Cyclin D1 G870A Polymorphism and Risk of Nasopharyngeal Carcinoma: A Case-Control Study and Meta-Analysis

Background

Cyclin D1 (CCND1) plays a key role in cell cycle regulation. It is a well-established human oncogene which is frequently amplified or overexpressed in cancers. The association between CCND1 G870A polymorphism and cancer risk has been widely assessed. However, a definitive conclusion between CCND1 G870A polymorphism and risk of nasopharyngeal carcinoma (NPC) remains elusive.

Methods

We firstly performed a hospital-based case-control study involving 165 NPC cases and 191 cancer-free controls in central-south China, and then conducted a meta-analysis with six case-control studies to evaluate the association between NPC risk and CCND1 G870A polymorphism.

Results

The case-control study found a significant association between CCND1 G870A polymorphism and NPC risk in various comparison models (AA vs. GG: OR = 2.300, 95% CI 1.089–4.857, p = 0.029; AG vs. GG: OR = 2.832, 95% CI 1.367–5.867, p = 0.005; AA/AG vs. GG: OR = 2.597, 95% CI 1.288–5.237, p = 0.008; AA vs. AG/GG: OR = 0.984, 95% CI 0.638–1.518, p = 0.944). Further meta-analysis showed that there was no significant association between CCND1 G870A polymorphism and NPC risk in overall analysis. In the stratified analysis by race, however, significant associations were only found in Caucasians (for the allele model A vs. G: OR = 0.75, 95% CI 0.59–0.97, p = 0.03; for the co-dominant model AA vs. GG: OR = 0.52, 95% CI 0.32–0.86, p = 0.01; for the dominant model AA/AG vs. GG: OR = 0.49, 95% CI 0.32–0.74, p<0.01; for the recessive model AA vs. AG/GG: OR = 0.90, 95% CI 0.61–1.34, p = 0.60).

Conclusions

A significant association between CCND1 G870A polymorphism and NPC risk was found in the central-southern Chinese population. The meta-analysis indicated that CCND1 G870A polymorphism may contribute to the development of NPC in Caucasians.     

Cyclin D1 (CCND1) G870A gene polymorphism is an ethnicity-dependent risk factor for digestive tract cancers: a meta-analysis comprising 20,271 subjects

Published data on the association between Cyclin D1 (CCND1) G870A gene polymorphism and digestive tract cancers (DTC) are inconclusive. We carried out a meta-analysis of published case-control studies to derive a more precise estimation of the association. Relevant studies were identified from PubMed, EMBASE, and China National Knowledge Infrastructure up to February 1st, 2011. Crude odds ratios (OR) and 95% confidence intervals (CI) were used to investigate the strength of the association. Data were available from a total of 33 case-control studies with 8534 cases and 11,737 controls. The combined results based on all studies showed that there was a statistically significant link between CCND1 G870A polymorphism and DTC risk (GG vs. AA: OR=0.83, 95%CI=0.71-0.96). In the analysis of ethnic groups, we found the A allele carriers had a significantly increased DTC susceptibility among Caucasians, but not among Asians. When stratified for tumor location, the results based on all studies only showed the variant allele 870A might have a significantly increased risk of colorectal cancer (CRC), especially of rectal cancer (GG vs. AA: OR=0.71, 95%CI=0.58-0.89). When stratifying by the stage and histological differentiation of CRC, we only observed that patients had a significantly higher frequency of CCND1 870 AA than non-cancer patients among Caucasians. The A allele carriers (hetero- or homozygotes) were significantly more common in cases with a family history of CRC than in controls. There was no evidence of publication bias for CCND1 G870A polymorphism with DTC risk. In summary, this meta-analysis demonstrates that the CCND1 G870A polymorphism may be an ethnicity-dependent risk factor for DTC. And this genetic variant may increase the risk of rectal cancer, but not colon cancer.     

Potential role of CCND1 G870A genotype as a predictor for urothelial carcinoma susceptibility and muscle-invasiveness in Taiwan

The cell cycle regulator cyclin D1 (CCND1) is thought to play a major role in the transition of cell cycle from G1 to S phase. It is known that a common CCND1 G870A genotype is associated with bladder cancer in Japan and China, but not in the Western World. There is neither a report about its role in Taiwan's population, nor its genetic role of CCND1 G870A in another worldwide urothelial cancer, upper tract urothelial cancer (UTUC). Therefore, we aimed at investigating the role of CCND1 G870A in both bladder cancer and UTUC in Taiwanese cohorts. The CCND1 G870A genotypes of 171 (101 bladder cancer and 70 UTUC) patients and 243 control subjects were determined by PCR-RFLP and their correlation with clinical and histopathological data was evaluated. The genotype analysis results showed that CCND1 GG genotype was associated with a lower risk overall in urothelial (P = 0.008, OR = 0.44, 95% CI = 0.24-0.81) and bladder cancer patients (P = 0.008, OR = 0.34, 95% CI = 0.15-0.76) than those of the AA genotype. In addition, patients carrying the AG genotype had a 0.29-fold lower odds ratio of muscle-invasive cancer procession (95% CI = 0.12-0.70) compared with those carrying the AA genotype in bladder cancer patients. Surprisingly, the GG genotype had a 5.88-fold higher odds ratio of muscle-invasive cancer procession (95% CI = 1.08-32.01) compared with those carrying the AA genotype in UTUC. No association between any CCND1 G870A genotype and higher-grade risk was found. Our results suggest that the G allele of the CCND1 G870A polymorphism may be a potential predictive and prognostic biomarker to distinguish between bladder cancer and UTUC in Taiwan.     

CCND1 G870A polymorphism interaction with cigarette smoking increases lung cancer risk: meta-analyses based on 5008 cases and 5214 controls

Evidence indicates CCND1 G870A polymorphisms as a risk factor for a number of cancers. Increasing studies have been conducted on the association of CCND1 G870A polymorphism with lung cancer risk. However, the results were controversial. The aim of the present study was to derive a more precise estimation of the relationship. Meta-analyses examining the association between CCND1 G870A polymorphism and lung cancer were performed. Subgroup analyses regarding ethnicity, smoking status, histological types and source of controls were also implemented. All eligible studies for the period up to May 2012 were identified. The overall data from ten case–control studies including 5,008 cases and 5,214 controls indicated that variant A allele may have an association with increased lung cancer risk (AA vs GG: OR = 1.21; 95 % CI = 1.08–1.36, dominant model: OR = 1.09; 95 % CI = 1.00–1.19, recessive model: OR = 1.23; 95 % CI = 1.01–1.49). In the subgroup analysis by ethnicity, A allele may elevate lung cancer risk among Asians but not Caucasians or Mixed ethnicities. In smoking status subgroup, A allele was shown to associate with increased lung cancer risk among smokers but not non-smokers. In the subgroup analysis by histological types, increased cancer risks were shown in adenocarcinoma but not squamous cell carcinoma, under the homozygote comparison and recessive models. Collectively, the results of the present study suggest that CCND1 G870A polymorphism might be a low-penetrant risk factor for lung cancer, particularly among Asians and smokers. Moreover, homozygous AA alleles might have a correlation with increased lung adenocarcinoma susceptibility.     

Cyclin D1 G870A polymorphism is associated with an increased risk of hepatocellular carcinoma in the Turkish population: Case–control study

Background: A common G to A polymorphism (G870A) in the splice donor region of exon 4 of cyclin D1 (CCND1) gene generates two mRNAs (cyclin D1a and D1b) through an alternative splicing at the site of this polymorphism. Cyclin D1a and b proteins differ in their COOH-terminus, a region involved in protein degradation. We examined the association between this CCDN1 genotype and the susceptibility to hepatocellular carcinoma (HCC) in a Turkish population. Methods: The genotype frequency of this polymorphism was determined by using a polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) assay. Hospital-based case–control study was designed consisting of 160 diagnosis subjects with hepatocellular carcinoma and 160 cancer-free control subjects matched on age, gender, smoking and alcohol status. Results: The allele frequencies of case subjects (A, 0.55; G, 0.45) were significantly different from those of control subjects (A, 0.42; G, 0.58) (p = 0.002). The odds ratios (ORs) for the CCND1 870 GA and AA genotypes when compared with the GG genotypes were 1.39 (95% confidence interval [CI] 0.82–2.36, p = 0.22) and 2.52 (95% CI 1.38–4.62, p = 0.003) respectively. The presence of at least one CCND1 870A allele was associated with increased risk for HCC (OR, 1.73; 95% CI, 1.06–2.82, p = 0.03). When combining the GG and GA genotypes as a reference genotype, we found that the OR for the AA genotype was 2.06 (95% CI 1.24–3.44, p = 0.006). Conclusion: Our results suggest that the CCND1 G870A single nucleotide polymorphism is associated with an increased risk of HCC in our Turkish population.     

Cyclin D1 G870A polymorphism and breast cancer risk: a meta-analysis comprising 9,911 cases and 11,171 controls

Cyclin D1 represents a key molecule in the regulation of cell cycle. CCND1 G870A (rs603965) polymorphism has drawn considerable attention as the A allele may generate a variant splice product with possible oncogenic actions. A meta-analysis examining the association between CCND1 G870A polymorphism and breast cancer risk was performed. Separate analyses on Caucasian and Chinese populations were also implemented. Eligible articles were identified for the period up to July 2010. Pooled odds ratios (OR) were appropriately derived from fixed-effects or random-effects models. Sensitivity analysis excluding studies whose genotype frequencies in controls significantly deviated from Hardy–Weinberg Equilibrium (HWE) was performed. Nine case–control studies on Caucasians (7,304 cases and 8,149 controls) and four case–control studies on Chinese (2,607 cases and 3,022 controls) were eligible. At the overall analysis the A allele seemed to be associated with elevated breast cancer risk; the effect seemed to be confined to homozygous carriers (pooled OR = 1.091, 95% CI: 1.008–1.179, P = 0.030, fixed effects) as heterozygous carriers did not exhibit significantly elevated breast cancer risk. No statistically significant associations were demonstrated in Caucasians. On the other hand, Chinese AA carriers exhibited marginally elevated breast cancer risk (pooled OR = 1.144, 95% CI: 0.984–1.329, P = 0.080, fixed effects). Nevertheless, the controls in two out of the four Chinese studies deviated from HWE. In conclusion, this meta-analysis suggests that the A allele of the CCND1 G870A polymorphism may confer additional breast cancer risk when it comes to homozygosity and Chinese populations. The need for additional, methodologically sound studies on Chinese populations seems warranted.     

Influence of cyclin D1 splicing variants expression on breast cancer chemoresistance via CDK4/CyclinD1-pRB-E2F1 pathway

Cyclin D1 (CCND1), a mediator of cell cycle control, has a G870A polymorphism which results in the formation of two splicing variants: full-length CCND1 (CCND1a) and C-terminally truncated CCND1 species (CCND1b). However, the role of CCND1a and CCND1b variants in cancer chemoresistance remains unknown. Therefore, this study aimed to explore the molecular mechanism of alternative splicing of CCND1 in breast cancer (BC) chemoresistance. To address the contribution of G870A polymorphism to the production of CCND1 variants in BC chemoresistance, we sequenced the G870A polymorphism and analysed the expressions of CCND1a and CCND1b in MCF-7 and MCF-7/ADM cells. In comparison with MCF-7 cells, MCF-7/ADM cells with the A allele could enhance alternative splicing with the increase of SC-35, upregulate the ratio of CCND1b/a at both mRNA and protein levels, and activate the CDK4/CyclinD1-pRB-E2F1 pathway. Furthermore, CCND1b expression and the downstream signalling pathway were analysed through Western blotting and cell cycle in MCF-7/ADM cells with knockdown of CCND1b. Knockdown of CCND1b downregulated the ratio of CCND1b/a, demoted cell proliferation, decelerated cell cycle progression, inhibited the CDK4/CyclinD1-pRB-E2F1 pathway and thereby decreased the chemoresistance of MCF-7/ADM cells. Finally, CCND1 G870A polymorphism, the alternative splicing of CCDN1 was detected through Sequenom Mass ARRAY platform, Sanger sequencing, semi-quantitative RT-PCR, Western blotting and immunohistochemistry in clinical BC specimens. The increase of the ratio of CCND1b/a caused by G870A polymorphism was involved in BC chemoresistance. Thus, these findings revealed that CCND1b/a ratio caused by the polymorphism is involved in BC chemoresistance via CDK4/CyclinD1-pRB-E2F1 pathway.     

Cyclin D1 splice variant and risk for non-Hodgkin lymphoma

To investigate the role of cell cycle gene variations in lymphomagenesis, we evaluated associations (odds ratios [OR] and 95% confidence intervals [CI]) in polymorphisms from seven candidate genes in 1,172 non-Hodgkin lymphoma (NHL) cases and 982 population-based controls. The cyclin D1 (CCND1) splice variant G870A (rs603965) increased NHL risk (OR_AA = 1.4, 95% CI = 1.1–1.8, P-trend = 0.021), which was consistent for four B-cell subtypes. As CCND1 expression indicates poor NHL prognosis, our results, if true, would support its potentially dual importance in NHL etiology and survival.Electronic Supplementary Material Supplementary material is available to authorised users in the online version of this article at .     

Genetic association between IL-27 rs153109 polymorphism and cancer risk in Chinese population: a meta-analysis

IL-27 plays an important role in anti-cancer activity. The -964A/G polymorphism in IL-27 gene has been implicated in susceptibility to cancer, but the results were conflicting. The aim of this study was to assess the association between this polymorphism and cancer risk. Pubmed and Wanfang database were searched for all publications concerning IL-27 -964A/G polymorphism and cancer risk. Odds ratio (OR) and 95% confidence interval (CI) were used to assess the strength of association. Statistical analysis was performed using Stata 11.0 software. A total of eight case–control studies including 2044 cancer cases and 2197 controls were identified. Overall, significant association between IL-27 -964A/G polymorphism and cancer risk was observed (GG versus AA: OR?=?1.26, 95% CI?=?1.03–1.52; GG versus AG?+?AA: OR?=?1.20, 95% CI?=?1.00–1.44). In subgroup analysis based on cancer type, significant association was found in colorectal cancer (GG versus AA: OR?=?1.55, 95% CI?=?1.07–2.27; AG versus AA: OR?=?1.31, 95% CI?=?1.02–1.67). The current meta-analysis suggests that IL-27 -964A/G polymorphism might enhance cancer risk. However, large-scale and well-designed studies are still needed to confirm the result of our meta-analysis. The association of IL-27 polymorphism with colorectal cancer may provide insight for future therapies.     

Lung cancer risk in north Indian population: role of genetic polymorphisms and smoking

Lung cancer (LC) is the leading cause of cancer-related mortality in developing as well as developed countries. Life style choices, particularly tobacco smoking, have been implicated as the main cause in the development of the LC. Despite the fact that majority cases of the LC occur among smokers, only 1–15% of smokers develop LC. In the present study, we have explored the role of genetic polymorphism, smoking habit and their association to LC in a cohort of north Indian population. The polymorphic genes explored were CYP1A1, GSTM1, GSTP1 and GSTT1 using techniques of Polymerase chain reaction (PCR), Restriction Fragment Length Polymorphism (RFLP), Real Time PCR (RT PCR), and gene sequencing. Genetic polymorphism was analysed in 253 normal participants (control) and 93 LC patients originating from Lucknow, India. Data were compared using odds ratio and Fisher Exact Test. We found that smoking increases the susceptibility to LC threefold (OR = 2.9; 95% CI: 0.9–2.8). The most significant risk for LC (OR = 3.2; 95% CI: 0.7–3.8) was found in the association of the homozygous variant of CYP1A1 gene at A2455G base change at Exon 7 (Val/Val) genotype. There was a marginally significant association between LC and GSTT1 null genotype (OR = 1.3; 95% CI: 1.0–1.7) while no significant risk association was found between GSTP1 polymorphism and LC. The present study demonstrates that the presence of null genotype of GSTM1/GSTT1 taken together with CYP1A1 (Val/Val) genotype increases the susceptibility to LC eightfold in comparison to CYP1A1 (Ile/Ile) and GSTM1/ GSTT1 genotype.     

Current evidence on the relationship between CYP1B1 polymorphisms and lung cancer risk: a meta-analysis

The association between single-nucleotide polymorphisms (SNPs) of the CYP1B1 gene and lung cancer risk is still ambiguous. In this meta analysis, we assessed 10 case–control studies included 7,067 cases and 9,374 controls of the association between CYP1B1 SNPs of Leu432Val (rs1056836, 432C>G), Asn453Ser (rs1800440, 453A>G), Ala119Ser (rs1056827, 119G>T), Arg48Gly (rs10012, 48C>G) and the risk of lung cancer. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the strength of association between the polymorphism and lung cancer risk under codominant model, dominant model and additive model respectively. Although there were limitations, this meta analysis indicated that individuals with 432GG genotype had a 39.7% higher risk of having lung cancer than those with the 432CC genotype, and individuals with the 432G allele had a 26.3% increased risk as well. An increased risk of lung cancer of 2.13 fold was observed in individuals with 119TT genotype. For Arg48Gly, individuals with 48GG genotype had a significantly increased risk of lung cancer compared with individuals with 48CC (OR 3.859; 95% CI 2.536–5.87). Elevated risk of lung cancer were observed in dominant model (OR 2.115; 95% CI 1.653–2.705) as well. The risk of lung cancer was elevated as the frequency of G allele increased in additive model (P = 0.000). For individuals with the polymorphism at codon 453, no evidence of such association was observed. Furthermore, a possible association between the CYP1B1 polymorphism at codon 432 and the lung cancer could be detected in individuals of Caucasian origin, while a negative association was suggested in Asians and African-Americans. An increased lung cancer risk was also found in women with polymorphism at codon 453. These results are supportive for the hypothesis that the CYP1B1 432GG, 119TT and 48GG genotypes are low-penetrance risk factors for developing lung cancer, and further studies are needed to validate these associations.     

Susceptibility of XPD and RAD51 genetic variants to carcinoma of urinary bladder in North Indian population

For the present study, two polymorphisms, xeroderma pigmentosum, complementation group D (XPD) Lys751Gln and RAD51 135G/C were studied with regard to bladder cancer. For XPD Lys751Gln polymorphism, an increased risk of bladder cancer was found to be associated with the Gln variant allele (odds ratio [OR]=1.86, 95% confidence interval [CI]=1.27-2.73), on taking AA (Lys/Lys) as the referent genotype. In males, the XPD 751C (Gln) allele was found to be associated with a significantly increased risk (OR=2.33, 95% CI=1.52-3.56). The inhabitants of rural areas showed a significantly increased risk with the XPD Gln allele (OR=2.59, 95% CI=1.46-4.62) when compared with those of urban areas. In smokers (OR=5.30, 95% CI=2.42-11.68), alcohol drinkers (OR=4.33, 95% CI=2.17-8.70), and nonvegetarians (OR=2.21, 95% CI=1.26-3.87), the XPD Gln allele showed a significantly increased risk toward bladder cancer. For RAD51 135G/C polymorphism, no significant difference was observed in the allelic and genotypic frequencies. Even after stratification, no significant association could be seen. After stratifying histopathologically, the RAD51 CC genotype was associted with decreased risk in subjects having superficial stage (OR=0.51, 95% CI=0.27-0.99) and with those having G2 grade (OR=0.24, 95% CI=0.09-0.62) of bladder cancer. XPD polymorphism may be a predisposing factor, but the same cannot be said for RAD51 gene polymorphism.     

KCNQ1 rs2237892 C→T gene polymorphism and type 2 diabetes mellitus in the Asian population: a meta‐analysis of 15,736 patients

The KCNQ1 rs2237892 C→T gene polymorphism is reportedly associated with T2DM susceptibility, but various studies show conflicting results. To explore this association in the Asian population, a meta‐analysis of 15,736 patients from 10 individual studies was performed. The pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were evaluated using random‐effect or fixed‐effect models. A significant relationship between the KCNQ1 rs2237892 C→T gene polymorphism and T2DM was observed in the Asian population under the allelic (OR, 1.350; 95% CI, 1.240–1.480; P < 0.00001), recessive (OR: 0.650; 95% CI: 0.570–0.730; P < 0.00001), dominant (OR: 1.450; 95% CI: 1.286–1.634; P < 0.00001), and additive (OR: 1.346; 95% CI: 1.275–1.422; P < 0.00001) genetic models. In the subgroup analysis by race, a significant association was found in Chinese, Korean and Malaysia population, but not in Indian population. KCNQ1 rs2237892 C→T gene polymorphism was found to be significantly associated with increased T2DM risk in the Asian population, except Indian population. The C allele of the KCNQ1 rs2237892 C→T gene polymorphism may confer susceptibility to T2DM.     

DNA methylation and breast tumor clinicopathological features: The Western New York Exposures and Breast Cancer (WEB) study

We evaluated the association between methylation of 9 genes, SCGB3A1, GSTP1, RARB, SYK, FHIT, CDKN2A, CCND2, BRCA1, and SFN in tumor samples from 720 breast cancer cases with clinicopathological features of the tumors and survival. Logistic regression was used to estimate odds ratios (OR) of methylation and Cox proportional hazards models to estimate hazard ratios (HR) between methylation and breast cancer related mortality. Estrogen receptor (ER) and progesterone receptor (PR) positivity were associated with increased SCGB3A1 methylation among pre- and post-menopausal cases. Among premenopausal women, compared with Stage 0 cases, cases of invasive cancer were more likely to have increased methylation of RARB (Stage I OR = 4.7, 95% CI: 1.1–19.0; Stage IIA/IIB OR = 9.7, 95% CI: 2.4–39.9; Stage III/IV OR = 5.6, 95% CI: 1.1–29.4) and lower methylation of FHIT (Stage I OR = 0.2, 95% CI: 0.1–0.9; Stage IIA/IIB OR = 0.2, 95% CI: 0.1–0.8; Stage III/IV OR = 0.6, 95% CI: 0.1–3.4). Among postmenopausal women, methylation of SYK was associated with increased tumor size (OR = 1.7, 95% CI: 1.0–2.7) and higher nuclear grade (OR = 2.0, 95% CI 1.2–3.6). Associations between methylation and breast cancer related mortality were observed among pre- but not post-menopausal women. Methylation of SCGB3A1 was associated with reduced risk of death from breast cancer (HR = 0.41, 95% CI: 0.17–0.99) as was BRCA1 (HR = 0.41, 95% CI: 0.16–0.97). CCND2 methylation was associated with increased risk of breast cancer mortality (HR = 3.4, 95% CI: 1.1–10.5). We observed differences in methylation associated with tumor characteristics; methylation of these genes was also associated with breast cancer survival among premenopausal cases. Understanding of the associations of DNA methylation with other clinicopathological features may have implications for prevention and treatment.     

Role of OGG1 Ser326Cys polymorphism and 8-oxoguanine DNA damage in risk assessment of squamous cell carcinoma of head and neck in North Indian population

Squamous cell carcinoma of head and neck (SCCHN), one of the leading cancers worldwide, is most prevalent in Indian sub-continent. The major risk factors involved are smoking and consumption of alcohol, since they provide high free radical generating environment. We studied 8-oxoguanine DNA-glycosylase (OGG1) Ser326Cys polymorphism in 278 SCCHN cases and 278 matched controls by PCR-RFLP and observed that the variant genotype Ser/Cys exhibited an enhanced risk of ～1.7 folds (OR=1.71, 95% CI=1.20-2.93) and Cys/Cys ～2.5 folds (OR=2.55, 95% CI=1.29-5.00). Furthermore, we found a significant increase in salivary cell 8-OHdG with respect to Ser/Cys and Cys/Cys genotypes of OGG1 in SCCHN cases, when compared to Ser/Ser and Ser/Cys genotypes of the control population. Our results demonstrate that Ser326Cys variant genotype is associated with an increased risk of SCCHN in north India. Ser326Cys variant genotype was found to accumulate more of 8-OHdG, which may serve as a biomarker for early diagnosis of SCCHN.     

Impact of glutathione transferase M1, T1, and P1 gene polymorphisms in the genetic susceptibility of North Indian population to renal cell carcinoma

In this study, we investigated the association of GSTP1, GSTM1, and GSTP1 genetic variants with renal cell carcinoma (RCC) among North Indian patients. The difference in frequency of the GSTT1 null genotype between cases and control subjects was statistically significant (active ver. null, odds ratio [OR]=0.368; confidence intervals [CI] 95%=0.243-0.557, p=0.001). The differences in the frequency of GSTP1 genotypes were statistically significant (AA ver. AG/GG, OR=1.879; CI 95%=0.355-0.797, p=0.002). Higher allelic frequency of the GSTP1 G allele was associated with RCC cases (G ver. A allele, OR=1.534; 95% CI=1.159-2.030, p=0.003). The gene-gene interaction in terms of three-way combination of GSTM1 null, GSTT1 null, and GSTP1 (AG/GG) resulted in 4.5-fold increase in RCC risk (OR=4.452; 95% CI=2.220-9.294). Similarly, our study revealed that GST polymorphism might be a vital determinant of advancement to higher pathological stages and histological grades of RCC. Our findings suggest that genetic variability in members of the GST gene family may be associated with an increased susceptibility to RCC and its progression.     

Effect of cycline D1 (CCND1) gene polymorphism on tumor formation and behavior in patients with prolactinoma

The objective of this study was to investigate the effect of G870A gene polymorphism of CCND1 on the formation and behavioral features of prolactinomas. One hundred and thirteen patients with prolactinoma and 108 age and gender matched control were included in the study. The patients were divided into two groups as noninvasive and invasive tumors. CCND1 G870A gene polymorphism was compared in patients/control and invasive/noninvasive groups. A and G allele frequencies were found as 41.7% and 58.3% in the controls, and 61.1% and 38.9% in the patients (p<0.01). Rates of G/G, G/A and A/A genotypes were found as 11.8%, 55.9% and 32.4% in the noninvasive group, and 15.6%, 44.4% and 40.0% in the invasive group, respectively. Differences between patient and control groups were significant but were not between invasive and noninvasive groups in terms of the allele frequencies and genotype distribution. Mean tumor size and serum levels of prolactin at the time of diagnosis and change in these values after the treatment were not found statistically significant in genotype subgroups. CCND1 G870A gene polymorphism may be an important factor in the early stages of the tumor formation. However, it did not affect the features of the tumor.     

Interleukin-12B rs3212227 polymorphism and cancer risk: a meta-analysis

IL-12 plays a very important role in the development and progress of cancer. IL-12B rs3212227 polymorphism has been reported and many studies have focused on the role of this polymorphism in various cancers. However, the association between IL-12B rs3212227 polymorphism and cancer risk remains controversial. Therefore, we performed a systematic meta-analysis to estimate the overall cancer risk associated with this gene polymorphism and to quantify any potential between-study heterogeneity. PubMed and Embase databases were searched for case–control studies published up to April 1, 2012 that investigated IL-12B rs3212227 polymorphism and cancer risk. Odds ratios (OR) with 95?% confidence intervals (95?% CI) were used to access the strength of this association. Heterogeneity among articles and publication bias were also verified. Ten studies with 2,954 cancer patients and 3,276 healthy controls were included. This meta-analysis showed that there was a significant association between IL-12B rs3212227 polymorphism and overall cancer risk (CC/AC vs AA: OR?=?1.32, 95?% CI?=?1.06–1.63). When stratified by cancer type, we found a significant increased risk in cervical and nasopharyngeal cancer (OR?=?1.34, 95?% CI?=?1.04–1.73; OR?=?2.03, 95?% CI?=?1.57–2.63, respectively). In the stratified analysis, we also observed a similar association in population-based studies (OR?=?1.34, 95?% CI?=?1.00–1.80), Asian populations (OR?=?1.33, 95 % CI?=?1.06–1.67) and European populations (OR?=?1.54, 95 % CI?=?1.04–2.28). According to the results of our meta-analysis, IL-12B rs3212227 polymorphism probably is associated with a high risk of cancer.     

SULT1A1 Arg213His polymorphism, smoked meat, and breast cancer risk: a case-control study and meta-analysis

SULT1A1 is involved in both detoxification of estrogens and bioactivation of carcinogens in smoked meat. SULT1A1 Arg213His polymorphism's effect on breast cancer risk is still unclear. We recruited 400 case-control pairs to investigate the association between SULT1A1 genotypes and breast cancer risk, and the combined effect of SULT1A1 polymorphism and daily intake of smoked meat. Participants were questioned about their dietary habits and other risk factors, and their SULT1A1 genotypes were determined. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were estimated by multivariable unconditional logistic regression. We also performed a meta-analysis of relevant published studies to test these associations. In the case-control study, no significant associations were observed between SULT1A1 polymorphism and breast cancer risk. In the meta-analysis, SULT1A1 His/His genotype slightly increased risk among both overall and postmenopausal women (OR(pooled-overall)=1.12, 95% CI: 1.02-1.24; OR(pooled-post)=1.17, 95% CI: 1.03-1.32). A larger positive association was observed in Asian populations (OR(pooled-Asian)=2.01, 95% CI: 1.24-3.26). In our case-control study, high energy-adjusted daily intake of smoked meat was significantly associated with breast cancer risk in overall, pre- and postmenopausal women (aORs: 2.31-3.13, OR 95% CIs exclude 1). High smoked meat intake interacted positively with the His variant allele (all γ>1). These results correlated with those of the meta-analysis (γ(pooled-overall)=1.27). The SULT1A1 His/His genotype may increase the risk of breast cancer among Asian women, and dietary exposure to heterocyclic amines and polycyclic aromatic hydrocarbons, along with the SULT1A1 His/His variant genotype, may synergistically increase the risk of breast cancer.