Overview of role of survivin in cancer: expression, regulation, functions, and its potential as a therapeutic target

Survivin holds significant importance as a member of the inhibitor of apoptosis protein (IAP) family due to its predominant expression in tumours rather than normal terminally differentiated adult tissues. The high expression level of survivin in tumours is closely linked to chemotherapy resistance, heightened tumour recurrence, and increased tumour aggressiveness and serves as a negative prognostic factor for cancer patients. Consequently, survivin has emerged as a promising therapeutic target for cancer treatment. In this review, we delve into the various biological characteristics of survivin in cancers and its pivotal role in maintaining immune system homeostasis. Additionally, we explore different therapeutic strategies aimed at targeting survivin.

Transcriptional Regulation, Signaling Pathways, and Subcellular Localization of Corticotropin-Releasing Factor Receptors in the Central Nervous System

Corticotropin-releasing factor (CRF) receptors CRF-R1 and CRF-R2 are differentially distributed in body tissues, and although they respond differentially to stimuli due to their association with different signaling pathways, both receptors have a fundamental role in the response and adaptation to stressful stimuli. Here, we summarize the reported data on different forms of CRF-R1 and CRF-R2 regulation as well as on their subcellular localization. Although the presence of R1 has been described at pre- and postsynaptic sites, R2 is mainly associated with postsynaptic densities. Different studies have provided valuable information on how these receptors regulate responses at a central level, elucidating different and sometimes synergistic roles in response to stress, but despite their high sequence identity, both receptors have been described to be differentially regulated both by their ligands and by transcriptional factors. To date, and from the point of view of their promoter sequences, it has not yet been reported how the different consensus sites identified in silico could be modulating the transcriptional regulation and expression of the receptors under different conditions, which strongly limits the full understanding of their differential functions, providing a wide field to increase and expand the study of the regulation and role of CRF receptors in the CRF system. SIGNIFICANCE STATEMENT: A large number of physiological functions related to the organization of the stress response in different body tissues are associated with the corticotropin-releasing factor system. This system also plays a relevant role in depression and anxiety disorders, as well as being a direct connection between stress and addiction. A better understanding of how the receptors of this system are regulated would help to expand the understanding of how these receptors respond differently to both drugs and stressful stimuli.

Possibility for Transcriptional Targeting of Cancer-Associated Fibroblasts-Limitations and Opportunities

Cancer-associated fibroblasts (CAF) are attractive therapeutic targets in the tumor microenvironment. The possibility of using CAFs as a source of therapeutic molecules is a challenging approach in gene therapy. This requires transcriptional targeting of transgene expression by cis-regulatory elements (CRE). Little is known about which CREs can provide selective transgene expression in CAFs. We hypothesized that the promoters of FAP, CXCL12, IGFBP2, CTGF, JAG1, SNAI1, and SPARC genes, the expression of whose is increased in CAFs, could be used for transcriptional targeting. Analysis of the transcription of the corresponding genes revealed that unique transcription in model CAFs was characteristic for the CXCL12 and FAP genes. However, none of the promoters in luciferase reporter constructs show selective activity in these fibroblasts. The CTGF, IGFBP2, JAG1, and SPARC promoters can provide higher transgene expression in fibroblasts than in cancer cells, but the nonspecific viral promoters CMV, SV40, and the recently studied universal PCNA promoter have the same features. The patterns of changes in activity of various promoters relative to each other observed for human cell lines were similar to the patterns of activity for the same promoters both in vivo and in vitro in mouse models. Our results reveal restrictions and features for CAF transcriptional targeting.

Lovastatin-mediated MCF-7 cancer cell death involves LKB1-AMPK-p38MAPK-p53-survivin signalling cascade

There is increasing evidence that statins, which are widely used in lowering serum cholesterol and the incidence of cardiovascular diseases, also exhibits anti‐tumour properties. The underlying mechanisms by which statins‐induced cancer cell death, however, remain incompletely understood. In this study, we explored the anti‐tumour mechanisms of a lipophilic statin, lovastatin, in MCF‐7 breast cancer cells. Lovastatin inhibited cell proliferation and induced cell apoptosis. Lovastatin caused p21 elevation while reduced cyclin D1 and survivin levels. Lovastatin also increased p53 phosphorylation, acetylation and its reporter activities. Results from chromatin immunoprecipitation analysis showed that p53 binding to the survivin promoter region was increased, while Sp1 binding to the region was decreased, in MCF‐7 cells after lovastatin exposure. These actions were associated with liver kinase B1 (LKB1), AMP‐activated protein kinase (AMPK) and p38 mitogen‐activated protein kinase (p38MAPK) activation. Lovastatin's enhancing effects on p53 activation, p21 elevation and survivin reduction were significantly reduced in the presence of p38MAPK signalling inhibitor. Furthermore, LKB1‐AMPK signalling blockade abrogated lovastatin‐induced p38MAPK and p53 phosphorylation. Together these results suggest that lovastatin may activate LKB1‐AMPK‐p38MAPK‐p53‐survivin cascade to cause MCF‐7 cell death. The present study establishes, at least in part, the signalling cascade by which lovastatin induces breast cancer cell death.

Survivin modulatory role in autoimmune and autoinflammatory diseases

Baculoviral IAP repeat containing 5 (BIRC5) gene encodes the important protein as survivin, a multifunctional protein, which is involved in cellular and molecular networks, progression of cell cycle, homeostasis, developmental morphogenesis, and apoptosis. The proximal BIRC5 promoter possesses specific binding sites for key transcription factors such as nuclear factor κB and signal transducer and activator of transcription 3. Upregulation of survivin exacerbates the autoimmune diseases (AIDs) including multiple sclerosis and myasthenia gravis by reducing the activity threshold of survivin-specific cytotoxic T cells. DNA damage along with upregulation or downregulation of survivin have been demonstrated in initiation and pathogenesis of cancers and AIDs. However, detailed mechanism of survivin function in pathogenesis of AIDs is not well understood. This review focuses on the structure, specificity, regulation, and function of survivin in physiologic conditions and pathogenesis of AIDs.

A Novel Hydroxamate-Based Compound WMJ-J-09 Causes Head and Neck Squamous Cell Carcinoma Cell Death via LKB1-AMPK-p38MAPK-p63-Survivin Cascade

Growing evidence shows that hydroxamate-based compounds exhibit broad-spectrum pharmacological properties including anti-tumor activity. However, the precise mechanisms underlying hydroxamate derivative-induced cancer cell death remain incomplete understood. In this study, we explored the anti-tumor mechanisms of a novel aliphatic hydroxamate-based compound, WMJ-J-09, in FaDu head and neck squamous cell carcinoma (HNSCC) cells. WMJ-J-09 induced G2/M cell cycle arrest and apoptosis in FaDu cells. These actions were associated with liver kinase B1 (LKB1), AMP-activated protein kinase (AMPK) and p38 mitogen-activated protein kinase (p38MAPK) activation, transcription factor p63 phosphorylation, as well as modulation of p21 and survivin. LKB1-AMPK-p38MAPK signaling blockade reduced WMJ-J-09’s enhancing effects in p63 phosphorylation, p21 elevation and survivin reduction. Moreover, WMJ-J-09 caused an increase in α-tubulin acetylation and interfered with microtubule assembly. Furthermore, WMJ-J-09 suppressed the growth of subcutaneous FaDu xenografts in vivo. Taken together, WMJ-J-09-induced FaDu cell death may involve LKB1-AMPK-p38MAPK-p63-survivin signaling cascade. HDACs inhibition and disruption of microtubule assembly may also contribute to WMJ-J-09’s actions in FaDu cells. This study suggests that WMJ-J-09 may be a potential lead compound and warrant the clinical development in the treatment of HNSCC.

Epigenetic mechanism of survivin dysregulation in human cancer

Survivin (coding gene BIRC5) is a dual functional protein acting as a critical inhibitor of apoptosis (IAP) and key regulator of cell cycle progression. It is usually produced in embryonic tissues during development and undetectable in most adult tissues. Overexpression of Survivin frequently occurs in various human cancers and increased Survivin correlates with poor clinic outcome, tumor recurrence, and therapeutic resistance. Because of its selective expression in tumor, but not normal tissues, Survivin has been recognized as an attractive target for cancer treatment. Although several therapeutic approaches targeting Survivin are actively under clinical trials in human cancers, to date no Survivin-targeted therapy has been approved for cancer treatment. Numerous studies have devoted to uncovering the underlying mechanism resulting in Survivin dysregulation at multiple levels, such as transcriptional and post-transcriptional regulation. The current article provides a literature review on the transcriptional and epigenetic regulation of Survivin expression in human cancers. We focus on the impact of DNA methylation and histone modifications, including specific lysine methylation, demethylation, and acetylation on the expression of Survivin. The latest development of epigenetic approaches targeting Survivin for cancer treatment are also discussed.

WMJ-8-B, a novel hydroxamate derivative, induces MDA-MB-231 breast cancer cell death via the SHP-1-STAT3-survivin cascade

BACKGROUND AND PURPOSE

Histone deacetylase (HDAC) inhibitors have been demonstrate to have broad-spectrum anti-tumour properties and have attracted lots of attention in the field of drug discovery. However, the underlying anti-tumour mechanisms of HDAC inhibitors remain incompletely understood. In this study, we aimed to characterize the underlying mechanisms through which the novel hydroxamate-based HDAC inhibitor, WMJ-8-B, induces the death of MDA-MB-231 breast cancer cells.

EXPERIMENTAL APPROACH

Effects of WMJ-8-B on cell viability, cell cycle distribution, apoptosis and signalling molecules were analysed by the MTT assay, flowcytometric analysis, immunoblotting, reporter assay, chromatin immunoprecipitation analysis and use of siRNAs. A xenograft model was used to determine anti-tumour effects of WMJ-8-B in vivo.

KEY RESULTS

WMJ-8-B induced survivin reduction, G2/M cell cycle arrest and apoptosis in MDA-MB-231 cells. STAT3 phosphorylation, transactivity and its binding to the survivin promoter region were reduced in WMJ-8-B-treated cells. WMJ-8-B activated the protein phosphatase SHP-1 and when SHP-1 signalling was blocked, the effects of WMJ-8-B on STAT3 phosphorylation and survivin levels were abolished. However, WMJ-8-B increased the transcription factor Sp1 binding to the p21 promoter region and enhanced p21 levels. Moreover, WMJ-8-B induced α-tubulin acetylation and disrupted microtubule assembly. Inhibition of HDACs was shown to contribute to WMJ-8-B's actions. Furthermore, WMJ-8-B suppressed the growth of MDA-MB-231 xenografts in mammary fat pads in vivo.

CONCLUSIONS AND IMPLICATIONS

The SHP-1-STAT3-survivin and Sp1-p21 cascades are involved in WMJ-8-B-induced MDA-MB-231 breast cancer cell death. These results also indicate the potential of WMJ-8-B as a lead compound for treatment of breast cancer and warrant its clinical development.

MicroRNA-141 enhances anoikis resistance in metastatic progression of ovarian cancer through targeting KLF12/Sp1/survivin axis

BACKGROUND

Cancer metastasis is determined by the formation of the metastatic niche and the ability of cancer cells to adapt to microenvironmental stresses. Anoikis resistance is a fundamental feature of metastatic cancer cell survival during metastatic cancer progression. However, the mechanisms underlying anoikis resistance in ovarian cancer are still unclear.

METHODS

Expressions of miRNA-141 and its downstream targets were evaluated by qPCR, Western blotting, Immunohistochemical (IHC) and in situ hybridization (ISH) assays. The luciferase assays were used to prove KLF12 as the downstream target of miR-141. The cDNA microarray and apoptotic protein arrays were used to identify the targets of miR-141 and KLF12. The competition of KLF12 and Sp1 on survivin promoter was examined by ChIP assay. IHC analysis on ovarian cancer tissue array was used to evaluate the expressions of KLF12 and miR-141 and to show the clinical relevance. The functional studies were performed by in vitro and in vivo tumorigenic assays.

RESULTS

Enforced expression of miR-141 promotes, while knockdown of miR-141 expression inhibits, cell proliferation, anchorage-independent capacity, anoikis resistance, tumor growth and peritoneal metastases of ovarian cancer cells. Bioinformatics and functional analysis identified that Kruppel-related zinc finger protein AP-2rep (KLF12) is directly targeted by miR-141. Consistent with this finding, knockdown of KLF12 phenocopied the effects of miR-141 overexpression in ovarian cancer cells. In contrast, restoration of KLF12 in miR-141-expressing cells significantly attenuated anoikis resistance in ovarian cancer cells via interfering with Sp1-mediated survivin transcription, which inhibits the intrinsic apoptotic pathway and is crucial for ovarian cancer cell survival, anoikis resistance and peritoneal metastases. Immunohistochemical (IHC) and in situ hybridization (ISH) assays confirmed that miRNA-141 expression is inversely correlated with KLF12 expression and significantly associated with advanced ovarian cancers accompanied with distal metastases, underscoring the clinical relevance of our findings.

CONCLUSIONS

Our data identify a novel signaling axis of miR-141/KLF12/Sp1/survivin in enhancing anoikis resistance and likely serves as a potential therapeutic target for metastatic ovarian cancer.

Lovastatin causes FaDu hypopharyngeal carcinoma cell death via AMPK-p63-survivin signaling cascade

Statins are used widely to lower serum cholesterol and the incidence of cardiovascular diseases. Growing evidence shows that statins also exhibit beneficial effects against cancers. In this study, we investigated the molecular mechanisms involved in lovastatin-induced cell death in Fadu hypopharyngeal carcinoma cells. Lovastatin caused cell cycle arrest and apoptosis in FaDu cells. Lovastatin increased p21^cip/Waf1 level while the survivin level was decreased in the presence of lovastatin. Survivin siRNA reduced cell viability and induced cell apoptosis in FaDu cells. Lovastatin induced phosphorylation of AMP-activated protein kinase (AMPK), p38 mitogen-activated protein kinase (MAPK) and transcription factor p63. Lovastatin also caused p63 acetylation and increased p63 binding to survivin promoter region in FaDu cells. AMPK-p38MAPK signaling blockade abrogated lovastatin-induced p63 phosphorylation. Lovastatin’s enhancing effect on p63 acetylation was reduced in HDAC3- or HDAC4- transfected cells. Moreover, transfection of cells with AMPK dominant negative mutant (AMPK-DN), HDAC3, HDAC4 or p63 siRNA significantly reduced lovastatin’s effects on p21^cip/Waf1 and survivin. Furthermore, lovastatin inhibited subcutaneous FaDu xenografts growth in vivo. Taken together, lovastatin may activate AMPK-p38MAPK-p63-survivin cascade to cause FaDu cell death. This study establishes, at least in part, the signaling cascade by which lovastatin induces hypopharyngeal carcinoma cell death.

Novel interactions between the HTLV antisense proteins HBZ and APH-2 and the NFAR protein family: Implications for the HTLV lifecycles

The human T-cell leukaemia virus type 1 and type 2 (HTLV-1/HTLV-2) antisense proteins HBZ and APH-2 play key roles in the HTLV lifecycles and persistence in the host. Nuclear Factors Associated with double-stranded RNA (NFAR) proteins NF90/110 function in the lifecycles of several viruses and participate in host innate immunity against infection and oncogenesis. Using GST pulldown and co-immunoprecipitation assays we demonstrate specific novel interactions between HBZ/APH-2 and NF90/110 and characterised the protein domains involved. Moreover we show that NF90/110 significantly enhance Tax mediated LTR activation, an effect that was abolished by HBZ but enhanced by APH-2. Additionally we found that HBZ and APH-2 modulate the promoter activity of survivin and are capable of antagonising NF110-mediated survivin activation. Thus interactions between HTLV antisense proteins and the NFAR protein family have an overall positive impact on HTLV infection. Hence NFARs may represent potential therapeutic targets in HTLV infected cells.

The effects of a novel aliphatic-chain hydroxamate derivative WMJ-S-001 in HCT116 colorectal cancer cell death

Hydroxamate derivatives have attracted considerable attention due to their broad pharmacological properties and have been extensively investigated. We recently demonstrated that WMJ-S-001, a novel aliphatic hydroxamate derivative, exhibits anti-inflammatory and anti-angiogenic activities. In this study, we explored the underlying mechanisms by which WMJ-S-001 induces HCT116 colorectal cancer cell death. WMJ-S-001 inhibited cell proliferation and induced cell apoptosis in HCT116 cells. These actions were associated with AMP-activated protein kinase (AMPK) and p38 mitogen-activated protein kinase (MAPK) activation, p53 phosphorylation and acetylation, as well as the modulation of p21(cip/Waf1), cyclin D1, survivin and Bax. AMPK-p38MAPK signaling blockade reduced WMJ-S-001-induced p53 phosphorylation. Transfection with AMPK dominant negative mutant (DN) reduced WMJ-S-001's effects on p53 and Sp1 binding to the survivn promoter region. Transfection with HDAC3-Flag or HDAC4-Flag also abrogated WMJ-S-001's enhancing effect on p53 acetylation. WMJ-S-001's actions on p21(cip/Waf1), cyclin D1, survivin, Bax were reduced in p53-null HCT116 cells. Furthermore, WMJ-S-001 was shown to suppress the growth of subcutaneous xenografts of HCT116 cells in vivo. In summary, the death of HCT116 colorectal cancer cells exposed to WMJ-S-001 may involve AMPK-p38MAPK-p53-survivin cascade. These results support the role of WMJ-S-001 as a potential drug candidate and warrant the clinical development in the treatment of cancer.

Transcriptional regulation of BNIP3 by Sp3 in prostate cancer

BACKGROUND

The transcription factors Sp3/Sp1 are expressed in a various types of cancers and BNIP3 is overexpressed in prostate cancer. Although it has been demonstrated that BNIP3 is transcriptionally regulated by HIF-1α and is post-transcriptionally regulated by miR145, our previous data indicated that there might be some other transcription factors regulating BNIP3 in prostate cancer. This study is conducted to investigate whether BNIP3 expression is directly regulated by Sp3/Sp1 or not.

MATERIALS AND METHODS

Bioinformatics analysis shows that BNIP3 promoter contains several potential Sp3/Sp1 binding sites. And then it is demonstrated that SP3 could regulate the BNIP3 transcriptionally by binding to the predicted sites by dual reporter gene assays, ChIP, and EMSA. The biological effects of SP3 regulating BNIP3 on prostate cancer cells proliferation are measured by MTT, TUNEL, and flow cytometry.

RESULTS

Our data show that Sp3 but not Sp1, is positively related to BNIP3 overexpression in prostate cancer. Sp3 can directly regulate BNIP3 transcription by mainly binding to the Sp3 binding sites (-624~-615 and -350~-343) of BNIP3 promoter. Knockdown of Sp3 by RNA interference could reduce cells growth and lead to cells apoptosis in PC-3 and DU145. Sp3-dependent BNIP3 overexpression might be an important mechanism to promote prostate cancer cells proliferation.

CONCLUSION

This is the first study to provide direct evidence of Sp3-dependent BNIP3 expression. Sp3 might be the major transcriptional regulator of BNIP3 in prostate cancer and it is worthy to further study. The regulation of BNIP3 by Sp3 may be a new cancer-specific therapeutic target in prostate cancer.

Insulin Protects Cardiac Myocytes from Doxorubicin Toxicity by Sp1-Mediated Transactivation of Survivin

Insulin inhibits ischemia/reperfusion-induced myocardial apoptosis through the PI3K/Akt/mTOR pathway. Survivin is a key regulator of anti-apoptosis against doxorubicin-induced cardiotoxicity. Insulin increases survivin expression in cardiac myocytes to mediate cytoprotection. However, the mechanism by which survivin mediates the protective effect of insulin against doxorubicin-associated injury remains to be determined. In this study, we demonstrated that pretreatment of H9c2 cardiac myocytes with insulin resulted in a significant decrease in doxorubicin-induced apoptotic cell death by reducing cytochrome c release and caspase-3 activation. Doxorubicin-induced reduction of survivin mRNA and protein levels was also significantly perturbed by insulin pretreatment. Reducing survivin expression with survivin siRNA abrogated insulin-mediated inhibition of caspase-3 activation, suggesting that insulin signals to survivin inhibited caspase-3 activation. Interestingly, pretreatment of H9c2 cells with insulin or MG132, a proteasome inhibitor, inhibited doxorubicin-induced degradation of the transcription factor Sp1. ChIP assay showed that pretreatment with insulin inhibited doxorubicin-stimulated Sp1 dissociation from the survivin promoter. Finally using pharmacological inhibitors of the PI3K pathway, we showed that insulin-mediated activation of the PI3K/Akt/mTORC1 pathway prevented doxorubicin-induced proteasome-mediated degradation of Sp1. Taken together, insulin pretreatment confers a protective effect against doxorubicin-induced cardiotoxicity by promoting Sp1-mediated transactivation of survivin to inhibit apoptosis. Our study is the first to define a role for survivin in cellular protection by insulin against doxorubicin-associated injury and show that Sp1 is a critical factor in the transcriptional regulation of survivin.

Novel robust biomarkers for human bladder cancer based on activation of intracellular signaling pathways

We recently proposed a new bioinformatic algorithm called OncoFinder for quantifying the activation of intracellular signaling pathways. It was proved advantageous for minimizing errors of high-throughput gene expression analyses and showed strong potential for identifying new biomarkers. Here, for the first time, we applied OncoFinder for normal and cancerous tissues of the human bladder to identify biomarkers of bladder cancer. Using Illumina HT12v4 microarrays, we profiled gene expression in 17 cancer and seven non-cancerous bladder tissue samples. These experiments were done in two independent laboratories located in Russia and Canada. We calculated pathway activation strength values for the investigated transcriptomes and identified signaling pathways that were regulated differently in bladder cancer (BC) tissues compared with normal controls. We found, for both experimental datasets, 44 signaling pathways that serve as excellent new biomarkers of BC, supported by high area under the curve (AUC) values. We conclude that the OncoFinder approach is highly efficient in finding new biomarkers for cancer. These markers are mathematical functions involving multiple gene products, which distinguishes them from “traditional” expression biomarkers that only assess concentrations of single genes.

Survivin in survival of hepatocellular carcinoma

Survivin is an anti-apoptotic protein belonging to the inhibitor of apoptosis protein (IAP) family. It is involved in the regulation of important physiological and pathological processes in cells and functions to inhibit cell apoptosis and promote cell proliferation. Normally and terminally differentiated tissues are nearly negative for survivin. In contrast, survivin is highly expressed in most human tumor tissues, including hepatocellular carcinoma (HCC). The abnormal overexpression of survivin is closely related to the malignant biological behaviors of tumors. During the development and progression of HCC, the high level of survivin expression promotes cancer cell proliferation, inhibits cancer cell apoptosis, induces tumor stromal angiogenesis, reduces the sensitivity of cancer cells to radiotherapy and chemotherapy, and ultimately affects the prognosis of patients with HCC. Survivin expression is regulated by a large number of factors. The latest discovery indicated that the transcription factor octamer-binding transcription factor 4 (OCT4) enhances the expression of survivin though cyclin D1 (CCND1), which, in part, accounts for tumor cell proliferation, recurrence and metastasis. Survivin plays key roles in HCC, which renders it an ideal target for the treatment of HCC. The present article reviews the research progress on the relationship between survivin and HCC and on the HCC treatment strategies targeting survivin.

Therapeutic properties of a vector carrying the HSV thymidine kinase and GM-CSF genes and delivered as a complex with a cationic copolymer

BACKGROUND

Gene-directed enzyme prodrug therapy (GDEPT) represents a technology to improve drug selectivity for cancer cells. It consists of delivery into tumor cells of a suicide gene responsible for in situ conversion of a prodrug into cytotoxic metabolites. Major limitations of GDEPT that hinder its clinical application include inefficient delivery into cancer cells and poor prodrug activation by suicide enzymes. We tried to overcome these constraints through a combination of suicide gene therapy with immunomodulating therapy. Viral vectors dominate in present-day GDEPT clinical trials due to efficient transfection and production of therapeutic genes. However, safety concerns associated with severe immune and inflammatory responses as well as high cost of the production of therapeutic viruses can limit therapeutic use of virus-based therapeutics. We tried to overcome this problem by using a simple nonviral delivery system.

METHODS

We studied the antitumor efficacy of a PEI (polyethylenimine)-PEG (polyethylene glycol) copolymer carrying the HSVtk gene combined in one vector with granulocyte-macrophage colony-stimulating factor (GM-CSF) cDNA. The system HSVtk-GM-CSF/PEI-PEG was tested in vitro in various mouse and human cell lines, ex vivo and in vivo using mouse models.

RESULTS

We showed that the HSVtk-GM-CSF/PEI-PEG system effectively inhibited the growth of transplanted human and mouse tumors, suppressed metastasis and increased animal lifespan.

CONCLUSIONS

We demonstrated that appreciable tumor shrinkage and metastasis inhibition could be achieved with a simple and low toxic chemical carrier - a PEI-PEG copolymer. Our data indicate that combined suicide and cytokine gene therapy may provide a powerful approach for the treatment of solid tumors and their metastases.

Variation in Sp1 binding sites correlates with expression of survivin in breast cancer

Survivin is the smallest member of the inhibitor of apoptosis (IAP) family and is deregulated in breast cancer, where it is associated with a poor overall prognosis. It is well established that survivin overexpression predominately occurs at the transcriptional level. Numerous transcription factors bind to specific sequences in the promoter regions of genes and are involved in transcriptional regulation. Specificity protein (Sp) 1 binding sites have been found in the promoter region of the survivin gene. The present study aimed to investigate whether variations in Sp1 binding sites affect survivin expression. Nested polymerase chain reaction followed by DNA sequencing were performed to analyze the survivin gene promoter region in 42 breast cancer tissue samples. Furthermore, survivin expression was assessed using immunohistochemistry. High survivin protein expression was found in 66.7% (28/42) of breast cancer tissue samples. In addition, 15 variations in seven Sp1 binding sites were detected in 12 samples and Sp1 binding site variation was found to be associated with low survivin expression in the 42 samples. These findings suggested that variations in Sp1 binding sites may be associated with survivin expression.

A model for cancer tissue heterogeneity

An important problem in the study of cancer is the understanding of the heterogeneous nature of the cell population. The clonal evolution of the tumor cells results in the tumors being composed of multiple subpopulations. Each subpopulation reacts differently to any given therapy. This calls for the development of novel (regulatory network) models, which can accommodate heterogeneity in cancerous tissues. In this paper, we present a new approach to model heterogeneity in cancer. We model heterogeneity as an ensemble of deterministic Boolean networks based on prior pathway knowledge. We develop the model considering the use of qPCR data. By observing gene expressions when the tissue is subjected to various stimuli, the compositional breakup of the tissue under study can be determined. We demonstrate the viability of this approach by using our model on synthetic data, and real-world data collected from fibroblasts.

Association between survivin -31G>C polymorphism and cancer risk: meta-analysis of 29 studies

PURPOSE

A growing body of evidence has shown the possible relevance of survivin -31G>C (rs9904341) promoter polymorphism to the genetic susceptibility of cancer. Because of the lack of available conclusive data, we performed a meta-analysis of all relevant available studies to derive a more precise estimation of the relationship.

METHODS

A comprehensive literature search of Medline electronic database was conducted to collect relevant studies until August 18, 2013. References of the retrieved articles were also screened. The extracted data were statistically analyzed, and pooled odds ratios (ORs) with 95 % confidence intervals (CIs) were calculated to estimate the association strength using Stata version 11.2 software.

RESULTS

A total of 29 studies with 7,473 cancer cases and 9,086 controls were included in the meta-analysis. Overall, the pooled analysis revealed that suvivin -31G>C polymorphism was significantly associated with increased cancer risk under multiple genetic models (CC vs. GG: OR = 1.37, 95 % CI 1.06–1.76; CC vs. CG: OR = 1.27, 95 % CI = 1.10–1.46; CC vs. CG + GG: OR = 1.31, 95 % CI = 1.10–1.57). In subgroup analysis with different cancer types, the -31G>C polymorphism significantly increased the risk of colorectal, gastric, and urothelial cancers, while this SNP remarkably decreased the susceptibility to hepatocellular carcinoma. Further stratification analysis by ethnicity showed an increasing cancer risk in the Asian population (CC vs. GG: OR = 1.61, 95 % CI 1.17–2.21; CC vs. CG: OR = 1.31, 95 % CI 1.12–1.53; CC vs. CG + GG: OR = 1.43, 95 % CI 1.16–1.77) but not in Europeans.

CONCLUSIONS

The survivin -31G>C polymorphism is associated with elevated cancer risk, especially among colorectal, gastric, and urothelial cancers and Asian populations.

Inhibition of specificity protein 1 by dibenzylideneacetone, a curcumin analogue, induces apoptosis in mucoepidermoid carcinomas and tumor xenografts through Bim and truncated Bid

OBJECTIVES

Dibenzylideneacetone (DBA), a curcumin analogue that has anti-cancer activity in a variety of tumor cells. In this study, we investigated the apoptotic effects of DBA and its molecular mechanism in human mucoepidermoid carcinoma (MEC) cell lines and tumor xenografts.

MATERIAL AND METHODS

The apoptotic effects and related molecular mechanisms of DBA on MEC cell lines were evaluated using cell viability assay, DAPI staining, Western blot analysis, reverse transcriptase-polymerase chain reaction (RT-PCR) and Dual-luciferase Reporter Assay. The anti-tumor activity using in vivo were determined by Nude mouse xenograft assay and histopathological examination.

RESULTS

DBA decreased cell viability and induced apoptosis in MEC cells. These events were accompanied by inhibition of specificity protein 1 (Sp1). DBA did not induce major changes in Sp1 mRNA and promoter activity. Furthermore, inhibition of protein synthesis by cycloheximide demonstrated that DBA decreased Sp1 protein stability, but DBA did not attenuate phosphorylation of eIF4E. DBA also increased Bim and truncated Bid (t-Bid) via Sp1. Finally, DBA exhibited significant anti-tumor activity in athymic nude mice xenografts bearing MC-3 cells by regulating Sp1, Bim and t-Bid without any systemic toxicity.

CONCLUSION

These results elucidate a crucial apoptotic mechanism of DBA and suggest that DBA may be a potent anticancer drug candidate for MEC.

Survivin rs9904341 (G>C) polymorphism contributes to cancer risk: an updated meta-analysis of 26 studies

Survivin, a member of the inhibitor of apoptosis protein family, encoded by BIRC5, is involved in the regulation of apoptosis and in cell cycle control. Emerging evidences indicate that polymorphism in BIRC5 promoter (rs9904341) is associated with cancer risk, but the results of individually published studies are inconclusive. Thus, an updated meta-analysis was performed. PubMed was searched for all eligible studies. Pooled odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated to assess the association strength. Stratified analysis was performed by cancer type, source of control, genotyping method, and ethnicity. A number of 26 studies, including 6,041 cases and 7,567 controls were analyzed in this meta-analysis. Overall, significantly increased cancer risk was associated with survivin rs9904341 polymorphism when all studies were pooled (CC vs. GG: OR = 1.36, 95 % CI = 1.09-1.69; P heterogeneity < 0.001; CC vs GC/GG: OR = 1.32, 95 % CI = 1.11-1.57; P heterogeneity < 0.001). Stratified analysis by cancer type revealed that the survivin rs9904341 polymorphism may increase the risk of colorectal cancer, renal cell cancer, gastric cancer, and bladder cancer. Further subgroup analysis by ethnicity indicated that there was a statistically increased cancer risk in Asians but not Caucasians. In this updated meta-analysis of 26 studies, we conclude that the survivin rs9904341 polymorphism might contribute to risk of various cancers, especially in Asian populations.

Anti-leukemic response of a NSAID, tolfenamic acid

Tolfenamic acid (TA), a non-steroidal anti-inflammatory drug, is known to inhibit human cancer cells and mouse tumor growth in some cancer models; however, its anti-leukemic response has not been evaluated. TA targets specificity protein (Sp) transcription factors that mediate the expression of several genes associated with cancer including survivin, a key member of inhibitor of apoptosis protein family. Our aim was to test the anti-leukemic efficacy of TA in pre-clinical experiments. The anti-leukemic response of TA was determined using Jurkat and Nalm-6 cell lines. Cells were treated with increasing (25/50/75 μM) concentrations of TA, and cell viability was measured at 24, 48, and 72 h post-treatment. TA showed a steady and consistent decrease in cell viability following a clear dose and time dependent response. Apoptosis and cell cycle analysis was performed using flow cytometry. Results showed a significant increase in the apoptotic fraction (annexin V positive) following TA treatment, while cell cycle phase distribution analysis showed G0/G1 arrest. TA-induced apoptosis was further confirmed by examining the activation of caspase 3/7 and the expression of cleaved PARP. TA modulated the expression of critical candidates associated with the early phases of cell cycle and validated its efficacy in causing G0/G1 arrest. The Western blot results revealed that TA significantly decreases Sp1 and survivin expression. These results demonstrate that the anti-leukemic response of TA occurs potentially through targeting Sp1 and inhibiting survivin and suggest the efficacy of TA as a novel therapeutic agent for leukemia.

Simvastatin induced HCT116 colorectal cancer cell apoptosis through p38MAPK-p53-survivin signaling cascade

BACKGROUND

Statins, the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors with cholesterol-lowering properties, were recently shown to exhibit anti-cancer effects. However, the molecular mechanism underlying statin-induced cancer cell death remains to be elucidated. Elevated level of survivin is often found over-expressed in human cancers and has been implicated in the progression of tumorigenesis. Given its central role in cell division and action as an apoptosis suppressor, survivin represents a potential molecular target in cancer management.

METHODS

In this study, we explored the underlying mechanisms in simvastatin-induced HCT116 colorectal cancer cell apoptosis.

RESULTS

Simvastatin decreased cell viability and induced cell apoptosis in HCT116 cells. These results are associated with the modulation of p21(cip/Waf1) and survivin. Survivin knockdown using survivin siRNAs also decreased cell viability and induced cell apoptosis. Simvastatin's actions on p21(cip/Waf1), survivin and apoptosis were reduced in p53 null HCT116 cells. Simvastatin caused an increase in p53 phosphorylation and acetylation. In addition, simvastatin activated p38 mitogen-activated protein kinase (p38MAPK), whereas an inhibitor of p38MAPK signaling abrogated simvastatin's effects of increasing p53 and p21(cip/Waf1) promoter luciferase activity. Cell viability and survivin promoter luciferase activity in the presence of simvastatin were also restored by p38MAPK inhibitor. Furthermore, Sp1 binding to the survivin promoter region decreased while p53 and p63 binding to the promoter region increased after simvastatin exposure.

CONCLUSIONS

Simvastatin activates the p38MAPK-p53-survivin cascade to cause HCT116 colorectal cancer cell apoptosis.

GENERAL SIGNIFICANCE

This study delineates, in part, the underlying mechanisms of simvastatin in decreasing survivin and subsequent colorectal cancer cell apoptosis.

OCT4 increases BIRC5 and CCND1 expression and promotes cancer progression in hepatocellular carcinoma

Background

OCT4 and BIRC5 are preferentially expressed in human cancer cells and mediate cancer cell survival and tumor maintenance. However, the molecular mechanism that regulates OCT4 and BIRC5 expression is not well characterized.

Methods

By manipulating OCT4 and BIRC5 expression in hepatocellular carcinoma (HCC) cell lines, the regulatory mechanism of OCT4 on BIRC5 and CCND1 were investigated.

Results

Increasing or decreasing OCT4 expression could enhance or suppress BIRC5 expression, respectively, by regulating the activity of BIRC5 promoter. Because there is no binding site for OCT4 within BIRC5 promoter, the effect of OCT4 on BIRC5 promoter is indirect. An octamer motif for OCT4 in the CCND1 promoter has directly and partly participated in the regulation of CCND1 promoter activity, suggesting that OCT4 also could upregulated the expression of CCND1. Co-suppression of OCT4 and BIRC5 induced cancer cell apoptosis and cell cycle arrest, thereby efficiently inhibiting the proliferative activity of cancer cells and suppressing the growth of HCC xenogrfts in nude mice.

Conclusion

OCT4 can upregulate BIRC5 and CCND1 expression by increasing their promoter activity. These factors collusively promotes HCC cell proliferation, and co-suppression of OCT4 and BIRC5 is potentially beneficial for HCC treatment.

Activity of the upstream component of tandem TERT/survivin promoters depends on features of the downstream component

We spliced the promoters of the human telomerase and human survivin genes (PhTERT and PhSurv, respectively) widely used for gene therapy and known to have the broadest cancer type spectrum of activity. Two head-to-tail constructs were obtained: the PhTERT-PhSurv and PhSurv-PhTERT tandems. The splicing caused quantitative and qualitative changes in the promoter features. In both constructs, only the promoter proximal to the transcribed gene retained its ability to initiate transcription, whereas the distal promoter was silent, the phenomenon never reported before. However, the distal promoter modulated the activity of the proximal one by increasing its strength and causing an appearance of additional transcription start sites. We suggested that this suppression might be due to the presence of Sp1 transcription factor binding sites in both promoters and Sp1-bridges between these sites. Such Sp1-bridges might convert the tandem promoter linear DNA into a stem-loop structure. If localized inside the formed loop, the distal promoter could lose its ability to initiate transcription. To test this hypothesis, we constructed two modified double promoters, where the proximal PhSurv promoter was replaced either by a shortened variant of the survivin promoter (PhSurv269) or by the mouse survivin promoter. Both PhSurv substitutes were considerably shorter than PhSurv and had different numbers and/or positions of Sp1 sites. In modified tandems, transcription was initiated from both promoters. We also prepared two mutant forms of the PhSurv-PhTERT tandem with two or four Sp1 sites removed from the distal "long" PhSurv promoter. In the first case, the distal PhSurv promoter remained silent, whereas the removal of four Sp1 binding sites restored its activity. In the majority of studied cancer cell lines the efficiency of transcription from the hTERT-(shortened hSurv269) promoter tandem was markedly higher than from each constituent promoter. In normal lung fibroblast cells, the tandem promoter activity was considerably lower.

Functional promoter -31G>C variant in survivin gene is associated with risk and progression of renal cell cancer in a Chinese population

Background

Survivin is an inhibitor of apoptosis protein and is involved in the occurrence and progression of human malignancies. Recently, a functional polymorphism (−31G>C, rs9904341) in the promoter of survivin has been shown to influence its expression and confer susceptibility to different types of cancer. The present study was aimed to investigate whether the polymorphism also influences susceptibility and progression of renal cell cancer (RCC) in a Chinese population.

Methods

We genotyped this polymorphism using the TaqMan assay in a case-control study comprised of 710 RCC patients and 760 controls. The logistic regression was used to assess the genetic association with occurrence and progression of RCC.

Results

Compared with the genotypes containing G allele (GG and GC), we found a statistically significant increased occurrence of RCC associated with the CC genotype [P = 0.006, adjusted odds ratio (OR) = 1.38, 95% confidence interval (CI) = 1.08–1.76]. The polymorphism was associated with risk of developing advanced stage (OR = 2.02, 95%CI = 1.34–3.07) and moderately differentiated (OR = 1.75; 95%CI = 1.20–2.54) RCC. Furthermore, the patients carrying the CC genotype had a significantly greater prevalence of high clinical stage disease (P_trend = 0.003). Similar results were also observed when we restricted the analysis to clear cell RCC, a major histological type of RCC.

Conclusions

Our results suggest that the functional −31G>C polymorphism in the promoter of survivin may influence the susceptibility and progression of RCC in the Chinese population. Large population-based prospective studies are required to validate our findings.

Tolfenamic acid inhibits neuroblastoma cell proliferation and induces apoptosis: a novel therapeutic agent for neuroblastoma

Current therapeutic options for recurrent neuroblastoma have poor outcomes that warrant the development of novel therapeutic strategies. Specificity protein (Sp) transcription factors regulate several genes involved in cell proliferation, survival, and angiogenesis. Sp1 regulates genes believed to be important determinants of the biological behavior of neuroblastoma. Tolfenamic acid (TA), a non-steroidal anti-inflammatory drug, is known to induce the degradation of Sp proteins and may serve as a novel anti-cancer agent. The objective of this investigation was to examine the anti-cancer activity of TA using established human neuroblastoma cell lines. We tested the anti-proliferative effect of TA using SH-SY5Y, CHLA90, LA1 55n, SHEP, Be2c, CMP 13Y, and SMS KCNR cell lines. Cells were treated with TA (0/25/50/100 µM) and cell viability was measured at 24, 48, and 72 h post-treatment. Selected neuroblastoma cell lines were treated with 50 µM TA for 24 and 48 h and tested for cell apoptosis using Annexin-V staining. Caspase activity was measured with caspase 3/7 Glo kit. Cell lysates were prepared and the expression of Sp1, survivin, and c-PARP were evaluated through Western blot analysis. TA significantly inhibited the growth of neuroblastoma cells in a dose/time-dependent manner and significantly decreased Sp1 and survivin expression. Apart from cell cycle (G0/G1) arrest, TA caused significant increase in the apoptotic cell population, caspase 3/7 activity, and c-PARP expression. These results show that TA effectively inhibits neuroblastoma cell growth potentially through suppressing mitosis, Sp1, and survivin expression, and inducing apoptosis. These results show TA as a novel therapeutic agent for neuroblastoma.

Trichostatin A and sirtinol suppressed survivin expression through AMPK and p38MAPK in HT29 colon cancer cells

BACKGROUND

Elevated levels of survivin and histone deacetylases (HDACs) are often found over-expressed in human cancers, including colorectal cancer, and have been implicated in tumorigenesis. HDAC inhibition induces growth arrest and cell death in various transformed cell; however, the mechanisms by which this reduces cell viability in colorectal cancer cells remain unexplained.

METHODS

We explored the actions of two HDAC inhibitors, trichostatin A (TSA) and sirtinol, in HT29 colon cancer cells.

RESULTS

TSA and sirtinol induced apoptosis and inhibited cell proliferation in HT29 cells. These results are associated with the modulation of survivin. Survivin promoter luciferase activity and Sp1, a transcription factor that contributes to survivin expression, were suppressed in cells exposed to TSA or sirtinol. TSA and sirtinol also activated p38 mitogen-activated protein kinase (p38MAPK) and AMP-activated protein kinase (AMPK). Inhibitors of p38MAPK or AMPK signaling abrogated TSA and sirtinol's effects of decreasing cell viability. Survivin promoter luciferase activity in the presence of TSA or sirtinol was restored by AMPK dominant negative mutant or p38MAPK inhibitor. Furthermore, Sp1 binding to the survivin promoter region decreased while p63 binding to the promoter region increased after TSA or sirtinol exposure.

CONCLUSIONS

We report a p38MAPK- and AMPK-mediated downregulation of survivin, and its functional correlation with decreased colon cancer cell viability in the presence of HDAC inhibitor. p63 and Sp1 may also contribute to TSA and sirtinol actions.

GENERAL SIGNIFICANCE

This study delineates, in part, the underlying mechanisms of TSA and sirtinol in decreasing survivin expression and subsequent colon cancer cell viability.

Significant biological role of sp1 transactivation in multiple myeloma

PURPOSE

The transcription factor specificity protein 1 (Sp1) controls number of cellular processes by regulating the expression of critical cell cycle, differentiation, and apoptosis-related genes containing proximal GC/GT-rich promoter elements. We here provide experimental and clinical evidence that Sp1 plays an important regulatory role in multiple myeloma (MM) cell growth and survival.

EXPERIMENTAL DESIGN

We have investigated the functional Sp1 activity in MM cells using a plasmid with Firefly luciferase reporter gene driven by Sp1-responsive promoter. We have also used both siRNA- and short hairpin RNA-mediated Sp1 knockdown to investigate the growth and survival effects of Sp1 on MM cells and further investigated the anti-MM activity of terameprocol (TMP), a small molecule that specifically competes with Sp1-DNA binding in vitro and in vivo.

RESULTS

We have confirmed high Sp1 activity in MM cells that is further induced by adhesion to bone marrow stromal cells (BMSC). Sp1 knockdown decreases MM cell proliferation and induces apoptosis. Sp1-DNA binding inhibition by TMP inhibits MM cell growth both in vitro and in vivo, inducing caspase-9-dependent apoptosis and overcoming the protective effects of BMSCs.

CONCLUSIONS

Our results show Sp1 as an important transcription factor in myeloma that can be therapeutically targeted for clinical application by TMP.

Sp1 upregulates survivin expression in adenocarcinoma of lung cell line A549

Survivin has been implicated in tumor genesis, progression, and resistance to anticancer agents. However, the precise regulatory mechanism for survivin expression is not thoroughly defined. In this study, we showed that Sp1 was co-overexpressed with survivin in adenocarcinoma of lung cells A549, but not in differentiated human bronchial epithelial cells 4F0439 or small airway epithelial cells 3F1584. Subsequently, transfection experiments demonstrated that the inhibition of Sp1 signaling suppressed survivin expression in A549 cells, whereas Sp1 overexpression increased the level of survivin protein as well as its mRNA. We also found that Sp1 could decrease capase-9 activity, which is shown to be suppressed by survivin during apoptosis inhibition. Finally, Luciferase activity and ChIP assays revealed that Sp1 activated survivin promoter by direct interaction with it. Taken together, our data suggest Sp1 plays a potent role in the upregulation of survivin expression in lung cancer cells at the transcriptional level.

p53 in trichostatin A induced C6 glioma cell death

BACKGROUND

Histone deacetylase (HDAC) inhibitors were demonstrated to induce cell cycle arrest, promote cell differentiation or apoptosis, and inhibit metastasis. HDAC inhibitors have thus emerged as a new class of anti-tumor agents for various types of tumors. However, the mechanisms by which HDAC inhibition-induced cell death remain to be fully defined.

METHODS

In the present study, we explored the apoptotic actions of trichostatin A (TSA), a HDAC inhibitor, in C6 glioma cells.

RESULTS

TSA activated p38 mitogen-activated protein kinase (p38MAPK), leading to p53 phosphorylation and activation. P53, a proapoptotic transcription factor, in turn transactivated the expression of a proapoptotic protein, Bax. In addition, survivin, a member of inhibitor of apoptotic protein, was significantly decreased in TSA-treated C6 cells. P53 recruited to the endogenous survivin promoter region was increased and accompanied by decreasing recruitment of SP1 in response to TSA. TSA was also shown to induce IKK dephosphorylation and to suppress NF-κB reporter activity.

CONCLUSIONS

TSA may cause C6 cell apoptosis through activating p38MAPK-p53 cascade resulting in Bax expression and survivin suppression. Negative regulation of IKK-NF-κB signaling may also lead to p53 activation and contribute to TSA apoptotic actions.

GENERAL SIGNIFICANCE

TSA-induced p53 activation may occur through p53 modification by phosphorylation or by acetylation via IKK inactivation. The present study delineates, in part, the signaling pathways involved in TSA-induced glioma cell death.

Survivin -31C/G polymorphism and gastric cancer risk in a Brazilian population

Gastric cancer, despite its decline in incidence, remains a public health problem worldwide, especially in Brazil, where higher incidence indexes are still described. The Survivin gene codifies a multifunctional protein involved in the regulation of the cell cycle and inhibition of the apoptotic pathway, and a polymorphism (-31C/G) located in its promoter region is associated with gene regulation. In order to evaluate the correlation of this polymorphism with gastric cancer risk in a northern Brazil population, we sequenced a fragment containing the polymorphism in individuals with gastric cancer and controls. We observed no differences of alleles and genotype frequencies between cases and controls. However, G carriers of the tumor group had an increased relative risk of developing tumors of diffuse type (OR: 2.22-IC 95%: 0.4835-10.2137), localized in the antrum (OR: 2.16-IC 95%: 0.4811-9.6971) and in younger patients (<50 years-old) (OR: 3.65-IC 95%: 0.4012-33.2429), although with no statistical significance. Nevertheless, C carriers with a high D17S250 microsatellite instability (TP53 gene) show a higher risk to develop gastric tumors (P = 0.0453; OR: 4.1556-IC95%: 0.9716-17.7728), suggesting that the mutate TP53 gene may fail in control and inhibition of Survivin expression, favoring the gastric carcinogenesis. The present result suggests that the presence of the C allele of -31C/G Survivin promoter polymorphism in combination with D17S250 instability may be used as a risk factor for gastric cancer in our population. However, other studies based on a larger sample size are required to properly assess such hypothesis.

Survivin -31C/G polymorphism and gastric cancer risk in a Brazilian population

Gastric cancer, despite its decline in incidence, remains a public health problem worldwide, especially in Brazil, where higher incidence indexes are still described. The Survivin gene codifies a multifunctional protein involved in the regulation of the cell cycle and inhibition of the apoptotic pathway, and a polymorphism (-31C/G) located in its promoter region is associated with gene regulation. In order to evaluate the correlation of this polymorphism with gastric cancer risk in a northern Brazil population, we sequenced a fragment containing the polymorphism in individuals with gastric cancer and controls. We observed no differences of alleles and genotype frequencies between cases and controls. However, G carriers of the tumor group had an increased relative risk of developing tumors of diffuse type (OR: 2.22-IC 95%: 0.4835-10.2137), localized in the antrum (OR: 2.16-IC 95%: 0.4811-9.6971) and in younger patients (<50 years-old) (OR: 3.65-IC 95%: 0.4012-33.2429), although with no statistical significance. Nevertheless, C carriers with a high D17S250 microsatellite instability (TP53 gene) show a higher risk to develop gastric tumors (P = 0.0453; OR: 4.1556-IC95%: 0.9716-17.7728), suggesting that the mutate TP53 gene may fail in control and inhibition of Survivin expression, favoring the gastric carcinogenesis. The present result suggests that the presence of the C allele of -31C/G Survivin promoter polymorphism in combination with D17S250 instability may be used as a risk factor for gastric cancer in our population. However, other studies based on a larger sample size are required to properly assess such hypothesis.