Genetic variations in microRNAs and the risk and survival of renal cell cancer.

MicroRNAs (miRNAs) are a class of short non-coding, single-stranded RNAs, which perform posttranscriptional regulatory functions as tumor suppressors or oncogenes. Single nucleotide polymorphisms (SNPs) in microRNAs (miRNAs) genes are currently being identified for contributing to cancer risk, prognosis and survival. We investigated whether genetic variations of miRNAs were associated with the risk and prognosis of renal cell carcinoma (RCC). We genotyped four common miRNA SNPs (i.e. miR-146a rs2910164, miR-149 rs2292832, miR-196a2 rs11614913 and miR-499 rs3746444) to assess their associations with RCC risk in a two-stage case-control study (355 cases and 362 controls in discovery set, meanwhile 647 cases and 660 controls in validation set), as well as RCC survival in 311 patients. We found that the miR-196a2 SNP rs11614913 was associated with RCC susceptibility in recessive model [CC versus TT/TC, adjusted odds ratio = 0.65, 95% confidence interval (CI) = 0.52-0.83] and with survival of RCC in dominant model (TC/CC versus TT, adjusted hazard ratio = 0.40, 95% CI = 0.18-0.89). Meanwhile, the rs11614913 CC genotype was associated with the significantly decreased expression of miR-196a-5p in 26 renal cancer tissues (P = 0.018). Moreover, luciferase reporter assays revealed the potential effect of rs11614913 SNP on the binding of miR-196a-3p to its targets. These results suggested that the miR-196a2 rs11614913 may contribute to the genetic susceptibility and prognosis for RCC, which may act as a biomarker for RCC occurrence and prognosis.

A functional polymorphism C-1310G in the promoter region of Ku70/XRCC6 is associated with risk of renal cell carcinoma.

The DNA repair gene Ku70 plays a key role in the DNA double strand break (DSB) repair system. Defects in DSB repair capacity can lead to genomic instability. We hypothesized that the Ku70 C-1310G polymorphism (rs2267437) was associated with risk of renal cell carcinoma (RCC). We genotyped the Ku70 C-1310G polymorphism in a case-control study of 620 patients and 623 controls in a Chinese population and assessed the effects of C-1310G polymorphism on RCC susceptibility and survival. We then examined the functionality of this polymorphism. Compared with the Ku70-1310CC genotype, the CG and CG/GG genotypes had a significantly increased risk of RCC [adjusted odds ratio (OR) = 1.47, 95% confidence interval (CI) = 1.16-1.87 for CG and OR = 1.47, 95% CI = 1.16-1.86 for CG/GG]. However, the C-1310G polymorphism did not influence the survival of RCC. The in vivo experiments with normal renal tissues revealed statistically significantly lower Ku70 mRNA expression in samples with CG/GG genotypes relative to those with the CC genotype (P < 0.05). In vitro luciferase assays in various cell lines showed lower luciferase activity for the -1310G allele than for the -1310C allele. These results suggest that the Ku70 C-1310G polymorphism is involved in the etiology of RCC and thus may be a marker for genetic susceptibility to RCC in Chinese populations. Larger studies are warranted to validate our findings.

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.

NP-induced biophysical and biochemical alterations of rat testicular Sertoli cell membranes related to disturbed intracellular Ca(2+) homeostasis.

Nonylphenol (NP) is a representative endocrine disruptor that has an adverse effect on male reproduction and posses direct hazard to Sertoli cells, but the mechanism remains incompletely elucidated. In the present study, based on the structural comparability and high affinity between NP and membrane phospholipid molecules, we tested the hypothesis that entrance of NP into Sertoli cells would alter membrane biophysical characteristics and biochemical functions. First, we used gas chromatography-mass spectrometry (GC-MS) to investigate the distribution and pharmacokinetics of NP in Sertoli cells with the result revealing that NP could penetrate plasma membrane of Sertoli cells. Meanwhile, Sertoli cells treated with NP exhibited abnormal membrane potential; that is an early depolarization following short treatment and hyperpolarization after longer treatment with the highest concentration of NP. Studies on the membrane dynamics indicated that the NP exposure rendered increased membrane fluidity and decreased microviscosity and molecular order. The result of lactate dehydrogenase (LDH) leakage assay demonstrated that NP increased membrane permeability in time-dose-dependent manners. Atomic force microscopic (AFM) imaging was applied to examine the membrane topography, and the images showed that NP treatment caused disturbance of membrane topography. The activities of plasma membrane Ca(2+)-ATPase, Ca(2+)-Mg(2+)-ATPase and Na(+)-K(+)-ATPase were also changed following NP exposure. However, FSH receptor as an important membrane protein was not significantly altered. All the above changes led to the disturbed intracellular Ca(2+) homeostasis which was an important signal triggering apoptosis. Hence, cellular membranes represented a plausible target for NP-induced cytotoxicity.

Effects of Astragalus polysaccharides (APS) on the expression of immune response genes in head kidney, gill and spleen of the common carp, Cyprinus carpio L.

For fish immune defences, cytokines and anti-microbial peptides (lysozyme) in circulating system play important roles. In the present study, the effects of Astragalus polysaccharides (APS) injection on gene expression of interleukin 1beta (IL-1beta), tumor necrosis factoralpha (TNF-alpha) and lysozyme-C in the head kidney, gill and spleen of common carp were determined using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). After injection of APS, IL-1beta mRNA level increased in a dose-dependent manner in the head kidney, while no significant changes were found in the gill and spleen. High dose of APS up regulated TNF-alpha transcription in the gill and spleen, while TNF-alpha mRNA level decreased significantly in the head kidney of low dose of APS. Lysozyme-C mRNA levels were up regulated in the gill of low dose of APS and spleen of middle dose of APS. No effect of the APS on lysozyme-C expression was observed in head kidney. These results constitute a first step toward the understanding of APS effect on cytokines and immune-related gene expression in different organs of common carp.