Relationship between gene polymorphisms and prostate cancer risk

SNPs-Panel Polymorphism Variations in GHRL and GHSR Genes Are Not Associated with Prostate Cancer

Prostate cancer (PCa) is a major public health problem worldwide. Recent studies have suggested that ghrelin and its receptor could be involved in the susceptibility to several cancers such as PCa, leading to their use as an important predictive way for the clinical progression and prognosis of cancer. However, conflicting results of single nucleotide polymorphisms (SNPs) with ghrelin (GHRL) and its receptor (GHSR) genes were demonstrated in different studies. Thus, the present case-control study was undertaken to investigate the association of GHRL and GHSR polymorphisms with the susceptibility to sporadic PCa. A cohort of 120 PCa patients and 95 healthy subjects were enrolled in this study. Genotyping of six SNPs was performed: three tag SNPs in GHRL (rs696217, rs4684677, rs3491141) and three tag SNPs in the GHSR (rs2922126, rs572169, rs2948694) using TaqMan. The allele and genotype distribution, as well as haplotypes frequencies and linked disequilibrium (LD), were established. Multifactor dimensionality reduction (MDR) analysis was used to study gene-gene interactions between the six SNPs. Our results showed no significant association of the target polymorphisms with PCa (p > 0.05). Nevertheless, SNPs are often just markers that help identify or delimit specific genomic regions that may harbour functional variants rather than the variants causing the disease. Furthermore, we found that one GHSR rs2922126, namely the TT genotype, was significantly more frequent in PCa patients than in controls (p = 0.040). These data suggest that this genotype could be a PCa susceptibility genotype. MDR analyses revealed that the rs2922126 and rs572169 combination was the best model, with 81.08% accuracy (p = 0.0001) for predicting susceptibility to PCa. The results also showed a precision of 98.1% (p < 0.0001) and a PR-AUC of 1.00. Our findings provide new insights into the influence of GHRL and GHSR polymorphisms and significant evidence for gene-gene interactions in PCa susceptibility, and they may guide clinical decision-making to prevent overtreatment and enhance patients' quality of life.

Role of Genetic Variations in CDK2, CCNE1 and p27KIP1 in Prostate Cancer

BACKGROUND/AIM

Our aim was to investigate possible influences of genetic variants in genes involved in the G₁/S transition [cyclin-dependent kinase-2 (CDK2), cyclin E1 (CCNE1) and cyclin-dependent kinase inhibitor 1B (p27^KIP1)] on the expression/activity of their corresponding proteins and to assess the functional impact of these variants on the risk of prostate cancer.

MATERIALS AND METHODS

We genotyped 530 cases and 562 healthy controls for two relevant single nucleotide polymorphisms (CDK2 rs2069408 and CCNE1 rs997669) by TaqMan genotyping assay. p27^KIP1 rs2066827 polymorphisms were studied by polymerase chain reaction-restriction fragment length polymorphism assay. In addition, the expression of CDK2, CCNE1 and p27^KIP1 was evaluated by quantitative real-time-polymerase chain reaction and western blotting in 44 prostate cancer tissues and 31 benign prostatic hyperplasia tissues.

RESULTS

No association was found between CDK2 rs2069408, CCNE1 rs997669 or p27^KIP1 rs2066827 polymorphisms and an increased risk of prostate cancer development. Higher CDK2 expression was more prevalent in those with rs2069408 GG genotype than in AA carriers (p>0.05). We also noted reduced p27^KIP1 protein expression in those with the p27^KIP1 G109 allele. No difference was observed for CCNE1 expression in relation to the risky genotype (CC). A significant association was detected between CCNE1 mRNA overexpression and development of higher-grade carcinomas (Gleason score >7, p<0.05).

CONCLUSION

Polymorphisms CDK2 rs2069408, CCNE1 rs997669 and p27^KIP1 rs2066827 have no significant impact on prostate cancer risk nor on the gene and protein expression of CDK2, CCNE1 and p27^KIP1, although high CCNE1 expression was significantly associated with a higher tumour grade in patients with prostate cancer.

Association Between CYP17A1, CYB5A Polymorphisms and Efficacy of Abiraterone Acetate/Prednisone Treatment in Castration-Resistant Prostate Cancer Patients

PURPOSE

The purpose of this study was to investigate the association between single nucleotide polymorphisms (SNPs) of CYP17A1, CYB5A and the efficacy of abiraterone acetate treatment in patients with castration-resistant prostate cancer (CRPC).

PATIENTS AND METHODS

Data were collected from 58 CRPC patients who had been treated with abiraterone acetate/prednisone (AA/P). The SNPs rs743572 and rs10883783 on CYP17A1 and SNPs rs1790834 and rs1790858 on CYB5A were assayed, and their relationship with prostate-specific antigen (PSA) response in patients after AA/P treatment, overall survival (OS) and progression-free survival (PFS) were analyzed by logistic regression, Cox regression, Kaplan-Meier and Log rank analyses.

RESULTS

The SNP rs1790834 on CYB5A showed significant association with PSA response in CRPC patients treated with AA/P (P < 0.05), but rs743572, rs10883783 and rs1790858 did not. The rs1790834 variant significantly decreased both PFS and OS (P < 0.05).

CONCLUSION

The CYB5A rs790834 genotype is a novel SNP related to CRPC and may be used as a biomarker for CRPC treatment.

The CYP17 MSP AI (T-34C) and CYP19A1 (Trp39Arg) variants in polycystic ovary syndrome: A case-control study

Background

Polycystic ovary syndrome (PCOS) is a common and chronic disorder of endocrine glands where genetic factors play a major role in the susceptibility to the disease. The cytochrome (CYP) 17 enzyme is essential for androgens biosynthesis. Also, the CYP19 enzyme converts the androgens to the aromatic estrogens.

Objective

We aimed to investigate the association of CYP 17 MSP AI (T-34C) and CYP 19A1 (Trp39Arg) variants with the pathogenesis of PCOS in a population from Western Iran with Kurdish ethnic background.

Materials and Methods

The present case-control study consisted of 50 patients with PCOS and 109 controls. The CYP17 T-34C and CYP19A1 (Trp39Arg) polymorphisms were identified by polymerase chain reaction-restriction fragment length polymorphism. The serum lipid and lipoprotein profile were detected by the Bionic Diagnostic Kits. Estradiol, dehydroepiandrosterone (DHEA), and sex hormone-binding globulin (SHBG) levels were measured using the chemiluminescent method.

Results

The serum levels of estradiol and SHBG in PCOS patients were lower than controls (p < 0.001 and p = 0.06, respectively). However, the level of DHEA was higher (p = 0.01) in patients compared to controls. The higher frequency of CYP17 TC genotype in patients (30%) compared to controls (15.6%) was associated with 2.31-fold susceptibility to PCOS (p = 0.038). The frequency of CYP19 TC genotype was 6.4% in controls and 10% in patients (p = 0.42).

Conclusion

The present study suggests that CYP17 TC genotype could be associated with the risk of PCOS. Also, the study indicated the sex steroid hormones level alteration and the lower level of SHBG in PCOS patients compared to healthy individuals.

CDKN1B Val 109 Gly variant is not related to risk of prostate cancer

Association between CDKN1B gene Val 109 Gly polymorphism and prostate cancer (PCa) susceptibility has been investigated in several studies but with inconsistent conclusions. We adopted odds ratios (ORs) and 95% confidence intervals (CIs) to assess the correlation between CDKN1B Val 109 Gly variant and PCa susceptibility. Moreover, we used in-silico tools to evaluate the relationship of CDKN1B expression and overall survival (OS) or disease free survival (DFS) time in PCa patients. The overall results demonstrated no association of the CDKN1B variant on PCa risk [allelic contrast (OR = 0.78, 95% CI = 0.45 - 1.35, P_{heterogeneity}  = 0.038); GV vs VV (OR = 0.83, 95% CI = 0.56 - 1.25, P_{heterogeneity}  = 0.253); GG vs VV (OR = 0.48, 95% CI = 0.23 - 1.01, P_{heterogeneity}  = 0.161); GG+GV vs VV (OR = 0.75, 95% CI = 0.52 -1.08, P_{heterogeneity}  = 0.132) and GG vs GV+VV (OR = 0.63, 95% CI = 0.25 - 1.11, P_{heterogeneity}  = 0.152)]. In subgroup analysis by ethnicity and source of control, we also identified similar results. In-silico results showed that expression of CDKN1B was decreased in PCa tissue, especially in less advanced PCa (Gleason score = 6 or 7). No significant difference of OS or DFS time was indicated between the low and high expression of CDKN1B. Our present study showed evidence that CDKN1B Val 109 Gly variant is not related to PCa risk. Future studies with large sample size are needed to confirm this correlation in more details.

p27-V109G Polymorphism Is Not Associated with the Risk of Prostate Cancer: A Case-Control Study of Han Chinese Men in Central China

Objective

We conducted an update meta-analysis aiming to verify the association between p27-V109G polymorphism and cancer risk, particular for prostate cancer (PCa). Then, we conducted a case-control study of Han Chinese in central China to verify the evidence-based results.

Methods

Relevant studies were collected from diverse databases up to March 2017. In addition, a hospital-based (H-B) case-control study enrolling 90 PCa patients and 140 healthy controls was included to verify these evidence-based findings. Genetic risk was calculated by odds ratio (OR) with its corresponding 95% confidence interval (CI). The p27-V109G polymorphism was determined by MassARRAY genotyping method.

Results

Finally, twenty-four published studies comprising 9627 cases and 12,102 controls were enrolled for the current meta-analysis. Overall analysis suggested that p27-V109G polymorphism decreased overall cancer risk in allelic contrast, heterozygote, and dominant models. When stratified analysis was conducted by ethnicity, data revealed that p27-V109G polymorphism was associated with a decreased cancer risk in Caucasians. Highlighted in the subgroup analysis by cancer type, we uncovered a significantly decreased risk of PCa in allelic contrast, dominant, homogeneous, and recessive models. However, in the validation case-control study, we failed to uncover a positive association between p27-V109G polymorphism and PCa risk. In addition, negative results were also identified when subgroup analyses were stratified by age, tumor grade, tumor stage, PSA levels, and other measurements.

Conclusion

Although evidence-based results suggest that p27-V109G polymorphism plays a protective role in overall cancer risk, particularly for PCa, our case-control study failed to validate any association between this particular polymorphism and PCa risk.

Association of the CYP17 MSP AI (T-34C) and CYP19 codon 39 (Trp/Arg) polymorphisms with susceptibility to acne vulgaris

The aim of this study was to detect the association of the cytochrome P450 (CYP) 17 T-34C and CYP19 T<C polymorphisms with the risk of acne vulgaris (AV). The study enrolled 198 patients with AV (mild, moderate and severe) and 195 unrelated age-matched healthy controls from western Iran who had Kurdish ethnic background. The presence of the CYP17 TC genotype significantly increased the risk of mild, moderate and severe AV by 2.68, 2.28 and 2.94 times, respectively, while the presence of the CYP19 TC genotype significantly elevated the risk of overall AV and mild AV by 2.1 and 3.2 times, respectively. There was a synergy between the CYP 17 TC and CYP19 TT genotypes, which increased the risk of AV by 2.45-fold (P < 0.001). To our knowledge, this is the first study showing that the CYP17 T-34C and CYP19 T<C variants and their synergy are associated with susceptibility to AV in an Iranian population.

Androgen receptor gene polymorphisms and risk of prostate cancer: a meta-analysis

Although the association between CAG and GGN repeats in the androgen receptor gene and prostate cancer risk has been widely studied, it remains controversial from previous meta-analyses and narrative reviews. Therefore, we performed this meta-analysis to provide more precise estimates with sufficient power. A total of 51 publications with 61 studies for CAG repeats and 14 publications with 16 studies for GGN repeats were identified in the meta-analysis. The results showed that short CAG repeats (<22 repeats) carriers presented an elevated risk of prostate cancer than long CAG repeats (≥22) carriers (OR = 1.31, 95% CI 1.16 to 1.47). Prostate cancer cases presented an average fewer CAG repeats (MD = −0.85, 95% CI −1.28 to −0.42) than controls. Short GGN repeats (≤16) carriers presented an increased risk of prostate cancer than long GGN repeats (>16) carriers (OR = 1.38, 95% CI 1.05 to 1.82). In subgroup analyses, the abovementioned significant association was predominantly observed in Caucasian populations. The meta-analysis showed that short CAG and GGN repeats in androgen receptor gene were associated with increased risk of prostate cancer, especially in Caucasians.