Comprehensive analyses of DNA repair pathways, smoking and bladder cancer risk in Los Angeles and Shanghai

X-ray cross-complementing family: the bridge linking DNA damage repair and cancer

Genomic instability is a common hallmark of human tumours. As a carrier of genetic information, DNA is constantly threatened by various damaging factors that, if not repaired in time, can affect the transmission of genetic information and lead to cellular carcinogenesis. In response to these threats, cells have evolved a range of DNA damage response mechanisms, including DNA damage repair, to maintain genomic stability. The X-ray repair cross-complementary gene family (XRCC) comprises an important class of DNA damage repair genes that encode proteins that play important roles in DNA single-strand breakage and DNA base damage repair. The dysfunction of the XRCC gene family is associated with the development of various tumours. In the context of tumours, mutations in XRCC and its aberrant expression, result in abnormal DNA damage repair, thus contributing to the malignant progression of tumour cells. In this review, we summarise the significant roles played by XRCC in diverse tumour types. In addition, we discuss the correlation between the XRCC family members and tumour therapeutic sensitivity.

Current and Emerging Treatments for Urothelial Carcinoma: A Focus on Enfortumab Vedotin

Urothelial carcinoma is a common malignancy that affects the urinary system, with bladder cancer being the most prevalent form. Although the management of early-stage disease has seen significant improvements, the treatment of locally advanced and metastatic urothelial carcinoma remains challenging. Over the past decade, there has been an explosion in the number of therapies available for the treatment of advanced disease, with immune checkpoint inhibitors and antibody-drug conjugates leading the way. Enfortumab vedotin is an antibody-drug conjugate that targets Nectin-4, a protein that is overexpressed in urothelial carcinoma cells. In clinical trials, it has shown promising outcomes for the treatment of advanced urothelial carcinoma that has progressed after chemotherapy or immunotherapy. The US Food and Drug Administration has granted expedited approval for enfortumab vedotin in the treatment of advanced urothelial carcinoma. This review provides an overview of the current and emerging treatments for urothelial carcinoma, with a particular focus on enfortumab vedotin. We discuss the mechanisms of action, clinical efficacy, safety, and ongoing research of enfortumab vedotin, along with the current landscape of other approved therapies and promising agents in development. The aim of this review is to provide a comprehensive and up-to-date summary of the available treatment options for urothelial carcinoma, including their limitations and future prospects.

Genetic variations in nucleotide excision repair pathway genes and hepatoblastoma susceptibility

The etiology of hepatoblastoma is largely unknown due to the rarity of this disease. Nucleotide excision repair (NER), a versatile system in repairing DNA damage, is highly implicated in carcinogenesis. However, it remains unclear whether single nucleotide polymorphisms (SNPs) of genes in the NER pathway are related to hepatoblastoma risk. A total of 313 Chinese children diagnosed with hepatoblastoma and 1446 controls were recruited from seven hospitals across China. TaqMan assay was adopted to genotype 19 SNPs in NER pathway genes including ERCC1, XPA, XPC, XPD, XPF and XPG. Of them, only two SNPs in XPC gene predisposed to hepatoblastoma risk. The XPC rs2607775 polymorphism significantly contributed to hepatoblastoma risk (dominant model: adjusted OR = 1.44, 95% CI = 1.01-2.05, P = .046). However, XPC rs1870134 conferred a significantly decreased risk of hepatoblastoma in recessive model (adjusted OR = 0.50, 95% CI = 0.26-0.98, P = .042). Stratified analysis revealed that rs2607775 CG/GG genotype, rs1870134 CC genotype and four to five risk genotypes were associated with the risk of hepatoblastoma under certain subgroups. The significant relationships were confirmed by haplotype analyses and false-positive report probability analyses. In addition, expression quantitative trait locus analysis suggested that rs2607775 G increased expression of XPC mRNA. Collectively, our discover a promising candidate XPC gene as a biomarker for the risk of hepatoblastoma.

DNA Repair Gene Polymorphisms and Susceptibility to Urothelial Carcinoma in a Southeastern European Population

Single nucleotide polymorphisms (SNPs) in DNA repair genes may predispose to urothelial carcinoma of the bladder (UCB). This study focused on three specific SNPs in a population with high exposure to environmental carcinogens including tobacco and alcohol. A case-control study design was used to assess for presence of XPC PAT +/-, XRCC3 Thr241Met, and ERCC2 Lys751Gln DNA repair gene SNPs in peripheral blood from patients with UCB and healthy individuals. One hundred patients and equal number of healthy subjects were enrolled. The XPC PAT +/+ genotype was associated with a 2-fold increased risk of UCB (OR = 2.16; 95%CI: 1.14-4; p = 0.01). The -/+ and +/+ XPC PAT genotypes were more frequently present in patients with multiple versus single tumors (p = 0.01). No association was detected between ERCC2 Lys751Gln genotypes/alleles, and risk for developing UCB. Presence of the XRCC3 TT genotype (OR = 0.14; 95%CI:0.07-0.25; p < 0.01) and of the T allele overall (OR = 0.26; 95%CI:0.16-0.41; p < 0.01) conferred a protective effect against developing UCB. The XPC PAT -/+ and XRCC3 Thr241Met SNPs are associated with predisposition to UCB. The XPC PAT -/+ SNP is also an indicator of bladder tumor multiplicity, which might require a more individualized surveillance and treatment.

Cyclic GMP-AMP synthase promotes the inflammatory and autophagy responses in Huntington disease

Huntington disease (HD) is a genetic disorder caused by glutamine-expansion in the huntingtin (mHTT) protein, which affects motor, psychiatric, and cognitive function, but the mechanisms remain unclear. mHTT is known to induce DNA damage and affect autophagy, both associated with inflammatory responses, but what mediates all these were unknown. Here we report that cGAS, a DNA damage sensor, is highly upregulated in the striatum of a mouse model and HD human patient’s tissue. We found ribosomes, which make proteins, are robustly accumulated on the cGAS mRNA in HD cells. cGAS depletion decreases—and cGAS expression increases—both inflammatory and autophagy responses in HD striatal cells. Thus, cGAS is a therapeutic target for HD. Blocking cGAS will prevent/slow down HD symptoms.

Huntington disease (HD) is caused by an expansion mutation of the N-terminal polyglutamine of huntingtin (mHTT). mHTT is ubiquitously present, but it induces noticeable damage to the brain’s striatum, thereby affecting motor, psychiatric, and cognitive functions. The striatal damage and progression of HD are associated with the inflammatory response; however, the underlying molecular mechanisms remain unclear. Here, we report that cGMP-AMP synthase (cGAS), a DNA sensor, is a critical regulator of inflammatory and autophagy responses in HD. Ribosome profiling revealed that the cGAS mRNA has high ribosome occupancy at exon 1 and codon-specific pauses at positions 171 (CCG) and 172 (CGT) in HD striatal cells. Moreover, the protein levels and activity of cGAS (based on the phosphorylated STING and phosphorylated TBK1 levels), and the expression and ribosome occupancy of cGAS-dependent inflammatory genes (Ccl5 and Cxcl10) are increased in HD striatum. Depletion of cGAS diminishes cGAS activity and decreases the expression of inflammatory genes while suppressing the up-regulation of autophagy in HD cells. In contrast, reinstating cGAS in cGAS-depleted HD cells activates cGAS activity and promotes inflammatory and autophagy responses. Ribosome profiling also revealed that LC3A and LC3B, the two major autophagy initiators, show altered ribosome occupancy in HD cells. We also detected the presence of numerous micronuclei, which are known to induce cGAS, in the cytoplasm of neurons derived from human HD embryonic stem cells. Collectively, our results indicate that cGAS is up-regulated in HD and mediates inflammatory and autophagy responses. Thus, targeting the cGAS pathway may offer therapeutic benefits in HD.

Association of select vitamin D receptor gene polymorphisms with the risk of tobacco-related cancers - a meta-analysis

The observed increase in morbidity and mortality due to tobacco-related cancers, especially those in the respiratory system and esophagus, is becoming a public health challenge. Smoking cigarettes is one of the main risk factors predisposing individuals to many types of cancers. The aim of this study was to determine the role of select vitamin D receptor (VDR) gene polymorphisms as risk factors in tobacco-related cancers. The MEDLINE and ResearchGate databases were used to search for articles up to June 2017, and 12 articles including 26 studies concerning FokI, ApaI, TaqI and BsmI polymorphisms and lung, neck, head, esophageal and oral cancers were chosen. In total, 5 113 cases and 5 657 controls were included in the pooled analysis. We found a significant relationship between tobacco-related cancers and the occurrence of the "t" allele in the TaqI polymorphism of VDR. The occurrence of the "t" allele reduced the risk of tobacco-related cancers by 17% (OR = 0.83, 0.72-0.96 95% CI, p-value = 0.0114). Our analysis revealed that there is a correlation between the TaqI polymorphism of VDR and the risk of tobacco-related cancers.

Modeling the Complex Exposure History of Smoking in Predicting Bladder Cancer: A Pooled Analysis of 15 Case-Control Studies

BACKGROUND

Few studies have modeled smoking histories by combining smoking intensity and duration to show what profile of smoking behavior is associated with highest risk of bladder cancer. This study aims to provide insight into the association between smoking exposure history and bladder cancer risk by modeling both smoking intensity and duration in a pooled analysis.

METHODS

We used data from 15 case-control studies included in the bladder cancer epidemiology and nutritional determinants study, including a total of 6,874 cases and 17,727 controls. To jointly interpret the effects of intensity and duration of smoking, we modeled excess odds ratios per pack-year by intensity continuously to estimate the risk difference between smokers with long duration/low intensity and short duration/high intensity.

RESULTS

The pattern observed from the pooled excess odds ratios model indicated that for a fixed number of pack-years, smoking for a longer duration at lower intensity was more deleterious for bladder cancer risk than smoking more cigarettes/day for a shorter duration. We observed similar patterns within individual study samples.

CONCLUSIONS

This pooled analysis shows that long duration/low intensity smoking is associated with a greater increase in bladder cancer risk than short duration/high intensity smoking within equal pack-year categories, thus confirming studies in other smoking-related cancers and demonstrating that reducing exposure history to a single metric such as pack-years was too restrictive.

Correlation of IL-31 gene polymorphisms with susceptibility and clinical recurrence of bladder cancer

Interleukin-31 is a crucial cytokine triggering inflammation which could be one of the risk factors of tumors. However, data for correlation between IL-31 and tumors are limited. The purpose of our study was to discuss whether genetic polymorphisms of IL-31 were associated with the susceptibility and clinical outcomes of bladder cancer. Our study enrolled 478 controls, 156 non-muscle-invasive bladder cancer (NMIBC) and 138 muscle-invasive bladder cancer (MIBC) patients. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used for genotyping two single nucleotide polymorphisms (SNPs) of IL-31 gene including rs7977932 and rs4758680. Our results showed that A allele and CA/AA genotypes of rs4758680 were associated with susceptibility to bladder cancer (P = 0.04, OR 1.32, 95% CI 1.01-1.72, and P = 0.02, OR 1.43, 95% CI 1.05-1.96, respectively), and G allele of rs7977932 might be a protect factor for tobacco smoking patients compared with non-smoking patients (P = 0.005, OR 0.42, 95% CI 0.23-0.76). Furthermore, CA/AA genotypes of rs4758680 might be the independent risk factors for the decreased recurrence-free survival of the patients with MIBC (P = 0.03, OR 2.02, 95% CI 1.06-3.85. Our data indicated that polymorphisms of IL-31 are associated with bladder cancer, and rs4758680 could be an independent prediction for MIBC patients with a high risk of recurrence.

Polymorphisms in DNA repair pathway genes and ABCG2 gene in advanced colorectal cancer: correlation with tumor characteristics and clinical outcome in oxaliplatin-based chemotherapy

Objective

Multiple factors are involved in oxaliplatin-resistant process in colorectal cancer (CRC) patients including decreased drug accumulation and enhanced capacity to repair and tolerate DNA damage. In the present study, we aimed to assess the impact of six single-nucleotide polymorphisms (SNPs) in DNA repair genes and ABCG2 gene on prognosis in advanced CRC patients treated with oxaliplatin-based chemotherapy.

Methods

In this study, 580 advanced CRC patients were recruited. Six SNPs of DNA repair genes (XPA rs10817938, XPA rs2808668, XPC rs2607775, and WRN rs1346044) and ABCG2 gene (rs2231142 and rs2622621) were genotyped by using the TaqMan assay.

Results

Regarding interaction with environmental factors, ABCG2 rs2231142 and the first-degree family history of cancer and XPC rs2607775 or ABCG2 rs2622621 and lymph node metastases status demonstrated significant interactions. Of these six SNPs, XPA rs10817938 CT/ TT genotypes retained its significant association with longer overall survival (OS) (P=0.008) in CRC patients receiving oxaliplatin-based chemotherapy (n=580). Furthermore, a significantly better impact on the disease-free survival (DFS) (P=0.001) and OS (P<0.0001) was found in ABCG2 rs2231142CA/AA carriers. Furthermore, ABCG2 rs2622621 CG/GG genotype was verified to be an independent poor prognostic factor in DFS (P=0.010) and OS (P=0.030). In the stratification analysis, XPA rs10817938 CT/CC, rs2231142 CA/AA, and rs2622621 CC genotypes of ABCG2 were predictive of significantly better prognosis in the patients with tumor differentiation grade 3 (n=523), clinical stage IV (n=73), or lymph node-positive status (n=557). Additionally, multivariate logistic regression and multiple dimension reduction analysis consistently revealed that the combination of selected SNPs and five known risk factors showed a better prediction prognosis and represented the best model to predict CRC prognosis.

Conclusion

The current data indicated that the XPA gene and ABCG2 gene had significant interaction with environmental factors and prognosis, which could provide a comprehensive understanding of the implications of those SNPs in the prediction of prognosis in advanced CRC patients receiving oxaliplatin-based chemotherapy.

Epidemiology of Bladder Cancer: A Systematic Review and Contemporary Update of Risk Factors in 2018

CONTEXT

Bladder cancer (BC) is a significant health problem, and understanding the risk factors for this disease could improve prevention and early detection.

OBJECTIVE

To provide a systematic review and summary of novel developments in epidemiology and risk factors for BC.

EVIDENCE ACQUISITION

A systematic review of original articles was performed by two pairs of reviewers (M.G.C., I.J., F.E., and K.P.) using PubMed/Medline in December 2017, updated in April 2018. To address our primary objective of reporting contemporary studies, we restricted our search to include studies from the last 5yr. We subdivided our review according to specific risk factors (PICO [Population Intervention Comparator Outcome]).

EVIDENCE SYNTHESIS

Our search found 2191 articles, of which 279 full-text manuscripts were included. We separated our manuscripts by the specific risk factor they addressed (PICO). According to GLOBOCAN estimates, there were 430000 new BC cases and 165000 deaths worldwide in 2012. Tobacco smoking and occupational exposure to carcinogens remain the factors with the highest attributable risk. The literature was limited by heterogeneity of data.

CONCLUSIONS

Evidence is emerging regarding gene-environment interactions, particularly for tobacco and occupational exposures. In some populations, incidence rates are declining, which may reflect a decrease in smoking. Standardisation of reporting may help improve epidemiologic evaluation of risk.

PATIENT SUMMARY

Bladder cancer is common worldwide, and the main risk factors are tobacco smoking and exposure to certain chemicals in the working and general environments. There is ongoing research to identify and reduce risk factors, as well as to understand the impact of genetics on bladder cancer risk.

The association between smoking cessation before and after diagnosis and non-muscle-invasive bladder cancer recurrence: a prospective cohort study

BACKGROUND

Smoking is a major risk factor for bladder cancer, but the relationship between smoking cessation after initial treatment and bladder cancer recurrence has been investigated less frequently and not prospectively yet.

METHODS

722 non-muscle-invasive bladder cancer (NMIBC) patients (pTa, pT1, and CIS) from the prospective Bladder Cancer Prognosis Programme (BCPP) cohort, selected in the UK between 2005 and 2011, provided complete data on smoking behavior before and up to 5 years after diagnosis. The impact of smoking behavior on NMIBC recurrence was explored by multivariable Cox regression models investigating time-to-first NMIBC recurrence.

RESULTS

Over a median follow-up period of 4.21 years, 403 pathologically confirmed NMIBC recurrences occurred in 210 patients. Only 25 current smokers at diagnosis quit smoking (14%) during follow-up and smoking cessation after diagnosis did not decrease risk of recurrence compared to continuing smokers (p = 0.352).

CONCLUSIONS

Although quitting smoking after diagnosis might reduce the risk of recurrence based on retrospective evidence, this is not confirmed in this prospective study because the number of NMIBC patients quitting smoking before their first recurrence was too low. Nevertheless, this indicates an important role for urologists and other health care professionals in promoting smoking cessation in NMIBC.

Bladder Cancer Genetic Susceptibility. A Systematic Review

Background:

The variant/gene candidate approach to explore bladder cancer (BC) genetic susceptibility has been applied in many studies with significant findings reported. However, results are not always conclusive due to the lack of replication by subsequent studies.

Objectives:

To identify all epidemiological investigations on the genetic associations with BC risk, to quantify the likely magnitude of the associations by applying metaanalysis methodology and to assess whether there is a potential for publication/reporting bias.

Methods:

To address our aims, we have catalogued all genetic association studies published in the field of BC risk since 2000. Furthermore, we metaanalysed all polymorphisms with data available from at least three independent case-control studies with subjects of Caucasian origin analyzed under the same mode of inheritance.

Results:

The characterization of the genetic susceptibility of BC is composed of 28 variants, GWAS contributing most of them. Most of the significant variants associated with BC risk are located in genes belonging to chemical carcinogenesis, DNA repair, and cell cycle pathways. Causal relationship was also provided by functional analysis for GSTM1-null, NAT2-slow, APOBEC-rs1014971, CCNE1-rs8102137, SLC14A1-rs10775480, PSCA-rs2294008, UGT1A-rs1189203, and TP63-rs35592567.

Conclusions:

Genetic susceptibility of BC is still poorly defined, with GWAS contributing most of the strongest evidence. The systematic review did not provide evidence of further genetic associations. The potential public health translation of the existing knowledge on genetic susceptibility on BC is still limited.

Effects of the Ser326Cys Polymorphism in the DNA Repair OGG1 Gene on Cancer, Cardiovascular, and All-Cause Mortality in the PREDIMED Study: Modulation by Diet

BACKGROUND

Oxidatively induced DNA damage, an important factor in cancer etiology, is repaired by oxyguanine glycosylase 1 (OGG1). The lower repair capacity genotype (homozygote Cys326Cys) in the OGG1-rs1052133 (Ser326Cys) polymorphism has been associated with cancer risk. However, no information is available in relation to cancer mortality, other causes of death, and modulation by diet.

OBJECTIVE

Our aim was to evaluate the association of the OGG1-rs1052133 with total, cancer, and cardiovascular disease (CVD) mortality and to analyze its modulation by the Mediterranean diet, focusing especially on total vegetable intake as one of the main characteristics of this diet.

DESIGN

Secondary analysis in the PREDIMED (Prevención con Dieta Mediterránea) trial is a randomized, controlled trial conducted in Spain from 2003 to 2010.

PARTICIPANTS/SETTING

Study participants (n=7,170) were at high risk for CVD and were aged 55 to 80 years.

INTERVENTION

Participants were randomly allocated to two groups with a Mediterranean diet intervention or a control diet. Vegetable intake was measured at baseline.

MAIN OUTCOME MEASURES

Main outcomes were all-cause, cancer, and CVD mortality after a median follow-up of 4.8 years.

STATISTICAL ANALYSES

Multivariable-adjusted Cox regression models were fitted.

RESULTS

Three hundred eighteen deaths were detected (cancer, n=127; CVD, n=81; and other, n=110). Cys326Cys individuals (prevalence 4.2%) presented higher total mortality rates than Ser326-carriers (P=0.009). The multivariable-adjusted hazard ratio for Cys326Cys vs Ser326-carriers was 1.69 (95% CI 1.09 to 2.62; P=0.018). This association was greater for CVD mortality (P=0.001). No relationship was detected for cancer mortality in the whole population (hazard ratio 1.07; 95% CI 0.47 to 2.45; P=0.867), but a significant age interaction (P=0.048) was observed, as Cys326Cys was associated with cancer mortality in participants <66.5 years (P=0.029). Recessive effects limited our ability to investigate Cys326Cys×diet interactions for cancer mortality. No statistically significant interactions for total or CVD mortality were found for the Mediterranean diet intervention. However, significant protective interactions for CVD mortality were found for vegetable intake (hazard ratio interaction per standard deviation 0.42; 95% CI 0.18 to 0.98; P=0.046).

CONCLUSIONS

In this population, the Cys326Cys-OGG1 genotype was associated with all-cause mortality, mainly CVD instead of cancer mortality. Additional studies are needed to provide further evidence on its dietary modulation.

Two SNPs in the promoter region of Toll-like receptor 4 gene are not associated with smoking in Saudi Arabia

Defects in the innate immune system, particularly in Toll-like receptors (TLRs), have been reported in several cigarette smoke-promoted diseases. The aim of this study was to examine the impact of tobacco smoke on allelic frequencies of TLR4 single-nucleotide polymorphisms (SNPs) and to compare the genotypic distribution of these SNPs in a Saudi Arabian population with that in previously studied populations. DNA was extracted from 303 saliva samples collected from smokers and nonsmokers. Two transitional SNPs in the promoter region of TLR4 were selected, rs2770150 (T/C) and rs10759931 (G/A). Genotype frequencies were determined using quantitative polymerase chain reaction. Our results showed a slight effect of smoking on the distribution of rs2770150 and rs10759931. However, the differences were not significant. Thus, we conclude that the SNPs selected for this study were independent of smoking and may not be related to smoking-induced diseases.

Association between MDM2 SNP309 T>G polymorphism and the risk of bladder cancer: new data in a Chinese population and an updated meta-analysis

Objective

Human murine double minute 2 protein (MDM2) is mainly a negative regulator of p53 tumor suppressor pathway. We aimed to investigate the association between MDM2 SNP309 polymorphism and bladder cancer risk.

Methods

A total of 535 bladder cancer patients and 649 health controls were recruited for our study. MDM2 SNP309 T>G polymorphism was genotyped by polymerase chain reaction-ligase detection reaction method. Logistic regression was used to analyze the relationship between the genotype and susceptibility of bladder cancer. Kaplan–Meier estimates and log-rank test were obtained to analyze the association between the genotype and risk of recrudesce in nonmuscle-invasive bladder cancer patients. A multivariable Cox proportional hazards model was fitted to identify independent prognostic factors. To further investigate the association, we conducted a meta-analysis including six studies.

Results

The frequency of the MDM2 SNP309 T>G polymorphism showed no significant difference between cases and controls (all P>0.05). In the stratification analysis, the results showed that G allele carriers were prone to have a significant decrease in risk of low-grade bladder cancer (adjusted odds ratio: 0.613, 95% confidence interval: 0.427–0.881), and G variant was associated with a significantly reduced risk of recurrence in nonmuscle-invasive bladder cancer patients with or without chemotherapy (P<0.05). The results of the meta-analysis showed that G allele and GG genotype of MDM2 SNP309 polymorphism were significantly associated with increased risk of bladder cancer in Caucasians (both P<0.05), and no association was observed in total populations and Asians (P>0.05).

Conclusion

MDM2 SNP309 T>G polymorphism has no influence on bladder cancer risk in Asians, but this single nucleotide polymorphism may be associated with genetic susceptibility of bladder cancer among Caucasians.

Targeting Hsp90 in urothelial carcinoma

Urothelial carcinoma, or transitional cell carcinoma, is the most common urologic malignancy that carries significant morbidity, mortality, recurrence risk and associated health care costs. Despite use of current chemotherapies and immunotherapies, long-term remission in patients with muscle-invasive or metastatic disease remains low, and disease recurrence is common. The molecular chaperone Heat Shock Protein-90 (Hsp90) may offer an ideal treatment target, as it is a critical signaling hub in urothelial carcinoma pathogenesis and potentiates chemoradiation. Preclinical testing with Hsp90 inhibitors has demonstrated reduced proliferation, enhanced apoptosis and synergism with chemotherapies and radiation. Despite promising preclinical data, clinical trials utilizing Hsp90 inhibitors for other malignancies had modest efficacy. Therefore, we propose that Hsp90 inhibition would best serve as an adjuvant treatment in advanced muscle-invasive or metastatic bladder cancers to potentiate other therapies. An overview of bladder cancer biology, current treatments, molecular targeted therapies, and the role for Hsp90 inhibitors in the treatment of urothelial carcinoma is the focus of this review.

Association between PSCA mRNA expression levels and rs2294008 polymorphism in transitional cell cancer of the bladder

Prostate stem cell antigen (PSCA) was originally identified as a gene that is overexpressed in prostate cancer, and correlates with prostate cancer progression and prognosis. Recently, a significant association has been identified between the PSCA rs2294008 (C>T) polymorphism and the risk of developing bladder cancer. Therefore, the present study investigated the different expression levels of PSCA mRNA in transitional cell carcinoma (TCC) of the bladder and normal bladder tissue. Furthermore, the association between PSCA mRNA expression levels in TCC and different rs2294008 (C>T) genotypes and various clinicopathological features, including tumor stage and grade, were evaluated. Reverse transcription-quantitative polymerase chain reaction was performed on 80 TCC samples and 38 samples of normal bladder urothelium from TCC patients who underwent transurethral resection of bladder tumor or radical cystectomy at the Beijing Friendship Hospital (Beijing, China) between September 2010 and May 2011. Genomic DNA was extracted from tumor tissue and sequenced to determine the rs2294008 (C>T) genotype. PSCA mRNA expression was detected in all samples (100%); however, tumor samples exhibited significantly higher PSCA expression levels compared with the normal urothelium samples (P=0.038). PSCA mRNA expression was positively correlated with the histological grade of the tumor (G1-2 vs. G3; P=0.001); however, no significant difference was detected between patients with superficial (Ta or T1) and muscle-invasive (≥pT2) tumors (P=0.250). Thus, PSCA mRNA expression levels were associated with TCC and tumor histological grade, but not the tumor stage. Additionally, PSCA mRNA expression levels were significantly higher in T allele carriers compared with CC homozygous patients (P=0.001), indicating that the presence of the T allele may increase PSCA mRNA expression. Therefore, rs2294008 (C>T) may be associated with the biological properties of TCC and, thus, future research should focus on the physiological function of PSCA and the mechanism of rs2294008.