Genetic variant in SWI/SNF complexes influences hepatocellular carcinoma risk: a new clue for the contribution of chromatin remodeling in carcinogenesis

Moura A, Filho ODMM, Pessoa C, Miranda Furtado CL. Hypomethylation at H19DMR in penile squamous cell carcinoma is not related to HPV infection

Penile squamous cell carcinoma (SCC) is a rare and aggressive tumour mainly related to lifestyle behaviour and human papillomavirus (HPV) infection. Environmentally induced loss of imprinting (LOI) at the H19 differentially methylated region (H19DMR) is associated with many cancers in the early events of tumorigenesis and may be involved in the pathogenesis of penile SCC. We sought to evaluate the DNA methylation pattern at H19DMR and its association with HPV infection in men with penile SCC by bisulfite sequencing (bis-seq). We observed an average methylation of 32.2% ± 11.6% at the H19DMR of penile SCC and did not observe an association between the p16INK4a+ (p = 0.59) and high-risk HPV+ (p = 0.338) markers with methylation level. The average methylation did not change according to HPV positive for p16INK4a+ or hrHPV+ (35.4% ± 10%) and negative for both markers (32.4% ± 10.1%) groups. As the region analysed has a binding site for the CTCF protein, the hypomethylation at the surrounding CpG sites might alter its insulator function. In addition, there was a positive correlation between intense polymorphonuclear cell infiltration and hypomethylation at H19DMR (p = 0.035). Here, we report that hypomethylation at H19DMR in penile SCC might contribute to tumour progression and aggressiveness regardless of HPV infection.

Genetic alterations and expression characteristics of ARID1A impact tumor immune contexture and survival in early-onset gastric cancer

The AT-rich Interactive Domain 1A (ARID1A) is one of the most frequently mutated genes in gastric cancer. Here, we found that genetic variants in noncoding regions of ARID1A associated with altered protein levels by target sequencing. Notably, tumors with ARID1A variants in the 3'untranslated region (3'UTR) exhibited remarkably increased heterogeneity of ARID1A protein. In general, genetic variants and protein deficiency of ARID1A in tumors were associated with a better survival. Strikingly, altered patterns and heterogeneity of ARID1A protein expression were observed in peritumor tissues and carried significant implications in defining tumor immune contexture by multiplex immunohistochemistry. By analyzing the spatial distribution of TILs, we showed that reduced ARID1A protein levels in both tumor and peritumor tissues were significantly correlated with increased density and proximity of TILs to tumor cells. In contrast, high heterogeneity of ARID1A expression was associated with increased TIL density, but reduced proximity of TILs to tumor cells. Collectively, our study characterized ARID1A genetic alterations and its protein expression patterns in EOGC, demonstrating new strategies for clinically assessing its molecular impact on tumor onset and progression, tumor immune response, and patient survival.

Suppression of ARID1A associated with decreased CD8 T cells improves cell survival of ovarian clear cell carcinoma

Objective

AT-rich interactive domain 1A (ARID1A) plays an important role as a tumor suppressor gene in ovarian clear cell carcinoma (OCCC), but the clinical application of ARID1A remains unclear. The aim of this study was to analyze clinicopathological parameters, molecular interactions and immune-infiltration in patients with low ARID1A expression and to provide candidate target drugs.

Methods

We investigated the clinicopathologic parameters, specific gene sets/genes, and immunological relevance according to ARID1A expression in 998 OCCC patients from 12 eligible studies (using meta-analyses); 30 OCCC patients from the Hanyang University Guri Hospital (HYGH) cohort; and 52 OCCC patients from gene set enrichment (GSE) 65986 (25 patients), 63885 (9 patients), and 54809 (6 patients and 12 healthy people) of the Gene Expression Omnibus (GEO). We analyzed network-based pathways based on gene set enrichment analysis (GSEA) and performed in vitro drug screening.

Results

Low ARID1A expression was associated with poor survival in OCCC from the meta-analysis, HYGH cohort and GEO data. In GSEA, low ARID1A expression was related to the tumor invasion process as well as a low immune-infiltration. In silico cytometry showed that CD8 T cells were decreased with low ARID1A expression. In pathway analysis, ARID1A was associated with angiogenic endothelial cell signaling. In vitro drug screening revealed that cabozantinib and bicalutamide effectively inhibited specific hub genes, such as vascular endothelial growth factor-A and androgen receptor, in OCCC cells with low ARID1A expression.

Conclusions

Therapeutic strategies making use of low ARID1A could contribute to better clinical management/research for patients with OCCC.

The roles of mutated SWI/SNF complexes in the initiation and development of hepatocellular carcinoma and its regulatory effect on the immune system: A review

Hepatocellular carcinoma (HCC) is a primary liver malignancy with a high global prevalence and a dismal prognosis. Studies are urgently needed to examine the molecular pathogenesis and biological characteristics of HCC. Chromatin remodelling, an integral component of the DNA damage response, protects against DNA damage‐induced genome instability and tumorigenesis by triggering the signalling events that activate the interconnected DNA repair pathways. The SWI/SNF complexes are one of the most extensively investigated adenosine triphosphate‐dependent chromatin remodelling complexes, and mutations in genes encoding SWI/SNF subunits are frequently observed in various human cancers, including HCC. The mutated SWI/SNF complex subunits exert dual functions by accelerating or inhibiting HCC initiation and progression. Furthermore, the abnormal SWI/SNF complexes influence the transcription of interferon‐stimulated genes, as well as the differentiation, activation and recruitment of several immune cell types. In addition, they exhibit synergistic effects with immune checkpoint inhibitors in the treatment of diverse tumour types. Therefore, understanding the mutations and deficiencies of the SMI/SNF complexes, together with the associated functional mechanisms, may provide a novel strategy to treat HCC through targeting the related genes or modulating the tumour microenvironment.

Oncogene-dependent function of BRG1 in hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is the major type of primary liver cancer. Genomic studies have revealed that HCC is a heterogeneous disease with multiple subtypes. BRG1, encoded by the SMARCA4 gene, is a key component of SWI/SNF chromatin-remodeling complexes. Based on TCGA studies, somatic mutations of SMARCA4 occur in ~3% of human HCC samples. Additional studies suggest that BRG1 is overexpressed in human HCC specimens and may promote HCC growth and invasion. However, the precise functional roles of BRG1 in HCC remain poorly delineated. Here, we analyzed BRG1 in human HCC samples as well as in mouse models. We found that BRG1 is overexpressed in most of human HCC samples, especially in those associated with poorer prognosis. BRG1 expression levels positively correlate with cell cycle and negatively with metabolic pathways in the Cancer Genome Atlas (TCGA) human HCC data set. In a murine HCC model induced by c-MYC overexpression, ablation of the Brg1 gene completely repressed HCC formation. In striking contrast, however, we discovered that concomitant deletion of Brg1 and overexpression of c-Met or mutant NRas (NRAS^V12) triggered HCC formation in mice. Altogether, the present data indicate that BRG1 possesses both oncogenic and tumor-suppressing roles depending on the oncogenic stimuli during hepatocarcinogenesis.

Brahma related gene 1 (Brg1) contributes to liver regeneration by epigenetically activating the Wnt/β-catenin pathway in mice

Liver regeneration is a complicated pathophysiologic process that is regulated by a myriad of signaling pathways and transcription factors. The interaction among these pathways and factors, either cooperatively or antagonistically, may ultimately lead to recovery and restoration of liver function or permanent loss of liver function and liver failure. In the present study, we investigated the mechanism whereby the chromatin remodeling protein brahma related gene 1 (Brg1) regulates liver regeneration in mice. The Smarca4-Flox strain of mice was crossbred with the Alb-Cre strain to generate hepatocyte-specific Brg1 knockout mice. Liver injury was induced by partial hepatectomy (PHx). We report that Brg1 deletion in hepatocyte compromised liver regeneration and dampened survival after PHx in mice. Brg1 interacted with β-catenin to potentiate Wnt signaling and promote hepatocyte proliferation. Mechanistically, Brg1 recruited lysine demethylase 4 (KDM4) to activate β-catenin target genes. Our data suggest that Brg1 might play an essential role maintaining hepatic homeostasis and contributing to liver repair.-Li, N., Kong, M., Zeng, S., Hao, C., Li, M., Li, L., Xu, Z., Zhu, M., Xu, Y. Brahma related gene 1 (Brg1) contributes to liver regeneration by epigenetically activating the Wnt/β-catenin pathway in mice.

Variants in the SMARCA4 gene was associated with coronary heart disease susceptibility in Chinese han population

BACKGROUND

Coronary heart disease (CHD) is the leading cause of death worldwide. Many single-nucleotide polymorphisms (SNPs) are found to be related to the risk of CHD in previous studies. This study investigated whether polymorphism of SMARCA4 gene is associated with CHD.

MATERIALS AND METHODS

Genotypes at five CHD-relevant SNPs were determined in 456 cases of incident CHD and 685 unaffected controls in Chinese Han population using χ2 test, genetic model analysis and haplotype analysis. We also analysis the differences in continuous variables among the subjects with three genotypes of related genes were assessed using the ANOVA.

RESULTS

We identified two susceptibility SNPs in the SMARCA4 gene that were potentially associated with a decreased risk of CHD. We identified rs11879293 (OR, 0.74; 95% CI, 0.59-0.96; P = 0.012) and rs12232780 (OR, 0.70; 95% CI, 0.54-0.90; P = 0.005) were associated with a decreased risk of CHD risk under the log-additive model adjusted by gender and age. Meanwhile, we also found that significant differences in glucose concentrations with rs11879293 and rs1122608 different genotype. Serum LDL-C and HDL-C were seen among the 3 genotypes of rs12232780 exist differences.

CONCLUSION

This study provides an evidence for polymorphism of SMARCA4 gene associated with CHD development in Chinese Han population.

The contribution of serum hepatitis B virus load in the carcinogenesis and prognosis of hepatocellular carcinoma: evidence from two meta-analyses

BACKGROUND AND AIM

The meta-analysis aimed to quantify and summarize the contribution of serum hepatitis B virus (HBV) DNA load in the carcinogenesis and prognosis of hepatocellular carcinoma (HCC).

RESULTS

Nine independent studies with a total of 1162 cases and 9365 participants on risk of HCC and seventeen studies with 1342 cases and 2891 participants on recurrence of HCC were finally included. The non-liner dose-response association between HBV DNA level and HCC risk was observed, with P value equal to 0.02 for linear test. Compared with 2 log10copies/ml HBV DNA level carriers, the summary relative risk of HCC were 1.65(95% CI: 0.94-2.92) for 4.5 log10copies/ml, 2.20(95% CI: 1.00-4.85) for 5.5 log10copies/ml, 3.06(95% CI: 1.11-8.44) for 6.5 log10copies/ml. Moreover, individuals with high viral load (HBV DNA levels > 105copies/ml) presented significant association with increased risk of HCC recurrence, with the pooled RR of 1.69 (95% CI: 1.49-1.92).

MATERIALS AND METHODS

Pertinent studies were identified by searching PubMed, Embase and ISI Web of science databases up to January 2016 and by reviewing the references of retrieved articles. The dose-response meta-analysis was precisely performed to calculate the summary relative risks (RRs) by quantizing the association between HBV load and risk of HCC. Besides, the contribution of HBV load on recurrence of HCC was further clarified by general meta-analysis.

CONCLUSIONS

These findings indicated a non-linear dose-response relationship between serum HBV DNA level and risk of HCC, and confirmed the significant contribution of serum HBV DNA level in the prognosis of HCC.

The SWI/SNF complex subunit genes: Their functions, variations, and links to risk and survival outcomes in human cancers

SWI/SNF is a multiprotein complex essential for regulation of eukaryotic gene expression. In this article, we review the function and characteristics of this complex and its subunits in cancer-related phenotypes. We also present and discuss the publically available survival analysis data for TCGA patient cohorts, revealing novel relationships between the expression levels of the SWI/SNF subunit genes and patient survival times in several cancers. Overall, multiple lines of research point to a wide-spread role for the SWI/SNF complex genes in human cancer susceptibility and patient survival times. Examples include the mutations in ARID1A with cancer-driving effects, associations of tumor SWI/SNF gene expression levels and patient survival times, and two BRM promoter region polymorphisms linked to risk or patient outcomes in multiple human cancers. These findings should motivate comprehensive studies in order to fully dissect these relationships and verify the potential clinical utility of the SWI/SNF genes in controlling cancer.

Chromatin remodeling gene ARID2 targets cyclin D1 and cyclin E1 to suppress hepatoma cell progression

Exome and whole-genome sequencing studies have drawn attention to the role of somatic mutations in SWI/SNF chromatin remodeling complexes in the carcinogenesis of hepatocellular carcinoma (HCC). Here, we explored the molecular mechanisms underlying the biological roles of AT-rich interactive domain 2 (ARID2) in the pathogenesis of HCC. We found that ARID2 expression was significantly downregulated in HCC tissues compared with non-tumorous tissues. Restoration of ARID2 expression in hepatoma cells was sufficient to suppress cell proliferation and tumor growth in mice, whereas ARID2 knockdown contributed to the enhancement of cellular proliferation and tumorigenicity. Suppression of ARID2 expression accelerated G1/S transition associated with upregulation of cyclin D1, cyclin E1, CDK4, and phosphorylation of the retinoblastoma protein (Rb). Furthermore, we demonstrated that ARID2 physically interacts with E2F1 and decreases binding of E2F1/RNA Pol II to the promoters of CCND1 and CCNE1. Taken together, these results demonstrate that ARID2 suppresses tumor cell growth through repression of cyclin D1 and cyclin E1 expression, thereby retarding cell cycle progression and cell proliferation in hepatoma cells. These findings highlight the potential role of ARID2 as a tumor growth suppressor in HCC.

Genetic alterations in hepatocellular carcinoma: An update

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. Although recent advances in therapeutic approaches for treating HCC have improved the prognoses of patients with HCC, this cancer is still associated with a poor survival rate mainly due to late diagnosis. Therefore, a diagnosis must be made sufficiently early to perform curative and effective treatments. There is a need for a deeper understanding of the molecular mechanisms underlying the initiation and progression of HCC because these mechanisms are critical for making early diagnoses and developing novel therapeutic strategies. Over the past decade, much progress has been made in elucidating the molecular mechanisms underlying hepatocarcinogenesis. In particular, recent advances in next-generation sequencing technologies have revealed numerous genetic alterations, including recurrently mutated genes and dysregulated signaling pathways in HCC. A better understanding of the genetic alterations in HCC could contribute to identifying potential driver mutations and discovering novel therapeutic targets in the future. In this article, we summarize the current advances in research on the genetic alterations, including genomic instability, single-nucleotide polymorphisms, somatic mutations and deregulated signaling pathways, implicated in the initiation and progression of HCC. We also attempt to elucidate some of the genetic mechanisms that contribute to making early diagnoses of and developing molecularly targeted therapies for HCC.

Loss of ARID1A expression predicts poor survival prognosis in gastric cancer: a systematic meta-analysis from 14 studies

The chromatin remodeling gene, AT-rich interactive domain 1A gene (ARID1A), frequently mutates inactively in gastric cancer (GC). However, its prognostic value remains controversial. To address this issue, a comprehensive meta-analysis was performed. Studies published until March 2016 were systematically searched. A total of 15 cohorts from 14 literatures involving 3183 patients were subjected to this meta-analysis. The pooled data showed that ARID1A expression loss predicted poor overall survival (OS) in GC (Hazard Ratio (HR) = 1.60; 95% Confidence Interval (CI) = 1.40-1.81; P < 0.001), with low heterogeneity among these studies (I(2) = 21.5%; P = 0.214). Stratification analyses revealed that ARID1A expression loss was associated with poor OS in Asians (HR = 1.65, 95% CI = 1.44-1.89), proportion of proximal disease ≤30% subgroup (HR = 1.80, 95% CI = 1.36-2.38) and Epstein-Barr virus (EBV) (+) > 5% subgroup (HR = 1.59, 95% CI = 1.18-2.15). The robust results were suggested by sensitivity analyses and no evidence of significant publication bias was detected. This study demonstrated a significant relationship between deletion of ARID1A expression and poor OS in GC. Moreover, ethnicity, tumor location and EBV infection status might be potential key factors influencing this correlation.

Clinicopathological and Targeted Exome Gene Features of a Patient with Metastatic Acinic Cell Carcinoma of the Parotid Gland Harboring an ARID2 Nonsense Mutation and CDKN2A/B Deletion

We describe the presentation, treatment, clinical outcome, and targeted genome analysis of a metastatic salivary acinic cell carcinoma (AciCC). A 71-year-old male presented with a 3 cm right tail of a parotid lesion, first detected as a nodule by the patient seven months earlier. He had a right total parotidectomy with cranial nerve VII resection, right facial nerve resection and grafting, resection of the right conchal cartilage, and right modified radical neck dissection. The primary tumor revealed AciCC with two distinct areas: a well-differentiated component with glandular architecture and a dedifferentiated component with infiltrative growth pattern associated with prominent stromal response, necrosis, perineural invasion, and cellular pleomorphism. Tumor staging was pT4 N0 MX. Immunohistochemistry staining showed pankeratin (+), CD56 (−), and a Ki67 proliferation index of 15%. Upon microscopic inspection, 49 local lymph nodes resected during parotidectomy were negative for cancer cells. Targeted sequencing of the primary tumor revealed deletions of CDKN2A and CDKN2B, a nonsense mutation in ARID2, and single missense mutations of unknown significance in nine other genes. Despite postoperative localized radiation treatment, follow-up whole body PET/CT scan showed lung, soft tissue, bone, and liver metastases. The patient expired 9 months after resection of the primary tumor.

Functional and genetic deconstruction of the cellular origin in liver cancer

During the past decade, research on primary liver cancers has particularly highlighted the uncommon plasticity of differentiated parenchymal liver cells (that is, hepatocytes and cholangiocytes (also known as biliary epithelial cells)), the role of liver progenitor cells in malignant transformation, the importance of the tumour microenvironment and the molecular complexity of liver tumours. Whereas other reviews have focused on the landscape of genetic alterations that promote development and progression of primary liver cancers and the role of the tumour microenvironment, the crucial importance of the cellular origin of liver cancer has been much less explored. Therefore, in this Review, we emphasize the importance and complexity of the cellular origin in tumour initiation and progression, and attempt to integrate this aspect with recent discoveries in tumour genomics and the contribution of the disrupted hepatic microenvironment to liver carcinogenesis.

A genetic variant in microRNA-122 regulatory region confers risk for chronic hepatitis B virus infection and hepatocellular carcinoma in Han Chinese

miR-122 plays a vital role in the development of chronic hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC). Based on data from the Encyclopedia of DNA Elements (ENCODE), two single nucleotide polymorphisms (SNPs), rs4309483 and rs4503880, were identified in the upstream regulatory region of miR-122. A case-control study consisting of 1,300 HBV-positive HCC cases, 1,344 HBV carriers, and 1,344 persons who cleared HBV naturally was carried out to test the association between the two SNPs and the risk for chronic HBV infection and HCC. The CA/AA genotypes of rs4309483 were associated with significantly increased risk for HCC [adjusted odds ratio (OR) = 1.21, 95% confidence intervals (CIs) = 1.02-1.43, P = 0.025] compared with HBV carriers, but decreased risk for chronic HBV infection (adjusted OR = 0.82, 95% CIs = 0.70-0.97, P = 0.017) compared with persons who cleared HBV naturally. The genotype-expression correlation between rs4309483 and the expression of primary or mature miR-122 expression was investigated in 29 pairs of HBV positive HCC and noncancerous liver tissues. In noncancerous liver tissues, subjects carrying the CA genotype exhibited significantly lower expression level of pri-miR-122 than those carrying the CC genotype. In addition, positive or inverse correlation between the expression levels of pri-miR-122 and mature miR-122 were observed in HCC tissues or noncancerous tissues, respectively. These findings indicate that the C to A base change of rs4309483 may alter the expression of miR-122, thus providing protective effect from chronic HBV infection but an increased risk for HCC in HBV carriers.

Rsf-1 overexpression serves as a prognostic marker in human hepatocellular carcinoma

Rsf-1 (HBXAP) was recently reported to be overexpressed in various cancers and associated with the malignant behavior of cancer cells. However, the expression of Rsf-1 and its clinical significance in human hepatocellular carcinoma (HCC) have not been reported. In the present study, we analyzed the expression pattern of Rsf-1 in human HCC tissues and found that Rsf-1 was overexpressed in 41.1 % of HCC specimens. There was a significant association between Rsf-1 overexpression and tumor stage (p = 0.0322), AFP (p = 0.0184), and tumor relapse (p = 0.0112). Furthermore, Rsf-1 overexpression correlated with poor overall survival in HCC patients (p < 0.001). Rsf-1 overexpression could serve as an independent predictor for poor recurrence-free survival (p = 0.0079). Small interfering RNA (siRNA) knockdown in SK-Hep-1 cells with high endogenous Rsf-1 expression inhibited cell proliferation and colony formation, with downregulation of cyclin E protein. In conclusion, Rsf-1 is overexpressed in HCCs and serves as a novel tumor marker. Rsf-1 contributes to hepatocellular carcinoma cell growth through regulation of cell cycle proteins.

Association of a functional RAD52 genetic variant locating in a miRNA binding site with risk of HBV-related hepatocellular carcinoma

As an important member in homologous recombination repair, RAD52 plays a crucial part in maintaining genomic stability and prevent carcinogenesis. Several cancer susceptibility RAD52 single nucleotide polymorphisms (SNPs) have been identified previously. However, little or nothing has been known about the RAD52 SNPs and their functional significance in hepatitis B viruses (HBV)-related hepatocellular carcinoma (HCC). Therefore, we investigated the association between five RAD52 SNPs (rs1051669, rs10774474, rs11571378, rs7963551, and rs6489769) and HBV-related HCC risk as well as its biological function in vivo. Genotypes were determined in two independent case-control sets from two regions of China. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by logistic regression. The allele-specific regulation on RAD52 expression by the functional genetic variant was examined with normal liver tissues. We found that only the RAD52 rs7963551 SNP was significantly associated with HCC risk, with the odds of having the rs7963551 CC genotype in patients was 0.59 (95% CI = 0.45-0.78, P = 1.5 × 10(-4), HCC cases versus chronic HBV carriers) or 0.65 (95% CI = 0.52-0.81, P = 1.1 × 10(-4), HCC cases versus healthy controls) compared with the AA genotype. In the genotype-phenotype correlation analyses of 44 human liver tissue samples, rs7963551 CC or AC was associated with a statistically significant increase of RAD52 mRNA expression, which are consistent to functional relevance of allelic regulation of RAD52 expression by rs7963551 SNP and miRNA let-7 in cancer cells. Our data demonstrated that RAD52 functional rs7963551 SNP contributes to susceptibility to developing HCC.

Replication study of ESCC susceptibility genetic polymorphisms locating in the ADH1B-ADH1C-ADH7 cluster identified by GWAS

China was one of the countries with highest esophageal squamous cell carcinoma (ESCC) incidence and mortality worldwide. Alcohol drinking has been identified as a major environmental risk-factor related to ESCC. The alcohol dehydrogenase (ADH) family are major enzymes involved in the alcohol-metabolizing pathways, including alcohol dehydrogenase 1B (ADH1B) and ADH1C. Interestingly, ADH1B and ADH1C genes locate tandemly with ADH7 in a genomic segment as a gene cluster, and are all polymorphic. Several ESCC susceptibility single nucleotide polymorphisms (SNPs) of the ADH1B-ADH1C-ADH7 cluster have been identified previously through a genome-wide association study (GWAS). In the study, we examined the association between five ADH1B-ADH1C-ADH7 cluster SNPs (rs1042026, rs17033, rs1614972, rs1789903 and rs17028973) and risk of developing ESCC. Genotypes were determined in two independent case-control sets from two regions of China. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by logistic regression. Our data demonstrated that these ADH1B-ADH1C-ADH7 cluster SNPs confer susceptibility to ESCC in these two case-control sets, which were consistent to results of the previous GWAS.

XPF-673C>T polymorphism effect on the susceptibility to esophageal cancer in Chinese population

Purpose

Xeroderma pigmentsum group F (XPF) plays a pivotal role in DNA nucleotide excision repair and has been linked to the development of various cancers. This study aims to assess the association of XPF genetic variants with the susceptibility to esophageal squamous cell carcinoma (ESCC) in Chinese population.

Methods

This two-stage case-control study was conducted in a total of 1524 patients with ESCC and 1524 controls. Genotype of XPF -673C>T and 11985A>G variants were determined by polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP). Logistic regression analysis was performed to estimate odd ratios (ORs) and 95% confidence intervals (95% CI).

Results

Our case-control study showed that XPF -673TT genotype was associated with a decreased risk of ESCC compared with CC genotype in both case-control sets (Tangshan set: OR = 0.58; 95%CI = 0.34–0.99, P = 0.040; Beijing set: OR = 0.66; 95%CI = 0.46–0.95, P = 0.027). Stratified analyses revealed that a multiplicative interaction between -673C>T variant and age, sex or smoking status was evident (Gene-age: P_interaction = 0.002; Gene-sex: P_interaction = 0.002; Gene-smoking: P_interaction = 0.002). For XPF 11985A>G polymorphism, there was no significant difference of genotype distribution between ESCC cases and controls.

Conclusion

These findings indicated that genetic variants in XPF might contribute to the susceptibility to ESCC.