Pathway-based analysis of genetic susceptibility to cervical cancer in situ: HLA-DPB1 affects risk in Swedish women

Human papillomavirus genomics: Understanding carcinogenicity

Human papillomavirus (HPV) causes virtually all cervical cancers and many cancers at other anatomical sites in both men and women. However, only 12 of 448 known HPV types are currently classified as carcinogens, and even the most carcinogenic type - HPV16 - only rarely leads to cancer. HPV is therefore necessary but insufficient for cervical cancer, with other contributing factors including host and viral genetics. Over the last decade, HPV whole genome sequencing has established that even fine-scale within-type HPV variation influences precancer/cancer risks, and that these risks vary by histology and host race/ethnicity. In this review, we place these findings in the context of the HPV life cycle and evolution at various levels of viral diversity: between-type, within-type, and within-host. We also discuss key concepts necessary for interpreting HPV genomic data, including features of the viral genome; events leading to carcinogenesis; the role of APOBEC3 in HPV infection and evolution; and methodologies that use deep (high-coverage) sequencing to characterize within-host variation, as opposed to relying on a single representative (consensus) sequence. Given the continued high burden of HPV-associated cancers, understanding HPV carcinogenicity remains important for better understanding, preventing, and treating cancers attributable to infection.

Analysis of human leukocyte antigen associations in human papillomavirus-positive and -negative head and neck cancer: Comparison with cervical cancer

Background

Although the majority of human papillomavirus (HPV) infections are cleared by the immune system, a small percentage of them progress to develop HPV‐driven cancers. Cervical cancer studies highlight that HPV persistence and cancer risk are associated with genetic factors, especially at the human leukocyte antigen (HLA) genes. This study was conducted to investigate such associations in head and neck cancer (HNC).

Methods

In all, 192 patients with HNC and 384 controls were genotyped with the Infinium Global Screening Array (Illumina, Inc). HLA variants were imputed with SNP2HLA, and an association analysis was performed by logistic regression.

Results

HPV‐positive HNCs were significantly associated with single‐nucleotide polymorphisms (SNPs) at DRB1_32660090 (P = 1.728 × 10^–6) and DRB1_32660116 (P = 1.728 × 10^–6) and with the amino acid variant DRB1_11_32660115 (P = 1.728 × 10^–6). None of these associations were observed in the HPV‐negative cohort, and this suggested their specificity to convey risk for HPV‐associated HNCs. In general, associations observed for HPV‐negative HNC were relatively weak, and variants in the HLA‐DPA1 region were the strongest among them (P = 4.531 × 10^–4). Several lead signals reported by previous HNC genome‐wide association studies, including SNPs rs3135001 (P = .012), rs1049055 (P = .012), and rs34518860 (P = .029) and allele HLA‐DQB1*06 (P = .009), were replicated in the current study. However, these associations were limited to the HPV‐positive HNC group. Several cervical cancer–associated HLA variants, including SNPs rs9272143 (P = .002) and rs9271858 (P = .002) and alleles HLA‐B‐1501 (P = .009) and HLA‐B‐15 (P = .015), were also exclusively associated with HPV‐positive HNC.

Conclusions

HPV‐positive HNC risk is associated with distinct HLA variants, and some of them are shared by both cervical cancer and HPV‐positive HNC.

Human papillomavirus (HPV)–positive head and neck cancer (HNC) risk is associated with distinct human leukocyte antigen variants, and some of them are shared by both cervical cancer and HPV‐positive HNC.

Lay Summary

Cervical cancer studies highlight that human papillomavirus (HPV)–driven cancer risk is linked with human leukocyte antigen (HLA) polymorphism.

Hence, the current study was designed to investigate the HLA associations in HPV‐positive and HPV‐negative head and neck cancer (HNC) and compare these associations with cervical cancer.

Several lead signals reported by previous HNC and cervical genome‐wide association studies were replicated in the current study.

However, these associations were limited to the HPV‐positive HNC group, and this suggests that HPV‐positive HNC risk is associated with distinct HLA variants, and some of them are shared by both cervical cancer and HPV‐positive HNC.

Tumor Immunity and Immunotherapy for HPV-Related Cancers

Human papillomavirus (HPV) infection drives tumorigenesis in the majority of cervical, oropharyngeal, anal, and vulvar cancers. Genetic and epidemiologic evidence has highlighted the role of immunosuppression in the oncogenesis of HPV-related malignancies. Here we review how HPV modulates the immune microenvironment and subsequent therapeutic implications. We describe the landscape of immunotherapies for these cancers with a focus on findings from early-phase studies exploring antigen-specific treatments, and discuss future directions. Although responses across these studies have been modest to date, a deeper understanding of HPV-related tumor biology and immunology may prove instrumental for the development of more efficacious immunotherapeutic approaches. SIGNIFICANCE: HPV modulates the microenvironment to create a protumorigenic state of immune suppression and evasion. Our understanding of these mechanisms has led to the development of immunomodulatory treatments that have shown early clinical promise in patients with HPV-related malignancies. This review summarizes our current understanding of the interactions of HPV and its microenvironment and provides insight into the progress and challenges of developing immunotherapies for HPV-related malignancies.

Leveraging Methylation Alterations to Discover Potential Causal Genes Associated With the Survival Risk of Cervical Cancer in TCGA Through a Two-Stage Inference Approach

BACKGROUND

Multiple genes were previously identified to be associated with cervical cancer; however, the genetic architecture of cervical cancer remains unknown and many potential causal genes are yet to be discovered.

METHODS

To explore potential causal genes related to cervical cancer, a two-stage causal inference approach was proposed within the framework of Mendelian randomization, where the gene expression was treated as exposure, with methylations located within the promoter regions of genes serving as instrumental variables. Five prediction models were first utilized to characterize the relationship between the expression and methylations for each gene; then, the methylation-regulated gene expression (MReX) was obtained and the association was evaluated via Cox mixed-effect model based on MReX. We further implemented the aggregated Cauchy association test (ACAT) combination to take advantage of respective strengths of these prediction models while accounting for dependency among the p-values.

RESULTS

A total of 14 potential causal genes were discovered to be associated with the survival risk of cervical cancer in TCGA when the five prediction models were separately employed. The total number of potential causal genes was brought to 23 when conducting ACAT. Some of the newly discovered genes may be novel (e.g., YJEFN3, SPATA5L1, IMMP1L, C5orf55, PPIP5K2, ZNF330, CRYZL1, PPM1A, ESCO2, ZNF605, ZNF225, ZNF266, FICD, and OSTC). Functional analyses showed that these genes were enriched in tumor-associated pathways. Additionally, four genes (i.e., COL6A1, SYDE1, ESCO2, and GIPC1) were differentially expressed between tumor and normal tissues.

CONCLUSION

Our study discovered promising candidate genes that were causally associated with the survival risk of cervical cancer and thus provided new insights into the genetic etiology of cervical cancer.

APOBEC: A molecular driver in cervical cancer pathogenesis

Cervical cancer is one of the foremost common cancers in women. Human papillomavirus (HPV) infection remains a major risk factor of cervical cancer. In addition, numerous other genetic and epigenetic factors also are involved in the underlying pathogenesis of cervical cancer. Recently, it has been reported that apolipoprotein B mRNA editing enzyme catalytic polypeptide like (APOBEC), DNA-editing protein plays an important role in the molecular pathogenesis of cancer. Particularly, the APOBEC3 family was shown to induce tumor mutations by aberrant DNA editing mechanism. In general, APOBEC3 enzymes play a pivotal role in the deamination of cytidine to uridine in DNA and RNA to control diverse biological processes such as regulation of protein expression, innate immunity, and embryonic development. Innate antiviral activity of the APOBEC3 family members restrict retroviruses, endogenous retro-element, and DNA viruses including the HPV that is the leading risk factor for cervical cancer. This review briefly describes the pathogenesis of cervical cancer and discusses in detail the recent findings on the role of APOBEC in the molecular pathogenesis of cervical cancer.

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APOBEC enzymes deaminate cytidine to uridine and control diverse biological processes including viral restriction.

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APOBEC3, DNA/RNA-editing enzyme plays an important role in the molecular pathogenesis of cervical cancer.

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APOBEC3-mediated DNA editing leads to the accumulation of somatic mutations in tumors and HPV genome.

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Deregulation of APOBEC3 family genes cause genomic instability and result in drug resistance, and immune-evasion in tumors.

The precision prevention and therapy of HPV-related cervical cancer: new concepts and clinical implications

Cervical cancer is the third most common cancer in women worldwide, with concepts and knowledge about its prevention and treatment evolving rapidly. Human papillomavirus (HPV) has been identified as a major factor that leads to cervical cancer, although HPV infection alone cannot cause the disease. In fact, HPV-driven cancer is a small probability event because most infections are transient and could be cleared spontaneously by host immune system. With persistent HPV infection, decades are required for progression to cervical cancer. Therefore, this long time window provides golden opportunity for clinical intervention, and the fundament here is to elucidate the carcinogenic pattern and applicable targets during HPV-host interaction. In this review, we discuss the key factors that contribute to the persistence of HPV and cervical carcinogenesis, emerging new concepts and technologies for cancer interventions, and more urgently, how these concepts and technologies might lead to clinical precision medicine which could provide prediction, prevention, and early treatment for patients.

Association between HLA-DP Gene Polymorphisms and Cervical Cancer Risk: A Meta-Analysis

Objective. We aimed to derive a more precise estimation of the associations between human leukocyte antigens DP (HLA-DP) gene polymorphisms and cervical cancer risk by meta-analysis. Methods. PubMed, EMBASE, ScienceDirect, Web of Science, Chinese National Knowledge Infrastructure (CNKI), and Wanfang databases were systematically searched to identify studies investigating the relationship between HLA-DP gene polymorphisms and cervical cancer. The associations between them were evaluated by pooled OR and 95% CI. Results. A total of 11 studies including 5008 cases and 9322 controls with 11 HLA-DP alleles were included in the current meta-analysis. Results. The results showed that HLA-DPB1⁎03:01 was significantly associated with an increased risk of cervical cancer (OR=1.252, 95%CI: 1.116-1.403, Pz=0.001), while HLA-DPB1⁎04:02 and HLA-DP rs3117027 G allele were significantly associated with a decreased risk of cervical cancer (OR=0.744, 95%CI: 0.652-0.848, Pz=0.001; OR=0.790, 95%CI: 0.745-0.837, Pz=0.001), and HLA-DP rs9277535 G allele was significantly associated with a decreased risk of cervical cancer in Asia (OR=0.802, 95%CI: 0.753-0.855, Pz=0.001). Subgroup analyses based on race system showed that HLA-DPB1⁎13:01 was significantly associated with an increased risk of cervical cancer in Asia (OR=1.834, 95%CI: 1.107-3.039, Pz=0.019). No significant association was established for the HLA-DP following alleles: DPB1⁎02:01, DPB1⁎02:02, DPB1⁎04:01, DPB1⁎05:01, rs4282438, and rs3077. Conclusion. HLA-DP gene polymorphisms (HLA-DPB1⁎03:01, DPB1⁎04:02, DPB1⁎13:01, rs9277535, and rs3117027) were significantly associated with cervical cancer.

The Intersection of HPV Epidemiology, Genomics and Mechanistic Studies of HPV-Mediated Carcinogenesis

Of the ~60 human papillomavirus (HPV) genotypes that infect the cervicovaginal epithelium, only 12–13 “high-risk” types are well-established as causing cervical cancer, with HPV16 accounting for over half of all cases worldwide. While HPV16 is the most important carcinogenic type, variants of HPV16 can differ in their carcinogenicity by 10-fold or more in epidemiologic studies. Strong genotype-phenotype associations embedded in the small 8-kb HPV16 genome motivate molecular studies to understand the underlying molecular mechanisms. Understanding the mechanisms of HPV genomic findings is complicated by the linkage of HPV genome variants. A panel of experts in various disciplines gathered on 21 November 2016 to discuss the interdisciplinary science of HPV oncogenesis. Here, we summarize the discussion of the complexity of the viral–host interaction and highlight important next steps for selected applied basic laboratory studies guided by epidemiological genomic findings.

A pathway-based association study reveals variants from Wnt signalling genes contributing to asthma susceptibility

BACKGROUND

Genetic susceptibility to asthma is currently linked to a handful of genes which have a limited ability to predict the overall disease risk, suggesting the existence of many other genes involved in disease development. Accumulated evidence from association studies in genes related by biological pathways could reveal novel asthma genes.

OBJECTIVE

To reveal novel asthma susceptibility genes by means of a pathway-based association study.

METHODS

Based on summary data from a previous a genomewide association study (GWAS) of asthma, we first identified significant biological pathways using a gene-set enrichment analysis. We then mapped all tested single nucleotide polymorphisms (SNPs) on the genes contributing to significant pathways and prioritized those with a disproportionate number of nominal significant associations for further studies. For those prioritized genes, association studies were performed for selected SNPs in independent case-control samples (n = 1765) using logistic regression models, and results were meta-analysed with those from the GWAS.

RESULTS

Two biological processes were significantly enriched: the cytokine-cytokine receptor interaction (P = 0.002) and the Wnt signalling (P = 0.012). From the 417 genes interacting in these two pathways, 10 showed an excess of nominal associations, including a known asthma susceptibility locus (encoding SMAD family member 3) and other novel candidate genes. From the latter, association studies of 14 selected SNPs evidenced replication in a locus near the frizzled class receptor 6 (FZD6) gene (P = 9.90 × 10^-4 ), which had a consistent direction of effects with the GWAS findings (meta-analysed odds ratio = 1.49; P = 5.87 × 10^-6 ) and was in high linkage disequilibrium with expression quantitative trait loci in lung tissues.

CONCLUSIONS AND CLINICAL RELEVANCE

This study revealed the importance of two biological pathways in asthma pathogenesis and identified a novel susceptibility locus near Wnt signalling genes.

Combined analysis of pri-miR-34b/c rs4938723 and TP53 Arg72Pro with cervical cancer risk

miR-34 family members can form a p53-miR-34 positive feedback loop and induce apoptosis, DNA repair, angiogenesis, and cell cycle arrest. We conducted a case-control study to examine whether two polymorphisms (i.e., rs4938723 in the promoter of pri-miR-34b/c and TP53 Arg72Pro) were linked to the carcinogenesis of cervical cancer among Chinese Han women. Genotypes of the two polymorphisms in 328 cervical cancer patients and 568 control subjects were determined by using a polymerase chain reaction-restriction fragment length polymorphism assay. We found a significantly increased cervical cancer risk in the pri-miR-34b/c rs4938723 under dominant and overdominant model (CT/CC vs. TT: adjusted OR = 1.34, 95 % CI = 1.01-1.77; CT vs. TT/CC: adjusted OR = 1.37, 95 % CI = 1.05-1.80, respectively). Increased cervical cancer risks were also found in the TP53 Arg72Pro under a heterozygous comparison and overdominant model (CG vs. GG: adjusted OR = 1.44, 95 % CI = 1.06-1.95; CG vs. GG/CC: adjusted OR = 1.47, 95 % CI = 1.12-1.94, respectively). Stratification analysis showed that patients carrying the pri-miR-34b/c rs4938723 CT genotype had a significantly increased risk for developing poorly differential status and clinical stage I. Moreover, increased cancer risks were observed for the TP53 Arg72Pro polymorphism in patients with poorly differential status, clinical stage II, and without lymph node metastasis. Combined analysis revealed that the genotypes of rs4938723 CT/CC and TP53 Arg72Pro CG/CC had an increased cervical cancer risk (OR = 2.21, 95 % CI = 1.38-3.53). These findings suggest that the pri-miR-34b/c rs4938723 and TP53 Arg72Pro polymorphisms may contribute to the genesis of cervical cancer.

TGFβ receptor 1: an immune susceptibility gene in HPV-associated cancer

Only a minority of those exposed to human papillomavirus (HPV) develop HPV-related cervical and oropharyngeal cancer. Because host immunity affects infection and progression to cancer, we tested the hypothesis that genetic variation in immune-related genes is a determinant of susceptibility to oropharyngeal cancer and other HPV-associated cancers by performing a multitier integrative computational analysis with oropharyngeal cancer data from a head and neck cancer genome-wide association study (GWAS). Independent analyses, including single-gene, gene-interconnectivity, protein-protein interaction, gene expression, and pathway analysis, identified immune genes and pathways significantly associated with oropharyngeal cancer. TGFβR1, which intersected all tiers of analysis and thus selected for validation, replicated significantly in the head and neck cancer GWAS limited to HPV-seropositive cases and an independent cervical cancer GWAS. The TGFβR1 containing p38-MAPK pathway was significantly associated with oropharyngeal cancer and cervical cancer, and TGFβR1 was overexpressed in oropharyngeal cancer, cervical cancer, and HPV(+) head and neck cancer tumors. These concordant analyses implicate TGFβR1 signaling as a process dysregulated across HPV-related cancers. This study demonstrates that genetic variation in immune-related genes is associated with susceptibility to oropharyngeal cancer and implicates TGFβR1/TGFβ signaling in the development of both oropharyngeal cancer and cervical cancer. Better understanding of the immunogenetic basis of susceptibility to HPV-associated cancers may provide insight into host/virus interactions and immune processes dysregulated in the minority of HPV-exposed individuals who progress to cancer.

Polymorphisms in immune mediators associate with risk of cervical cancer

OBJECTIVE

The immune system is critical for controlling the progression of HPV cervical disease and the development of cancer. This study aimed to identify cervical cancer susceptibility alleles in candidate immune-modulating genes.

METHODS

Our family-based study involved a cohort of 641 probands (women with ICC/CIN III) and their biologic parents or siblings (641 trios). In the discovery phase (stage 1), involving 288 of the trios, 80 tag single nucleotide polymorphisms (SNPs) in 11 immune-modulating genes (IFNG, IFNGR1, IFNGR2, JAK1, JAK2, STAT1, STAT6, IL12A, TNF, LTA and LTB) were evaluated on the GoldenGate platform. We used the combined dataset for a total of 641 trios (stage 2) and the Taqman platform to validate the SNPs that had proved significant in the discovery dataset. The transmission disequilibrium test was used to detect significant shifts in allelic transmissions in the datasets.

RESULTS

Two SNPs in JAK2 and one SNP in STAT6 showed significant allelic association with cervical cancer in the stage 1 discovery dataset and were replicated in the larger joint analysis stage 2 dataset (JAK2 rs10815144, P=0.0029 and rs12349785, P=0.0058; and STAT6 rs3024971, P=0.0127). An additional SNP in exon 19 of JAK2 (rs2230724) was also examined in the combined dataset due to its strong linkage disequilibrium (LD) with rs10815144. It was also significant (P=0.0335).

CONCLUSIONS

Our results suggest an association of SNPs in JAK2 and STAT6 with cervical cancer. This association should be investigated in additional cervical cancer populations.

Pathway analysis of cervical cancer genome-wide association study highlights the MHC region and pathways involved in response to infection

Cervical cancer is caused by infection with human papillomavirus (HPV). A genome-wide association study (GWAS) has identified several susceptibility loci for cervical cancer, but they explain only a small fraction of cervical cancer heritability. Other variants with weaker effect may be missed due to the stringent significance threshold. To identify important pathways in cervical carcinogenesis, we performed a two-stage pathway analysis in two independent GWASs in the Swedish population, using the single-nucleotide polymorphism (SNP) ratio test. The 565 predefined pathways from Kyoto Encyclopedia of Genes and Genomes and BioCarta databases were systematically evaluated in the discovery stage (1034 cases and 3948 controls with 632,668 SNPs) and the suggestive pathways were further validated in the replication stage (616 cases and 506 controls with 341,358 SNPs). We found 12 pathways that were significant in both stages, and these were further validated using set-based analysis. For 10 of these pathways, the effect was mainly due to genetic variation within the major histocompatibility complex (MHC) region. In addition, we identified a set of novel candidate genes outside the MHC region in the pathways denoted 'Staphylococcus aureus infection' and 'herpes simplex infection' that influenced susceptibility to cervical cancer (empirical P = 4.99 × 10(-5) and 4.99 × 10(-5) in the discovery study; empirical P = 8.98 × 10(-5) and 0.009 in the replication study, respectively). Staphylococcus aureus infection may evoke an inflammatory response that inadvertently enhances malignant progression caused by HPV infection, and Herpes simplex virus-2 infection may act in conjunction with HPV infection to increase the risk of cervical carcinoma development. These findings provide new insights into the etiology of cervical cancer.

A genome-wide association study identifies two new cervical cancer susceptibility loci at 4q12 and 17q12

To identify new genetic risk factors for cervical cancer, we conducted a genome-wide association study in the Han Chinese population. The initial discovery set included 1,364 individuals with cervical cancer (cases) and 3,028 female controls, and we selected a 'stringently matched samples' subset (829 cases and 990 controls) from the discovery set on the basis of principal component analysis; the follow-up stages included two independent sample sets (1,824 cases and 3,808 controls for follow-up 1 and 2,343 cases and 3,388 controls for follow-up 2). We identified strong evidence of associations between cervical cancer and two new loci: 4q12 (rs13117307, Pcombined, stringently matched=9.69×10(-9), per-allele odds ratio (OR)stringently matched=1.26) and 17q12 (rs8067378, Pcombined, stringently matched=2.00×10(-8), per-allele ORstringently matched=1.18). We additionally replicated an association between HLA-DPB1 and HLA-DPB2 (HLA-DPB1/2) at 6p21.32 and cervical cancer (rs4282438, Pcombined, stringently matched=4.52×10(-27), per-allele ORstringently matched=0.75). Our findings provide new insights into the genetic etiology of cervical cancer.

Genome-wide association study of susceptibility loci for cervical cancer

BACKGROUND

Cervical carcinoma has a heritable genetic component, but the genetic basis of cervical cancer is still not well understood.

METHODS

We performed a genome-wide association study of 731 422 single nucleotide polymorphisms (SNPs) in 1075 cervical cancer case subjects and 4014 control subjects and replicated it in 1140 case subjects and 1058 control subjects. The association between top SNPs and cervical cancer was estimated by odds ratios (ORs) and 95% confidence intervals (CIs) with unconditional logistic regression. All statistical tests were two-sided.

RESULTS

Three independent loci in the major histocompatibility complex (MHC) region at 6p21.3 were associated with cervical cancer: the first is adjacent to the MHC class I polypeptide-related sequence A gene (MICA) (rs2516448; OR = 1.42, 95% CI = 1.31 to 1.54; P = 1.6×10(-18)); the second is between HLA-DRB1 and HLA-DQA1 (rs9272143; OR = 0.67, 95% CI = 0.62 to 0.72; P = 9.3×10(-24)); and the third is at HLA-DPB2 (rs3117027; OR=1.25, 95% CI = 1.15 to 1.35; P = 4.9×10(-8)). We also confirmed previously reported associations of B*0702 and DRB1*1501-DQB1*0602 with susceptibility to and DRB1*1301-DQA1*0103-DQB1*0603 with protection against cervical cancer. The three new loci are statistically independent of these specific human leukocyte antigen alleles/haplotypes. MICA encodes a membrane-bound protein that acts as a ligand for NKG2D to activate antitumor effects. The risk allele of rs2516448 is in perfect linkage disequilibrium with a frameshift mutation (A5.1) of MICA, which results in a truncated protein. Functional analysis shows that women carrying this mutation have lower levels of membrane-bound MICA.

CONCLUSIONS

Three novel loci in the MHC may affect susceptibility to cervical cancer in situ, including the MICA-A5.1 allele that may cause impaired immune activation and increased risk of tumor development.

Genetic variants in HLA-DP/DQ contribute to risk of cervical cancer: a two-stage study in Chinese women

OBJECTIVE

Human leukocyte antigens (HLA) play an important role in presenting virus antigens to immune cells that are responsible for the clearance of virus-infected cells and tumor cells. Herein, we evaluated whether genetic variants of HLA-DP and HLA-DQ are associated with cervical cancer risk.

METHODS

We genotyped four single nucleotide polymorphisms (SNPs) in HLA-DP (rs3077 and rs9277535) and HLA-DQ (rs2856718 and rs7453920) in a two-stage case-control study with a total of 2317 cervical cancer cases and 2109 cancer-free controls using TaqMan allelic discrimination assay.

RESULTS

We found consistently significant associations of HLA-DP rs3077 and rs9277535 with increased risks of cervical cancer (dominant genetic model: adjusted OR=1.51, 95% CI=1.32-1.71 for rs3077; adjusted OR=1.29, 95% CI=1.12-1.49 for rs9277535). When combining the effects of HLA-DP rs3077 and rs9277535, subjects carrying "≥1" variant alleles had a 1.55-fold increased risk of cervical cancer (95% CI=1.32-1.81), compared with those carrying "0" variant allele. And cervical cancer risk significantly increased with the increasing number of variant alleles of the two SNPs in a dose-dependent manner (P for trend=4.33×10(-10)). However, there were no significant associations for HLA-DQ rs2856718 and rs7453920 in our population.

CONCLUSIONS

These findings indicate that HLA-DP rs3077 and rs9277535 were candidate susceptibility markers for cervical cancer in Chinese females. Further validation studies with different ethnic background, biological function analyses and especially HPV typing together were needed.

Nucleotide variation in IL-10 and IL-12 and their receptors and cervical and vulvar cancer risk: a hybrid case-parent triad and case-control study

Given the important role of cell mediated immunity in viral clearance and control of premalignant lesions, we hypothesize that variation in the IL-12/IL-10 cytokine and cytokine receptor genes may influence cervical and vulvar cancer risk. We evaluated 76 tagSNPs from seven candidate genes (IL-10, IL-12A, IL-12B, IL-10RA, IL-10RB, IL-12RB1, and IL12RB2) in case-parent sets (n=43 cervical squamous cell carcinoma (SCC), n=96 cervical adenocarcinoma, n=53 vulvar SCC), additional cases (n=356 cervical SCC, n=406 cervical adenocarcinoma, and n=473 vulvar SCC) and population based controls (1,111). We calculated log-additive odds ratios (ORs) and 95% confidence intervals (CIs) for the association between tagSNP and cancer risk using a pseudo-likelihood based method which combined genotype information on cases, parents, and population controls. After correction for multiple comparisons, we identified several statistically significant SNP associations. Cervical SCC risk was associated with the minor alleles of the IL10RA rs9610 3' UTR SNP (OR=1.76, 95% CI=1.15-2.68) and two synonymous IL12RB2 SNPs (rs4297265, OR=0.46, 95% CI=0.26-0.82; rs2229546, OR=0.43, 95% CI=0.21-0.87). Cervical adenocarcinoma risk was associated with the minor alleles of the IL10RA rs4252314 intronic SNP (OR=2.23, 95% CI=1.26-3.96) and IL12RB1 rs11575934 non-synonymous SNP (OR=1.51, 95% CI=1.12-2.05). Finally, the minor allele of the IL12B rs3181224 3' UTR SNP was associated with a reduced risk of vulvar SCC (OR=0.30, 95% CI=0.12-0.74). These results raise the possibility that a shift in the balance of the immune response due to genetic variants in key cytokine genes could influence the development of cervical and vulvar cancer.

HLA and SNP haplotype mapping in the Japanese population

The genes that encode the human leukocyte antigen (HLA) class I and II molecules are highly polymorphic and located in the major histocompatibility complex (MHC) region, where there is a high density of immune-related genes. Numerous studies have identified disease susceptibility in this region; however, interpretation of the results is complicated because of the strong linkage disequilibrium (LD) among HLA alleles and single-nucleotide polymorphisms (SNPs). In this study, we evaluated the correlation between the HLA alleles of 6 loci (HLA-A, C, B, DRB1, DQB1 and DPB1) and 6502 SNPs within 8 Mb of the extended MHC region using 92 Japanese subjects to identify SNP single loci or haplotypes that tag HLA alleles. We found a total of 39 HLA alleles that showed strong LD (r(2)≥0.8) with SNPs, including 11 non-synonymous SNPs in non-HLA genes. In addition, we identified several SNP haplotypes in strong LD (r(2)≥0.8) with eight HLA alleles, which do not possess tag SNPs. Our detailed list of tag SNPs and haplotypes could be utilized for a better understanding of the results obtained by association studies in the Japanese population and for the characterization of the differences in LD structures between races.