Polymorphisms in the cytotoxic T-lymphocyte antigen 4 gene and cancer risk: a meta-analysis

Evidence of Association between CTLA-4 Gene Polymorphisms and Colorectal Cancers in Saudi Patients

Cytotoxic T lymphocyte antigen-4 (CTLA-4) has been identified as an immunosuppressive molecule involved in the negative regulation of T cells. It is highly expressed in several types of autoimmune diseases and cancers including colorectal cancer (CRC). (1) Objective: To explore the association between CTLA-4 single nucleotide polymorphisms (SNP) and risk to (CRC) in the Saudi population. (2) Methods: In this case-control study, 100 patients with CRC and 100 matched healthy controls were genotyped for three CTLA-4 SNPs: rs11571317 (-658C > T), rs231775 (+49A > G) and rs3087243 (CT60 G > A), using TaqMan assay method. Associations were evaluated using odds ratios (ORs) and 95% confidence intervals (95% CIs) for five inheritance models (co-dominant, dominant, recessive, over-dominant and log-additive). Furthermore, CTLA-4 expression levels were evaluated using quantitative real-time PCR (Q-RT-PCR) in colon cancer and adjacent colon tissues. (3) Results: Our result showed a significant association of the G allele (OR = 2.337, p < 0.0001) and GG genotype of the missense SNP +49A > G with increased risk of developing CRC in codominant (OR = 8.93, p < 0.0001) and recessive (OR = 16.32, p < 0.0001) models. Inversely, the AG genotype was significantly associated with decreased risk to CRC in the codominant model (OR = 0.23, p < 0.0001). In addition, the CT60 G > A polymorphism exhibited a strong association with a high risk of developing CRC for the AA genotype in codominant (OR = 3.323, p = 0.0053) and in allele models (OR = 1.816, p = 0.005). No significant association was found between -658C > T and CRC. The haplotype analysis showed that the G-A-G haplotype of the rs11571317, rs231775 and rs3087243 was associated with high risk for CRC (OR = 57.66; p < 0.001). The CTLA-4 mRNA gene expression was found significantly higher in tumors compared to normal adjacent colon samples (p < 0.001). (4) Conclusions: Our findings support an association between the CTLA-4 rs231775 (+49A > G) and rs3087243 (CT60 G > A) polymorphisms and CRC risk in the Saudi population. Further validation in a larger cohort size is needed prior to utilizing these SNPs as a potential screening marker in the Saudi population.

Associations of interleukin-4 and interleukin-4 receptor loci with esophageal squamous cell carcinoma susceptibility

Some functional polymorphisms in immune-regulating genes could affect the development of esophageal squamous cell carcinoma (ESCC). We enrolled 721 patients with ESCC and 1,208 healthy controls to explore the roles of rs2227282 (C > G) and rs2243283 (C > G) loci in the interleukin-4 (IL4) gene and rs1801275 loci in the interleukin-4 receptor (IL4R) gene for the occurrence of ESCC. As for IL4, the single nucleotide polymorphism rs2227282 (C > G) conferred an overall decreased risk for ESCC (adjusted P = 0.005, power = 0.816 in GG vs. CC genetic models). A stratification analysis of IL4 rs2227282 (C > G) and rs2243283 (C > G) and IL4R rs1801275 (A > G) loci with the ESCC risk revealed that the IL4 rs2243283 (C > G) polymorphism was a protective factor for the susceptibility to ESCC in some subgroups (women: power = 0.932 in CG vs. CC and 0.956 in CG/GG vs. CC; subjects aged ≥63 years: power = 0.844 in CG/GG vs. CC; never-smokers: power = 0.893 in CG vs. CC and 0.882 in CG/GG vs. CC; never-drinkers: power = 0.904 in CG vs. CC and 0.862 in CG/GG vs. CC). We also investigated the association of IL4 rs2227282 and rs2243283 and IL4R rs1801275 loci with the lymph node status. However, a null relationship was found. In conclusion, the present study highlighted that IL4 rs2227282 (C > G) and rs2243283 (C > G) loci are protective factors for the occurrence of ESCC.

Immune Checkpoint Molecules-Inherited Variations as Markers for Cancer Risk

In recent years, immunotherapy has been revolutionized by a new approach that works by blocking receptors called immune checkpoints (IC). These molecules play a key role in maintaining immune homeostasis, mainly by suppressing the immune response and by preventing its overactivation. Since inhibition of the immune response by IC can be used by cancer to avoid recognition and destruction by immune system, blocking them enhances the anti-tumor response. This therapeutic approach has brought spectacular clinical effects. The ICs present heterogeneous expression patterns on immune cells, which may affect the effectiveness of immunotherapy. The inherited genetic variants in regulatory regions of ICs genes can be considered as potential factors responsible for observed inter-individual differences in ICs expression levels on immune cells. Additionally, polymorphism located in exons may introduce changes to ICs amino acid sequences with potential impact on functional properties of these molecules. Since genetic variants may affect both expression and structure of ICs, they are considered as risk factors of cancer development. Inherited genetic markers such as SNPs may also be useful in stratification patients into groups which will benefit from particular immunotherapy. In this review, we have comprehensively summarized the current understanding of the relationship between inherited variations of CTLA-4, PDCD1, PD-L1, BTLA, TIM-3, and LAG-3 genes in order to select SNPs which can be used as predictive biomarkers in personalized evaluation of cancer risk development and outcomes as well as possible response to immunotherapy.

A systematic review and network meta-analysis of single nucleotide polymorphisms associated with pancreatic cancer risk

In this meta-analysis, we systematically investigated the correlation between single nucleotide polymorphisms (SNPs) and pancreatic cancer (PC) risk. We searched PubMed, Network Science, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), China Science and Technology Periodical Database (VIP), and Wanfang databases up to January 2020 for studies on PC risk-associated SNPs. We identified 45 case-control studies (36,360 PC patients and 54,752 non-cancer individuals) relating to investigations of 27 genes and 54 SNPs for this meta-analysis. Direct meta-analysis followed by network meta-analysis and Thakkinstian algorithm analysis showed that homozygous genetic models for CTLA-4 rs231775 (OR =0.326; 95% CI: 0.218-0.488) and VDR rs2228570 (OR = 1.976; 95% CI: 1.496-2.611) and additive gene model for TP53 rs9895829 (OR = 1.231; 95% CI: 1.143-1.326) were significantly associated with PC risk. TP53 rs9895829 was the most optimal SNP for diagnosing PC susceptibility with a false positive report probability < 0.2 at a stringent prior probability value of 0.00001. This systematic review and meta-analysis suggest that TP53 rs9895829, VDR rs2228570, and CTLA-4 rs231775 are significantly associated with PC risk. We also demonstrate that TP53 rs9895829 is a potential diagnostic biomarker for estimating PC risk.

FOXP3 and CTLA-4 genetic variants' influence on the susceptibility and clinical course of basal cell carcinoma

Introduction

The pathogenesis of basal cell carcinoma (BCC) is multifactorial and not fully elucidated. Previous studies showed that behaviour of the tumour may be influenced by the immune system and identified CD4⁺CD25⁺FoxP3⁺ regulatory T cells (T_regs) as dominant immune cells in BCC microenvironment. The function and development of Tregs is regulated by FOXP3, encoding transcription factor Forkhead box P3. FOXP3 regulates transcription of many genes, including up-regulation of cytotoxic lymphocyte-associated antigen-4 gene (CTLA-4). Expressed on Tregs, CTLA-4 interacts with antigen-presenting cells to inhibit T-cell activation.

Aim

To investigate the role of two polymorphisms (rs3761548 and rs2232365) of FOXP3 and CTLA-4 polymorphism (rs5742909) in BCC patients from northern Poland.

Material and methods

We analysed 280 unrelated patients with BCC of mean age 70.93 ±11.53 (70.54 ±12.55 women, 71.38 ±10.26 men) and 200 healthy, unrelated age- and sex-matched volunteers.

Results

The differences in the occurrence of BCC between genotypes and alleles of the analysed polymorphisms were not statistically significant. In the studied group, the presence of the CC genotype in CTLA-4 rs5742909 polymorphism was statistically more frequent in patients with multiple BCCs.

Conclusions

It seems that the analysed FOXP3 and CTLA-4 polymorphisms do not influence the BCC susceptibility. CTLA-4 rs5742909 polymorphism may influence the susceptibility to multiple BCCs.

Identification of porcine CTLA4 gene polymorphism and their association with piglet diarrhea and performance traits

The objective of this study was to evaluate the association between the cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) gene and piglet diarrhea. In this study, the mRNA expression of the CTLA4 gene increased significantly in IPEC-J2 cells after Escherichia coli K88 infection. Single nucleotide polymorphisms (SNPs) located in the 5' flanking region (SNPs g.107281989C>T) and 3'-untranslated region (3'-UTR; SNPs g.107288753C>A) were identified, and they were in linkage disequilibrium in both Min pigs and the Landrace population. Association analysis showed that Landrace piglets with a TT or AA genotype had a lower diarrhea index, and AA animals had higher average daily gain when compared to CC pigs, respectively (p < 0.05). However, the relationship between SNPs and diarrhea and performance traits in the Min population was not significant. Haplotype analysis indicated that the TC haplotype had the lowest diarrhea index. The 5' flanking deletion assay suggested that SNP g.107281989C>T was a molecular marker instead of the functional marker. This research demonstrated that genetic variances in the CTLA4 gene had significant effects on Landrace piglet diarrhea resistance.

CTLA4 tagging polymorphisms and risk of colorectal cancer: a case-control study involving 2,306 subjects

Background

CTLA4 is a candidate gene which has been implicated in the development of colorectal cancer (CRC).

Patients and Methods

To determine the important role of CTLA-4 polymorphisms on risk of CRC, we genotyped four CTLA-4 tagging polymorphisms and calculated crude/adjusted ORs with their 95% CIs. We recruited 1,003 sporadic CRC cases and 1,303 controls.

Results

The findings suggested that CTLA-4 rs231775 G>A polymorphism increased the risk of CRC (homozygote model: adjusted OR=1.40, 95% CI=1.05-1.87, P=0.022; dominant model: adjusted OR=1.19, 95% CI=1.00-1.41, P=0.047; and recessive model: adjusted OR=1.38, 95% CI=1.05-1.82, P=0.021). In a stratified analysis by site of tumor, this association was also found in colon cancer. We also found that CTLA-4 rs231775 GA/AA genotypes might be associated with an increased risk of CRC in Zhenjiang cohort. In addition, we found the CTLA-4 rs16840252 C>T polymorphism was associated with the risk of colon cancer. Haplotype comparison analysis showed that CTLA-4 G_rs3087243C_rs16840252C_rs733618 A_rs231775, G_rs3087243C_rs16840252T_rs733618A_rs231775, and other haplotypes increased the risk of CRC (P<0.001, <0.001, and 0.002, respectively).

Conclusion

This study evidences an association of CTLA-4 tagging polymorphisms and haplotypes with CRC risk. Additional well-designed studies with large sample sizes are required to confirm our findings.

Diagnostic performance of CTLA-4, carcinoembryonic antigen and CYFRA 21-1 for malignant pleural effusion

OBJECTIVES

The diagnosis of malignant pleural effusion (MPE) remains a clinical challenge. As a negative regulator of T-cell activation, cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) has been associated with many malignant diseases. However, there is limited data about the relationship between CTLA-4 and MPE. The present study aims to investigate whether CTLA-4 levels may correlate with presence of MPE and to assess its potential diagnostic accuracy relative to that of the established markers carcinoembryonic antigen (CEA) and cytokeratin 19 fragment (CYFRA21-1).

METHODS

Pleural effusion samples were collected from 36 patients with MPE and 48 patients with benign pleural effusion (BPE). Pleural levels of CTLA-4 were measured by ELISA; levels of CEA and CYFRA 21-1, by electrochemiluminescence immunoassay. Receiver operating characteristic curves were calculated to evaluate the ability of CTLA-4, CEA and CYFRA 21-1 to differentiate MPE from BPE.

RESULTS

Pleural levels of CTLA-4 were significantly higher in MPE than in BPE patients (471.73 ± 378.86 vs. 289.22 ± 173.67 pg/ml, p = 0.004). At a cut-off value of 351.25 pg/ml, the sensitivity and specificity of CTLA-4 in diagnosing MPE were 58.30% and 83.30%, respectively, and the area under the curve was 0.72. Pleural levels of CEA and CYFRA 21-1 were also higher in MPE. Using the combination of CTLA-4, CEA and CYFRA 21-1 increased diagnostic sensitivity to 88.89% and the area under the curve to 0.92.

CONCLUSION

The results of this preliminary study suggest that increased levels of CTLA-4 correlate with MPE, and that CTLA-4 may have some diagnostic usefulness when used in combination with conventional tumor markers such as CEA and CYFRA 21-1. These results justify larger, more rigorous studies to validate our findings.

Is the Genetic Background of Co-Stimulatory CD28/CTLA-4 Pathway the Risk Factor for Prostate Cancer?

The impairment of immunological surveillance caused by aberrant T cell activation can lead to an inadequate anti-tumor response. Therefore, deregulation in co-stimulatory pathway might be associated with cancer susceptibility. Here we undertook a prospective study to investigate whether genetic variations in gene encoding molecule CD28 and CTLA-4 playing pivotal role in regulating adoptive immune response can influence susceptibility to prostate cancer. Single nucleotide polymorphisms (SNPs) in CTLA-4 and CD28 genes were genotyped in 301 prostate cancer (PCa) patients and 301 controls. The distributions of the genotypes and haplotypes in the CTLA-4/CD28 SNPs were similar in both studied groups. However, the overrepresentation of carriers of CTLA-4c.49A>G[A] allele and carriers of CTLA-4g.319C>T[T] allele in PCa as compared to controls was observed (p = 0.082 and p = 0.13, respectively). The risk of disease was higher (OR 1.78) for carriers of both susceptibility alleles as compared to carriers of protective genotypes (p = 0.03). The CTLA-4c.49A>G and CTLA-4g.319C>T SNPs might be considered as low risk susceptibility locus for PCa.

Investigation of Cytotoxic T-lymphocyte antigen 4 Polymorphisms in Gastric Cardia Adenocarcinoma

To assess the potential effects of Cytotoxic T-lymphocyte antigen 4 (CTLA4) gene polymorphisms on susceptibility to gastric cardia adenocarcinoma (GCA), we genotyped four polymorphisms (rs733618 A>G, rs16840252 C>T, rs231775 G>A and rs3087243 G>A) in CTLA4 and calculated odds ratios (ORs) with the corresponding 95% confidence intervals (95% CIs) for the genotype and allele distributions between GCA cases and controls. The CTLA4 genotypes were determined by the polymerase chain reaction-ligase detection reaction (PCR-LDR) analysis in 330 GCA patients and 608 unrelated cancer-free controls. In this case-control study, there was no significant difference in the genotype and allele distributions of four CTLA4 polymorphisms between GCA patients and controls. However, haplotype association analysis indicated that compared with CTLA4 Grs733618 Crs16840252 Grs231775 Crs3087243 , CTLA4 Grs733618 Crs16840252 Ars231775 Grs3087243 and Ars733618 Crs16840252 Grs231775 Ars3087243 haplotypes conferred increased risks of GCA (OR = 6.46, 95% CI = 1.33-31.28; P = 0.012; both); however, CTLA4 Ars733618 Crs16840252 Ars231775 Grs3087243 and Ars733618 Trs16840252 Grs231775 Grs3087243 haplotypes conferred decreased risks of GCA (P = 0.001 and P = 0.011, respectively). These results highlight that the rare CTLA4 haplotypes may affect the development of GCA in the Chinese population.

Association between the cytotoxic T-lymphocyte antigen 4-318C/T polymorphism and malignant tumor risk

The cytotoxic T-lymphocyte antigen 4 (CTLA-4) polymorphic loci -318 cytosine/thymine (-318C/T) has been previously implicated in malignant tumor susceptibility. However, there were no precise conclusions about the correlation, the results from published studies were inconclusive. The aim of the current meta-analysis was to investigate the associations between CTLA-4 -318C/T polymorphisms and risk of malignant tumors in Asian population. We conducted a search in PubMed, Embase, the Chinese Journals Full-Text Database, Chinese Biomedical Database, and the Wanfang database. All studies were published up to September 30, 2015. Two reviewers analysed the data independently. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the association. In total, 20 case-controlled studies with 3,539 cases and 4,690 controls were included in the final meta-analysis. The overall estimation demonstrated a significant association between CTLA-4 -318C/T polymorphism and malignant tumor risk in the Asian populations (TT+TC vs. CC: OR, 1.28; 95% CI, 1.07-1.53. TT vs. TC+CC: OR, 1.43; 95% CI, 1.03-1.99; TT vs. CC: OR, 1.51; 95% CI, 1.09-2.10. TC vs. CC: OR, 1.26; 95% CI, 1.06-1.50. T vs. C: OR, 1.25, 95% CI, 1.05-1.47). In the subgroup analysis by countries, we found that the dominant model (TT+TC vs. CC) revealed an increased risk of developing malignant tumors in the Chinese study population (OR, 1.41; 95% CI, 1.13-1.76), but no association was demonstrated in the other countries. The current meta-analysis suggests that CTLA-4 -318C/T polymorphism is significantly associated with the risk of malignance tumors in Asian populations, especially in those from China. Further studies for additional Asian countries are required to further evaluate the association.

Current evidence on the cytotoxic T-lymphocyte antigen 4 + 49G > A polymorphism and digestive system cancer risks: a meta-analysis involving 11,923 subjects

Cytotoxic T-lymphocyte antigen (CTLA-4) plays an important role in downregulating T cell activation and proliferation. The CTLA-4 + 49G > A polymorphism is one of the most commonly studied polymorphisms in this gene due to its association with many cancer types, but the association between CTLA-4 + 49G > A polymorphism and digestive system cancer risks remain inconclusive. An updated meta-analysis based on 17 independent case-control studies consisting of 5176 cancer patients and 6747 controls was performed to address this association. Overall, there was no statistically increased risk of digestive system cancers in every genetic comparison. In subgroup analysis, this polymorphism was significantly linked to higher risks for pancreatic cancer (GG vs. AA, OR = 1.976, 95% CI = 1.496-2.611; GA vs. AA, OR = 1.433, 95% CI = 1.093-1.879; GG/GA vs. AA, OR = 1.668, 95% CI = 1.286-2.164; GG vs. GA/AA, OR = 1.502, 95% CI = 1.098-2.054; G vs. A, OR = 1.394, 95% CI = 1.098-1.770). We also observed increased susceptibility of hepatocellular cell carcinoma in homozygote comparison (OR = 1.433, 95% CI = 1.100-1.866) and dominant model (OR = 1.360, 95% CI = 1.059-1.746). According to the source of controls, significant effects were only observed in hospital-based studies (GA/AA vs. GG, OR = 1.257, 95% CI = 1.129-1.399). In the stratified analysis by ethnicity, no significantly increased risks were found in either Asian or Caucasian. Our findings suggest that the CTLA-4 + 49G > A polymorphism may be associated with the risk of pancreatic cancer and hepatocellular cell carcinoma.

CTLA-4 and CD28 genes' polymorphisms and renal cell carcinoma susceptibility in the Polish population--a prospective study

Polymorphisms in co-stimulatory genes are associated with susceptibility to several malignances such as breast cancer, cervical cancer and chronic lymphocytic leukemia, but have been scarcely investigated in renal cell cancer (RCC). A total of 310 RCC patients and 518 controls were genotyped for single-nucleotide polymorphisms (SNPs) in the CTLA-4 and CD28 genes: CTLA-4c.49A>G (rs231775), CTLA-4g.319C>T (rs5742909), CTLA-4g.*6230G>A (CT60; rs3087243), CTLA-4g.*10223G>T (Jo31; rs11571302), CD28c.17+3T>C (rs3116496) and CD28c.-1042G>A (rs3181098). The distribution of the alleles, genotypes and haplotypes in the CTLA-4 and CD28 genes were similar in the RCC patients and in the controls. However, among the patients with a clear cell RCC (CCRCC), the G allele carriers of CT60 and Jo31 SNPs were overrepresented, and the overrepresentation became significant for the carriers of CT60[G] allele in CCRCC patients with necrosis in the primary tumor (P = 0.046). The CTLA-4c.49A>G[A]/CTLA-4g.319C>T[C]/CT60[A]/Jo31[T]/CD28c.17+3T>C[T]/ CD28c.1042G>A[G] haplotype was associated with an approximately threefold increased risk of primary tumor necrosis in CCRCC patients (P corrected = 0.0000007) and with the advanced stage of disease (IV) (P corrected = 0.001). When stratified by gender, CD28c.-1042G>A[GG] genotype was more frequent in the female CCRCC patients compared with healthy women (P = 0.042). Polymorphisms in the CTLA-4 and CD28 genes, in particular considered together as haplotypes, were associated with increased risk of CCRCC, especially with necrosis and with the advanced stage of disease. The CD28c.-1042G>A SNP modulates the risk of CCRCC in women. These findings indicate that the associations of the CTLA-4 and CD28 polymorphisms with the risk of renal cancer are worth further study in a larger group of patients.

CTLA4 polymorphisms and de novo malignancy risk after renal transplantation in Chinese recipients

Genetic polymorphisms in cytotoxic T lymphocyte-associated antigen 4 (CTLA4) play an influential role in graft rejection and the long-term clinical outcome of organ transplantation. We investigated the association of five CTLA4 single-nucleotide polymorphisms (SNPs) (rs733618 C/T, rs4553808 A/G, rs5742909 C/T, rs231775 A/G, and rs3087243 G/A) with de novo malignancy in 1463 Chinese renal transplantation (RT) recipients who underwent a 192-month follow-up. Multivariate analyses revealed that recipient rs231775 genotype is significantly associated with tumorigenesis (P = 0.012). Multiplicative interaction between rs231775 AA and possible risk factors of malignancy revealed two significant results: rs231775 AA × primary diseases and rs231775 AA × number of HLA-mismatch. The frequency of haplotype TACAG was significantly higher in the tumor group (17.07%) than that in the nontumor group (1.53%). In addition, aristolochic acid nephropathy (P = 0.003) and the time of discovery of tumor (P = 0.000) also were independently associated with tumorigenesis. Our data show that the CTLA4 genotype rs231775 AA may be one of risk factors for the development of malignancy and haplotype TACAG was susceptible haplotype in Chinese kidney transplant recipients.

The association of CD28 polymorphism, rs3116496, with Cancer: A meta-analysis

OBJECTIVE

To determine the relationship between CD28 polymorphisms, rs3116496, and cancer.

DESIGN

Meta-analysis.

METHODS

PubMed, EMBASE, Web of Science, and Cochrane library databases were searched to identify studies reporting the association between CD28 polymorphism and cancer. Two authors selected identified studies, extracted, and analyzed the data independently.

RESULTS

Individuals carrying a T allele (TT homozygotes and TT+TC heterozygotes) at rs3116496 had a lower incidence of cancer than carriers of a C allele. Subgroup analysis showed that this association held true for Asians, but not Europeans.

CONCLUSION

CD28 polymorphism, rs3116496, contributes to cancer susceptibility in the case of multiple cancers.

PD-1 gene promoter polymorphisms correlate with a poor prognosis in non-small cell lung cancer

An imbalance to the regulation of the immune system changes the tumor-specific T-cell immunity in the cancer microenvironment and adjusts the tumor progression and metastasis. Inhibiting the interactions of the immune function mediates the antitumor activity in preclinical models. The programmed death 1 (PD-1) gene -606 G/A polymorphism, which may modify promoter activity and is Asian-specific, was investigated by TaqMan quantitative polymerase chain reaction assay in surgically treated non-small cell lung cancer (NSCLC) cases. In the present study, 583 surgically removed NSCLC cases were included for single-nucleotide polymorphism (SNP) analyses. The PD-1 SNP statuses at the promoter region (rs36084323) were 146 AA (25.0%), 293 GA (50.3%) and 144 GG (24.7%). The ratio was extremely similar to the healthy control in a previous study: 24.9% AA, 47.8% GA and 27.3% GG. The ratio of the GG phenotype was not significantly different for gender (25.1% males and 23.9% female), age (25.2% ≤65 years and 24.4% >65 years), smoking status (26.1% smoker and 21.8% non-smoker) and pathological subtypes [25.4% adenocarcinoma (adeno) and 24.2% squamous cell carcinoma (SCC)]. The GG ratio of PD-1 was not significantly different between pathological stage II-IV (25.5%) and stage I cases (24.1%; P=0.6245). The survival time of the patients with the -606 GG phenotype of PD-1 was significantly lower (n=147, 50 succumbed) compared to the patients with -606 GA or -606 AA (n=435, 109 succumbed) (P=0.0183). The GG phenotype patients had a significantly worse prognosis in the SCC population (P=0.009), however, this was not different to the adeno population (P=0.2594). Thus, PD-1 may promote tumor prognosis and provide a candidate for the blockade of its function as a strategy to antagonize the progression process in NSCLC, particularly lung SCC.

Lack of association between cytotoxic T-lymphocyte antigen 4 (CTLA-4) -1722T/C (rs733618) polymorphism and cancer risk: from a case-control study to a meta-analysis

BACKGROUND

The association between cytotoxic T-lymphocyte antigen 4 (CTLA-4) gene -1722T/C polymorphism (rs733618) and cancer has been widely assessed, and a definitive conclusion remains elusive. We first performed a hospital based case-control study to measure this association of esophageal cancer with CTLA-4 -1722T/C polymorphism in Han Chinese population, and then carried out a meta-analysis to obtain a comprehensive evaluation for this issue.

METHODOLOGY/PRINCIPAL FINDINGS

This case-control study involved 629 esophageal squamous cell carcinoma (ESCC) cases and 686 age and gender well matched cancer-free controls. PCR-LDR (polymerase chain reaction-ligase detection reactions) method was used to identify genotypes. Meta-analysis was conducted by STATA (v12.0) software. This case-control study showed no significant difference in the genotype and allele distributions of CTLA-4 -1722T/C polymorphism between esophageal cancer cases and control subjects, in accord with the findings of the further meta-analysis in all genetic models. Evidence of large heterogeneity was observed among all eligible studies in the recessive model. Further subgroup analyses by ethnicity, cancer type and system, detected null associations in this meta-analysis.

CONCLUSION

This case-control study and the further meta-analysis, failed to identify the association between CTLA-4 -1722T/C polymorphism and cancer risk.

Impact of XRCC2 Arg188His polymorphism on cancer susceptibility: a meta-analysis

Background

Association between the single nucleotide polymorphism rs3218536 (known as Arg188His) located in the X-ray repair cross complementing group 2 (XRCC2) gene and cancer susceptibility has been widely investigated. However, results thus far have remained controversial. A meta-analysis was performed to identify the impact of this polymorphism on cancer susceptibility.

Methods

PubMed and Embase databases were searched systematically until September 7, 2013 to obtain all the records evaluating the association between the XRCC2 Arg188His polymorphism and the risk of all types of cancers. We used the odds ratio (OR) as measure of effect, and pooled the data in a Mantel-Haenszel weighed random-effects meta-analysis to provide a summary estimate of the impact of this polymorphism on breast cancer, ovarian cancer and other cancers. All the analyses were carried out in STATA 12.0.

Results

With 30868 cases and 38656 controls, a total of 45 case-control studies from 26 publications were eventually included in our meta-analysis. No significant association was observed between the XRCC2 Arg188His polymorphism and breast cancer susceptibility (dominant model: OR = 0.94, 95%CI = 0.86–1.04, P = 0.232). However, a significant impact of this polymorphism was detected on decreased ovarian cancer risk (dominant model: OR = 0.83, 95%CI = 0.73–0.95, P = 0.007). In addition, we found this polymorphism was associated with increased upper aerodigestive tract (UADT) cancer susceptibility (dominant model: OR = 1.51, 95%CI = 1.04–2.20, P = 0.032).

Conclusion

The Arg188His polymorphism might play different roles in carcinogenesis of various cancer types. Current evidence did not suggest that this polymorphism was directly associated with breast cancer susceptibility. However, this polymorphism might contribute to decreased gynecological cancer risk and increased UADT cancer risk. More preclinical and epidemiological studies were still imperative for further evaluation.

The association between cytotoxic T lymphocyte-associated antigen-4 and cervical cancer

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) gene polymorphisms have been associated with many autoimmune diseases and malignancy susceptibility, but the relationship between CTLA-4 and cervical cancer is still controversial. Hence, a meta-analysis of the published studies for the CTLA-4 gene polymorphisms and the risk of cervical cancer was performed to evaluate the association between them. Odds ratios (ORs) and 95% confidence intervals (CIs) for the codominant, dominant, and recessive genetic models were assessed. The fixed or random effect pooled measure was selected on the basis of the heterogeneity test among studies. The heterogeneity among studies was evaluated using the I (2). Eight studies with 2,835 cases and 2,560 controls were included. In seven studies for the CTLA-4 +49A/G polymorphism, a significant association was showed between the A allele and the increased risk of cervical cancer in the codominant (OR 1.16, 95% CI 1.05-1.29), dominant (OR 1.18, 95% CI 1.03-1.36), and recessive (OR 1.24, 95% CI 1.05-1.56) models. In five studies for the CTLA-4 -318C/T polymorphism, the meta-analysis showed a significant association of the C allele with the reduced risk of cervical cancer in the codominant (OR 0.79, 95% CI 0.66-0.94) and recessive (OR 0.76, 95% CI 0.63-0.93) models. This meta-analysis suggested that +49A/G and -318C/T polymorphisms of the CTLA-4 gene were significantly associated with the risk of cervical cancer. However, further studies are required to draw a solid conclusion on the relation between the CTLA-4 polymorphism and the risk of cervical cancer.

Association between cytotoxic T lymphocyte antigen-4 +49A/G, -1722T/C, and -1661A/G polymorphisms and cancer risk: a meta-analysis

Cytotoxic T lymphocyte antigen-4 (CTLA-4), a key gene that contributes to the susceptibility and clinical course of cancer, is an important down-regulator of T cell activation and proliferation. The +49A/G polymorphism is commonly studied because of its association with cancer risks. However, other polymorphisms, such as -1722T/C and -1661A/G, have not been studied in detail. We performed a meta-analysis using 43 eligible case-control studies with a total of 19,089 patients and 21,388 controls to examine the association between CTLA-4 +49A/G, -1722T/C, and -1661A/G polymorphisms and cancer risk. We searched the PubMed and EMBASE databases for all articles published up to July 17, 2013. Individuals with the +49 A allele (AA/AG vs. GG, odds ratio (OR) = 1.21, 95% confidence interval (95% CI) = 1.16-1.27) and -1661 G allele (AG/GG vs. AA, OR = 1.52, 95% CI = 1.34-1.73) had increased cancer risk. However, no significant association between cancer risk and the -1722T/C polymorphism was found (CC/CT vs. TT, OR = 1.04, 95% CI = 0.92-1.16). In subgroup analysis for the +49A/G polymorphism, increased cancer risk remained in the subgroups of Asians (OR = 1.25, 95 % CI = 1.18-1.31), patients with breast cancer (OR = 1.28, 95% CI = 1.15-1.42), and patients with lung cancer (OR = 1.20, 95 % CI = 1.07-1.35). For the -1661A/G polymorphism, increased cancer risk remained in the subgroups of Asians (OR = 1.52, 95% CI = 1.34-1.73), patients with breast cancer (OR = 1.48, 95% CI = 1.07-2.03), and patients with oral cancer (OR = 3.16, 95% CI = 1.84-5.45). However, no significant increase in cancer risk was found in the subgroups for the -1722T/C polymorphism. In conclusion, the results suggest that +49A/G and -1661A/G polymorphisms in CTLA-4 are risk factors for cancers, whereas the -1722T/C polymorphism is not associated with an increased risk of cancer.

Association between the cytotoxic T-lymphocyte antigen 4 +49A/G polymorphism and bladder cancer risk

Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is a potent immunoregulatory molecule that suppresses antitumor response by downregulating T cell activation. The most studied CTLA-4 +49A/G polymorphism has been associated with various cancers risks. However, little is known about the association between CTLA-4 +49A/G polymorphism and bladder cancer risk. A hospital-based case-control study was conducted in 300 patients with bladder cancer and 300 healthy controls matched with age and sex. The CTLA-4 +49A/G polymorphism was genotyped using polymerase chain reaction-restriction fragment length polymorphism. Patients with bladder cancer had a significantly lower frequency of CTLA-4 +49GG genotype [odds ratio (OR) = 0.44, 95 % confidence interval (CI) = 0.23, 0.85; P = 0.01] and G allele (OR = 0.73, 95 % CI = 0.56, 0.96; P = 0.02) than healthy controls. When stratifying by the stage, grade, and histological type of bladder cancer, we found no statistical association. This is the first study to highlight the significant association between CTLA-4 +49A/G polymorphism and bladder cancer risk. Additional studies are needed to confirm this finding.

NBS1 Glu185Gln polymorphism and cancer risk: update on current evidence

A number of studies have investigated the association between NBS1 Glu185Gln (rs1805794, E185Q) polymorphism and cancer risk, but the results remained controversial. Previous meta-analysis found a borderline significant impact of this polymorphism on cancer risk; however, the result might be relatively unreliable due to absence of numerous newly published studies. Thus, we conducted an updated meta-analysis. A systematic search was performed in PubMed and Embase databases until April 9, 2013. The odds ratios were pooled by the fixed-effects/random-effects model in STATA 12.0 software. As a result, a total of 48 case-control studies with 17,159 cases and 22,002 controls were included. No significant association was detected between the Glu185Gln polymorphism and overall cancer risk. As to subgroup analysis by cancer site, the results showed that this polymorphism could increase the risk for leukemia and nasopharyngeal cancer. Notably, the Glu185Gln polymorphism was found to be related to increased risk for urinary system cancer, but decreased risk for digestive system cancer. No significant associations were obtained for other subgroup analyses such as ethnicity, sample size and smoking status. In conclusion, current evidence did not suggest that the NBS1 Glu185Gln polymorphism was associated with overall cancer risk, but this polymorphism might contribute to the risk for some specific cancer sites due to potential different mechanisms. More well-designed studies are imperative to identify the exact function of this polymorphism in carcinogenesis.

Ctla-4 expression and polymorphisms in lung tissue of patients with diagnosed non-small-cell lung cancer

Cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) is a potent immunoregulatory molecule that downregulates T-cell activation and thus influences the antitumor immune response. CTLA-4 polymorphisms are associated with various cancers, and CTLA-4 mRNA/protein increased expression is found in several tumor types. However, most of the studies are based on peripheral blood mononuclear cells, and much less is known about the relationship between CTLA-4 expression, especially gene expression, and its polymorphic variants in cancer tissue. In our study we assessed the distribution of CTLA-4 two polymorphisms (+49A/G and −318C/T), using TaqMan probes (rs231775 and rs5742909, resp.), and CTLA-4 gene expression in real-time PCR assay in non-small-cell lung cancer (NSCLC) tissue samples. The increased CTLA-4 expression was observed in the majority of NSCLC patients, and it was significantly correlated with TT genotype (−318C/T) and with tumor size (T2 versus T3 + T4). The presence of G allele and GG genotype in cancer tissue (+49A/G) was significantly associated with the increased NSCLC risk. Additionally, we compared genotype distributions in the corresponding tumor and blood samples and found statistically significant differences. The shift from one genotype in the blood to another in the tumor may confirm the complexity of gene functionality in cancer tissue.

CTLA-4 gene polymorphism at position +49 A>G in exon 1: a risk factor for cervical cancer in Indian women

Single nucleotide polymorphisms (SNPs) in the CTLA-4 gene exert differential effects on T-cell response to viral infection. We aimed to evaluate the association of two SNPs of the CTLA-4 gene with cervical cancer in Indian women. The two polymorphic loci, one in the promoter region -318 C>T, rs5742909 (100 cervical cancer cases and 101 controls) and the other in exon 1 +49 A>G, rs231775 (104 cervical cancer cases and 162 controls) were genotyped using polymerase chain reaction-restriction fragment length polymorphism methods. Haplotype block structure was determined using Haploview 4.2. The statistical analyses were performed using a commercially available statistical software package, whereas PyPop was used to calculate the haplotypic frequencies. In this case-control study, the A/A genotype frequency (30.76% vs. 17.6%, P = 0.01) as well as the allelic frequency for A (52.8% vs. 43.5%, P = 0.04) was significantly higher in cases compared to controls. No significant association was seen in the -318 C>T polymorphism. In forward stepwise binary logistic regression analysis considering age and parity as potential confounders, significant association was demonstrated between +49 A/A and cervical cancer. Most likely, this is the first study from India to highlight the significant association between the CTLA-4 gene +49 A/A SNP and cervical cancer, thus adding to the global knowledge of the association of this SNP with cervical cancer.

Association of CTLA-4 polymorphisms with improved overall survival in melanoma patients treated with CTLA-4 blockade: a pilot study

CTLA-4 blockade with monoclonal antibodies can lead to cancer regression in patients with metastatic melanoma (MM). CTLA-4 gene polymorphisms may influence the response to anti-CTLA-4 antibodies although few data are available regarding this issue. We analyzed six CTLA-4 single nucleotide polymorphisms (-1661A > G, -1577G > A, -658C > T, -319C > T, +49A > G, and CT60G > A) in 14 Italian MM patients and 45 healthy subjects. We found a significant association between the -1577G/A and CT60G/A genotypes and improved overall survival (Pc < 0.006, Bonferroni corrected), further confirmed by the diplotype analysis (-1577 & CT60 GG-AA diplotype, p < 0.001). A positive trend toward an association between these genotypes and response to therapy was also observed.

Rationale for targeting the immune system through checkpoint molecule blockade in the treatment of non-small-cell lung cancer

BACKGROUND

Treatments of non-small-cell lung cancer (NSCLC)-particularly of the squamous subtype-are limited. In this article, we describe the immunomodulatory environment in NSCLC and the potential for therapeutic targeting of the immune system through cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed death-1 (PD-1) immune-checkpoint pathway blockade.

MATERIALS AND METHODS

We searched PubMed and presented abstracts for publications describing the clinical benefit of checkpoint blockade in NSCLC.

RESULTS

Antibody-mediated checkpoint molecule blockade is being investigated in NSCLC, and of these approaches, the anti-CTLA-4 antibody ipilimumab has undergone the most extensive clinical study. By targeting the immune system rather than specific antigens, checkpoint blockade agents differ from vaccine therapy. In a phase II study in advanced NSCLC, phased ipilimumab with chemotherapy demonstrated the greatest efficacy in squamous NSCLC. A phase I study of nivolumab, an anti-PD-1 antibody, has suggested that this agent is also active against squamous and non-squamous NSCLC. Ongoing phase III studies are evaluating the therapeutic potential of these agents.

CONCLUSIONS

Although treatment options for NSCLC are limited, a better understanding of the immune profile of this disease has facilitated the development of immunotherapeutics that target checkpoint blockade molecules, and clinical evaluation to date supports combining checkpoint blockade with chemotherapy for squamous NSCLC.

A multi-factorial genetic model for prognostic assessment of high risk melanoma patients receiving adjuvant interferon

Purpose

IFNa was the first cytokine to demonstrate anti-tumor activity in advanced melanoma. Despite the ability of high-dose IFNa reducing relapse and mortality by up to 33%, large majority of patients experience side effects and toxicity which outweigh the benefits. The current study attempts to identify genetic markers likely to be associated with benefit from IFN-a2b treatment and predictive for survival.

Experimental design

We tested the association of variants in FOXP3 microsatellites, CTLA4 SNPs and HLA genotype in 284 melanoma patients and their association with prognosis and survival of melanoma patients who received IFNa adjuvant therapy.

Results

Univariate survival analysis suggested that patients bearing either the DRB1*15 or HLA-Cw7 allele suffered worse OS while patients bearing either HLA-Cw6 or HLA-B44 enjoyed better OS. DRB1*15 positive patients suffered also worse RFS and conversely HLA-Cw6 positive patients had better RFS. Multivariate analysis revealed that a five-marker genotyping signature was prognostic of OS independent of disease stage. In the multivariate Cox regression model, HLA-B38 (p = 0.021), HLA-C15 (p = 0.025), HLA-C3 (p = 0.014), DRB1*15 (p = 0.005) and CT60*G/G (0.081) were significantly associated with OS with risk ratio of 0.097 (95% CI, 0.013–0.709), 0.387 (95% CI, 0.169–0.889), 0.449 (95% CI, 0.237–0.851), 1.948 (95% CI, 1.221–3.109) and 1.484 (95% IC, 0.953–2.312) respectively.

Conclusion

These results suggest that gene polymorphisms relevant to a biological occurrence are more likely to be informative when studied in concert to address potential redundant or conflicting functions that may limit each gene individual contribution. The five markers identified here exemplify this concept though prospective validation in independent cohorts is needed.