Jian Qian

miR-134 Functions as a Tumor Suppressor in Cell Proliferation and Epithelial-to-Mesenchymal Transition by Targeting KRAS in Renal Cell Carcinoma Cells

Aberrant microRNAs (miRNAs) are reported to contribute to the pathogenesis of most human malignancies. The miRNA, miR-134, has been found to be downregulated in renal cell carcinoma (RCC), but its function in the disease is unknown. The aims of this study were to detect the expression of miR-134 in human RCC samples and explore its function in RCC cell lines. Real-time qualitative polymerase chain reaction (qPCR) was used to quantify miR-134 in human RCC samples. Assays for cell cycle, viability, migration, and invasion were performed to assess the phenotypic changes in RCC cells. A luciferase reporter assay was carried out to confirm whether KRAS (Kirsten rat sarcoma viral oncogene homolog) is a direct target of miR-134. Western blot was used to identify the potential signaling pathways that had an impact on RCC cell growth and alterations of markers for epithelial-mesenchymal transition (EMT), which affected metastasis by miR-134. miR-134 was found to be downregulated in RCC samples (p<0.05), while overexpression of miR-134 suppressed proliferation (p<0.05) by triggering G1/G0 cell cycle arrest (p<0.05). Forced expression of miR-134 could also inhibit migration (p<0.05) and invasion (p<0.05) by blocking EMT in RCC cell lines. KRAS was identified as a target of miR-134, and miR-134 may act as a tumor suppressor through the KRAS-related MAPK/ERK pathway other than PI3K/AKT signaling. Thus, miR-134 may function as a tumor suppressor in cell proliferation and EMT by targeting KRAS in RCC cells.

A potentially functional polymorphism in the promoter region of miR-34b/c is associated with renal cell cancer risk in a Chinese population

Members of the miR-34 family have been shown to be transcriptional targets of the tumour suppressor gene P53. Aberration expression of miR-34 impairs p53-mediated cell cycle arrest and apoptosis. A single nucleotide polymorphism T > C (rs4938723) located within the CpG island in the promoter region of pri-miR-34b/c may affect its expression and has been suggested to influence cancer risk. In this study, we genotyped rs4938723 using the TaqMan method to explore the relationship between this polymorphism and the risk of renal cell cancer (RCC) in a case-control study of 710 RCC patients and 760 control subjects. We found that individuals carrying the CC genotype had a significantly increased RCC risk compared with those with TT or TT/TC genotypes [odds ratio (OR) = 1.53, 95% confidence interval (CI) = 1.06-2.21 for CC vs. TT and OR = 1.48, 95% CI = 1.05-2.10 for CC vs. TT/TC). Furthermore, the increased risk was more evident in the subgroups of older subjects (OR = 1.80, 95% CI = 1.08-3.01), males (OR = 1.64, 95% CI = 1.08-2.51), smokers (OR = 2.07, 95% CI = 1.16-3.69) and drinkers (OR = 1.94, 95% CI = 1.01-3.73), although no interaction between rs4938723 and these characteristics was observed. Twenty-seven normal tissues adjacent to tumour were used to evaluate the association between the expression level of miR-34b/c and the polymorphism, which revealed higher expression levels of miR-34b/c in normal renal tissues with TT+TC genotypes than in those with CC genotypes (P < 0.01). Furthermore, a luciferase gene assay in 293-T cells showed that the luciferase activities with rs4938723 T allele are higher than that with C allele (P < 0.05). These results suggest that the miR-34b/c rs4938723 C allele may increase susceptibility to RCC by decreasing the activity of pri-miR-34b/c promoter.

Association of the Glutathione S-Transferase M1, T1 Polymorphisms with Cancer: Evidence from a Meta-Analysis

Background Glutathione S-transferases (GSTs) are a family of multifunctional enzymes that are involved in the metabolism of many xenobiotics, including a wide range of environmental carcinogens. While the null genotypes in GSTM1 and GSTT1 have been implicated in tumorigenesis, it remains inconsistent and inconclusive. Herein, we aimed to assess the possible associations of the GSTM1 and GSTT1 null genotype in cancer risks. Methods A meta-analysis based on 506 case-control studies was performed. Odds ratios (OR) with corresponding 95% confidence intervals (CIs) were used to assess the association. Results The null genotypes of GSTM1 and GSTT1 polymorphisms were associated with a significantly increased risk in cancer (for GSTM1: OR = 1.17; 95%CI = 1.14–1.21; for GSTT1: OR = 1.16; 95%CI = 1.11–1.21, respectively). When the analysis was performed based on their smoking history, the risk associated of GSTM1 null and GSTT1 null genotypes with cancer is further increased (for GSTM1: OR = 2.66; 95%CI = 2.19–3.24; for GSTT1: OR = 2.46; 95%CI = 1.83–3.32, respectively). Conclusions These findings indicate that GSTM1 and GSTT1 polymorphisms may play critical roles in the development of cancer, especially in smokers.

Expression Pattern of Long Non-Coding RNAs in Renal Cell Carcinoma Revealed by Microarray

Background Recent large-scale transcriptome analyses have found large numbers of transcripts, including that of long non-coding RNAs (lncRNAs), which are aberrant in various diseases, especially cancers. However, it is not clear whether lncRNAs are involved specifically in renal cell carcinoma (RCC). We investigated the expression patterns of lncRNAs in five RCC tumor samples (T) relative to those of matched adjacent non-tumor tissues (N) via microarray. Methods A microarray with 33,045 lncRNA probes and 30,215 mRNA probes was used to identify deregulated lncRNAs in five RCC patients. Furthermore, we confirmed the relative expression levels of AK096725 and ENST00000453068 in 70 paired samples by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Results The lncRNA microarray revealed 27,279 lncRNAs in RCC samples, of which 480 were significantly upregulated (P<0.05; T/N>1.5) and 417 were significantly downregulated (P<0.05; N/T>1.5) compared with the matched non-tumor samples. In addition, 19,995 mRNAs were detected, of which 458 were significantly upregulated (P<0.05; T/N>1.5) and 413 were significantly downregulated (P<0.05; N/T>1.5). The expression level changes of AK096725 (P = 0.043) and ENST00000453068 (P<0.001) in 70 paired samples were in accord with the microarray data. Conclusions The study uncovered expression patterns of lncRNAs in 5 RCC patients, as well as a number of aberrant lncRNAs and mRNAs in tumor samples compared with the non-tumor tissues. The revelation of an association between AK096725 expression and RCC is especially noteworthy. These findings may help to find new biomarkers in RCC.

Genetic Polymorphisms in IGF-I and IGFBP-3 Are Associated with Prostate Cancer in the Chinese Population

Insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) are members of the insulin-like growth factor (IGF) family that play important roles in carcinogenesis. We hypothesized that the functional polymorphisms in IGF-I and IGFBP-3 may be associated with the risk of prostate cancer (PCa) in the Chinese population. This hospital-based case-control study included 664 PCa patients and 702 cancer-free controls. Nine SNPs in IGF-I and IGFBP-3 were genotyped using the TaqMan assay. The genetic associations between the pathogenesis and progression of PCa were assessed by logistic regression. We found that the genotype and allele frequency distribution of rs6218, rs35767 and rs5742612 were significantly different when comparing PCa cases to controls (P  = 0.005, 0.005 and 0.020, respectively). In the combined analysis, individuals with 2–6 risk alleles had an elevated risk of PCa compared to those with 0–1 risk alleles. We also found that the association between the combined risk alleles and the risk of PCa appeared stronger in the following subgroups: individuals older than 71 years of age (OR  = 1.41, 95%CI  = 1.05–1.91, P  = 0.020), nonsmokers (OR  = 1.68, 95%CI  = 1.21–2.32, P  = 0.002), nondrinkers (OR  = 1.32, 95%CI  = 1.02–1.61, P  = 0.002), and those with a negative family history of PCa (OR  = 1.28, 95%CI  = 1.02–1.71, P  = 0.022). Our results indicate that the three SNPs (rs6218, rs35767 and rs5742612) and the joint genotypes with 2–6 risk alleles, may contribute to the susceptibility to PCa, but not the progression, in the Chinese population.

PAI-1 4G/5G Polymorphism Contributes to Cancer Susceptibility: Evidence from Meta-Analysis

Background The plasminogen activator inhibitor-1 (PAI-1) is expressed in many cancer cell types and allows the modulation of cancer growth, invasion and angiogenesis. To date, studies investigated the association between a functional polymorphism in PAI-1 (4G/5G) and risk of cancer have shown inclusive results. Methods A meta-analysis based on 25 case-control studies was performed to address this issue. Odds ratios (OR) with corresponding 95% confidence intervals (CIs) were used to assess the association. The statistical heterogeneity across studies was examined with I2 test. Results Overall, a significant increased risk of cancer was associated with the PAI-1 4G/4G polymorphism for the allele contrast (4G vs. 5G: OR = 1.10, CI = 1.03–1.18, I2 = 49.5%), the additive genetic model (4G/4G vs. 5G/5G: OR = 1.21, CI = 1.06–1.39, I2 = 51.9%), the recessive genetic model (4G/4G vs. 4G/5G+5G/5G: OR = 1.11, CI = 1.04–1.18, I2 = 20.8%). In the subgroup analysis by ethnicity, the results indicated that individuals with 4G/4G genotype had a significantly higher cancer risk among Caucasians (4G/4G vs. 5G/5G: OR = 1.31, 95%CI = 1.09–1.59, I2 = 59.6%; 4G/4G vs. 4G/5G: OR = 1.12, 95%CI = 1.04–1.21, I2 = 3.6%; recessive model: OR = 1.12, 95%CI = 1.05–1.21, I2 = 25.3%). Conclusions The results of the present meta-analysis support an association between the PAI-1 4G/5G polymorphism and increasing cancer risk, especially among Caucasians, and those with 4G allele have a high risk to develop colorectal cancer and endometrial cancer.

The Cytochrome P4501A1 gene polymorphisms and idiopathic male infertility risk: A meta-analysis

Studies of the relationship between male infertility and CYP1A1 polymorphisms are inconclusive. To drive a more precise estimation, we performed a meta-analysis based on 1060 cases and 1225 controls from 7 published case-control studies. PubMed and CNKI literature search were conducted to identify all eligible studies investigating such a relationship. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association in the additive model, dominant model, recessive model, and allele-frequency genetic model. In the overall analysis, the frequency of CYP1A12A genotype was significantly associated with susceptibility to idiopathic male infertility. Further stratified analysis by ethnicity showed notable association between the polymorphism and the risk of idiopathic male infertility in Asians. In conclusion, these results support that the CYP1A1 2A genotype polymorphism mainly contributes to idiopathic male infertility susceptibility in Asians but not in Caucasians.

Genetic variants in RKIP are associated with clear cell renal cell carcinoma risk in a Chinese population.

Background Raf-1 kinase inhibitor protein (RKIP) plays a critical role in tumor development by regulating cell functions such as invasion, apoptosis and differentiation. Down-regulation of RKIP expression has been implicated in the development and progression of renal cell carcinoma (RCC). Herein, we hypothesized that genetic polymorphisms in RKIP might be associated with susceptibility and progression of RCC. Methods A total of 5 tagging single-nucleotide polymorphisms (tSNPs) in RKIP were selected and genotyped by SNapShot method in a case-control study of 859 RCC patients and 1004 controls. The logistic regression was used to evaluate the genetic association with occurrence and progression of RCC. The functionality of the important SNP was preliminary examined by qRT-PCR. Result We found that the rs17512051 in the promoter region of RKIP was significantly associated with decreased clear cell RCC (ccRCC) risk (TA/AA vs. TT: P = 0.039, OR = 0.78, 95%CI = 0.62–0.99). Another SNP (rs1051470) in the 3′UTR region of RKIP was marginally associated with increased ccRCC risk (TT vs. CC+CT: OR = 1.45, 95%CI = 1.01–2.09). In the stratified analysis, the protective effect of rs17512051 was more predominant in the subgroups of male, non-smokers, non-drinkers as well as subjects without history of diabetes. Furthermore, we observed higher RKIP mRNA levels in the presence of the rs17512051A allele in normal renal tissues. Conclusion Our results suggest that the potentially functional RKIP rs17512051 polymorphism may affect ccRCC susceptibility through altering the endogenous RKIP expression level. Risk effects and the functional impact of this polymorphism need further validation.

Laparoscopic Partial Nephrectomy with Precise Segmental Renal Artery Clamping for Clinical T1b Tumors

OBJECTIVE To assess the technique and short-term outcomes of laparoscopic partial nephrectomy (LPN) with precise segmental renal artery clamping for clinical T1b (cT1b) tumors and to analyze the possible factors affecting the glomerular filtration rate (GFR) reduction. MATERIALS AND METHODS This retrospective study investigated the outcomes of 72 patients with cT1b tumors who received LPN from June 2008 to May 2014. Based on three-dimensional dynamic renal vascular models built before surgery, target arteries were precisely clamped and tumors were removed under regional parenchymal ischemia. Perioperative and follow-up outcomes were analyzed. RESULTS All the LPN procedures were effectively performed using the novel technique, without converting to main renal artery clamping or open surgery. The mean operative time was 86 min, with a mean warm ischemic time of 25 min. The median estimated blood loss was 200 mL (range: 80-800). The postoperative mean GFR was 64% of the preoperative baseline, and the total complication rate was 19.4%. In multivariable analyses, the two independent factors affecting postoperative GFR were the RENAL nephrometry score (RNS) and number of intraoperative clamped segmental arteries. The median follow-up was 24 months (range: 6-72). The overall, recurrence-free, and cancer-specific survival rates were 100%, 95.8%, and 100%, respectively. CONCLUSIONS For patients with cT1b tumor, LPN with precise segmental renal artery clamping is safe and feasible for removing tumors and preserving the blood supply and normal renal parenchyma. Short-term oncologic and functional outcomes were satisfactory. Postoperative GFR was related to the preoperative RNS and number of intraoperative clamped segmental arteries.

Association of erythropoietin gene rs576236 polymorphism and risk of adrenal tumors in a Chinese population.

Abstract Erythropoietin (EPO) is a circulating glycosylated protein hormone and has been implicated in the development and progression of non-hematopoietic tissue tumors. The objective of the present study was to determine if the EPO rs576236 polymorphism was associated with the risk of adrenal tumors. We genotyped the EPO rs576236 polymorphism in a case-control study of 288 adrenal tumor patients and 456 cancer-free controls by using the TaqMan method, and assessed the association between the polymorphism and the adrenal tumor risk by logistic regression. Furthermore, 95% confidence interval (CI) was used to assess the genetic association between the polymorphism and the risk of adrenal tumor. Compared with the TT genotype, the TC genotype had a significantly increased risk of adrenal tumor [adjusted odds ratio (OR)  =  1.24, 95% CI  =  1.12–2.22]. Furthermore a significantly increased risk of adrenal tumor was found in the combined variant genotypes TC+CC compared with the TT genotype (adjusted OR  =  1.17, 95% CI  =  1.12–2.21). Our present study suggests that the rs576236 polymorphism of EPO confers susceptibility to adrenal tumor in the Chinese population.