Association of Ku70 A-31G polymorphism and risk of renal cell carcinoma in a Chinese population

The DNA repair gene Ku70 plays a key role in the DNA double-strand breaks (DSBs) repair system. Defects in DSBs repair capacity can lead to genomic instability. We hypothesized that the Ku70 A-31G polymorphism (rs132770) was associated with the risk of renal cell carcinoma (RCC). In a hospital-based case-control study of 620 RCC patients and 623 cancer-free controls frequency matched by age and sex, we genotyped the functional polymorphism Ku70 A-31G (rs132770). Thirty-eight normal renal tissue samples with different genotypes were tested to estimate the Ku70 mRNA expression by real-time quantitative reverse transcription. Compared with the GG genotype, the GA and GA/AA genotypes had a significantly decreased risk of RCC [adjusted odds ratio (OR) = 0.62, 95% confidence interval (CI) = 0.44-0.87 for GA, and OR = 0.62, 95% CI = 0.45-0.86 for GA/AA]. The in vivo experiments with normal renal tissues revealed that a statistically significantly higher Ku70 mRNA expression was identified in samples with GA/AA genotypes compared with those with GG genotypes (p = 0.001). These results suggested that the Ku70 A-31G polymorphism is involved in the etiology of RCC and, thus, may be a marker for genetic susceptibility to RCC in the Chinese populations.

microRNA-133 inhibits cell proliferation, migration and invasion in prostate cancer cells by targeting the epidermal growth factor receptor

It has been shown that regulation of EGFR expression in prostate cancer cells is mostly at the transcriptional level. microRNA-133 (miR-133) has long been recognized as a muscle-specific miRNA which may regulate myoblast differentiation and participate in many myogenic diseases. Recently, it has been reported that miR-133 is also involved in other tumors, such as bladder cancer, esophageal cancer and may regulate cell motility in these cancer cells. In the present study, we examined the expression and effects of miR-133 in two hormone-insensitive prostate cancer cell lines. The expression of miR-133a and miR-133b were analyzed by quantitative RT-PCR. After transfection of miR-133a and miR-133b, cell viability assay, luciferase assay, western blot analysis, cell migration and invasion assay were conducted in Du145 and PC3 cells. In this study, we showed that miR‑133a and miR-133b are expressed at the detection limit in two hormone-insensitive prostate cancer cell lines, PC3 and DU145. Ectopic expression of miR-133 inhibited cell proliferation, migration and invasion in these cells. We also provide the first evidence that miR-133 may target EGFR. Our study provided the first glimpse of the functional role of miR-133 in two hormone-independent prostate cancer cell lines. These results may add to our knowledge on the molecular basis of prostate cancer progression.

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.

The polymorphisms of IL-4, IL-4R and IL-13 genes and bladder cancer risk in a Chinese population: a case-control study

Accumulating evidence suggests that inflammatory process may play a role in bladder carcinogenesis. However, the exact mechanisms of how the inflammatory factors associate with bladder cancer risk are still unknown. In this study, we explored whether polymorphisms (i.e. IL-4 C-590T, IL-4R Ile50Val, IL-4R Ser478Pro, IL-4R Gln551Arg, IL-13 C-1055T and IL-13 Arg130Gln) of IL-4, IL-4R and IL-13 genes predicted Chinese bladder cancer risk in 817 bladder cancer and 1,141 controls. Genotyping was performed by using the TaqMan method. We did not find any overall association between these single nucleotide polymorphisms (SNPs) and bladder cancer susceptibility in a Chinese population. However, in the classification and regression tree (CART) analysis, we found that carriers of IL-13 C-1055T variant genotype in smokers had a 2.57-fold increased bladder cancer risk with a 55% patient rate (OR = 2.57; 95% CI = 1.93-3.43), comparing with non-smokers. Similar result was also observed in combination of IL-13 C-1055T and IL-13 Arg130Gln in smokers. By multifactor dimensionality reduction (MDR) analysis, the best interaction model was the two-factor model that smokers with the IL-13 C-1055T genotypes were the subgroup to predict bladder cancer risk. The results suggested that the genetic variants in IL-4, IL-4R and IL-13 genes might modulate the bladder cancer risk in a Chinese population.

Chromosome 11q13.3 variant modifies renal cell cancer risk in a Chinese population

A recent genome-wide association study of renal cell carcinoma (RCC) in European population has identified genetic variants in the regions of 2p21 (rs7579899), 11q13.3 (rs7105934) and 12q24.31 (rs4765623) conferred susceptibility to RCC. In our study, we assessed whether these polymorphisms are also associated with RCC risk in a Chinese population. We genotyped these polymorphisms using TaqMan method and assessed their associations with RCC risk in a case-control study of 710 patients with histologically confirmed RCC and 760 cancer-free controls. Normal renal tissues adjacent to tumors were used to evaluate the functional consequences of these polymorphisms. We found that rs7105934 was significantly associated with reduced RCC risk [adjusted odds ratio (OR) = 0.67, 95% confidence intervals (CIs) = 0.47-0.95, GA+AA versus GG], particularly among subgroups of normal-weight individuals (OR = 0.51, 95%CI = 0.29-0.88), never-smokers (OR = 0.53, 95%CI = 0.33-0.85) and non-drinkers (OR = 0.57, 95%CI = 0.370.87). Furthermore, the rs7105934 GA genotype was associated with lower levels of CCND1 mRNA compared with GG genotype, although this association was only marginally significant (P = 0.055). No significant association between rs7579899 or rs7105934 and RCC risk was observed. Our results suggest that rs7105934 on 11q13.3 may confer susceptibility to RCC in our population. Large population-based prospective and functional studies are required to validate the associations between these loci and RCC risk.

Replication and cumulative effects of GWAS-identified genetic variations for prostate cancer in Asians: a case-control study in the ChinaPCa consortium

A recent genome-wide association study has identified five new genetic variants for prostate cancer susceptibility in a Japanese population, but it is unknown whether these newly identified variants are associated with prostate cancer risk in other populations, including Chinese men. We genotyped these five variants in a case-control study of 1524 patients diagnosed with prostate cancer and 2169 control subjects from the Chinese Consortium for Prostate Cancer Genetics (ChinaPCa). We found that three of the five genetic variants were associated with prostate cancer risk (P = 4.33 × 10(-8) for rs12653946 at 5p15, 4.43 × 10(-5) for rs339331 at 6q22 and 8.42 × 10(-4) for rs9600079 at 13q22, respectively). A cumulative effect was observed in a dose-dependent manner with increasing numbers of risk variant alleles (P(trend) = 2.58 × 10(-13)), and men with 5-6 risk alleles had a 2-fold higher risk of prostate cancer than men with 0-2 risk alleles (odds ratio = 2.26, 95% confidence interval = 1.78-2.87). Furthermore, rs339331 T allele was significantly associated with RFX6 and GPRC6A higher messenger RNA expression, compared with the C allele. However, none of the variants was associated with clinical stage, Gleason score or family history. These results provide further evidence that the risk loci identified in Japanese men also contribute to prostate cancer susceptibility in Chinese men.

Treatment of angiostrongyliasis using a combination of albendazole and dexamethasone: the results of a retrospective and comparative study

As the information available on the treatment of angiostrongyliasis with a combination of albendazole and dexamethasone is limited, the efficacy of such therapy was assessed using data collected during the 2006 outbreak of angiostrongyliasis in Beijing. In a retrospective and controlled study, 35 patients treated with albendazole-dexamethasone (given 20 mg albendazole/kg and 3 mg dexamethasone daily for 7 days) were compared with 34 controls who were treated only symptomatically (with acetaminophen or other drugs). Compared with the controls, the patients given the combination were less likely to have headaches after 7 days (P = 0·038), tended to have headaches that cleared quicker (P = 0·010), and received fewer doses of acetaminophen (P = 0·036). Since no serious adverse effects were observed, a 1-week treatment with a combination of albendazole and dexamethasone appears both safe and beneficial in the treatment of angiostrongyliasis.

Association between VHL single nucleotide polymorphism (rs779805) and the susceptibility to prostate cancer in Chinese

The Von Hippel-Lindau (VHL) tumor suppressor gene is a crucial regulator of the hypoxia response pathway and plays an important role in tumorigenesis, particularly in tumor growth and vascularization. We hypothesize that polymorphisms in the functional region of VHL may influence susceptibility to prostate cancer (PCa). We genotyped a potentially functional polymorphism (rs779805) in 5' UTR region of VHL in a case-control study of 665 PCa patients and 715 cancer-free controls in a Chinese population using the Taqman assay. The genetic associations between the incidence and progression of PCa were assessed by logistic regression. We observed that the rs779805 A>G polymorphism was significantly associated with risk for PCa. Compared with the AA genotype, the AG and AG/GG genotypes were associated with decreased risk of PCa (adjusted odds ratio [OR]=0.79, 95% confidence interval [CI]=0.62-0.99, and adjusted OR=0.76, 95% CI=0.61-0.95, respectively). Further, this decreased risk was more pronounced in the subgroups of nonsmokers (OR=0.73, 95% CI=0.54-0.98), nondrinkers (OR=0.70, 95% CI=0.54-0.91) and patients without family history of cancer (OR=0.72, 95% CI=0.57-0.92). In addition, the decreased risk associated with rs779805 variant genotypes (AG/GG) was more pronounced among the prostate specific antigen (PSA)>20 ng/mL subgroup (OR=0.68, 95% CI=0.49-0.95). Our findings suggest that the rs779805 A>G polymorphism in VHL may confer susceptibility to PCa in the Chinese population.

The interleukin-10-1082 promoter polymorphism and cancer risk: a meta-analysis

Interleukin-10 (IL-10) is a multifunctional cytokine with both immunosuppressive and anti-angiogenic properties and play an important role in the pathogenesis of cancer. IL-10-1082A>G polymorphism is the most extensively studied polymorphism in the IL-10 gene in cancer susceptibility. To date, a number of case-control studies were conducted to investigate the association between IL-10-1082A>G polymorphism and cancer risk in humans. However, the association between the IL-10-1082A>G polymorphism and cancer risk is still ambiguous. In an effort to solve this controversy, we performed a meta-analysis based on 61 case-control studies, including 14,499 cancer cases and 16,967 controls. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. In the stratified analyses by specific cancer type, increased risk was found in lung cancer (OR = 3.16, 95% CI = 1.16-8.63 for GA versus AA; OR = 2.07, 95% CI = 1.16-3.70 for GG versus AA; OR = 3.17, 95% CI = 1.31-7.68 for GA/GG versus AA) and non-Hodgkin's lymphoma (OR = 1.18, 95% CI = 1.02-1.36 for GA versus AA; OR = 1.17, 95% CI = 1.02-1.35 for GA/GG versus AA). The meta-analysis also indicated that the variant genotypes were associated with a moderately increased risk in Asians in all genetic models (OR = 1.80, 95% CI = 1.17-2.76 for GA versus AA; OR = 3.32, 95% CI = 1.62-6.82 for GG versus AA; OR = 1.67, 95% CI = 1.07-2.60 for GA/GG versus AA; OR= 2.93, 95% CI = 1.43-6.03 for GG versus AA/GA). The meta-analysis suggested that the IL-10-1082A>G polymorphism was associated with increased risk of cancer in Asians and lung cancer and non-Hodgkin's lymphoma. To draw comprehensive and true conclusions, more researches with larger numbers of worldwide participants are needed to examine associations between IL-10-1082A>G polymorphism and cancer risk.

GPx-1 polymorphism (rs1050450) contributes to tumor susceptibility: evidence from meta-analysis

PURPOSE

Accumulating evidences implicate the selenium-containing cytosolic glutathione peroxidase, GPx-1, as a determinant of cancer risk and a mediator of the chemopreventive properties of selenium. Since the identification of a well-characterized functional polymorphism named Pro198Leu (rs1050450 C>T) in GPx-1, abundant studies have evaluated the association between Pro198Leu polymorphism and tumor risk in diverse population. But, the available results are conflicting.

METHODS

To derive a more precise estimation, we performed a meta-analysis based on 14,372 cases with different tumor types and 18,081 controls from 31 published case-control studies. Published literature from PubMed was retrieved. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of the association.

RESULTS

Overall, the results indicated that individuals who carried variant Leu allele (Pro/Leu and Leu/Leu) were associated with an increased cancer risk [odds ratio (OR) = 1.12, 95% confidence interval (CI) = 1.02-1.23] in a dominant genetic model. In further subgroup analyses, the increased risk of cancer was observed in subgroup of Asians and sample size more than 500 subjects.

CONCLUSION

These results suggest that the GPx-1 Pro198Leo polymorphism contributes to cancer susceptibility through a disturbed antioxidant balance.

The polymorphisms in the VHL and HIF1A genes are associated with the prognosis but not the development of renal cell carcinoma

BACKGROUND

The von Hippel-Lindau (VHL) tumor suppressor gene and hypoxia-inducible factor-1α (HIF1A) play a pivotal role in renal carcinogenesis. This study was aimed to clarify the influence of VHL and HIF1A polymorphisms on renal cell cancer (RCC) susceptibility and survival.

SUBJECTS AND METHODS

We genotyped four potentially functional single-nucleotide polymorphisms (rs779805 in VHL and rs11549465, rs11549467, and rs2057482 in HIF1A) and assessed their associations with RCC risk, clinicopathologic parameters in a case-control study of 620 patients and 623 controls, and the prognosis of RCC in a cohort of 311 patients.

RESULTS

No significant differences in VHL or HIF1A genotypes were observed between RCC cases and controls. However, individuals with ≥2 variant alleles of the four polymorphisms were associated with less frequent lymph node metastasis and lower clinical stage (P = 0.032 and P = 0.041, respectively). And the number of variant alleles was associated with improved survival in a dose-response manner (P(trend) = 0.013). Furthermore, multivariate Cox regression analysis showed that the number of variant alleles (≥1 versus 0) was an independent prognostic factor for RCC survival (P = 0.036) together with clinical stage and tumor grade.

CONCLUSION

The VHL and HIF1A polymorphisms may not influence RCC susceptibility but may jointly influence RCC progression and survival.

Functional polymorphisms in cell death pathway genes FAS and FAS ligand and risk of prostate cancer in a Chinese population

BACKGROUND

Apoptosis is the physiological mechanism of programmed cell death and abnormal regulation of this pathway can lead to carcinogenesis. We hypothesized that the FAS -1377G>A, -670A>G, and FASL -844T>C polymorphisms are associated with risk of prostate cancer (PCa).

MATERIALS AND METHODS

We genotyped polymorphisms in a hospital-based case-control study of 602 patients diagnosed with PCa and 703 cancer-free controls in a Chinese population using polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

We found a significantly decreased risk associated with FAS -1377GA [adjusted odds ratio (OR) = 0.71, 95% confidence interval (CI) = 0.56-0.90] genotype compared with the -1377GG genotype and decreased risk associated with FAS -670AG and -670GG genotypes (OR 0.75, 95% CI: 0.59-0.95; OR 0.70, 95% CI: 0.50-0.96) compared with the -670AA genotype. Consistently, we found that individuals carrying haplotype genotype with 0 or 1 risk allele (-1377G and -670A) had a lower risk of PCa than those with two risk alleles (OR 0.48, 95% CI: 0.28-0.80; OR 0.60, 95% CI: 0.41-0.87; OR 0.82, 95% CI: 0.69-0.97 for the AA, GG, and AG haplotype, respectively). In addition, when we evaluated these two FAS polymorphisms together, we found that the combined genotype with 4 risk alleles was associated with a significantly increased risk of PCa compared with those with 0-3 variants (OR 1.51, 95% CI: 1.19-1.91), and this increased risk was more pronounced among subgroups of Gleason score <7 and >7, and PSA > 20 ng/ml (OR 1.49, 95% CI: 1.08-2.04; OR 1.72, 95% CI: 1.25-2.44; OR 1.61, 95% CI: 1.23-2.13, respectively).

CONCLUSIONS

These results suggested that the FAS polymorphisms may contribute to PCa risk in a Chinese population.

Genetic polymorphisms in APE1 are associated with renal cell carcinoma risk in a Chinese population

Apurinic/apyrimidinic endonuclease 1 (APE1) is a DNA repair protein, which plays important roles in the base excision repair (BER) pathway. Genetic variations of APE1 have been shown to influence an individual's susceptibility to carcinogenesis. We hypothesized the genetic polymorphisms of APE1 are associated with the risk of renal cell carcinoma (RCC). In a case-control study of 612 RCC patients and 632 age and sex matched healthy controls, we genotyped two APE1 functional polymorphisms (-656 T>G, rs1760944 and 1349 T>G, rs1130409) and assessed their associations with risk of RCC. We found that, compared with 1349 TT/TG genotypes, the variant genotype 1349 GG had a significantly increased RCC risk [adjusted odds ratio (OR) = 1.47, 95% confidence interval (CI) = 1.10-1.95], particularly among subgroups of BMI > 23 kg/m(2) (OR = 1.54, 95% CI = 1.06-2.22), male (OR = 1.70, 95% CI = 1.17-2.46), never smokers (OR = 1.56, 95% CI = 1.11-2.21), light smokers (OR = 2.01, 95%CI = 1.02-3.95), and drinkers (OR = 2.00, 95% CI = 1.13-3.54). Furthermore, the polymorphism was significantly associated with risk of developing localized stage RCC. No altered RCC risk was associated with the -656 T>G polymorphism, but we found individuals who were homozygous for both risk alleles of the two SNPs had a 2.17-fold increased risk for RCC, compared to individuals with 0 risk alleles. Our results suggest that polymorphisms of APE1 may confer susceptibility to RCC.

Association of IL-4 -590 T>C polymorphism and risk of renal cell carcinoma in a Chinese population

Interleukin 4 (IL-4) is a typical pleiotropic T helper 2 (Th2) cytokine. This cytokine is a critical mediator of the Th1/Th2 balance and apoptosis potential and involved in the process of inflammation-mediated carcinogenesis in human organs, including renal cell carcinoma (RCC). The effects of functional promoter polymorphism of the IL-4 gene on risk of RCC in Chinese are still unknown. In this study, we genotyped functional polymorphism in IL-4-590 T>C in a hospital-based case-control study of 340 patients with diagnosed RCC and 342 cancer-free controls in a Chinese population. Compared with IL-4-590 TT genotype, the CC genotype had a significantly decreased RCC risk [adjusted odds ratio (OR) = 0.44, 95% confidence interval (CI) = 0.22-0.89]. Furthermore, a significant decreased risk of RCC was found in the combined variant genotypes CT + CC compared with the TT genotype (adjusted OR = 0.68, 95% CI = 0.50-0.93). The IL-4 C allele frequency was 0.178 among the cases and 0.237 among the controls, and the difference was statistically significant (P = 0.007). These results suggest that the IL-4-590 T>C polymorphism is involved in susceptibility to developing RCC in Chinese populations. Larger studies are warranted to validate our findings.

Chromosome 4p16.3 variant modify bladder cancer risk in a Chinese population

A recent genome-wide association study identified a common variant (rs798766) on 4p16.3 that confers susceptibility to bladder cancer. The aim of this study was to assess whether rs798766 is associated with risk of bladder cancer in a Chinese population as well. We genotyped this variant using TaqMan technology in a case-control study of 815 histologically confirmed bladder cancer patients and 1141 controls. Normal bladder tissues adjacent to tumors were used to evaluate the functionality of rs798766 using quantitative real-time reverse transcription-polymerase chain reaction. We found that rs798766 CT/TT genotypes were associated with a significantly increased risk of bladder cancer (odds ratio = 1.36, 95% confidence interval = 1.10-1.67), compared with the CC genotype. Furthermore, rs798766 was significantly associated with FGFR3 messenger RNA expression. However, no significant interaction between rs798766 and tobacco smoking on bladder cancer risk was observed (P(multiplicative) = 0.785). Our results suggest that rs798766 on 4p16.3 may contribute to bladder cancer susceptibility in a Chinese population and explains an additional 3.65% of population attributable risk for bladder cancer.

Role of oxidative tissue injury in the pathophysiology of experimentally induced equine laminitis: a comparison of 2 models

BACKGROUND

Oxidative stress reportedly plays a role in sepsis-induced organ dysfunction and failure in many species. In septic horses, laminae are targeted; evidence of laminar oxidative stress has been reported experimentally in the black walnut extract (BWE) model. Carbohydrate (CHO)-induced laminitis may be more similar to clinical sepsis-related laminitis than the BWE model in that animals with CHO-induced disease commonly develop laminar failure. The role of oxidative stress in the CHO model remains unknown.

HYPOTHESIS/OBJECTIVES

Markers of oxidative stress will be increased in laminae from horses with BWE- and CHO-induced laminitis.

ANIMALS

Banked laminar tissue from various time points from animals subjected to BWE (n = 15) and CHO (n = 20) protocols.

METHODS

Laminar 4-hydroxynonenal (4-HNE) and protein carbonyl content were evaluated by slot blot analysis. Laminar 3-nitrotyrosine (3-NT) immunohistochemistry was performed.

RESULTS

The number of laminar 3-NT (+) cells was increased at developmental and Obel grade 1 (OG1) time points in the BWE model (versus control [CON]; P= .013) and lower in OG1 tissues than CON in the CHO model (P = .04). No change in 4-HNE content was observed in the CHO model, and no increase in laminar protein carbonyl content was present in either model (P > .05).

CONCLUSIONS AND CLINICAL IMPORTANCE

These results do not support a prominent role for oxidative stress at examined time points in CHO-overload laminitis and support transient oxidative stress in the BWE model. Tissue oxidation does not appear to be a central early pathophysiologic event in CHO-associated laminitis.