TRPM2

Gene Summary

Gene:TRPM2; transient receptor potential cation channel subfamily M member 2
Aliases: KNP3, EREG1, TRPC7, LTRPC2, NUDT9H, LTrpC-2, NUDT9L1
Location:21q22.3
Summary:The protein encoded by this gene forms a tetrameric cation channel that is permeable to calcium, sodium, and potassium and is regulated by free intracellular ADP-ribose. The encoded protein is activated by oxidative stress and confers susceptibility to cell death. Alternative splicing results in multiple transcript variants encoding distinct protein isoforms. Additional transcript variants of this gene have been described, but their full-length nature is not known. [provided by RefSeq, Feb 2016]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:transient receptor potential cation channel subfamily M member 2
Source:NCBIAccessed: 13 March, 2017

Ontology:

What does this gene/protein do?
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Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 13 March 2017 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 13 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (4)

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: TRPM2 (cancer-related)

Tellez T, Garcia-Aranda M, Redondo M
The Role of Clusterin in Carcinogenesis and its Potential Utility as Therapeutic Target.
Curr Med Chem. 2016; 23(38):4297-4308 [PubMed] Related Publications
Clusterin is a glycoprotein that has been implicated in many processes, including apoptosis, cell cycle regulation and DNA repair. Since clusterin expression has also been associated with tumorigenesis and the progression of various malignancies including prevalent tumors like prostate, colon, bladder and breast, this protein has been proposed as a good candidate for future treatments. There have been numerous studies conducted in cell lines and xenograft models with successful results that, in general, justify the use of clusterin as a therapeutic target. However, it is still necessary to continue with these studies in order to achieve a better understanding of the role of this protein in carcinogenesis and to determine those specific situations in which its therapeutic use may be more favorable. In this review, we will make a brief description of clusterin structure and genetics, its implication in tumorigenesis and cancer progression and its prognosis utility. Finally, we will analyze the effects of clusterin inhibition in different types of cancer.

Lee JY, Kim HJ, Rho SB, Lee SH
eIF3f reduces tumor growth by directly interrupting clusterin with anti-apoptotic property in cancer cells.
Oncotarget. 2016; 7(14):18541-57 [PubMed] Free Access to Full Article Related Publications
Clusterin is a secretory heterodimeric glycoprotein and the overexpression of secretory clusterin (sCLU) promotes cancer cell proliferation and reduces chemosensitivity. Therefore, sCLU might be an effective target for anticancer therapy. In the current study, we identified eIF3f as a novel CLU-interacting protein and demonstrated its novel function as a CLU inhibitor. The overexpression of eIF3f retarded cancer cell growth significantly and induced apoptosis. In addition, eIF3f interacted with the α-chain (1-227) of sCLU. This interaction blocked modification of psCLU, thereby decreasing the expression and secretion of α/β CLU. Consequently, the overexpression of eIF3f suppressed Akt and ERK signaling and subsequently depleted CLU expression. In addition, eIF3F stabilized p53, which increased the expression of p21 and Bax. Interestingly, the expression of Bax was increased without the activation of p53. eIF3f injected into a xenograft model of human cervical cancer in nude mice markedly inhibited tumor growth. The identification of this novel function of eIF3f as a sCLU inhibitor might open novel avenues for developing improved strategies for CLU-targeted anti-cancer therapies.

Wang C, Zhang Y, Guo K, et al.
Heat shock proteins in hepatocellular carcinoma: Molecular mechanism and therapeutic potential.
Int J Cancer. 2016; 138(8):1824-34 [PubMed] Related Publications
Heat shock proteins (HSPs) are highly conserved proteins, which are expressed at low levels under normal conditions, but significantly induced in response to cellular stresses. As molecular chaperones, HSPs play crucial roles in protein homeostasis, apoptosis, invasion and cellular signaling transduction. The induction of HSPs is an important part of heat shock response, which could help cancer cells to adapt to stress conditions. Because of the constant stress condition in tumor microenvironment, HSPs overexpression is widely reported in many human cancers. In light of the significance of HSPs for cancer cells to survive and obtain invasive phenotype under stress condition, HSPs are often associated with poor prognosis and treatment resistance in many types of human cancers. It has been described that upregulation of HSPs may serve as diagnostic and prognostic markers in hepatocellular carcinoma (HCC). Targeting HSPs with specific inhibitor alone or in combination with chemotherapy regimens holds promise for the improvement of outcomes for HCC patients. In this review, we summarize the expression profiles, functions and molecular mechanisms of HSPs (HSP27, HSP70 and HSP90) as well as a HSP-like protein (clusterin) in HCC. In addition, we address progression and challenges in targeting these HSPs as novel therapeutic strategies in HCC.

Klumpp D, Misovic M, Szteyn K, et al.
Targeting TRPM2 Channels Impairs Radiation-Induced Cell Cycle Arrest and Fosters Cell Death of T Cell Leukemia Cells in a Bcl-2-Dependent Manner.
Oxid Med Cell Longev. 2016; 2016:8026702 [PubMed] Free Access to Full Article Related Publications
Messenger RNA data of lymphohematopoietic cancer lines suggest a correlation between expression of the cation channel TRPM2 and the antiapoptotic protein Bcl-2. The latter is overexpressed in various tumor entities and mediates therapy resistance. Here, we analyzed the crosstalk between Bcl-2 and TRPM2 channels in T cell leukemia cells during oxidative stress as conferred by ionizing radiation (IR). To this end, the effects of TRPM2 inhibition or knock-down on plasma membrane currents, Ca(2+) signaling, mitochondrial superoxide anion formation, and cell cycle progression were compared between irradiated (0-10 Gy) Bcl-2-overexpressing and empty vector-transfected Jurkat cells. As a result, IR stimulated a TRPM2-mediated Ca(2+)-entry, which was higher in Bcl-2-overexpressing than in control cells and which contributed to IR-induced G2/M cell cycle arrest. TRPM2 inhibition induced a release from G2/M arrest resulting in cell death. Collectively, this data suggests a pivotal function of TRPM2 in the DNA damage response of T cell leukemia cells. Apoptosis-resistant Bcl-2-overexpressing cells even can afford higher TRPM2 activity without risking a hazardous Ca(2+)-overload-induced mitochondrial superoxide anion formation.

Chen X, Jiang Y, Huang Z, et al.
miRNA-378 reverses chemoresistance to cisplatin in lung adenocarcinoma cells by targeting secreted clusterin.
Sci Rep. 2016; 6:19455 [PubMed] Free Access to Full Article Related Publications
Cisplatin resistance is a major obstacle in the treatment of NSCLC, and its mechanism has not been fully elucidated. The objectives of the study were to determine the role of miR-378 in the sensitivity of lung adenocarcinoma cells to cisplatin (cDDP) and its working mechanism. With TargetScan and luciferase assay, miR-378 was found to directly target sCLU. miR-378 and sCLU were regulated in A549/cDDP and Anip973/cDDP cells to investigate the effect of miR-378 on the sensitivity and apoptotic effects of cDDP. The effect of miR-378 upregulation on tumor growth was analyzed in a nude mouse xenograft model. The correlation between miR-378 and chemoresistance was tested in patient samples. We found that upregulation of miR-378 in A549/cDDP and Anip973/cDDP cells significantly down-regulated sCLU expression, and sensitized these cells to cDDP. miR-378 overexpression inhibited tumor growth and sCLU expression in a xenograft animal model. Analysis of human lung adenocarcinoma tissues revealed that the cDDP sensitive group expressed higher levels of miR-378 and lower levels of sCLU. miR-378 and sCLU were negatively correlated. To conclude, we identified sCLU as a novel miR-378 target, and we showed that targeting sCLU via miR-378 may help disable the chemoresistance against cisplatin in lung adenocarcinoma cells.

Yu SY, Hong LC, Feng J, et al.
Integrative proteomics and transcriptomics identify novel invasive-related biomarkers of non-functioning pituitary adenomas.
Tumour Biol. 2016; 37(7):8923-30 [PubMed] Related Publications
Non-functioning pituitary adenomas (NFPAs) are usually macroadenomas and display invasion into surrounding tissues. The treatment for invasive NFPAs is still challenging. This study describes the differential patterns of gene expression between invasive and non-invasive NFPAs and identifies novel biomarkers involved in invasion of NFPAs for diagnosis and treatment. Using gene microarray technology, we examined the gene expression profile and found 1160 differentially expressed messenger RNA (mRNA) between invasive and non-invasive NFPAs. Then, we examined the protein profile by liquid chromatography tandem mass spectrometry (LC-MS/MS) and found 433 differentially expressed proteins between invasive and non-invasive NFPAs. Subsequently, we integrated the proteomics and transcriptomics datasets and identified 29 common changed molecules. Through bioinformatics analysis using Ingenuity Pathway Analysis (IPA) software, we showed that the 29 molecules were enriched in 25 canonical signaling pathways, 25 molecular and cellular functions, and 2 networks. Eight genes were identified involved in the invasion function by the molecular and cellular functions analysis, including CAT, CLU, CHGA, EZR, KRT8, LIMA1, SH3GLB2 and SLC2A1. Furthermore, we validated the decreased CHGA expression and increased CLU expression in invasive NFPAs by qRT-PCR and Western blot. Our study demonstrated that integration of proteomics and transcriptomics could prove advantageous for accelerating tumor biomarker discovery and CHGA and CLU might be important novel biomarkers and therapeutic targets for invasion of NFPAs.

Park YR, Chun JN, So I, et al.
Data-driven Analysis of TRP Channels in Cancer: Linking Variation in Gene Expression to Clinical Significance.
Cancer Genomics Proteomics. 2016 Jan-Feb; 13(1):83-90 [PubMed] Related Publications
BACKGROUND: Experimental evidence has suggested that transient receptor potential (TRP) channels play a crucial role in tumor biology. However, clinical relevance and significance of TRP channels in cancer remain largely unknown.
MATERIALS AND METHODS: We applied a data-driven approach to dissect the expression landscape of 27 TRP channel genes in 14 types of human cancer using International Cancer Genome Consortium data.
RESULTS: TRPM2 was found overexpressed in most tumors, whereas TRPM3 was broadly down-regulated. TRPV4 and TRPA1 were found up- and down-regulated respectively in a cancer type-specific manner. TRPC4 was found to be closely associated with incidence of head and neck cancer and poor survival of patients with kidney cancer. TRPM8 was identified as a new molecular marker for lung cancer diagnosis and TRPP1 for kidney cancer prognosis.
CONCLUSION: Our data-driven approach demonstrates that the variation in the expression of TRP channel genes is manifested across various human cancer types and genes, for certain TRP channels have strong predictive diagnostic and prognostic potential.

Chou YC, Chang MY, Wang MJ, et al.
Phenethyl isothiocyanate alters the gene expression and the levels of protein associated with cell cycle regulation in human glioblastoma GBM 8401 cells.
Environ Toxicol. 2017; 32(1):176-187 [PubMed] Related Publications
Glioblastoma is the most common and aggressive primary brain malignancy. Phenethyl isothiocyanate (PEITC), a member of the isothiocyanate family, can induce apoptosis in many human cancer cells. Our previous study disclosed that PEITC induces apoptosis through the extrinsic pathway, dysfunction of mitochondria, reactive oxygen species (ROS)-induced endoplasmic reticulum (ER) stress, and intrinsic (mitochondrial) pathway in human brain glioblastoma multiforme (GBM) 8401 cells. To the best of our knowledge, we first investigated the effects of PEITC on the genetic levels of GBM 8401 cells in vitro. PEITC may induce G0/G1 cell-cycle arrest through affecting the proteins such as cdk2, cyclin E, and p21 in GBM 8401 cells. Many genes associated with cell-cycle regulation of GBM 8401 cells were changed after PEITC treatment: 48 genes were upregulated and 118 were downregulated. The cell-division cycle protein 20 (CDC20), Budding uninhibited by benzimidazole 1 homolog beta (BUB1B), and cyclin B1 were downregulated, and clusterin was upregulated in GBM 8401 cells treated with PEITC. These changes of gene expression can provide the effects of PEITC on the genetic levels and potential biomarkers for glioblastoma. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 176-187, 2017.

Manzat-Saplacan RM, Balacescu L, Gherman C, et al.
Is there a correlation between peripheral blood expression of angiogenic transcriptional factors/receptors and colorectal cancer?
J BUON. 2015 Sep-Oct; 20(5):1193-200 [PubMed] Related Publications
PURPOSE: The aim of this study was to evaluate whether there is a correlation between peripheral blood expression of angiogenic transcriptional factors/receptors and colorectal cancer (CRC).
METHODS: Eighty six blood samples collected from patients with CRC (N=42), adenomas and/or hyperplastic polyps(AP, N=30) and individuals without colon pathology (control group/CTR, N=14) were used for this study. Twelve transcription factors and receptors were assessed by qRT-PCR in a case-control study. The molecules with a minimum of 30% differences in gene expression for CRC and AP compared to CTR were then analyzed separately for each sample. Gene expression was evaluated relatively to the CTR after normalization to the large ribosomal protein PO (RPLPO) housekeeping gene, and the differential expression between studied groups was assessed by ANOVA.
RESULTS: Seven out of 12 genes presented differences in expression between 10-29% in CRC and/or AP compared to CTR. Considering the selection criteria, we further individually evaluated the levels of expression of 5 genes that had a minimum of 30% expression in the case-control study. Our data showed a significant up-regulation of platelet derived growth factor (PDGF) C in the blood of the patients with CRC compared to CTR (p=0.007). Likewise, clusterin (CLU) was significantly up-regulated both in CRC and AP groups compared to healthy subjects (p=0.01). For VEGFR1, PDGFRA and TGFB1 we didn't find significantly differential expression between any of the studied groups, even if increased levels were observed in both CRC and AP vs CTR.
CONCLUSIONS: The results of our study indicated that increased blood level of PDGFC mRNA was associated with the presence of CRC (p=0.007). Additionally, high levels of circulating CLU mRNA were observed in both malignant and benign colorectal pathologies.

Mouraviev V, Lee B, Patel V, et al.
Clinical prospects of long noncoding RNAs as novel biomarkers and therapeutic targets in prostate cancer.
Prostate Cancer Prostatic Dis. 2016; 19(1):14-20 [PubMed] Related Publications
BACKGROUND: The lack of sensitive and specific biomarkers for prostate cancer (PCa) has led to over-diagnosis and overtreatment with uncertain benefit. Therefore, biomarkers for early diagnosis that can distinguish aggressive from indolent tumors and that can detect metastatic or recurrent disease are needed. Long noncoding RNAs (lncRNAs) are non-protein-coding RNA species. lncRNAs are dysregulated in many diseases including PCa and are emerging as major players in cancer development. lncRNAs have several features that make then suitable as both biomarkers and therapeutics, and lncRNAs regulate critical cancer hallmarks in prostate epithelial cells including proliferation and survival.
METHODS: The PubMed database was searched using the terms 'long noncoding RNA', 'biomarker' and 'prostate cancer'. Known lncRNAs implicated as biomarkers and potential therapeutic targets in PCa are reviewed.
RESULTS: We comprehensively review several lncRNAs with potential as biomarkers for PCa. lncRNAs including PCA3, PCATs, SChLAP1, SPRY4-IT1 and TRPM2-AS are upregulated in PCa and are cancer specific; they are, therefore, attractive lead candidate biomarkers for clinical application. Several lncRNA therapeutics are currently being investigated by several companies for the treatment of various cancers including PCa. Small interfering RNAs, antisense oligonucleotides, ribozymes, deoxyribozymes and aptemers are few promising technologies for future lncRNA bases therapeutics.
CONCLUSION: lncRNA expression is altered in cancer. Aberrant regulation promotes tumor formation, progression and metastasis. lncRNAs can use as tumor markers for PCa and may be attractive novel therapeutic targets for the diagnosis and treatment of PCa.

Zhou J, Chen X, Gilvary DL, et al.
HMGB1 induction of clusterin creates a chemoresistant niche in human prostate tumor cells.
Sci Rep. 2015; 5:15085 [PubMed] Free Access to Full Article Related Publications
Development of chemoresistance, especially to docetaxel (DTX), is the primary barrier to the cure of castration-resistant prostate cancer but its mechanism is obscure. Here, we report a seminal crosstalk between dying and residual live tumor cells during treatment with DTX that can result in outgrowth of a chemoresistant population. Survival was due to the induction of secretory/cytoplasmic clusterin (sCLU), which is a potent anti-apoptotic protein known to bind and sequester Bax from mitochondria, to prevent caspase 3 activation. sCLU induction in live cells depended on HMGB1 release from dying cells. Supernatants from DTX-treated DU145 tumor cells, which were shown to contain HMGB1, effectively induced sCLU from newly-plated DU145 tumor cells and protected them from DTX toxicity. Addition of anti-HMBG1 to the supernatant or pretreatment of newly-plated DU145 tumor cells with anti-TLR4 or anti-RAGE markedly abrogated sCLU induction and protective effect of the supernatant. Mechanistically, HMGB1 activated NFκB to promote sCLU gene expression and prevented the translocation of activated Bax to mitochondria to block cell death. Importantly, multiple currently-used chemotherapeutic drugs could release HMGB1 from tumor cells. These results suggest that acquisition of chemoresistance may involve the HMGB1/TLR4-RAGE/sCLU pathway triggered by dying cells to provide survival advantage to remnant live tumor cells.

Shapiro B, Tocci P, Haase G, et al.
Clusterin, a gene enriched in intestinal stem cells, is required for L1-mediated colon cancer metastasis.
Oncotarget. 2015; 6(33):34389-401 [PubMed] Free Access to Full Article Related Publications
Hyperactive Wnt signaling is a common feature in human colorectal cancer (CRC) cells. A central question is the identification and role of Wnt/β-catenin target genes in CRC and their relationship to genes enriched in colonic stem cells, since Lgr5+ intestinal stem cells were suggested to be the cell of CRC origin. Previously, we identified the neural immunoglobulin-like adhesion receptor L1 as a Wnt/β-catenin target gene localized in cells at the invasive front of CRC tissue and showed that L1 expression in CRC cells confers enhanced motility and liver metastasis. Here, we identified the clusterin (CLU) gene that is also enriched in Lgr5+ intestinal stem cells, as a gene induced during L1-mediated CRC metastasis. The increase in CLU levels by L1 in CRC cells resulted from transactivation of CLU by STAT-1. CLU overexpression in CRC cells enhanced their motility and the reduction in CLU levels in L1 overexpressing cells suppressed the ability of L1 to confer increased tumorigenesis and liver metastasis. Genes induced during L1-mediated CRC cell metastasis and enriched in intestinal stem cells might be important for both CRC progression and colonic epithelium homeostasis.

Fu Y, Lai Y, Liu J, et al.
Lentivirus-mediated shRNA interference of clusterin blocks proliferation, motility, invasion and cell cycle in the ovarian cancer cells.
J Ovarian Res. 2015; 8:59 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: In a previous analysis on the patients with ovarian cancers, we have found that clusterin is a biomarker associated with ovarian cancer in vivo and may be a prognostic factor associated with adverse outcome. Here, we explored the effect of lentivirus-mediated shRNA interference of clusterin, investigated whether clusterin was associated with adverse outcome of ovarian cancer cells in vitro.
METHODS: OVCAR-3 and TOV-21G cell lines were infected with the lentivirus for delivering clusterin shRNA, and the stably transfected cells were selected. The effect of clusterin silencing was detected by western blotting assay. The proliferation, clonability, migration, invasion and cell cycle of two cell lines were detected separately by MTT assay, clone formation assay, scratch assay, transwell assay and fluorescence-activated cell sorting.
RESULTS: Following clusterin silencing with shRNA, the expression of clusterin in two cell lines were decreased. And the proliferation, clonability, migration, invasion of these two cell lines were down-regulated apparently. The cell cycle of two cell lines was disturbed, cells in G1 phase was increased, but cells in G2 and S phase was decreased.
CONCLUSIONS: The expression of clusterin is significantly correlated with the biological characteristics of ovarian cancer cells, it may be a potential molecular for ovarian cancer treatment.

Jun KH, Lee JE, Kim SH, et al.
Clinicopathological significance of N-cadherin and VEGF in advanced gastric cancer brain metastasis and the effects of metformin in preclinical models.
Oncol Rep. 2015; 34(4):2047-53 [PubMed] Related Publications
Gastric cancer is the second most common cause of cancer-related death worldwide. Although brain metastasis is a rare complication of gastric cancer, no standard therapy for gastric cancer brain metastasis has been established. We attempted to identify biological markers that predict brain metastasis, and investigated how to modulate such markers. A case-control study of patients newly diagnosed with gastric cancer who had developed brain metastasis during follow-up, was conducted. These patients were compared with patients who had advanced gastric cancer but no evidence of brain metastasis. Immunohistochemistry was used to analyze the expression of E-cadherin, N-cadherin, MSS1, claudin-3, claudin-4, Glut1, clusterin, ITGB4, vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR) and p53. The expression of VEGF tended to be higher in the case group (33.3 vs. 0%, p=0.055). Median survival was significantly correlated with vascular invasion (12 vs. 33 months, p=0.008) and N-cadherin expression (36 vs. 12 months, p=0.027). We also investigated the effects of metformin in tumor-bearing mouse models. VEGF expression was decreased and E-cadherin increased in the metformin‑treated group when compared with the control group. The expression of the mesenchymal marker MMP9 was decreased in the metformin-treated group. Brain metastasis of advanced gastric cancer was associated with the expression of VEGF. Metformin treatment may be useful for modulating the metastatic capacity by reducing VEGF expression and blocking epithelial-to-mesenchymal transition.

Yamamoto Y, Lin PJ, Beraldi E, et al.
siRNA Lipid Nanoparticle Potently Silences Clusterin and Delays Progression When Combined with Androgen Receptor Cotargeting in Enzalutamide-Resistant Prostate Cancer.
Clin Cancer Res. 2015; 21(21):4845-55 [PubMed] Related Publications
PURPOSE: Lipid nanoparticle (LNP) formulations facilitate tumor uptake and intracellular processing through an enhanced permeation and retention effect (EPR), and currently multiple products are undergoing clinical evaluation. Clusterin (CLU) is a cytoprotective chaperone induced by androgen receptor (AR) pathway inhibition to facilitate adaptive survival pathway signaling and treatment resistance. In our study, we investigated the efficacy of siRNA tumor delivery using LNP systems in an enzalutamide-resistant (ENZ-R) castration-resistant prostate cancer (CRPC) model.
EXPERIMENTAL DESIGN: Gene silencing of a luciferase reporter gene in the PC-3M-luc stable cell line was first assessed in subcutaneous and metastatic PC-3 xenograft tumors. Upon validation, the effect of LNP siRNA targeting CLU in combination with AR antisense oligonucleotides (ASO) was assessed in ENZ-R CRPC LNCaP in vitro and in vivo models.
RESULTS: LNP LUC-siRNA silenced luciferase expression in PC-3M-luc subcutaneous xenograft and metastatic models. LNP CLU-siRNA potently suppressed CLU and AR ASO-induced CLU and AKT and ERK phosphorylation in ENZ-R LNCaP cells in vitro, more potently inhibiting ENZ-R cell growth rates and increased apoptosis when compared with AR-ASO monotherapy. In subcutaneous ENZ-R LNCaP xenografts, combinatory treatment of LNP CLU-siRNA plus AR-ASO significantly suppressed tumor growth and serum PSA levels compared with LNP LUC-siRNA (control) and AR-ASO.
CONCLUSIONS: LNP siRNA can silence target genes in vivo and enable inhibition of traditionally non-druggable genes like CLU and other promising cotargeting approaches in ENZ-R CRPC therapeutics.

Alptekin M, Eroglu S, Tutar E, et al.
Gene expressions of TRP channels in glioblastoma multiforme and relation with survival.
Tumour Biol. 2015; 36(12):9209-13 [PubMed] Related Publications
Glioblastoma multiforme (GBM) is one of the most lethal forms of cancer in humans, with a median survival of 10 to 12 months. Glioblastoma is highly malignant since the cells are supported by a great number of blood vessels. Although new treatments have been developed by increasing knowledge of molecular nature of the disease, surgical operation remains the standard of care. The TRP (transient receptor potential) superfamily consists of cation-selective channels that have roles in sensory physiology such as thermo- and osmosensation and in several complex diseases such as cancer, cardiovascular, and neuronal diseases. The aim of this study was to investigate the expression levels of TRP channel genes in patients with glioblastoma multiforme and to evaluate the relationship between TRP gene expressions and survival of the patients. Thirty-three patients diagnosed with glioblastoma were enrolled to the study. The expression levels of 21 TRP genes were quantified by using qRT-PCR with dynamic array 48 × 48 chip (BioMark HD System, Fluidigm, South San Francisco, CA, USA). TRPC1, TRPC6, TRPM2, TRPM3, TRPM7, TRPM8, TRPV1, and TRPV2 were found significantly higher in glioblastoma patients. Moreover, there was a significant relationship between the overexpression of TRP genes and the survival of the patients. These results demonstrate for the first time that TRP channels contribute to the progression and survival of the glioblastoma patients.

Amente S, Milazzo G, Sorrentino MC, et al.
Lysine-specific demethylase (LSD1/KDM1A) and MYCN cooperatively repress tumor suppressor genes in neuroblastoma.
Oncotarget. 2015; 6(16):14572-83 [PubMed] Free Access to Full Article Related Publications
The chromatin-modifying enzyme lysine-specific demethylase 1, KDM1A/LSD1 is involved in maintaining the undifferentiated, malignant phenotype of neuroblastoma cells and its overexpression correlated with aggressive disease, poor differentiation and infaust outcome. Here, we show that LSD1 physically binds MYCN both in vitro and in vivo and that such an interaction requires the MYCN BoxIII. We found that LSD1 co-localizes with MYCN on promoter regions of CDKN1A/p21 and Clusterin (CLU) suppressor genes and cooperates with MYCN to repress the expression of these genes. KDM1A needs to engage with MYCN in order to associate with the CDKN1A and CLU promoters. The expression of CLU and CDKN1A can be restored in MYCN-amplified cells by pharmacological inhibition of LSD1 activity or knockdown of its expression. Combined pharmacological inhibition of MYCN and LSD1 through the use of small molecule inhibitors synergistically reduces MYCN-amplified Neuroblastoma cell viability in vitro. These findings demonstrate that LSD1 is a critical co-factor of the MYCN repressive function, and suggest that combination of LSD1 and MYCN inhibitors may have strong therapeutic relevance to counteract MYCN-driven oncogenesis.

Deb M, Sengupta D, Rath SK, et al.
Clusterin gene is predominantly regulated by histone modifications in human colon cancer and ectopic expression of the nuclear isoform induces cell death.
Biochim Biophys Acta. 2015; 1852(8):1630-45 [PubMed] Related Publications
Clusterin (CLU) is an important glycoprotein involved in various cellular functions. Different reports have mentioned that the two isoforms of CLU; secretary (sCLU) and nuclear (nCLU) have opposite (paradoxical) roles in cancer development. sCLU provides pro-survival signal, whereas nCLU is involved in pro-apoptotic signaling. However, the molecular mechanism of CLU gene regulation is not clear as of yet. We hypothesize that CLU gene is regulated by DNA methylation and histone modifications and clusterin plays an important role in colon cancer. To evaluate the hypothesis, we investigated CLU expression in colon cancer tissues and DNA methylation and histone modification status of CLU gene promoter. It is apparent from immonohistology data that both benign and cancerous (primary and metastasis) formalin fixed paraffin embedded (FFPE) tissue samples exhibit CLU expression. However and interestingly only noncancerous tissue samples show nCLU expression. Ectopic expression of nCLU either by epigenetic modulators or by nCLU transfection is responsible for colon cancer cell death. To clarify the molecular mechanisms for regulation of expression of CLU isoforms, we have analyzed DNA methylation and histone modifications, such as histone H3K9me3, H3K27me3, H3K4me3, and H3K9AcS10P patterns around the CLU promoter. There is no remarkable change in the DNA methylation status upon treatment of the cells by AZA, TSA and SAM. Our findings clearly show that promoter histone H3K9me3 and H3K27me3 marks are elevated in comparison to H3K4me3 and H3K9AcS10P marks in colon cancer cell lines.

Cao QF, Qian SB, Wang N, et al.
TRPM2 mediates histone deacetylase inhibition-induced apoptosis in bladder cancer cells.
Cancer Biother Radiopharm. 2015; 30(2):87-93 [PubMed] Related Publications
PURPOSE: Inhibition of histone deacetylase (HDAC) activity results in growth arrest and apoptosis in multiple types of cancer cells. It has been well established that p21 is responsible for HDAC inhibitor (HDACi)-induced growth inhibition, while the mechanism underlying HDACi-elicited apoptosis in bladder cancer cells remains largely unknown.
METHODS: In this study, the apoptotic response to HDACi (trichostatin A and sodium butyrate) with different concentrations was determined by flow cytometry analysis and real-time polymerase chain reaction was conducted to examine the TRPM2 (Transient receptor potential cation channel, subfamily M, member 2) expression change on HDACi treatment. TRPM2 knockdown and overexpression were performed to investigate the role of TRPM2 in HDACi-induced apoptosis. The mechanism of HDACi-elicited upregulation of TRPM2 was studied by chromatin-immunoprecipitation.
RESULTS: HDACi efficiently induced cell apoptosis and TRPM2 upregulation in a time- and dose-dependent manner in T24 bladder cancer cells. Functional analysis revealed that TRPM2 overexpression promotes apoptosis of T24 cells. Conversely, TRPM2 depletion remarkably antagonized HDACi-induced apoptosis. Furthermore, HDAC inhibition-elicited TRPM2 upregulation is caused by the increase of acetylated H3K9 (H3K9Ac) enrichment in TRPM2 promoter.
CONCLUSIONS: These data suggest that the HDACi-elicited upregulation of TRPM2 expression is required for HDACi-induced apoptosis in bladder cancer cells and that HDACi activated the enrichment of H3K9Ac-represented permissive chromatin in TRPM2 promoter.

Wang C, Jin G, Jin H, et al.
Clusterin facilitates metastasis by EIF3I/Akt/MMP13 signaling in hepatocellular carcinoma.
Oncotarget. 2015; 6(5):2903-16 [PubMed] Free Access to Full Article Related Publications
Clusterin (CLU) is a stress-induced chaperone that confers proliferative and survival advantages to cancer cells. However, effects and molecular mechanisms of CLU in hepatocellular carcinoma (HCC) metastasis are still unknown. In this study, HCC tissue array (n = 198) was utilized to investigate correlation between CLU expression and clinicopathological features. Overexpression of CLU in HCC tissues was correlated with shorter overall survival and higher tumor recurrence. In vitro and in vivo assays demonstrated that silencing CLU attenuated the invasion and metastasis of HCC cells, whereas ectopic overexpression of CLU resulted in the forced metastasis of HCC cells. We also revealed that CLU activated Akt signaling through complexing with eukaryotic translation initiation factor 3 subunit I (EIF3I), which in turn promoted matrix metalloproteinase 13 (MMP13) expression and HCC metastasis. Positive correlations between CLU and MMP13, p-Akt, or EIF3I were found in HCC tissues. We further observed that CLU knockdown using the CLU inhibitor OGX-011 significantly suppressed HCC metastasis in two metastatic models through inhibiting EIF3I/Akt/MMP13 signaling. These findings indicate that CLU is an independent predictive factor for prognosis of HCC and it facilitates metastasis through EIF3I/Akt/MMP13 signaling. CLU suppression using OGX-011 may represent a promising therapeutic option for suppressing HCC metastasis.

Zheng W, Sai W, Yao M, et al.
Silencing clusterin gene transcription on effects of multidrug resistance reversing of human hepatoma HepG2/ADM cells.
Tumour Biol. 2015; 36(5):3995-4003 [PubMed] Related Publications
Abnormal clusterin (CLU) expression is associated with multidrug resistance (MDR) of hepatocellular carcinoma (HCC). In the present study, the CLU expression was analyzed in human hepatoma cells and chemoresistant counterpart HepG2/ADM cells. Compared with L02 cells, the overexpression of cellular CLU was identified in HepG2, HepG2/ADM, SMMC7721, Hep3B ,and PLC cells and relatively lower expression in Bel-7404, SNU-739, and MHCC97H cells. Specific short hairpin RNAs (shRNAs) to silence CLU gene transcription were designed, and the most effective sequences were screened. After the HepG2/ADM cells transfected with shRNA-1, the inhibition of CLU expression was 73.68 % at messenger RNA (mRNA) level by real-time quantitative RT-PCR with obvious enhancement in cell chemosensitivity, increasing apoptosis induced by doxorubicin using fluorescence kit, and Rh-123 retention qualified with flow cytometry. Knockdown CLU also significantly decreased the drug efflux pump activity through the depression of MDR1/P-glycoprotein (q = 11.739, P < 0.001). Moreover, silencing CLU led to downregulation of β-catenin (q = 13.544, P = 0.001), suggesting that downregulation of CLU might be a key point to reverse multidrug resistance of HepG2/ADM cells.

Zhang F, Kumano M, Beraldi E, et al.
Clusterin facilitates stress-induced lipidation of LC3 and autophagosome biogenesis to enhance cancer cell survival.
Nat Commun. 2014; 5:5775 [PubMed] Free Access to Full Article Related Publications
We define stress-induced adaptive survival pathways linking autophagy with the molecular chaperone clusterin (CLU) that function to promote anticancer treatment resistance. During treatment stress, CLU co-localizes with LC3 via an LIR-binding sequence within autophagosome membranes, functioning to facilitate LC3-Atg3 heterocomplex stability and LC3 lipidation, and thereby enhance autophagosome biogenesis and autophagy activation. Stress-induced autophagy is attenuated with CLU silencing in CLU(-/-) mice and human prostate cancer cells. CLU-enhanced cell survival occurs via autophagy-dependent pathways, and is reduced following autophagy inhibition. Combining CLU inhibition with anticancer treatments attenuates autophagy activation, increases apoptosis and reduces prostate cancer growth. This study defines a novel adaptor protein function for CLU under stress conditions, and highlights how co-targeting CLU and autophagy can amplify proteotoxic stress to delay cancer progression.

Bonacini M, Coletta M, Ramazzina I, et al.
Distinct promoters, subjected to epigenetic regulation, drive the expression of two clusterin mRNAs in prostate cancer cells.
Biochim Biophys Acta. 2015; 1849(1):44-54 [PubMed] Related Publications
The human clusterin (CLU) gene codes for several mRNAs characterized by different sequences at their 5' end. We investigated the expression of two CLU mRNAs, called CLU 1 and CLU 2, in immortalized (PNT1a) and tumorigenic (PC3 and DU145) prostate epithelial cells, as well as in normal fetal fibroblasts (WI38) following the administration of the epigenetic drugs 5-aza-2'-deoxycytidine (AZDC) and trichostatin A (TSA) given either as single or combined treatment (AZDC-TSA). Our experimental evidences show that: a) CLU 1 is the most abundant transcript variant. b) CLU 2 is expressed at a low level in normal fibroblasts and virtually absent in prostate cancer cells. c) CLU 1, and to a greater extent CLU 2 expression, increased by AZDC-TSA treatment in prostate cancer cells. d) Both CLU 1 and CLU 2 encode for secreted CLU. e) P2, a novel promoter that overlaps the CLU 2 Transcription Start Site (TSS), drives CLU 2 expression. f) A CpG island, methylated in prostate cancer cells and not in normal fibroblasts, is responsible for long-term heritable regulation of CLU 1 expression. g) ChIP assay of histone tail modifications at CLU promoters (P1 and P2) shows that treatment of prostate cancer cells with AZDC-TSA causes enrichment of Histone3(Lys9)acetylated (H3K9ac) and reduction of Histone3(Lys27)trimethylated (H3K27me3), inducing active transcription of both CLU variants. In conclusion, we show for the first time that the expression of CLU 2 mRNA is driven by a novel promoter, P2, whose activity responds to epigenetic drugs treatment through changes in histone modifications.

Lee JH, Lee JY, Rho SB, et al.
PACAP inhibits tumor growth and interferes with clusterin in cervical carcinomas.
FEBS Lett. 2014; 588(24):4730-9 [PubMed] Related Publications
Secretory clusterin (sCLU), an anti-apoptotic protein, is overexpressed in many tumors and enhances tumorigenesis and chemo-resistance. However, the regulation mechanism controlling the sCLU maturation process or activity remains undetermined. In this study, we found PACAP as a negative regulator of CLU. Overexpression of the PACAP gene in cervical cancer cell lines lacking PACAP expression significantly inhibited cell growth and induced apoptosis. We further demonstrated that interaction of PACAP with CLU significantly downregulated CLU expression and secretion, inhibited the Akt-Raf-ERK pathway, and suppressed the growth of human tumor xenografts in nude mice. This novel inhibitory function of PACAP may be applicable for developing novel molecular therapies for tumors with increased sCLU expression.

Chen SJ, Hoffman NE, Shanmughapriya S, et al.
A splice variant of the human ion channel TRPM2 modulates neuroblastoma tumor growth through hypoxia-inducible factor (HIF)-1/2α.
J Biol Chem. 2014; 289(52):36284-302 [PubMed] Free Access to Full Article Related Publications
The calcium-permeable ion channel TRPM2 is highly expressed in a number of cancers. In neuroblastoma, full-length TRPM2 (TRPM2-L) protected cells from moderate oxidative stress through increased levels of forkhead box transcription factor 3a (FOXO3a) and superoxide dismutase 2. Cells expressing the dominant negative short isoform (TRPM2-S) had reduced FOXO3a and superoxide dismutase 2 levels, reduced calcium influx in response to oxidative stress, and enhanced reactive oxygen species, leading to decreased cell viability. Here, in xenografts generated with SH-SY5Y neuroblastoma cells stably expressing TRPM2 isoforms, growth of tumors expressing TRPM2-S was significantly reduced compared with tumors expressing TRPM2-L. Expression of hypoxia-inducible factor (HIF)-1/2α was significantly reduced in TRPM2-S-expressing tumor cells as was expression of target proteins regulated by HIF-1/2α including those involved in glycolysis (lactate dehydrogenase A and enolase 2), oxidant stress (FOXO3a), angiogenesis (VEGF), mitophagy and mitochondrial function (BNIP3 and NDUFA4L2), and mitochondrial electron transport chain activity (cytochrome oxidase 4.1/4.2 in complex IV). The reduction in HIF-1/2α was mediated through both significantly reduced HIF-1/2α mRNA levels and increased levels of von Hippel-Lindau E3 ligase in TRPM2-S-expressing cells. Inhibition of TRPM2-L by pretreatment with clotrimazole or expression of TRPM2-S significantly increased sensitivity of cells to doxorubicin. Reduced survival of TRPM2-S-expressing cells after doxorubicin treatment was rescued by gain of HIF-1 or -2α function. These data suggest that TRPM2 activity is important for tumor growth and for cell viability and survival following doxorubicin treatment and that interference with TRPM2-L function may be a novel approach to reduce tumor growth through modulation of HIF-1/2α, mitochondrial function, and mitophagy.

Chun YJ
Knockdown of clusterin expression increases the in vitro sensitivity of human prostate cancer cells to paclitaxel.
J Toxicol Environ Health A. 2014; 77(22-24):1443-50 [PubMed] Related Publications
Clusterin/apolipoprotein J is a secreted heterodimeric glycoprotein that is implicated in several pathophysiological processes, including tissue remodeling, reproduction, lipid transport, and apoptosis. Although previous studies demonstrated that clusterin is able to protect against apoptosis, the role of the clusterin in cellular proliferation remains elusive. To determine whether clusterin plays an important role in cellular proliferation, the function of clusterin was examined using a small interfering RNA (siRNA) in PC3 human prostate cancer cells. Transient transfection with clusterin siRNA resulted in significant suppression of clusterin mRNA and protein expression. Clusterin knockdown resulted in a decrease in protein expression of phospho-Akt and an increase in expression of proteins phosphatase type 2AC (PP2AC) and phosphorylation of p38. However, treatment with PP2AC siRNA exerted minimal effects on clusterin expression. Interestingly, clusterin mRNA expression was reduced in paclitaxel-treated cells, and the cytotoxic effect of paclitaxel was more potent when cells were incubated with clusterin siRNA. In addition, co-treatment with paclitaxel and clusterin siRNA significantly enhanced PP2AC levels. Taken together, these results indicate that clusterin plays a crucial role in PC3 cell proliferation and that clusterin depletion may contribute to enhanced sensitivity of PC3 cells to anticancer agents such as paclitaxel.

Grazia G, Vegetti C, Benigni F, et al.
Synergistic anti-tumor activity and inhibition of angiogenesis by cotargeting of oncogenic and death receptor pathways in human melanoma.
Cell Death Dis. 2014; 5:e1434 [PubMed] Free Access to Full Article Related Publications
Improving treatment of advanced melanoma may require the development of effective strategies to overcome resistance to different anti-tumor agents and to counteract relevant pro-tumoral mechanisms in the microenvironment. Here we provide preclinical evidence that these goals can be achieved in most melanomas, by co-targeting of oncogenic and death receptor pathways, and independently of their BRAF, NRAS, p53 and PTEN status. In 49 melanoma cell lines, we found independent susceptibility profiles for response to the MEK1/2 inhibitor AZD6244, the PI3K/mTOR inhibitor BEZ235 and the death receptor ligand TRAIL, supporting the rationale for their association. Drug interaction analysis indicated that a strong synergistic anti-tumor activity could be achieved by the three agents and the AZD6244-TRAIL association on 20/21 melanomas, including cell lines resistant to the inhibitors or to TRAIL. Mechanistically, synergy was explained by enhanced induction of caspase-dependent apoptosis, mitochondrial depolarization and modulation of key regulators of extrinsic and intrinsic cell death pathways, including c-FLIP, BIM, BAX, clusterin, Mcl-1 and several IAP family members. Moreover, silencing experiments confirmed the central role of Apollon downmodulation in promoting the apoptotic response of melanoma cells to the combinatorial treatments. In SCID mice, the AZD6244-TRAIL association induced significant growth inhibition of a tumor resistant to TRAIL and poorly responsive to AZD6244, with no detectable adverse events on body weight and tissue histology. Reduction in tumor volume was associated not only with promotion of tumor apoptosis but also with suppression of the pro-angiogenic molecules HIF1α, VEGFα, IL-8 and TGFβ1 and with inhibition of tumor angiogenesis. These results suggest that synergistic co-targeting of oncogenic and death receptor pathways can not only overcome melanoma resistance to different anti-tumor agents in vitro but can also promote pro-apoptotic effects and inhibition of tumor angiogenesis in vivo.

Teoh JY, Chan NH, Cheung HY, et al.
Inflammatory myofibroblastic tumors of the urinary bladder: a systematic review.
Urology. 2014; 84(3):503-8 [PubMed] Related Publications
We systemically reviewed the literature on inflammatory myofibroblastic tumors (IMTs) of the urinary bladder and compared between anaplastic lymphoma kinase (ALK)-positive and ALK-negative IMTs. An extensive search of the literature was performed in Medline and Web of Science using the following terms: "inflammatory myofibrolastic tumor," "inflammatory pseudotumor," and "bladder." A manual search was also performed using the web-based search engine Google Scholar. Reference lists of the retrieved articles were reviewed for other relevant studies. Patients' and disease characteristics of each individual case were reviewed. Further analyses were performed to compare between ALK-positive and ALK-negative IMTs. Forty-one studies were identified, and 182 patients were included for review and subsequent analyses. Of the IMTs, 65% were ALK-positive. Local tumor recurrence rate was 4%, and no cases of distant metastases have been reported. Compared with ALK-negative IMTs, ALK-positive IMTs had a female predilection with a sex ratio (male:female) of 1:1.67 (P = .048). ALK-positive IMTs also appeared to occur in younger patients (P = .072). No significant differences were noted in terms of their clinical presentations and histologic features. On immunohistochemical staining, ALK-positive IMTs had more positive results for desmin (P = .042) and p53 (P = .05), and more negative results for clusterin (P = .003). In summary, ALK-positive IMTs of the urinary bladder had a female predilection, appeared to occur more frequently in younger patients, and had different immunohistochemical staining patterns when compared with ALK-negative IMTs. Regardless of its ALK status, IMT of the urinary bladder has a good prognosis after surgical resection.

Zhang B, Liu ZM, Hao FG, Wang M
siRNA-directed clusterin silencing promotes cisplatin antitumor activity in human non-small cell lung cancer xenografts in immunodeficient mice.
Eur Rev Med Pharmacol Sci. 2014; 18(11):1595-601 [PubMed] Related Publications
OBJECTIVES: In a previous analysis using a lung cancer cell lines model, we have found that therapies directed against sCLU and its downstream signaling targets pAkt and pERK1/2 may have the potential to enhance the efficacy of cisplatin (DDP)-based chemotherapy in vitro. Here, we investigated the therapies directed against sCLU on the DDP-based chemotherapy in vivo, and explored the mechanism.
MATERIALS AND METHODS: Using lung cancer cell lines, A549 cells and DDP-resistant A549 cells (A549DDP), we determined the effect of sCLU silencing using short interfering double-stranded RNA (siRNA) on chemosensitivity in immunocompromised mice bearing A549DDP tumors. We then determined the effect of sCLU overexpression via stable sCLU transfection on chemosensitivity in immunocompromised mice bearing A549 tumors. The effect of sCLU silencing or overexpression on pAkt and pERK1/2 expression and chemosensitivity in vivo was detected by western blot assay.
RESULTS: The results showed sCLU silencing increased the chemosensitivity of A549DDP cells to DDP in vivo via downregulation of pAkt and pERK1/2 expression. And sCLU overexpression decreased the chemosensitivity of A549 cells to DDP in vivo via upregulation of pAkt and pERK1/2 expression.
CONCLUSIONS: DDP-induced sCLU activation, which involved induction of pAkt and pERK1/2 activation that confer DDP resistance in immunocompromised mice. Alteration of this balance allows sensitisation to the antitumor activity of cisplatin chemotherapy.

Orfanelli U, Jachetti E, Chiacchiera F, et al.
Antisense transcription at the TRPM2 locus as a novel prognostic marker and therapeutic target in prostate cancer.
Oncogene. 2015; 34(16):2094-102 [PubMed] Related Publications
Overwhelming evidence indicates that cancer is a genetic disease caused by the accumulation of mutations in oncogenes and tumor suppressor genes. It is also increasingly apparent, however, that cancer depends not only on mutations in these coding genes but also on alterations in the large class of non-coding RNAs. Here, we report that one such long non-coding RNA, TRPM2-AS, an antisense transcript of TRPM2, which encodes an oxidative stress-activated ion channel, is overexpressed in prostate cancer (PCa). The high expression of TRPM2-AS and its related gene signature were found to be linked to poor clinical outcome, with the related gene signature working also independently of the patient's Gleason score. Mechanistically, TRPM2-AS knockdown led to PCa cell apoptosis, with a transcriptional profile that indicated an unbearable increase in cellular stress in the dying cells, which was coupled to cell cycle arrest, an increase in intracellular hydrogen peroxide and activation of the sense TRPM2 gene. Moreover, targets of existing drugs and treatments were found to be consistently associated with high TRPM2-AS levels in both targeted cells and patients, ultimately suggesting that the measurement of the expression levels of TRPM2-AS allows not only for the early identification of aggressive PCa tumors, but also identifies a subset of at-risk patients who would benefit from currently available, but mostly differently purposed, therapeutic agents.

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Cite this page: Cotterill SJ. TRPM2, Cancer Genetics Web: http://www.cancer-genetics.org/TRPM2.htm Accessed:

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