Genetic polymorphisms of FAS and FASL (CD95/CD95L) genes in cervical carcinogenesis: An analysis of haplotype and gene-gene interaction

Prioritization and Meta-analysis of regulatory SNPs identified IL6, TGFB1, TLR9 and MMP7 as significantly associated with cervical cancer

Cervical cancer is a leading women cancer globally with respect to both incidence and mortality. Its increased risk has been linked with HPV infection and genetic variations like single nucleotide polymorphisms (SNPs). Although, studies have been published which evaluates the effect of SNPs in a few candidate genes, however the role of number of regulatory SNPs (rSNPs) in cervical cancer is not available. As literature evidence has shown that non-coding rSNPs are related with increasing cervical cancer risk, we undertook this study to prioritize the important rSNPs and elucidate their role. A search was conducted in PubMed up to December 2020, which led to the identification of 263 articles and 969 SNPs in the non-coding region. These 969 SNPs were analysed through rSNPBase and RegulomeDB, leading to identification of 105 rSNPs. Afterwards, a regulatory module was constructed using protein-protein interaction data and a hub of highly interacting 23 target genes (corresponding to 34 rSNPs) was identified using MCODE. To further understand the mechanism of action of the 34 rSNPs, their transcription factor information with respect to cervical cancer was retrieved. To evaluate the pooled effect of these prioritized polymorphisms in cervical cancer patients, a meta-analysis was performed on 10,537 cases and 11,252 controls from 30 studies corresponding to 8 rSNPs. It led to identification of polymorphisms in IL6 (rs2069837), TGFB1 (rs1800469), TLR9 (rs187084) and MMP7 (rs11568818) which are significantly (p < 0.05) associated with increased cervical cancer risk at the population level. Overall, the study demonstrates that rSNPs targeting immune and inflammatory genes (IL1B, IL6, IL10, IL18, TGFB1, CCR5, CD40, TLR9, and MMP7) are associated with cervical cancer.

Genomic variants in Fas-mediated apoptosis pathway predict a poor response to Platinum-based Chemotherapy for Chinese Gastric Cancer Patients

Platinum-based adjuvant chemotherapy is very common for gastric cancer (GC) patients, but the chemotherapy sensitivity is very heterogeneous. The genomic variants and the gene-gene interactions involved in Fas-mediated apoptosis pathway including Fas (FAS 1377 G > A and 670 A > G), FasL (FASL 844 C > T) and caspase-8 (CASP8 -652 6N ins > del or I > D), may paly vital roles in the response to platinum-based treatment. In our investigation, 662 stage II-III postoperative GC patients were enrolled between 1998 and 2006. 261 patients accepted platinum-based regimens and the remaining 401 were not. The log rank tests, Kaplan Meier plots, Pearson chi-square tests, Student t-tests and Cox regression analyses were performed. For the chemotherapy cohort, FAS 1377 G > A or FAS 670 A > G variants alone was related with inferior survival, and a greater than additive effect was identified when patients simultaneously carrying FAS 1377 GA and FAS 670 GA genotypes. But the poor response was neutralized when patients simultaneously carrying FASL 844 C > T or CASP8 -652 6N ins > del mutations. Our study suggested that FAS 1377 G > A and FAS 670 A > G variants may serve as potential biomarkers to predict the response to platinum-based adjuvant chemotherapy, and the gene-gene interactions involved in Fas-mediated apoptosis pathway may enhance or neutralize the chemosensitivity.

Genetic Susceptibility for Cervical Cancer in African Populations: What Are the Host Genetic Drivers?

Human papillomavirus (HPV) is an essential but not a sufficient cervical cancer etiological factor. Cancer promoters, such as host genetic mutations, significantly modulate therapeutic responses and susceptibility. In cervical cancer, of interest have been viral clearing genes and HPV oncoprotein targets, for which conflicting data have been reported among different populations. This expert analysis evaluates cervical cancer genetic susceptibility biomarkers studied in African populations. Notably, the past decade has seen Africa as a hotbed of biomarker and precision medicine innovations, thus potentially informing worldwide biomarker development strategies. We conducted a critical literature search in PubMed/MEDLINE, Google Scholar, and Scopus databases for case-control studies reporting on cervical cancer genetic polymorphisms among Africans. We found that seven African countries conducted cervical cancer molecular epidemiology studies in one of Casp8, p53, CCR2, FASL, HLA, IL10, TGF-beta, and TNF-alpha genes. This analysis reveals a remarkable gap in cervical cancer molecular epidemiology among Africans, whereas cervical cancer continues to disproportionately have an impact on African populations. Genome-wide association, whole exome- and whole-genome sequencing studies confirmed the contribution of candidate genes in cervical cancer. With such advances and omics technologies, the role of genetic susceptibility biomarkers can be exploited to develop novel interventions to improve current screening, diagnostic and prognostic methods worldwide. Exploring these genetic variations is crucial because African populations are genetically diverse and some variants or their combined effects are yet to be discovered and translated into tangible clinical applications. Thus, translational medicine and flourishing system sciences in Africa warrant further emphasis in the coming decade.

Genetic variations in the SULF1 gene alter the risk of cervical cancer and precancerous lesions

Human papillomavirus (HPV) infection alone is not sufficient to explain the development of cervical cancer. Genetic variants have been linked to the development of precancerous lesions and cervical cancer. In this study, we aimed to evaluate the association of 10 single nucleotide polymorphisms (SNPs) of the Fas cell surface death receptor (FAS), trinucleotide repeat containing 6C (TNRC6C), transmembrane channel like 8 (TMC8), DNA meiotic recombinase 1 (DMC1), deoxyuridine triphosphatase (DUT), sulfatase 1 (SULF1), 2′-5-oligoadenylate synthetase 3 (OAS3), general transcription factor IIH subunit 4 (GTF2H4) and interferon gamma (IFNG) genes with susceptibility to precancerous lesions and cervical cancer. In total, 608 female participants, consisting of 199 patients with persistent low-grade precancerous lesions (CIN1), 100 with high-grade precancerous lesions (CIN2/3), 17 patients with cervical cancer and 292 healthy controls, were enrolled in this study. SNPs were tested for associations with each of the above-mentioned cervical group lesions or when considering an overall patient group. A significant difference for rs4737999 was observed between the controls and the overall patient group considering the recessive mode of inheritance [odds ratio (OR), 0.48; 95% confidence interval (CI), 0.24–0.96; P=0.033]. This effect was even stronger on the risk of CIN1 lesions. Carriers of the rs4737999 AA genotype were almost 3-fold less likely of having low grade lesions compared to the other genotypes. On the whole, this study provides evidence of an influence of the SULF1 gene rs4737999 SNP in the development of precancerous lesions/cervical cancer.

Genetic Polymorphisms of Fas/FasL Promoter Associated with Hepatitis C cirrhosis and HCC

Aim:

The present study was performed to determine any associations of genetic polymorphisms of Fas/FasL promoter regions, at Fas670 and Fas1377 and FasL844, with hepatitis C cirrhosis and HCC, with a focus on severity of disease.

Methods:

Totals of 120 patients with cirrhosis and 101 with hepatocellular carcinoma (HCC) were enrolled. All had chronic HCV infection as indicated by positive anti-HCV antibodies and positive HCV RNA on real time PCR. One hundred healthy control subjects were also included in the study. Patients were subjected to full clinical, radiological and histopathological examinations. In addition to routine laboratory tests for liver function tests, Fas670 and Fas1377 and FasL844 genetic polymorphisms of Fas/FasL promoter regions were assessed by RFLP-PCR (restriction fragment length polymorphism with polymerase chain reaction).

Results:

Significant higher levels of the AG genotype in Fas670 and Fas1773 were observed in patients with cirrhosis and HCC (P=0.0001) as compared to control subjects. In addition, the CC genotype in FASL844 was also more common in patients (P=0.01). Furtehrmore, there was a significant association of substitution of A by G alleles in Fas670 and Fas1773 with advanced BCA staging (P=0.02, P=0.0001 respectively) and larger tumor size >5cm (P=0.01, P=0.0001 respectively) and in Fas670 with advanced pathological grading (P=0.0001). Moreover the CC genotype of FASL844 was significantly linked with advanced BCA, large tumor size >5cm and advanced pathological grading (P=0.0001).

Conclusion:

The findings of the present study highlight associations of genetic polymorphisms of promoter regions in Fas and Fas L with cirrhosis and HCC associated with chronic HCV. Support was also obtained for the conclusion that single nucleotide polymorphisms of the Fas/ FasL system impact on clinical and histopathological grading of HCCs. Further large scale studies are recommended for confirmation.

Cervical Carcinogenesis and Immune Response Gene Polymorphisms: A Review

The local immune response is considered a key determinant in cervical carcinogenesis after persistent infection with oncogenic, high-risk human papillomavirus (HPV) infections. Genetic variation in various immune response genes has been shown to influence risk of developing cervical cancer, as well as progression and survival among cervical cancer patients. We reviewed the literature on associations of immunogenetic single nucleotide polymorphism, allele, genotype, and haplotype distributions with risk and progression of cervical cancer. Studies on HLA and KIR gene polymorphisms were excluded due to the abundance on literature on that subject. We show that multiple genes and loci are associated with variation in risk of cervical cancer. Rather than one single gene being responsible for cervical carcinogenesis, we postulate that variations in the different immune response genes lead to subtle differences in the effectiveness of the antiviral and antitumour immune responses, ultimately leading to differences in risk of developing cervical cancer and progressive disease after HPV infection.

Genetic polymorphisms of FAS and EVER genes in a Greek population and their susceptibility to cervical cancer: a case control study

BACKGROUND

The aim of the study was to evaluate the association of two SNPs of EVER1/2 genes' region (rs2290907, rs16970849) and the FAS-670 polymorphism with the susceptibility to precancerous lesions and cervical cancer in a Greek population.

METHODS

Among the 515 women who were included in the statistical analysis, 113 belong to the case group and present with precancerous lesions or cervical cancer (27 with persistent CIN1, 66 with CIN2/3 and 20 with cervical cancer) and 402 belong to the control group. The chi-squared test was used to compare the case and the control groups with an allelic and a genotype-based analysis.

RESULTS

The results of the statistical analysis comparing the case and the control groups for all the SNPs tested were not statistically significant. Borderline significant difference (p value = 0.079) was only found by the allelic model between the control group and the CIN1/CIN2 patients' subgroup for the polymorphism rs16970849. The comparison of the other case subgroups with the control group did not show any statistically significant difference.

CONCLUSIONS

None of the SNPs included in the study can be associated with statistical significance with the development of precancerous lesions or cervical cancer.

Quantitative assessment of the association between Fas/FasL gene polymorphism and susceptibility to esophageal carcinoma in a north Chinese population

The case–control study aims to investigate the association of Fas and FasL genetic polymorphisms (Fas‐670A/G (rs1800682), Fas‐1377G/A (rs2234767) and FasL‐844T/C (rs763110)) with esophageal carcinoma susceptibility in a north Chinese population. A total of 204 patients with esophageal carcinoma and 248 healthy controls were enrolled from Henan, China and genotyped by the polymerase chain reaction and restriction fragment length polymorphism method. There were no significant differences in distributions of their genotypes frequencies between patients and controls in Fas‐670A/G, Fas‐1377G/A and FasL‐844T/C polymorphisms (P > 0.05). Stratified analysis showed that no significant association was found between esophageal carcinoma and gene polymorphisms of Fas‐670 A/G, Fas‐1377G/A, and FasL‐844T/C (P > 0.05). Genetic polymorphisms in the death pathway genes Fas and FasL were not associated with risk of developing esophageal carcinoma in a north Chinese population.

Fas-670A>G polymorphism is not associated with an increased risk of acute myeloid leukemia development

The association between the increased risk of acute myeloid leukemia (AML) and Fas promoter polymorphisms has been reported previously; however, the results are inconclusive. The present study performed one case-control study to investigate the association, and a total of 98 AML patients and 2,014 healthy controls were genotyped. The data showed that the distribution of Fas-670AA, GA and GG genotypes among the AML patients were not significantly different from those of the healthy controls, all P>0.05. Following this a sub-study was conducted to analyze individuals who neither smoked nor drank. The results demonstrated that there was still no significant association between the Fas-670 polymorphism and risk of AML development, all P>0.05. Furthermore, in order to address a more accurate estimation of the association, a meta-analysis was conducted. Data were systematically collected from the Pubmed, EMBASE and the Wanfang Library. A total of 3 studies were included in this meta-analysis, which contained 1,144 AML cases and 3,806 controls. No significant association was detected between the Fas-670A>G polymorphism and AML risk [GA+GG vs. AA: odds ratio (OR) 0.93; 95% confidence interval (CI), 0.79–1.09; GG vs. AA: OR, 1.01; 95% CI, 0.82–1.24; GA vs. AA: OR, 1.12; 95% CI, 0.94–1.32; GG vs. AA+GA: OR, 0.94; 95% CI, 0.79–1.12; G vs. A: OR, 1.01; 95% CI, 0.91–1.12; all P>0.05). The analysis clearly indicated that there was no significant connection between the Fas-670A>G polymorphism and the increased risk of AML.

Site disparities in apoptotic variants as predictors of risk for second primary malignancy in patients with squamous cell carcinoma of the head and neck

Background

FAS/FASL promoter variants are considered in altering transcriptional activity of those genes and consequently alter regulation of cell death. However, no studies have investigated whether tumor sites contribute to the association between FAS/FASL polymorphisms and risk for second primary malignancy (SPM).

Method

In this study, FAS670 A > G, FAS1377 G > A, FASL124 A > G, and FASL844C > T polymorphisms were genotyped in 752 OPC and 777 non-OPC patients. Both univariate and multivariable cox proportional hazard models were used to assess the associations.

Results

The univariate and multivariable analyses showed that patients with index OPC and FASL844 CT/TT genotype had significantly increased risk of SPM (cHR, 2.5; 95 % CI, 1.1–5.8, P = 0.043 and aHR, 2.7; 95 % CI, 1.2–6.0, P = 0.032) compared with those with FASL844 CC genotype as the reference group, while index non-OPC patients with FAS670 AG/GG and FasL844 CT/TT genotypes had significantly increased risk of SPM (cHR, 2.2 and 1.8; 95 % CI, 1.2–5.7 and 1.1–3.2; and P = 0.04 and 0.041, respectively and aHR, 2.4 and 1.7; 95 % CI, 1.1–5.1 and 1.0-3.0; and P = 0.043 and 0.049, respectively) compared with their corresponding AA and CC genotypes . Moreover, patients carrying more FAS/FASL variants significantly increased risk of SPM among index non-OPC patients. The stratified analysis showed that smoking status differently modified the associations between FAS/FASL polymorphisms and risk of SPM among index non-OPC from OPC patients.

Conclusion

These results suggested that FAS/FASL polymorphisms might significantly modify SPM risk among patients with SCCHN in a tumor site-specific manner.

The combined risks of reduced or increased function variants in cell death pathway genes differentially influence cervical cancer risk and herpes simplex virus type 2 infection among black Africans and the Mixed Ancestry population of South Africa

Background

Cervical cancer is one of the most important cancers worldwide with a high incident and mortality rate and is caused by the human papilloma virus (HPV). Among sexually active women who get infected with human papillomavirus (HPV), a small fraction progresses to cervical cancer disease pointing to possible roles of additional risk factors in development of the disease which include host genetic factors and other infections such as HSV-2. Since cellular apoptosis plays a role in controlling the spread of virus-infections in cells, gene variants altering the function of proteins involved in cell death pathways might be associated with the clearing of virus infections. Activity altering polymorphisms in FasR (−1377G > A and -670A > G), FasL (−844 T > C) and CASP8 (−652 6 N ins/del) genes have been shown to alter the mechanism of apoptosis by modifying the level of expression of their correspondent proteins.

In the present study, we set out to investigate the combined risks of CASP8, FasR, and FasL polymorphisms in cervical cancer, pre-cancerous lesions, HPV infection and HSV-2 infection.

Methods

Participants were 442 South African women of black African and mixed-ancestry origin with invasive cervical cancer and 278 control women matched by age, ethnicity and domicile status. FasR and FasL polymorphisms were genotyped by TaqMan and CASP8 polymorphism by PCR-RFLP. The results were analysed with R using haplo.stats software version 1.5.2.

Results

CASP8 -652 6 N del + FasR-670A was associated with a reduced risk (P = 0.019, Combined Polymorphism Score (CPS) = −2.34) and CASP8 -652 6 N ins + FasR-1377G was associated with a marginal increased risk (P = 0.047, CPS = 1.99) of cervical cancer among black Africans. When compared within the control group, CASP8 -652 6 N ins + FasR-1377A showed a reduced risk (P = 0.023, CPS = −2.28) of HSV-2 infection in both black African and mixed-ancestry population.

Conclusions

Our results show that the combined risks of variants in cell death pathway genes are associated with the cervical cancer as well as the HSV-2 infection in the black African and mixed-ancestry population.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1678-y) contains supplementary material, which is available to authorized users.

Genetic susceptibility to cervical cancer: role of common polymorphisms in apoptosis-related genes

Cervical cancer is a common malignancy which poses a significant health burden among women, especially those living in the developing countries. Although human papillomavirus (HPV) infection has been unequivocally implicated in the etiopathogenesis of the cancer, it alone is not adequate to contribute to the malignant transformation of cervical cells. Most HPV infections regress spontaneously, and only a small proportion of women have persistent infections which eventually lead to malignancy. This suggests that interplays between HPV infection and other cofactors certainly exist during the process of cervical carcinogenesis, which synergistically contribute to the differential susceptibility of an individual to the malignancy. Undoubtedly, host genetic factors represent a major element involved in such a synergistic interaction, and accumulating evidence suggests that polymorphisms in apoptosis-related genes play an important role in the genetic susceptibility to cervical cancer. This review consolidates the recent literatures on the role of common polymorphisms in apoptosis-related genes in genetic susceptibility to cervical cancer.

Apoptotic variants as predictors of risk of oropharyngeal cancer recurrence after definitive radiotherapy

Single nucleotide polymorphisms (SNPs) in the promoter region of FAS and FASLG may alter their transcriptional activity. Thus, we determined the associations between four FAS and FASLG promoter variants (FAS1377G>A, rs2234767; 670A>G, rs1800682; FASLG844T>C, rs763110 and 124A>G, rs5030772) and the risk of recurrence of squamous cell carcinoma of the oropharynx (SCCOP). We evaluated the associations between FAS and FASLG genetic variants and the risk of recurrence in a cohort of 1,008 patients. The log-rank test and multivariate Cox models were used to evaluate the associations. Compared with patients with common homozygous genotypes of FAS670 and FASLG844 polymorphisms, patients with variant genotypes had lower disease-free survival rates (log-rank p < 0.0001 and p < 0.0001, respectively) and an approximately threefold higher risk of SCCOP recurrence (HR, 3.2;95% CI, 2.2-4.6; and HR, 3.1; 95% CI, 2.2-4.4, respectively) after multivariate adjustment. Furthermore, among patients with HPV16-positive tumors, those with variant genotypes of these two polymorphisms had lower disease-free survival rates (log-rank, p < 0.0001 and p < 0.0001, respectively) and a higher recurrence risk than did patients with common homozygous genotypes (HR, 12.9; 95% CI, 3.8-43.6; and HR, 8.1; 95% CI, 3.6-18.6, respectively), whereas no significant associations were found for FAS1377 and FASLG124 polymorphisms. Our findings suggest that FAS670 and FASLG844 polymorphisms modulate the risk of recurrence of SCCOP, particularly in patients with HPV16-positive tumors. Larger studies are needed to validate these results.

Susceptibility to oral cancers with CD95 and CD95L promoter SNPs may vary with the site and gender

We investigated risk association of oral cancers (tongue and buccal mucosa cancers) with FAS (-1377G > A and FAS -670 A > G) and FASL (-844 T > C) SNPs, in males and females. A case-control study of 535 oral cancer and 525 control subjects was performed. SNPs were detected in the genomic DNA isolated from peripheral blood using PCR-RFLP. We report FASL -844 T > C SNPs increased risk for buccal mucosa cancer in females but not in males. On the other hand, FAS genotypes did not alter the risk of the cancers in both females and males. However, co-occurrence of FAS -1377 GA and -670 GG, FAS -1377 AA and -670 GG genotypes, and combined genotypes of FAS and FASL (FAS -1377 AA + FAS -670 GG + FASL -844 CC) alter male susceptibility towards tongue cancer. In females, combined genotypes of FAS (-1377GA and -670 AA) were found to be a risk factor of buccal mucosa cancer (OR = 3.27, CI = 1.28-8.36; P ≤ 0.01). FASL variants (GA and AA) increased tongue cancer risk in females who were tobacco users compared to non-tobacco users. In conclusion, SNPs of the FAS and FASL might alter risk of tongue and buccal mucosa cancers differentially, in a gender-dependent manner.

CD95 rs1800682A/G variant and tumor risk in Asians: evidence from a meta-analysis of 36 case-control studies containing 22,438 samples

Background

The CD95 gene plays a key role in regulating cell growth and tumor genesis. To date, several publications have focused on the CD95 rs1800682A/G site polymorphism and various types of tumors in Asians; however, this association is still controversial and obscure. Therefore, a meta-analysis combined with all publications to clarify this association is necessary.

Material/Methods

A search in the PubMed and SinoMed databases was performed to detect all relevant included publications. Odds ratio (OR) and 95% confidence intervals (CI) revealed association strengths.

Results

Overall, 36 case-control studies were chosen based on the search criteria. There was no association of the CD95 rs1800682A/G site polymorphism with tumor risk in total and ethnicity subgroup analysis. However, further stratified analysis in the cancer subgroup revealed weakly significant associations in hepatocellular carcinoma (AA+AG vs. GG: OR=0.93, 95% CI=0.87–0.99, P=0.035; AG vs. GG: OR=0.89, 95% CI=0.80–0.99, P=0.036).

Conclusions

The CD95 rs1800682A/G site polymorphism may be associated with hepatocellular carcinoma susceptibility. Further large-scale and well-designed studies regarding tumor types and ethnicities are still required to confirm our results.

The association between the SNP rs763110 and the risk of gynecological cancer: a meta-analysis

FAS and FAS ligand (FASL) are the principal genes of the apoptosis pathway, which play a vital role in the etiology of various gynecological cancers. Studies have revealed that polymorphism of FASL promoter -844C>T (rs763110) influences FASL transcription process, which involving in cancer risk. Moreover, estrogen has been proved to trigger T-cell apoptosis by up-regulating FAS/FASL system in cancer cells. However, results from the published studies on the association between FASL -844C>T polymorphism and risk of gynecological cancer are conflicting. We performed a meta-analysis based on 13 case-control studies, including a total of 6256 cancer cases and 5573 controls. We used odd ratios (ORs) with 95% confidence intervals (CIs) to assess the association strength. Overall, the FASL -844CT and TT genotypes were associated with a significantly reduced risk of gynecological cancer types in homozygote comparison (OR=0.80, 95% CI=0.64-0.99), heterozygote comparison (OR=0.81, 95% CI=0.67-0.98), and dominant model (OR=0.81, 95% CI=0.67-0.98). In the stratified analyses, we observed a similar association among Asian population (heterozygote comparison: OR=0.73, 95% CI=0.56-0.95; dominant model: OR=0.75, 95% CI=0.57-0.98) and hospital-based studies (homozygote comparison: OR=0.61, 95% CI=0.43-0.86). When stratified by cancer type, there was also a significantly lower risk of the ovarian cancer in different genetic models except the recessive one. The results suggested that the FASL -844C>T polymorphism may reduce the risk of gynecological cancer.

FasL -844T/C and Fas -1377G/A: mutations of pulmonary adenocarcinoma in South China and their clinical significances

Apoptosis is an important mechanism of malignant tumor formation and progression. Single nucleotide polymorphisms (SNPs) located within cell death genes may influence cancer risk. We explored the relationship between FasL −844T/C and/or Fas −1377G/A SNPs and pulmonary adenocarcinoma (AD). Two hundred seventy-five patients with pulmonary AD of South China admitted into Zhejiang Cancer Hospital from July 2007 to October 2011 were randomly selected, and their clinicopathological data were collected at the same time. Two hundred ninety-seven cases of healthy individuals were selected as control. FasL −844T/C and Fas −1377G/A SNPs were detected by PCR-RFLP technique to evaluate the relationships between these two SNPs and pulmonary AD. Age, FasL −844 and Fas −1377 SNPs were associated with increased risk of pulmonary AD susceptibility in main effect analysis. FasL −844CC and Fas −1377 AA were associated with an increased risk for the development of pulmonary AD only in age <60 years people, but not in those ≥60 years. FasL −844CC genotype was associated with an increased risk for pulmonary AD (adjusted OR = 2.010, 95 % CI 1.196–3.379, P = 0.008) compared with TT genotype. However, Fas −1377 AA was a risk factor only when FasL −844 genotype was CC. Fas −1377 genotypes showed significant effect modification of pulmonary AD risk by FasL −844 genotype with test of the interaction term adjusting for age, gender, and FasL −844 SNP. Fas −1377G/A was not associated with the clinicopathological factors, while FasL −844C/T was associated with tumor stage and lymph node metastasis in age ≥60 years people and tumor stage in those <60 years. In conclusion, FasL −844 SNP is associated with the susceptibility of pulmonary AD in age <60 years people. Fas −1377 SNP may modify the association of FasL −844 SNP with the risk of pulmonary AD. FasL −844 genotype plays an important role in the occurrence and progression of pulmonary AD.

FAS-670 gene polymorphism and cervical carcinogenesis risk: A meta-analysis

FAS is a cell surface receptor that plays an important role in the etiology of cancer. Previous studies on the association between FAS-670 polymorphism and cervical carcinogenesis failed to reach a consensus; therefore, this meta-analysis was conducted to estimate the association of FAS-670 polymorphism and the risk of cervical cancer. This meta-analysis included 10 studies on FAS-670 genotyping, including a total of 2,901 cases and 2,831 controls. The complete overdominant model was applied in our meta-analysis [AB vs. AA: odds ratio (OR)=0.879, 95% confidence interval (CI): 0.775-0.998, P=0.046; BB vs. AA: OR=0.903, 95% CI: 0.775-1.052, P=0.190]. The random effects OR was 1.13 (95% CI: 0.95-1.34, I²=52.7%, P_{heterogeneity}=0.03). An ethnic subgroup analysis was subsequently performed. The OR for Asians was 1.25 (6 comparisons, 95% CI: 1.05-1.48, I²=23.5%, P_{heterogeneity}=0.03), whereas for Caucasians, no significant association was observed between FAS-670 polymorphism and cervical carcinogenesis (4 comparisons, OR=0.96, 95% CI: 0.75-1.24, I²=45.9%, P_{heterogeneity}=0.14).

Association between CD95L polymorphism and cervical cancer risk: evidence from a meta-analysis

Several studies have assessed the association of CD95L polymorphism with cervical cancer risk, but the data lack the power to provide compelling evidence. In this study, we aimed to clarify the association through a meta-analysis. A comprehensive search was conducted in PubMed, Embase, and Web of Science. The fixed-effects model was used to calculate odds ratio (OR) with 95 % confidence intervals (CIs). A total of five papers with six case-control studies were derived and finally included in this meta-analysis. The overall estimate did not reveal any significant association between CD95L -844C/T polymorphism and cervical cancer risk. Subgroup analysis in Asian population indicated nonsignificant nevertheless potentially increased risk in CC genotype carriers in comparison with the carriers of CT+TT genotypes (ORCC vs. CT+TT=1.16, 95 % CI=0.99-1.36, P for heterogeneity=0.231). Based on current epidemiological studies, this meta-analysis suggests that CD95L polymorphism may not be a risk factor contributing to cervical cancer development.

Association of the polymorphisms in the Fas/FasL promoter regions with cancer susceptibility: a systematic review and meta-analysis of 52 studies

Fas and its ligand (FasL) play an important role in apoptosis and carcinogenesis. Therefore, the potential association of polymorphisms in the Fas (-670A>G, rs1800682; -1377G>A, rs2234767) and FasL (-844C>T, rs763110) with cancer risk has been widely investigated. However, all the currently available results are not always consistent. In this work, we performed a meta-analysis to further determine whether carriers of the polymorphisms in Fas and FasL of interest could confer an altered susceptibility to cancer. All relevant data were retrieved by PubMed and Web of Science, and 52 eligible studies were chosen for this meta-analysis. There was no association of the Fas -670A>G polymorphism with cancer risk in the pooled data. For the Fas -1377G>A and FasL -844C>T polymorphisms, results revealed that the homozygotes of -1377A and -844C were associated with elevated risk of cancer as a whole. Further stratified analysis indicated markedly increased risk for developing breast cancer, gastric cancer, and esophageal cancer, in particular in Asian population. We conclude that carriers of the Fas-1377A and the FasL -844C are more susceptible to the majority of cancers than non-carriers.

Association between the FAS rs2234767G/A polymorphism and cancer risk: a systematic review and meta-analysis

Abnormal regulation of apoptosis can lead to carcinogenesis. Single nucleotide polymorphisms in apoptotic genes have been associated with cancer risk, such as the FAS rs2234767G/A polymorphism, which alters transcription of the FAS promoter. Downregulation of FAS, with resultant cellular resistance to death signals, has been found in many cancers. However, the association between the FAS rs2234767G/A polymorphism and cancer risk is still controversial. Here, we performed a meta-analysis including 41 articles (44 case-control studies, 17,814 cases and 24,307 controls) identified from PubMed and Chinese language (CNKI and WanFang) databases related to cancer susceptibility and the FAS rs2234767G/A polymorphism. We used odds ratios (ORs) and 95% confidence intervals (CIs) to assess the strength of the associations. We found that the rs2234767 G-allele was a protective factor for cancer risk (GG vs. AA: OR=0.88, 95% CI=0.79-0.98; GG+GA vs. AA: OR=0.87, 95% CI=0.79-0.96). Similar associations were detected in the "source of control", ethnicity, and cancer type subgroups. Further studies on a larger sample size and considering gene-environment interactions should be conducted to confirm the role of FAS polymorphisms, especially rs2234767G/A, in cancer risk.

Association of Fas -1377 G/A polymorphism with susceptibility to cancer

BACKGROUND

The relationship between Fas -1377 G/A polymorphism and cancer susceptibility has been implicated in accumulating data. However, the data presented inconsistent results. This study was devised to investigate the association of Fas -1377 G/A polymorphism and cancer susceptibility in a large number of participants.

METHODS

The databases of PubMed, Embase, and Web of Science were searched and a total of 27 case-control studies including 13,355 cases and 16,078 controls were included in this meta-analysis. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the fixed-effects model. Statistical analyses were performed by using Stata software.

RESULTS

The results suggested that Fas -1377 G/A polymorphism was overall associated with cancer susceptibility (additive model: OR, 1.16, 95%CI = 1.06-1.27, Pheterogeneity = 0.381; recessive model: OR, 1.19, 95%CI = 1.10-1.29, Pheterogeneity= 0.137). In the subgroup analysis by cancer type, significantly increased risk was observed in breast cancer (additive model: OR, 1.24, 95%CI = 1.04-1.58, Pheterogeneity = 0.614; recessive model: OR, 1.24, 95%CI = 1.02-1.51, Pheterogeneity = 0.349) and lung cancer (recessive model: OR, 1.25, 95%CI = 1.04-1.49, Pheterogeneity = 0.090). Similarly, elevated cancer risk associated with Fas -1377 G/A polymorphism was revealed in Asians.

CONCLUSIONS

The combined results suggest that Fas -1377 G/A polymorphism might modulate cancer susceptibility in an Asian-specific manner.

Molecular profiling of cervical neoplasia

Cervical cancer, a potentially preventable disease, remains the second most common malignancy in women worldwide. Human papillomavirus is the single most important etiological agent in cervical cancer, contributing to neoplastic progression through the action of viral oncoproteins, mainly E6 and E7, which interfere with critical cell cycle pathways, p53 and retinoblastoma. However, evidence suggests that human papillomavirus infection alone is insufficient to induce malignant changes and that other host genetic variations are important in the development of cervical cancer. This article will discuss the latest molecular profiling techniques available and review the published literature relating to their role in the diagnosis and management of cervical dysplasia and cancer. It is hoped that these techniques will allow the detection of novel biomarkers at DNA, RNA, microRNA and protein levels, which may ultimately play a role in facilitating early disease diagnosis and in predicting response to therapies, thus allowing the development of personalized treatment strategies.

Associations between Fas/FasL polymorphisms and susceptibility to cervical cancer: a meta-analysis

Genetic polymorphisms in the Fas/Fas ligand (FasL) gene were proposed to be associated with susceptibility to cervical cancer, but previous studies reported controversial findings. We performed a meta-analysis to assess the associations between Fas/FasL polymorphisms and susceptibility to cervical cancer. We carried out a literature search in PubMed and Embase databases for studies on the associations between Fas/FasL polymorphisms and susceptibility to cervical cancer. The associations were assessed by odds ratio (OR) together with its 95% confidence intervals (CIs). Eleven individual studies with a total of 6,919 subjects were finally included into the meta-analysis. Overall, there was no association between Fas 1377G > A polymorphism and susceptibility to cervical cancer (A vs. G: OR = 0.99, 95% CI 0.88-1.12, P = 0.91; AA vs. GG: OR = 1.00, 95% CI 0.76-1.32, P = 0.99; AA/GA vs. GG: OR = 0.95, 95% CI 0.81-1.12, P = 0.54; AA vs.

GG/GA

OR = 1.11, 95% CI 0.85-1.43, P = 0.45). In addition, there was also no association between FasL 844 T > C polymorphism and susceptibility to cervical cancer (C vs. T: OR = 1.12, 95% CI 0.91-1.36, P = 0.28; CC vs. TT: OR = 1.17, 95% CI 0.90-1.51, P = 0.24; CC/TC vs. TT: OR = 1.13, 95% CI 0.92-1.39, P = 0.24; CC vs.

TT/TC

OR = 1.11, 95% CI 0.83-1.50, P = 0.47). In subgroup analysis by ethnicity, there were also no associations between Fas/FasL polymorphisms and susceptibility to cervical cancer in Asians and Africans. In conclusion, Fas 1377G > A polymorphism and FasL 844 T > C polymorphism are both not associated with susceptibility to cervical cancer.

FASL rs763110 polymorphism contributes to cancer risk: an updated meta-analysis involving 43,295 subjects

Background

Published studies investigating the association between genetic polymorphism -884C/T (rs763110) of the FAS ligand (FASL) promoter and cancer risk reported inconclusive results. To derive a more precise estimation of the relationship, we performed an updated meta-analysis of all eligible studies.

Methodology/Principal Findings

We carried out a meta-analysis, including 47 studies with 19,810 cases and 23,485 controls, to confirm a more conclusive association between the FASL rs763110 polymorphism and cancer susceptibility. Overall, significantly reduced cancer risk was associated with the variant -884T when all studies were pooled (TC vs. CC: OR = 0.83, 95%CI = 0.75–0.92; P_{heterogeneity}<0.001; TT+TC vs. CC: OR = 0.85, 95%CI = 0.77–0.94; P_{heterogeneity}<0.001). Stratified analysis revealed that there was a statistically reduced cancer risk in Asians (TC vs. CC: OR = 0.76, 95%CI = 0.67–0.87; P_{heterogeneity}<0.001; TT+TC vs. CC: OR = 0.79, 95%CI = 0.70–0.90; P_{heterogeneity}<0.001) and in patients with cancers of head and neck (TC vs. CC: OR = 0.87, 95%CI = 0.77–0.99; P_{heterogeneity} = 0.118; TT+TC vs. CC: OR = 0.88, 95%CI = 0.78–0.99; P_{heterogeneity} = 0.168) and ovarian cancer (TC vs. CC: OR = 0.67, 95%CI = 0.49–0.90; P_{heterogeneity} = 0.187; TT+TC vs. CC: OR = 0.64, 95%CI = 0.48–0.86; P_{heterogeneity} = 0.199). Meta-regression showed that ethnicity (p = 0.029) and genotyping method (p = 0.043) but not cancer types (p = 0.772), sample size (p = 0.518), or source of controls (p = 0.826) were the source of heterogeneity in heterozygote comparison.

Conclusion

Our results suggest that the FASL polymorphism rs763110 is associated with a significantly reduced risk of cancer, especially in Asian populations.

FAS-1377 G/A (rs2234767) polymorphism and cancer susceptibility: a meta-analysis of 17,858 cases and 24,311 controls

BACKGROUND AND OBJECTIVES

Disruption of apoptosis has been implicated in carcinogenesis. Specifically, various single-nucleotide polymorphisms (SNPs) in apoptotic genes, such as FAS-1377 G/A SNP, have been associated with cancer risk. FAS-1377 G/A SNP has been shown to alter FAS gene promoter transcriptional activity. Down-regulation of FAS and cell death resistance is key to many cancers, but an association between FAS-1377 G/A SNP and cancer risk is uncertain. Therefore, we conducted a meta-analysis of the current literature to clarify this relationship.

METHODOLOGY/PRINCIPAL FINDINGS

From PubMed and Chinese language (CNKI and WanFang) databases, we located articles published up to March 5, 2013, obtaining 44 case-control studies from 41 different articles containing 17,858 cases and 24,311 controls based on search criteria for cancer susceptibility related to the FAS gene -1377 G/A SNP. Odds ratios (ORs) and 95% confidence intervals (CI) revealed association strengths. Data show that the -1377 G allele was protective against cancer risk. Similar associations were detected in "source of control," ethnicity and cancer type subgroups. Lower cancer risk was found in both smokers with a GG+GA genotype and in non-smokers with the GG+GA genotype, when compared to smokers and nonsmokers with the AA genotype. Males carrying the -1377G allele (GG+GA) had lower cancer incidence than those with the AA genotype. Individuals who carried both FAS-1377(GG+GA)/FASL-844(TT+TC) genotypes appeared to have lower risk of cancer than those who carried both FAS-1377 AA/FASL-844 CC genotypes.

CONCLUSIONS/SIGNIFICANCE

The FAS-1377 G/A SNP may decrease cancer risk. Studies with larger samples to study gene-environment interactions are warranted to understand the role of FAS gene polymorphisms, especially -1377 G/A SNP, in cancer risk.

Lack of association between Fas rs180082 polymorphism and risk of cervical cancer: an update by meta-analysis

Background

The Fas rs180082 polymorphism has been reported to be associated with cervical cancer susceptibility, yet the results of these previous results have been inconsistent or controversial. The objective of this study was to explore whether the Fas rs180082 polymorphism confers susceptibility to cervical cancer.

Methods

The relevant studies were identified through a search of PubMed, Excerpta Medica Database (Embase), Elsevier Science Direct and Chinese Biomedical Literature Database (CBM) until July 2012. The association between the Fas rs180082 polymorphism and cervical cancer risk was assessed by odds ratios (ORs) together with their 95% confidence intervals (CIs).

Results

A total of 7 case–control studies were eventually identified. We found no association between Fas rs180082 polymorphism and cervical cancer susceptibility in overall population (G versus A: OR = 1.03, 95% CI = 0.99-1.07, P = 0.197; AG + GG versus AA: OR = 1.04, 95% CI = 0.98-1.09, P = 0.176; GG versus AA + AG: OR = 1.04, 95% CI = 0.84–1.31, P = 0.701). In subgroup analysis, similar results were found in Asian (G versus A: OR = 1.06, 95% CI = 0.97–1.15, P = 0.195; AG + GG versus AA: OR = 1.08, 95% CI = 0.98–1.19, P = 0.176; GG versus AA + AG: OR = 0.97, 95% CI = 0.51–1.84, P = 0.935) and African (G versus A: OR = 1.01, 95% CI = 0.97-1.15, P = 0.195; AG + GG versus AA: OR = 0.99, 95% CI = 0.91–1.07, P = 0.739; GG versus AA + AG: OR = 1.09, 95% CI = 0.94–1.25, P = 0.745).

Conclusion

This meta-analysis has shown that there is a lack of association of the Fas rs180082 polymorphisms with cervical cancer susceptibility. However, larger scale primary studies with the consideration of gene–gene and gene–environment interactions are still required to further evaluate the interaction of Fas rs180082 polymorphism with cervical cancer susceptibility.

Lack of association between the FAS/FASL polymorphisms and cervical cancer risk: A meta-analysis

FAS/FASL gene promoter polymorphisms are associated with cervical cancer risk, however, results from previous studies have been conflicting. To obtain a more precise estimation of the association between these polymorphisms and cancer risk, a meta-analysis was performed. All eligible studies up to November 1st, 2012, concerning FAS-670 A/G, FAS-1377 G/A and FASL-844 T/C polymorphisms and cervical cancer risk, were collected from the following electronic databases: PubMed, Excerpta Medica Database and Chinese Biomedical Literature Database. The odds ratio (OR) and 95% confidence interval (95% CI) were used to assess the strength of the association via the additive, codominant, dominant and recessive models. In total, 10 publications with 11 case-control studies (10 on FAS-670 A/G, 5 on FAS-1377 G/A and 6 on FASL-844 T/C polymorphisms) were included in this meta-analysis. No association between FAS-670 A/G, FAS-1377 G/A and FASL-844 T/C polymorphisms and cervical cancer susceptibility for all the genetic models was identified. Following stratification of the studies by ethnicity or source of controls, similar results were obtained. In conclusion, our findings showed that the FAS-670 A/G, FAS-1377 G/A and FASL-844 T/C polymorphisms are not associated with cervical cancer risk. Future studies with larger sample sizes are required to further evaluate these associations.

A comprehensive review on host genetic susceptibility to human papillomavirus infection and progression to cervical cancer

Cervical cancer is the second most common cancer in women worldwide. This is caused by oncogenic types of human papillomavirus (HPV) infection. Although large numbers of young sexually active women get HPV-infected, only a small fraction develop cervical cancer. This points to different co-factors for regression of HPV infection or progression to cervical cancer. Host genetic factors play an important role in the outcome of such complex or multifactor diseases such as cervical cancer and are also known to regulate the rate of disease progression. The aim of this review is to compile the advances in the field of host genetics of cervical cancer. MEDLINE database was searched using the terms, ‘HPV’, ‘cervical’, ‘CIN’, ‘polymorphism(s)’, ‘cervical’+ *the name of the gene* and ‘HPV’+ *the name of the gene*. This review focuses on the major host genes reported to affect the progression to cervical cancer in HPV infected individuals.

Genetic variations in T-cell activation and effector pathways modulate alloimmune responses after allogeneic hematopoietic stem cell transplantation in patients with hematologic malignancies

BACKGROUND

Recently, several important polymorphisms have been identified in T-cell activation and effector pathway genes and have been reported to be associated with inter-patient variability in alloimmune responses. The present study was designed to assess the impact of these genetic variations on the outcomes of allogeneic hematopoietic stem cell transplantation.

DESIGN AND METHODS

We first investigated ten single nucleotide polymorphisms in six genes, CD28, inducible co-stimulator, cytotoxic T-lymphocyte antigen 4, granzyme B, Fas and Fas ligand, in 138 pairs of patients and their unrelated donors and a second cohort of 102 pairs of patients and their HLA-identical sibling donors.

RESULTS

We observed that patients receiving stem cells from a donor with the cytotoxic T-lymphocyte antigen 4 gene CT60 variant allele (AA genotype) had a reduced incidence of grades II-IV acute graft-versus-host disease; however, they experienced early cytomegalovirus infection and relapsed more frequently, which suggested an interaction between the donor cytotoxic T-lymphocyte antigen 4 gene CT60 AA genotype and reduced T-cell alloreactivity. Furthermore, an unrelated donor with the granzyme B +55 variant genotype (AA) was an independent risk factor for development of grades II-IV acute graft-versus-host disease (P=0.024, RR=1.811). Among patients with acute myelogenous leukemia, those with the Fas -670 TT genotype were at higher risk of relapse (P=0.003, RR=3.823). The presence of these susceptible alleles in the donor and/or patient resulted in worse overall survival (54.9% versus 69.5%, P=0.029).

CONCLUSIONS

Our data suggest that genotype analysis of T-cell activation and effector pathway genes can be used for risk assessment for patients with hematologic malignancies before hematopoietic stem cell transplantation.

FASL-844 T/C polymorphism: a biomarker of good prognosis of breast cancer in the Tunisian population

The single nucleotide polymorphism, rs763110 (-844 T/C) of the FASL gene, is located within a putative binding motif of CAAT/enhancer-binding protein β transcription factor. Higher basal expression of FASL is significantly associated with the FASL-844 C allele compared with the FASL-844 T allele suggesting that the FASL-844 T/C polymorphism may influence FASL expression and FASL-mediated signalling, and ultimately, the susceptibility to cancer. Therefore, we carried out a population-based study to estimate the FASL-844 C allele frequency in our population and to investigate, in a case-control study, the potential association of the FASL-844 T/C polymorphism with the risk and prognosis of breast cancer in Tunisia. FASL-844 T/C polymorphism was examined in a Tunisian population-based case-control of 438 patients with breast cancer and 332 control subjects using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. By using TT genotype as reference, no significant association was found between any genotype and the risk of developing breast cancer. The frequency of the FASL-844 C allele was 46.3% among the cases and 43.7% among the controls. Similarly, by using T allele as reference, this difference was also not statistically significant. We observed FASL-844 CC genotype and FASL-844 C allele were significantly associated with SBR 1-2 tumour grade (OR=0.42, P=0.007; OR=0.65, P=0.005, respectively). In patients with diagnosis age ≤ 50 years, FASL-844 CC genotype and C allele showed significant associations with T(1)-T(2) clinical tumour size (OR=0.34, P=0.01; OR=0.65, P=0.02, respectively) and SBR grade 1-2 (OR=0.41, P=0.02; OR=0.62, P=0.01, respectively). A marginally significant association was also found with negative nodal status (OR=0.53, P=0.06; OR=0.73, P=0.07, respectively). Thus, the FASL-844 CC genotype and C allele seem to be associated with a good prognosis in patients with diagnosis age ≤ 50 years.

Modeling interactions with known risk loci-a Bayesian model averaging approach

Genome-wide association studies (GWAS) are now clearly established as a powerful method for detecting loci involved in the etiology of common complex diseases. Most diseases and traits studied using the GWAS approach now have several loci that have been shown to be convincingly replicated. It is generally the case that these loci have been identified using single locus association scans of genotyped or imputed SNPs and very few loci have been identified by taking interactions into account. We propose a method that assesses the evidence of association at each SNP by modeling the effect of the locus in combination with other known loci. We use a Bayesian model averaging approach that combines the evidence across several different plausible models for the way in which the loci interact. We show that the method has good power both when the association is the result of marginal effects only, and when interaction with a known locus occurs. The method is implemented as an option in the program SNPTEST.

Fas and FasL polymorphisms are not associated with acute myeloid leukemia risk in Koreans

Fas and Fas ligand (FasL) polymorphisms in the promoter regions influence transcriptional activities. The interaction of these two genes plays a crucial role in apoptotic cell death regulation. They have been associated with esophageal, lung, uterine cervical, and urinary bladder cancers in human. We performed a case-control study to investigate the association between Fas and FasL polymorphisms and acute myeloid leukemia (AML) risk. Fas−1377G>A (rs2234767), −670T>C (rs1800682), and FasL−844T>C (rs763110) polymorphisms in 592 AML patients and 858 healthy controls were genotyped and tested for associations between polymorphisms and AML risk. There were no significant differences in genotypic and haplotypic distributions and gene-gene interaction between patients and controls in the overall analysis (p>0.05). These results suggested that polymorphisms of Fas and FasL genes were not associated with AML risk in the Korean population.

Polymorphisms in the apoptosis-associated genes FAS and FASL and risk of oral cancer and malignant potential of oral premalignant lesions in a Taiwanese population

BACKGROUND

Our aim was to measure the relationship of FAS (-1377G>A and -670A>G), FASL (-844C>T) gene variants and risk of oral cancer.

METHODS

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was used to determine the FAS and FASL polymorphisms in 294 oral squamous cell carcinoma (OSCC), 53 oral submucous fibrosis (OSF), and 84 oral leukoplakia (OL) patients, as well as in 333 healthy controls. A standardized questionnaire was applied to collect demographic data, and potential confounding factors. JMP statistical software was used to analyze the association.

RESULTS

FAS and FASL polymorphisms were not correlated with OSCC development or the malignant potential of OL by simple and multivariate logistic regression. However, a two- to fourfold difference in the risks of betel quid chewing, alcohol consumption, and smoking on OSCC development were observed between participants with different FAS polymorphisms. FAS polymorphisms were significantly correlated with the malignant potential of OSF. Multivariate logistic regression analysis indicated that FAS A(-1377)-G(-670) vs. G(-1377)-A(-670) haplotype (OR = 2.26, 95% CI = 1.16-4.41) was correlated with the malignant potential of OSF.

CONCLUSIONS

We suggest that FAS and FASL polymorphisms are not significantly correlated with OSCC development or malignant potential of OL. The impact of substance usage on OSCC development could be differentiated by FAS polymorphisms. FAS A(-1377)-G(-670) haplotype may play a role in the malignant potential of OSF.

FAS and FASLG genetic variants and risk for second primary malignancy in patients with squamous cell carcinoma of the head and neck

BACKGROUND

Single-nucleotide polymorphisms in the promoter region of the FAS and FASLG may alter the transcriptional activity of these genes. We therefore investigated the association between the FAS and FASLG polymorphisms and risk for second primary malignancy (SPM) after index squamous cell carcinoma of the head and neck (SCCHN).

METHODS

We used log-rank test and Cox proportional hazard models to assess the association of the four single-nucleotide polymorphisms (FAS -1377 G > A, FAS -670 A > G, FASLG -844 C > T, and FASLG -124 A > G) with the SPM-free survival and SPM risk among 1,286 incident SCCHN patients.

RESULTS

Compared with patients having the FAS -670 AA or the FASLG -844 CC genotypes, the patients having variant genotypes of FAS -670 AG/GG or FASLG -844 CT/TT genotypes had significantly increased risk for SPM, respectively. A trend for significantly increased SPM risk with increasing number of risk genotypes of the four polymorphisms was observed in a dose-response manner. Moreover, the patients with three or four combined risk genotypes had an approximately 1.8- or 2.5-fold increased risk for developing SPM compared with patients with zero or one risk genotypes, respectively.

CONCLUSIONS

Our results suggest a modestly increased risk for SPM after index SCCHN with FAS -670 A > G and FASLG -844 C > T polymorphisms and an even greater risk for SPM with multiple combined FAS and FASLG risk genotypes.

IMPACT

The FAS and FASLG polymorphisms may serve as a susceptible marker for SCCHN patients at high SPM risk.

Fas and FasL gene polymorphisms are not associated with cervical cancer but differ among Black and Mixed-ancestry South Africans

Background

Cervical cancer is one of the most important cancers in African women. Polymorphisms in the Fas (FasR) and Fas ligand (FasL) genes have been reported to be associated with cervical cancer in certain populations. This study investigated whether these polymorphisms are associated with cervical cancer or human papillomavirus (HPV) infection in South African women.

Findings

Participants were 447 women with invasive cervical cancer (106 black African and 341 women of mixed-ancestry) and 424 healthy women controls, matched by age, (101 black African and 323 women of mixed-ancestry) and domicile (rural or urban). Two polymorphisms in Fas gene (FasR-1377G/A, FasR-670A/G) and one in FasL gene (FasL844T/C) were genotyped by TaqMan. None of the polymorphisms, or the Fas haplotypes, showed a significant association with cervical cancer. There was also no association with HPV infection in the control group. However, on analysis of the control group, highly significant allele, genotype and haplotype differences were found between the two ethnic groups. There were generally low frequencies of FasR-1377A alleles, FasR-670A alleles and FasL-844C alleles in black women compared to the women of mixed-ancestry.

Conclusion

This is the first study on the role of Fas and FasL polymorphisms in cervical cancer in African populations. Our results suggest that these SNPs are not associated with cervical cancer in these populations. The allele frequencies of the three SNPs differed markedly between the indigenous African black and mixed-ancestry populations.

Association of HLA-DRB1, interleukin-6 and cyclin D1 polymorphisms with cervical cancer in the Swedish population--a candidate gene approach

High-risk human papillomavirus (hrHPV) infection is the major risk factor for cervical cancer (CxCa). The role of genetic susceptibility in the disease has been suggested, but the existing data lack consistency. We conducted a nested case-control study on 973 CxCa cases and 1,763 matched controls, from two Swedish population-based cohorts to examine the association of common genetic variants with CxCa risk. Human leukocyte antigen (HLA) alleles and 24 other polymorphisms in 14 genes were selected on the basis of reported association or mechanistic plausibility with an HPV infection or cervical cancer development. Genotyping was conducted using multiplex PCR and Luminex technology. A significant association of CxCa with various polymorphisms was observed: rs1800797 in the IL-6 gene (odds ratio [OR] = 0.88, 95% confidence intervals [CI]: 0.79-0.99); rs1041981 in the LTA gene (OR = 0.87, 95% CI: 0.78-0.98), and rs9344 in the CCND1 gene (OR = 1.14, 95% CI: 1.02-1.27), for those individuals carrying the rare allele. Additionally, the alleles 0401 and 1501 of the HLA class II DRB1 locus were associated with an increased risk (OR = 1.23, 95% CI: 1.04-1.45 and OR = 1.29, 95% CI: 1.11-1.50, respectively), and allele 1301 was associated with decreased risk (OR = 0.59, 95% CI: 0.47-0.73). The effects of CCND1 and the HLA*DRB1 alleles were independent of the effect of smoking. We did not find any association of risk with polymorphisms in genes related to the innate immune system. In conclusion, our study provides evidence for genetic susceptibility to CxCa due to variations in genes involved in the immune system and in cell cycle.

FASLG polymorphism is associated with cancer risk

Many studies have reported the association between the FASLG -844T/C polymorphism and cancer risk, but the data are remaining controversial. A pooled analysis was performed to assess this relationship comprehensively. Medline, PubMed, Embase and Web of Science were searched, and data were extracted and cross-checked independently by three authors. A total of 18 published studies including 22389 subjects were involved in this analysis. Overall, the -844C allele was associated with a significantly increased cancer risk (for CC versus TT: OR=1.23, 95% confidence interval (CI)=1.04-1.45; for CC+TC versus TT: OR=1.15, 95% CI=1.01-1.30; for CC versus TT+TC: OR=1.20, 95% CI=1.05-1.38). In the subgroup analysis by ethnicity, significantly elevated risks were found among Asians (for CC versus TT: OR=1.61, 95% CI=1.37-1.89; for CC+TC versus TT: OR=1.36, 95% CI=1.16-1.60; for CC versus TT+TC: OR=1.44, 95% CI=1.22-1.70). In the subgroup analysis by study design, significantly increased risks were found among population-based case-control studies (for CC versus TT: OR=1.40, 95% CI=1.06-1.84; for CC+TC versus TT: OR=1.25, 95% CI=1.01-1.55; for CC versus TT+TC: OR=1.31, 95% CI=1.06-1.61). These findings indicate that the FASLG -844C allele is emerging as a low-penetrant cancer susceptibility allele for cancer development. However, more comprehensive understanding of the association would certainly have an immense prospect in the promising field of individualised preventive care.

The FAS ligand promoter polymorphism, rs763110 (-844C>T), contributes to cancer susceptibility: evidence from 19 case-control studies

The potentially functional polymorphism, rs763110 (-844C>T), in the promoter region of the FAS ligand (FASL) gene, has been implicated in cancer risk, but individually published studies show inconclusive results. To derive a more precise estimation of the association between the FASL rs763110 and risk of cancer, we performed a meta-analysis of 19 published studies that included 11,105 cancer cases and 11,372 controls. We used odds ratios (ORs) and 95% confidence intervals (CIs) to assess the strength of the associations. Overall, the rs763110 CT and TT variant genotypes were associated with a significantly reduced cancer risk of all cancer types in different genetic models (homozygote comparison: OR=0.80, 95% CI: 0.68-0.95, P(heterogeneity)=0.001; heterozygote comparison: OR=0.82, 95% CI: 0.72-0.95, P(heterogeneity)<0.001; dominant model comparison: OR=0.82, 95% CI: 0.71-0.94, P(heterogeneity)<0.001; and recessive model comparison: OR=0.88, 95% CI: 0.81-0.96, P(heterogeneity)=0.074). In the stratified analyses, the risk remained for studies of the smoking-related cancers and Asian populations, or population-based studies in all the genetic models. Although some modest bias could not be eliminated, this meta-analysis suggests that the FASL rs763110 T allele has a possible protective effect on cancer risk.

A common hereditary single-nucleotide polymorphism in the gene of FAS and colorectal cancer survival

Apoptosis plays an important role in embryogenesis, autoimmunity and tumourigenesis. Cell surface death receptors such as TNFRSF6 (FAS) confer a major apoptotic effect. A single-nucleotide polymorphism in the FAS promoter gene, −670A/G, modulates apoptotic signalling and has been related to susceptibility and progression of a variety of cancers. The present study aimed to evaluate the role of this polymorphism for survival of patients with colorectal cancer. We performed a retrospective analysis including 433 patients with histologically confirmed colorectal cancer. A Cox regression model including FAS -670 genotypes, age at diagnosis, tumour grading, primary tumour size, number of lymph nodes examined, number of metastatic lymph nodes, tumour stage and application of fluorouracil-based adjuvant chemotherapy was used to estimate the effect of the FAS genotype on survival. FAS −670A/G genotype frequencies were 24.2% (AA), 46.3% (AG) and 29.5% (GG). Forty-nine patients were excluded from the Cox regression analysis because of missing values. Out of the remaining 384 patients, 69 (18%) died during a follow-up of maximum 10 years. Mean follow-up time was 58 ± 34 months (median 55 months). Carriers of the homozygous FAS -670GG genotype had a significantly lower survival rate compared with AA/AG genotype carriers (relative risk 1.76, 95% confidence interval 1.08–2.87; P= 0.023). The FAS −670A/G polymorphism may be associated with overall survival time of patients with colorectal cancer.

FAS -1,377 G/A polymorphism is associated with cancer susceptibility: evidence from 10,564 cases and 12,075 controls

Published data on the association between FAS -1,377 G/A polymorphism and cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. A total of 17 studies including 10,564 cases and 12,075 controls were involved in this meta-analysis. Overall, significantly elevated cancer risk was associated with AA variant genotype when all the eligible studies were pooled into the meta-analysis (for AA vs GG: OR = 1.19; 95% CI = 1.01-1.40; P (heterogeneity) = 0.05; for recessive model: OR = 1.21; 95% CI = 1.04-1.41; P (heterogeneity) = 0.05). In the subgroup analysis by ethnicity, borderline statistically significantly increased risks were found among Asians for recessive model (OR = 1.20; 95% CI = 1.00-1.45; P (heterogeneity) = 0.01). In the subgroup analysis by population-based controls or hospital-based controls, statistically significantly increased risks were found among groups with population-based controls for AA versus GG (OR = 1.27; 95% CI = 1.02-1.58; P (heterogeneity) = 0.05) and recessive model (OR = 1.25; 95% CI = 1.00-1.59; P (heterogeneity) = 0.01). For breast cancer, borderline statistically significantly increased risks were found for AA versus GG (OR = 1.29; 95% CI = 1.00-1.67; P (heterogeneity) = 0.41). In summary, this meta-analysis suggests that the FAS -1,377 G/A polymorphism is associated with cancer susceptibility.