on tumor types and cell status. Here, we investigated the status of ING2 in a series of 64 Chinese non-small cell lung cancer (NSCLC)patients using immunohistochemistry (IHC) and confirmed the results with Western blotting. RT-PCR results revealed the expression level of ING2 was consistent with mRNA level. The IHC results showed that ING2 protein expression was significantly decreased in NSCLC samples compared with normal lung tissues (P

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