Five common functional polymorphisms in microRNAs (rs2910164, rs2292832, rs11614913, rs3746444, rs895819) and the susceptibility to breast cancer: evidence from 8361 cancer cases and 8504 controls

OBJECTIVES

To evaluate the relationship between the five common polymorphisms in miRNAs (miR-146a rs2910164 G>C, miR-149 rs2292832 C>T, miR-196a2 rs11614913 C>T, miR-499 rs3746444 A>G and miR-27a rs895819 A>G), and breast cancer (BC) risk.

METHODS

Meta-analyses were performed on 15 published studies involving 8, 361 BC patients and 8, 504 cancer-free controls. There were 8 studies with 4, 314 cases and 4, 485 controls for rs2910164, 3 studies with 1, 439 cases and 1, 508 controls for rs2292832, 10 studies with 4, 618 cases and 5, 590 controls for rs11614913, 5 studies with 2, 924 cases and 3, 563 controls for rs3746444, and 5 studies with 2, 912 cases and 3, 697 controls for rs895819. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the BC risk.

RESULTS

Meta-analyses showed that rs2910164 (miR-146a) was associated with BC risk in Caucasian population (homozygote comparison: OR = 1.29, 95%CI = 1.02-1.63, P=0.03; dominant model: OR = 1.31, 95% CI = 1.05-1.65, P=0.02), whereas negative results were obtained for Asians in all genetic models. rs11614913 (miR-196a2) was associated with BC risk in the overall population based on the recessive model (OR = 0.89, 95% CI = 0.80-0.99, P=0.03). Association of rs3746444 (miR-499) with BC risk was detected under three genetic models (allele contrast genetic model: OR = 1.13, 95%CI = 1.03-1.23, P=0.007; homozygote comparison: OR = 1.36, 95 %CI = 1.10-1.69, P=0.005 and recessive model: OR = 1.38, 95% CI = 1.12-1.70, P=0.003). When stratified by ethnicity, the effects remained in Asians. rs895819 (miR-27a) was associated with BC risk in the overall population based on the allele contrast genetic model (OR = 0.91, 95%CI = 0.85-0.98, P=0.02); heterozygote comparison (OR = 0.89, 95 %CI = 0.80-0.99, P=0.03) and the dominant model (OR = 0.89, 95% CI = 0.80-0.98, P=0.02). However, there was no association between rs2292832 (miR-149) polymorphism and BC susceptibility.

CONCLUSION

Our meta-analysis results suggested that the rs2910164 and rs3746444 polymorphisms are associated with increased BC risk, while the rs11614913 and rs895819 polymorphisms correlate with reduced BC risk.

PD-1 rs2227982 Polymorphism Is Associated With the Decreased Risk of Breast Cancer in Northwest Chinese Women: A Hospital-Based Observational Study

Programmed death-1 (PD-1) is crucial in cancer and is well characterized as a negative T-cell regulator that functions by delivering inhibitory signals. We aimed to evaluate the relationship between PD-1 polymorphisms (rs10204525, rs2227982, and rs7421861) and breast cancer risk.We selected 560 breast cancer patients and 583 age-, sex-, and ethnicity-matched healthy controls from Northwest China. The PD-1 polymorphisms were genotyped by using Sequenom MassARRAY. Associations were estimated with odds ratios (ORs) and 95% confidence intervals (95% CIs).For the rs10204525 and rs7421861 polymorphisms, no differences in breast cancer risk were found in any of the genetic models. For the rs2227982 polymorphism, the variant genotypes were significantly associated with decreased breast cancer risk (CT vs CC: OR = 0.68, 95% CI = 0.52-0.91; CT + TT vs CC: OR = 0.69, 95% CI = 0.53-0.90). In analyses stratified by age, the decreased risk was observed among the younger subjects (OR = 0.68, 95% CI = 0.47-0.97). We found that the decreased risk observed for the variant genotypes of rs2227982 was associated with the Her-2 status (CT vs CC: OR = 0.55, 95% CI = 0.37-0.84; CT + TT vs CC: OR = 0.56, 95% CI = 0.38-0.82). The haplotype analysis showed that the Ars10204525 Trs2227982 Crs7421861 haplotype was associated with a significantly decreased risk of breast cancer (OR = 0.50, 95% CI = 0.34-0.75).Our findings support an association between the PD-1 rs2227982 polymorphism and decreased breast cancer risk, especially in Her-2 positive breast cancer patients in the Chinese population.

Role of IL-17A rs2275913 and IL-17F rs763780 polymorphisms in risk of cancer development: an updated meta-analysis

Single nucleotide polymorphisms (SNPs) in the interleukin-17 (IL-17) gene have been shown to be correlated with susceptibility to cancer. However, various studies report different results of this association. The aim of the present work was to clarify the effects of IL-17A G197A (rs2275913) and IL-17F T7488C (rs763780) polymorphisms on cancer risk. We performed systematic searches of the PubMed and CNKI databases to obtain relevant publications. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the association of rs2275913 and rs763780 polymorphisms with cancer risk. Data were extracted from the selected studies, and statistical analysis was conducted using the STATA software. Our results indicated that rs2275913 and rs763780 polymorphisms significantly increase cancer risk, especially in gastric cancers. Subgroup analysis suggested the existence of a significant correlation between rs763780 polymorphism and cancer susceptibility in Caucasian populations. This updated meta-analysis confirms that rs2275913 and rs763780 polymorphisms are highly associated with increased risk for multiple forms of cancer.

Genetic Variation in Metastasis-Associated in Colon Cancer-1 and the Risk of Breast Cancer Among the Chinese Han Population: A STROBE-Compliant Observational Study

Metastasis-associated in colon cancer-1 (MACC1), a newly identified oncogene, is involved in angiogenesis, invasiveness, and metastasis in many cancers. Epidemiological studies have indicated the associations between MACC1 polymorphisms and cancer risk. However, the association between genetic polymorphisms in MACC1 and breast cancer (BC) was not clear. This study aimed to evaluate the relationship between MACC1 polymorphisms and BC risk.We genotyped 4 single-nucleotide polymorphisms (SNPs) in MACC1 (rs975263, rs1990172, rs3735615, rs4721888) to determine the haplotypes in 560 BC patients and 583 age-, sex-, and ethnicity-matched healthy individuals. Genotypes were determined using the Sequenom MassARRAY method. We estimated the odds ratios (ORs) and 95% confidence intervals (95% CIs) using the chi-square test.There were significant differences between patients and controls in the MACC1 rs975263 allelic (T vs C: OR = 0.76, 95% CI = 0.61-0.95, P = 0.014) and genotypic groups (TC vs TT: OR = 0.70, 95% CI = 0.54-0.92, P = 0.009; TC+CC vs TT: OR = 0.71, 95% CI = 0.55-0.92, P = 0.008). Analysis of clinical features demonstrated significant associations between rs975263 and Scarff-Bloom-Richardson (SBR) grade 3 cancer (P = 0.006) and postmenopausal women (P = 0.018). Compared with the rs4721888 CC genotype, the frequency of rs4721888 GC and GC+CC variants was higher in patients. Further analysis revealed that the variant genotypes were positively associated with lymph node metastasis. However, we failed to find any relationships between rs1990172 or rs3735615 polymorphism and BC risk. In addition, haplotype analysis indicated that the CTGG and CTCG haplotypes (rs975263, rs1990172, rs3735615, rs4721888) were significantly associated with decreased susceptibility to BC (P = 0.029 and 0.019 respectively).Our results suggest that rs975263 and rs4721888 polymorphisms in MACC1 are associated with the risk of BC susceptibility and may be involved in the progression of BC in Chinese women.

The Associations of Single Nucleotide Polymorphisms in miR196a2, miR-499, and miR-608 With Breast Cancer Susceptibility: A STROBE-Compliant Observational Study

MicroRNAs (miRNAs) play an important role as regulators of tumor suppressors and oncogenes in cancer-related processes. Single nucleotide polymorphisms (SNPs) in miRNAs have been shown to be relevant to various different cancers, including breast cancer (BC). The aim of this study was to estimate the associations between miRNA-related gene polymorphisms (miR-196a2, miR-499, and miR-608) and the risk of BC in a Chinese population. Gene polymorphisms were analyzed in 1143 subjects (controls = 583; BC = 560). The 3 SNPs were genotyped using the Sequenom Mass-ARRAY platform. The associations between the SNP frequencies and BC were assessed by computing odds ratios (ORs) and 95% confidence intervals (95% CIs), as well as by applying Chi-square tests. The miR-196a2 (rs11614913) T allele was associated with a decreased risk of BC based on results from dominant (OR = 0.67, 95% CI = 0.52-0.86), recessive (OR = 0.65, 95% CI = 0.48-0.86), and allele models (OR = 0.73, 95% CI = 0.62-0.86). In contrast, the miR-499 (rs3746444) AG/GG genotypes were associated with an increased risk of BC (OR = 1.45, 95% CI = 1.10-1.91), and miR-608 (rs4919510) was not significantly associated with BC risk. Our study suggested that the polymorphisms of rs11614913 and rs3746444 may be associated with BC risk in Chinese individuals.

Association Between Single Nucleotide Polymorphisms in DNA Polymerase Kappa Gene and Breast Cancer Risk in Chinese Han Population: A STROBE-Compliant Observational Study

DNA polymerases are responsible for ensuring stability of the genome and avoiding genotoxicity caused by a variety of factors during DNA replication. Consequently, these proteins have been associated with an increased cancer risk. DNA polymerase kappa (POLK) is a specialized DNA polymerase involved in translesion DNA synthesis (TLS) that allows DNA synthesis over the damaged DNA. Recently, some studies investigated relationships between POLK polymorphisms and cancer risk, but the role of POLK genetic variants in breast cancer (BC) remains to be defined. In this study, we aimed to evaluate the effects of POLK polymorphisms on BC risk.We used the Sequenom MassARRAY method to genotype 3 single nucleotide polymorphisms (SNPs) in POLK (rs3213801, rs10077427, and rs5744533), in order to determine the genotypes of 560 BC patients and 583 controls. The association of genotypes and BC was assessed by computing the odds ratio (OR) and 95% confidence intervals (95% CIs) from logistic regression analyses.We found a statistically significant difference between patient and control groups in the POLK rs10077427 genotypic groups, excluding the recessive model. A positive correlation was also found between positive progesterone receptor (PR) status, higher Ki67 index, and rs10077427 polymorphism. For rs5744533 polymorphism, the codominant, dominant, and allele models frequencies were significantly higher in BC patients compared to healthy controls. Furthermore, our results indicated that rs5744533 SNP has a protective role in the postmenopausal women. However, we failed to find any associations between rs3213801 polymorphism and susceptibility to BC.Our results indicate that POLK polymorphisms may influence the risk of developing BC, and, because of this, may serve as a prognostic biomarker among Chinese women.

Association of IL-23R Polymorphisms (rs6682925, rs10889677, rs1884444) With Cancer Risk: A PRISMA-Compliant Meta-Analysis

Although interleukin (IL)-23 receptor (IL-23R) plays an important role in the pathogenesis of multiple cancers, its association with cancer risk is inconsistent across different studies. We therefore conducted a meta-analysis with the aim of resolving the relationship among the 3 common polymorphisms of IL-23R (rs6682925, rs10889677, rs1884444) and cancer risk.Case-control studies evaluating the association between IL-23R polymorphisms (rs6682925, rs10889677, rs1884444) and cancer risk were searched in the PubMed, Web of Science, and CNKI databases.Data were included in the meta-analysis if they were from original studies adopting a case-control design investigating the association between IL-23R polymorphisms and risk of any cancer; all cancer cases must have been confirmed by histology or pathology, and controls selected from noncancer individuals. Case-only studies and review papers were excluded.Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the relationship of IL-23R polymorphisms (rs6682925, rs10889677, rs1884444) with cancer risk. A random-effects model or fixed-effects model was used depending on the heterogeneity of the data.Ultimately, 15 studies, involving 8784 cancer patients and 10,321 cancer-free controls, were included in our meta-analysis. In the overall analysis, the rs10889677 polymorphism was associated with breast cancer (BC) under the allelic, homozygous, dominant, and heterozygous models. Rs1884444 polymorphism was relevant to hepatocellular carcinoma (HCC) under the homozygous, recessive, and allelic models. However, no evidence of a relationship between IL-23R polymorphisms (rs6682925, rs10889677, rs1884444) and cancer risk was found in the overall population.Our meta-analysis provides no evidence supporting a global association of IL-23R polymorphisms (rs6682925, rs10889677, rs1884444) with the risk of cancer. However, rs10889677 may be associated with BC susceptibility and rs1884444 had association with HCC risk. Further large and well-designed studies are warranted to confirm this finding.

Association of Vitamin D Receptor Cdx-2 Polymorphism With Cancer Risk: A Meta-Analysis

Vitamin D receptor (VDR) Cdx-2 polymorphism (rs11568820) has been indicated to be associated to cancer susceptibility. However, published studies reported mixed results. This meta-analysis was conducted to get a more accurate estimation of the association between Cdx-2 polymorphism and cancer risk.We identified 25 independent studies with a total of 34,018 subjects published prior to March 2015. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the susceptibility to cancer. Separate analyses were conducted on features of the population such as ethnicity, source of controls, and cancer types.Meta-analysis results showed that Cdx-2 polymorphism significantly increased cancer risk in the homozygous model in overall analysis. According to the further stratified analysis, significant association was found between Cdx-2 variant and cancer risk in American-Africans in the homozygous, recessive, and dominant comparison models. However, no significant associations were found in Caucasians and Asians. When stratified by different cancer types, significant association was observed between Cdx-2 variant and an increased risk of colorectal cancer in the homozygous, recessive, and dominant models. In addition, ovarian cancer susceptibility increased based on the homozygous and dominant comparison models.Our study indicated that VDR Cdx-2 polymorphism was associated with an increased cancer risk, particularly in American-Africans, colorectal, and ovarian cancers. However, other factors may impact on the association. Further multicenter studies are needed to confirm the effects of Cdx-2 polymorphism on cancer susceptibility.

Flap endonuclease 1 polymorphisms (rs174538 and rs4246215) contribute to an increased cancer risk: Evidence from a meta-analysis

Flap endonuclease-1 (FEN1) is a key factor during the maintenance of genomic stability and protection against tumorigenesis. Since the identification of functional polymorphisms of FEN1 (rs174538 and rs4246215), numerous studies have evaluated the association between the two single-nucleotide polymorphisms and cancer risk. To derive a more precise estimation, a meta-analysis was performed on the association between the FEN1 polymorphisms (rs174538 and rs4246215) and cancer risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the strength of the associations. Thirteen case-control studies, including 5,108 cases and 6,382 case-free controls, were identified. For rs174538, individuals with the GG or GA genotype had an increased risk of cancer when compared to the -69AA genotype (AA vs. GG: OR, 1.85; 95% CI, 1.65-2.08; P<0.00001; AA vs. GA: OR, 1.43; 95% CI, 1.27-1.60; P<0.00001; AA vs. GG+GA: OR, 1.28; 95% CI, 1.16-1.42; P<0.00001). For rs4246215, similar results were identified, as the GG or GT genotype was significantly associated with the increased cancer risk when compared to TT (TT vs. GG: OR, 1.71; 95% CI, 1.52-1.92; P<0.00001; TT vs. GT: OR, 1.34; 95% CI, 1.20-1.50; P<0.00001; TT vs. GG+GT: OR, 1.50; 95% CI, 1.35-1.67; P<0.00001). The present meta-analysis indicated that FEN1 rs174538 and rs4246215 polymorphisms may contribute to an increased risk of cancer.

Quantitative Assessment of the Association between Genetic Variants in MicroRNAs and Colorectal Cancer Risk

Background. The associations between polymorphisms in microRNAs and the susceptibility of colorectal cancer (CRC) were inconsistent in previous studies. This study aims to quantify the strength of the correlation between the four common polymorphisms among microRNAs (hsa-mir-146a rs2910164, hsa-mir-149 rs2292832, hsa-mir-196a2 rs11614913, and hsa-mir-499 rs3746444) and CRC risk. Methods. We searched PubMed, Web of Knowledge, and CNKI to find relevant studies. The combined odds ratio (OR) with 95% confidence interval (95% CI) was used to estimate the strength of the association in a fixed or random effect model. Results. 15 studies involving 5,486 CRC patients and 7,184 controls were included. Meta-analyses showed that rs3746444 had association with CRC risk in Caucasians (OR = 0.57, 95% CI = 0.34–0.95). In the subgroup analysis, we found significant associations between rs2910164 and CRC in hospital based studies (OR = 1.24, 95% CI = 1.03–1.49). rs2292832 may be a high risk factor of CRC in population based studied (OR = 1.18, 95% CI = 1.08–1.38). Conclusion. This meta-analysis showed that rs2910164 and rs2292832 may increase the risk of CRC. However, rs11614913 polymorphism may reduce the risk of CRC. rs3746444 may have a decreased risk to CRC in Caucasians.

Relationship between apurinic endonuclease 1 Asp148Glu polymorphism and gastrointestinal cancer risk: An updated meta-analysis

AIM: To evaluate the relationship between apurinic endonuclease 1 (APE1) Asp148Glu polymorphism and the susceptibility to gastrointestinal (GI) cancers.

METHODS: We searched PubMed, ISI Web of Knowledge, and Chinese National Knowledge Infrastructure (CNKI) databases updated on July 15, 2014 for relevant studies. Only case-control studies comparing APE1 Asp148Glu polymorphism and GI cancer risk were included. We excluded studies reporting only standardized incidence ratios without control groups and those without detailed genotyping data. Meta-analysis was performed on 17 studies involving 4856 cancer patients and 6136 cancer-free controls. Review Manager version 5.1 was used to perform the meta-analysis. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were estimated under the allele contrast, homozygous, heterozygous, dominant and recessive genetic models. We also conducted subgroup analyses stratified by ethnicity and cancer type. Publication bias was evaluated using Begg’s test.

RESULTS: The meta-analysis showed a significant association between APE1 Asp148Glu polymorphism and GI cancer risk in three genetic models in the overall population (G vs T: OR = 1.18; 95%CI: 1.05-1.32; TG vs TT: OR = 1.28; 95%CI: 1.08-1.52; TG + GG vs TT: OR = 1.32; 95%CI: 1.10-1.57). Stratified analysis by ethnicity revealed a statistically increased GI cancer risk in Asians (G vs T: OR = 1.27; 95%CI: 1.07-1.51; GG vs TT: OR = 1.58; 95%CI: 1.05-2.38; TG vs TT: OR = 1.30; 95%CI, 1.01- 1.67; and TG + GG vs TT: OR = 1.38; 95%CI: 1.07-1.78), but not in Caucasians. Further subgroup analysis by cancer type indicated that APE1 Asp148Glu polymorphism may contribute to gastric cancer risk. However, Asp148Glu has no significant association with colorectal or esophageal cancer risk in any genetic model.

CONCLUSION: This meta-analysis suggests that the APE1 Asp148Glu polymorphism G allele is associated with an increased GI cancer risk, especially in gastric cancer.

Effects of PSCA rs2294008 (C/T) and c-MYC rs9642880 (G/T) polymorphisms on bladder cancer: evidence from a meta-analysis

Previous studies have investigated the associations between the two polymorphisms (prostate stem cell antigen (PSCA) rs2294008 C/T and c-MYC rs9642880 G/T) and bladder cancer (BC) risk. However, the results are inconsistent. We therefore carried out a meta-analysis to estimate the relationship between PSCA/c-MYC polymorphisms and BC risk. We searched PubMed up to November 2014 to identify potentially eligible literatures. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the strength of the associations, the data were further stratified by ethnicity. Heterogeneity was evaluated by Q test and I(2) statistics. Begg's funnel plot and Egger's test were used to assess the publication bias. 11 studies from 9 articles were identified, including a total of 16,814 cancer cases and 52,868 case-free controls. We found a significant association between PSCA rs2294008 polymorphism and BC risk (the allele contrast model: OR = 1.14, 95% CI = 1.11-1.18; homozygote comparison: OR = 1.28, 95% CI = 1.20-1.37; heterozygote comparison: OR = 1.23, 95% CI = 1.17-1.30; dominant model: OR = 1.25, 95% CI = 1.19-1.31 and recessive model: OR = 1.13, 95% CI = 1.07-1.20). Moreover, a significant increased risk of BC was confirmed both in Caucasian and in Asians. For c-MYC rs9642880 polymorphism, significant increased BC risk was detected under the following genetic models (the allele contrast model: OR = 1.20, 95% CI = 1.13-1.27; homozygote comparison: OR = 1.37, 95% CI = 1.21-1.55; heterozygote comparison: OR = 1.20, 95% CI = 1.09-1.32; dominant model: OR = 1.25, 95% CI = 1.14-1.37 and recessive model: OR = 1.26, 95% CI = 1.13-1.40). Further stratified analysis by ethnicity also observed the same results. This meta-analysis suggested that PSCA rs2294008 and c-MYC rs9642880 polymorphisms may increase the BC risk. Further studies are needed to clarify the effects.

PSCA rs2294008 C > T polymorphism contributes to gastric and bladder cancer risk

Background

Previous studies suggested genetic variations in PSCA (prostate stem cell antigen) may confer the susceptibility of cancer. Many case–control studies have reported the relationship between PSCA rs2294008 C > T polymorphism and cancer, especially gastric cancer and bladder cancer. However, the results are inconsistent. This meta-analysis is aimed at evaluating the association of rs2294008 polymorphism with cancer risk.

Methods

The databases of PubMed, ISI Web of Knowledge, EMBASE, and Chinese National Knowledge Infrastructure (CNKI) were searched for related publications. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the strength of the associations. Fixed models were used when heterogeneity among studies was not detected, otherwise the random model was used.

Results

Twenty-six studies from 24 articles with 30,050 multiple cancer cases and 51,670 controls were pooled into this meta-analysis. The results showed that the rs2294008 polymorphism was associated with increased cancer risk in any genetic model (T vs C, OR: 1.18, 95% CI: 1.08–1.28; TT vs CC, OR: 1.36, 95% CI: 1.14–1.62; TC vs CC, OR: 1.29, 95% CI: 1.17–1.44; TT + TC vs CC, OR: 1.32, 95% CI: 1.18–1.49; TT vs TC + CC, OR: 1.15, 95% CI: 1.02–1.30). In stratified analysis by cancer type, we found that the T allele had a significant high risk of gastric and bladder cancer, but not in other cancers. In subgroup analysis by ethnicity, increased cancer risk was found in both Asians and Caucasians.

Conclusion

Our study suggested that the PSCA rs2294008 C > T polymorphism is a risk factor for cancer, especially in gastric and bladder cancer.

Association of the four common polymorphisms in interleukin-10 (rs1800890, rs1800896, rs1800871, and rs1800872) with non-Hodgkin's lymphoma risk: a meta-analysis

Interleukin-10 (IL-10) single nucleotide polymorphisms (SNPs) have been indicated to be correlated with Non-Hodgkin's lymphoma (NHL) susceptibility. However, the results of these studies on the association remain inconsistent. This meta-analysis was conducted to derive a more accuracy estimation of the association between the common SNPs (rs1800890, rs1800896, rs1800871 and rs1800872) in IL-10 and NHL risk. Meta-analyses were performed on 21 studies with 7,749 cases and 8584 controls. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the NHL risk. Meta-analyses showed that rs1800890, rs1800871 and rs1800872 polymorphisms had no association with NHL risk. However, rs1800896 polymorphism has association with NHL risk based on the following comparison models (G vs. A: OR = 1.14, 95% CI = 1.00-1.29; AG vs. AA: OR = 1.20, 95% CI = 1.05-1.37; GG+AG vs. AA: OR = 1.22, 95% CI = 1.08-1.39). In the ethnic subgroup analysis, rs1800896 had an increased NHL risk in Caucasians based on the heterozygote model (OR = 1.21, 95% CI = 1.04-1.41) and dominant model (OR = 1.22, 95% CI = 1.00-1.48). When stratified by subtypes, rs1800890, rs1800896 and rs1800872 polymorphisms were found significant association with an increased risk of diffuse large B-cell Lymphoma (DLBCL) in different comparison models, whereas negative results were obtained for Follicular Lymphoma (FL) and chronic lymphocytic Leukemia/small lymphocytic Lymphoma (CLL/SLL) in all genetic models. Our meta-analysis suggested that the rs1800896 polymorphism had an increased risk with NHL susceptibility, where as the rs1800890, rs1800871 and rs1800872 had no association with NHL risk. Among the common subtypes of NHL, three polymorphisms (rs1800890, rs1800896 and rs1800872) had significant association with DLBCL risk.

Current evidence on the relationship between rs1256049 polymorphism in estrogen receptor-β gene and cancer risk

Previous studies have suggested that estrogen receptor-β (ESR2) rs1256049 polymorphism is associated with the susceptibility of cancer. However, the results are inconsistent. We performed a meta-analysis to evaluate the association between the rs1256049 polymorphism and cancer risk. PubMed, ISI Web of Knowledge, and Chinese National Knowledge Infrastructure (CNKI), were searched for eligible studies. The odds ratios (ORs) with 95% confidence interval (CI) were used to assess the strength of association. 22 studies including 22,994 cases and 30,514 controls were identified. There was no significant association between rs1256049 and cancer risk in the overall population. Stratified analysis by ethnicity revealed that the rs1256049 polymorphism was associated with cancer risk in Caucasians (A vs. G: OR = 1.09, 95% CI = 1.01-1.16; GA vs. GG: OR = 1.10, 95% CI = 1.02-1.18; AA+GA vs. GG: OR = 1.09, 95% CI = 1.02-1.17), but not in Asians. Further subgroup analysis by cancer type indicated that the rs1256049 polymorphism may contribute to prostate cancer risk (AA vs. GG: OR = 1.41, 95% CI = 1.02-1.96; AA vs. GG+GA: OR = 1.52, 95% CI = 1.10-2.10), whereas negative results were obtained for breast cancer in any genetic model. This meta-analysis suggested that the ESR2 rs1256049 polymorphism is a candidate gene polymorphism for cancer susceptibility in Caucasians, especially in prostate cancer.

Associations between C1772T polymorphism in hypoxia-inducible factor-1α gene and breast cancer: a meta-analysis

Background

A meta-analysis was performed to estimate the association between HIF-1α polymorphism (C1772T) and breast cancer risk.

Material/Methods

The relevant published literature was retrieved from PubMed, Web of Knowledge, and Embase. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the strength of the associations.

Results

Six case-control studies, including 2043 cases and 2146 controls were identified. Meta-analysis showed that there was no marked association between C1772T polymorphism and breast cancer risk in the overall population in the dominant model. The subgroup analysis showed an increased breast cancer risk in Asians based on homozygote comparison and the recessive model. There were no associations between C1772T polymorphism with clinicopathological parameters and habits.

Conclusions

The present meta-analysis suggests that HIF-1α C1772T polymorphism is a risk factor for susceptibility to breast cancer in Asians.

Association between genetic polymorphisms in AURKA (rs2273535 and rs1047972) and breast cancer risk: a meta-analysis involving 37,221 subjects

Background

Published data on the association between AURKA polymorphisms and breast cancer (BC) risk are inconclusive. This meta-analysis was performed to derive a more precise estimation on the relationship between AURKA polymorphisms (rs2273535 and rs1047972) and BC risk.

Methods

PubMed, Web of Knowledge and Embase were searched for relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the strength of associations. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were performed for allele contrast genetic model, homozygous genetic model, heterozygote genetic model, dominant model, and recessive model, respectively.

Results

A total of 13 studies (16,349 BC patients and 20,872 case-free controls) were involved in this meta-analysis. Meta-analysis showed that there was significant association between rs2273535 and BC risk in three genetic models in the overall population (A vs. T: OR = 1.08, 95% CI = 1.01–1.15, P = 0.02; AA vs. TT: OR = 1.36, 95% CI = 1.06-1.73, P < 0.00001; AA vs. TT + TA: OR = 1.15, 95% CI = 1.01-1.31, P = 0.04). In the subgroup analysis by ethnicity, the effects remained in Asians (allele contrast genetic model: OR = 1.12, 95% CI = 1.00-1.26, P = 0.04 and homozygote comparison: OR = 1.22, 95% CI = 1.06-1.41, P = 0.007). However, no genetic models reached statistical association in Cauasians. Rs1047972 polymorphism was associated with BC risk in the overall population based on homozygote comparison (AA vs. GG: OR = 0.81, 95% CI = 0.66-0.99, P = 0.04). When stratified by ethnicity, rs1047972 polymorphism had a decreased association with BC risk in Caucasians based on allele contrast genetic model, homozygote comparison, the dominant model and the recessive model. However, there was no association in any genetic model in Asians.

Conclusions

This meta-analysis suggests that AURKA rs2273535 polymorphism has an increased risk with BC, especially in Asians. However, rs1047972 polymorphism has a decreased BC risk in Caucasians. Further large scale multicenter epidemiological studies are warranted to confirm this finding.

Low-dose splenic radiation inhibits liver tumor development of rats through functional changes in CD4+CD25+Treg cells

The increased number of CD4(+)CD25(+)Treg cells in tumor local and peripheral splenic tissues is related to the low immune function as well as to tumor recurrence and metastasis. Our pre-clinical studies showed that low-dose radiation (LDR) of the spleen in liver cancer patients significantly improves immune functions. However, the molecular mechanisms of such radiation remained ill defined. This study explores the role of CD4(+)CD25(+)Treg cells in radiation-induced immunomodulatory effects. Using the diethylnitrosamine (DEN)-induced rat liver tumor model and in vitro cell experiments, the percentage of CD4(+)CD25(+)Treg/CD4(+) cells in the blood and the expressions of Foxp3(+), IL-10, TGF-β, and cytotoxic T lymphocyte-associated antigen-4(CTLA-4) in spleen and liver tumors significantly decreased after LDR of the spleen in rats with liver cancer. The tumors became smaller than those in the non-radiated group, with both showing a parallel relation. Flow cytometry and MTT results revealed that LDR failed to inhibit CD4(+)CD25(+)Treg cell proliferation. Conversely, apoptosis was reduced and proliferation was stimulated. This process also changed CTLA-4 molecule expression on the surfaces of CD4(+)CD25(+)Treg cells and reduced their inhibitory function against CD4(+)CD25(-)T cell proliferation, and the suppression function of CD4(+)CD25(+)Treg cells was further weakened with the introduction of the CTLA-4 inhibitor. Findings demonstrate that the reduction of CTLA-4 expression on the CD4(+)CD25(+)Treg cell surface and the further inhibition of cell function may be considered as important regulators of LDR-induced immunomodulatory effects. This study provides experimental evidence to elucidate the immune enhancement induced by this process and presents a novel method for liver cancer immunotherapy.

Association of the three common SNPs of cyclooxygenase-2 gene (rs20417, rs689466, and rs5275) with the susceptibility of breast cancer: an updated meta-analysis involving 34,590 subjects

Several single nucleotide polymorphisms have been identified in cyclooxygenase-2 (COX-2) genes (e.g., −765 G>C (rs20417), −1195G>A (rs689466), and 8473 C>T (rs5275)). The association of these SNPs with the risk of different cancer types is still controversial. This study aims to evaluate the correlation between these SNPs and breast cancer risk in different ethnic groups. We have searched PubMed, Web of Knowledge, and Embase for relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the strength of the associations. A total of 13 studies (15,330 cases and 19,260 controls) were eligible for meta-analysis. This meta-analysis showed that COX-2 rs20417 polymorphism was correlated with an increased risk of breast cancer in Caucasians, while rs689466 was associated with a decreased risk of breast cancer in Caucasians. The rs5275 polymorphism had no association with breast cancer risk.

Functional promoter -765 G > C variant in COX-2 gene is associated with the susceptibility of breast cancer in Chinese Han women

Background

Cyclooxygenase (COX) is a rate-limiting enzyme in prostaglandins synthesis which exists in two isoforms, COX-1 and COX-2. Over-expression of COX-2 was considered to increase the proliferation and enhance the invasiveness of breast cancer cells. It was suggested that genetic variations in COX-2 could influence its expression. Herein, the present study was aimed to investigate the associations between two mostly studied functional polymorphisms (-765 G > C and 8473 C > T) in COX-2 and breast cancer risk in Chinese Han women.

Methods

In the hospital-based case-control study, 465 breast cancer patients and 799 cancer-free controls were genotyped for the COX-2 -765 G > C and 8473 C > T polymorphisms using TaqMan assay. We estimated odds ratios (ORs) and 95% confidence intervals (95% CIs) using the logistic regression.

Results

Compared with the wild genotype of -765 G > C, we found a statistically significant increased risk of breast cancer associated with the variant genotypes [GC/CC vs. GG: OR = 1.56, 95% CI = 1.11–2.21]. In the stratified analysis, the increased risk was more predominant among the subgroups of younger subjects (OR = 1.61, 95% CI = 1.00–2.61). Furthermore, the variant genotypes were associated with large tumor size (OR = 3.01, 95% CI = 1.47–6.12). No significant association was observed for the 8473 C > T polymorphism.

Conclusions

Our results suggest that the functional -765 G > C polymorphism in the promoter of COX-2 may influence the susceptibility and progression of breast cancer in the Chinese Han population.

Association between MDM2 rs 2279744 polymorphism and breast cancer susceptibility: a meta-analysis based on 9,788 cases and 11,195 controls

Purpose

Previous studies have suggested associations between MDM2 (mouse double minute 2 homolog) polymorphisms and cancer risk. The aim of this study was to evaluate the relationship between the MDM2 rs 2279744 polymorphism and the susceptibility of breast cancer.

Methods

We searched PubMed, Web of Knowledge, Embase, and the Chinese National Knowledge Infrastructure (CNKI) database for case–control studies published up to October 2013 that investigated MDM2 rs 2279744 polymorphism and breast cancer risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of these associations.

Results

A total of 19 studies were identified for the meta-analysis, including 9,788 cases and 11,195 controls. The variant heterozygote (TG) was associated with breast cancer risk in the overall population (TG vs TT: OR =1.10, 95% CI =1.04–1.17, P=0.001, P=0.23 for heterogeneity test). In the subgroup analyses by ethnicity, a significantly increased risk was observed among Asians (G vs T: OR =1.12, 95% CI =1.02–1.23, P=0.02, P_het=0.04; GG vs TT: OR =1.29, 95% CI =1.06–1.56, P=0.01, P_het=0.04; TG vs TT: OR =1.36, 95% CI =1.15–1.60, P=0.0004, P_het=0.45; dominant model TG+GG vs TT: OR =1.21, 95% CI =1.03–1.41, P=0.02, P_het=0.07). However, among Caucasians, rs 2279744 was associated with breast cancer risk in only one genotype (TG vs TT: OR =1.09, 95% CI =1.00–1.18, P=0.04, P_het=0.37). No publication bias was found in the present study.

Conclusion

This meta-analysis provides evidence for the association between the MDM2 rs 2279744 polymorphism and breast cancer susceptibility. The results suggest that the MDM2 rs 2279744 polymorphism plays an important role in breast cancer, especially in Asians.

Association between APE1 Single Nucleotide Polymorphism (rs1760944) and Cancer Risk: a Meta-Analysis Based on 6,419 Cancer Cases and 6,781 Case-free Controls

Apurinic/apyrimidinic endonuclease 1 (APE1) is an essential enzyme in the base excision repair pathway. Epidemiological studies have suggested associations between APE1 rs1760944 polymorphism and cancer risk. This study was aimed to evaluate the relationship between APE1 rs1760944 polymorphism and cancer risk. We searched Pubmed, ISI Web of Knowledge, Embase, Chinese National Knowledge Infrastructure (CNKI) databases until September 2013 to identify eligible studies. Odds ratios (ORs) and 95 % confidence intervals (CIs) were used to estimate the strength of the associations. 12 studies from 11 articles on APE1 rs1760944 genotypes and cancer risk were identified, including a total of 6,419 cancer cases and 6,781 case-free controls. Overall, APE1 rs1760944 polymorphism was significantly associated with the decreased risk of cancer in any genetic models (G vs. T: OR = 0.86, 95% CI = 0.82-0.90; homozygote comparison: OR = 0.74, 95% CI = 0.67-0.82; heterozygote comparison: OR =0.88, 95%CI = 0.81-0.95; dominant model TG+GG vs. TT: OR = 0.82, 95% CI = 0.76-0.89; recessive model GG vs. TT+TG: OR = 0.81, 95%CI = 0.75-0.88). In the stratified analysis by populations, the effect was remain in studies of Asian population (homozygote comparison: OR = 0.71, 95%CI = 0.63-0.79; heterozygote comparison: OR = 0.86, 95 %CI = 0.79- 0.94; dominant model: OR = 0.80, 95% CI = 0.74 -0.87 and recessive model: OR = 0.78, 95%CI = 0.71-0.86). Moreover, a significantly decreased risk was found in lung cancer studies (homozygote comparison: OR = 0.68, 95% CI = 0.59-0.79; heterozygote comparison: OR = 0.86, 95%CI = 0.77- 0.98; dominant model: OR = 0.80, 95%CI = 0.72-0.90 and recessive model: OR= 0.77, 95% CI= 0.68-0.87). These findings support that APE1 rs1760944 polymorphism has a possible protective effect on cancer susceptibility particularly among Asians. Further studies based on different ethnicity and various cancer types are warranted to verify our findings.

Anti-angiogenic effect of the total flavonoids in Scutellaria barbata D. Don

Background

Angiogenesis is closely related to the growth, invasion and metastasis of tumors, also considered as the key target of anticancer therapy. Scutellaria barbata D. Don (S. barbata), a traditional Chinese medicine, is being used to treat various diseases, including cancer. However, the antitumor molecular mechanism of S. barbata was still unclear. This study aimed to investigate the inhibitory effects of the total flavones in S. barbata (TF-SB) on angiogenesis.

Methods

Human umbilical vein endothelial cells (HUVECs) were treated with various concentrations of TF-SB. Cell viability was examined using the MTT assay. The scratch assay was used to detect the migration of HUVECs after treatment with TF-SB. The ability of HUVECs to form network structures in vitro was demonstrated using the tube formation assay. The chick embryo chorioallantoic membrane assay was performed to detect the in vivo anti-angiogenic effect. The expression of VEGF was measured by the enzyme-linked immunosorbent.

Results

Results showed that TF-SB inhibited the proliferation and migration of HUVECs in a dose- dependent manner. Simultaneously, TF-SB significantly suppressed HUVEC angiogenesis in vitro and in vivo. Furthermore, VEGF was downregulated in both HUVECs and MHCC97-H cells after TF-SB treatment.

Conclusion

TF-SB could suppress the process of angiogenesis in vitro and in vivo. TF-SB potentially suppresses angiogenesis in HUVECs by regulating VEGF. These findings suggested that TF-SB may serve as a potent anti-angiogenic agent.

Anti-angiogenic effect of the total flavonoids in Scutellaria barbata D. Don

BACKGROUND

Angiogenesis is closely related to the growth, invasion and metastasis of tumors, also considered as the key target of anticancer therapy. Scutellaria barbata D. Don (S. barbata), a traditional Chinese medicine, is being used to treat various diseases, including cancer. However, the antitumor molecular mechanism of S. barbata was still unclear. This study aimed to investigate the inhibitory effects of the total flavones in S. barbata (TF-SB) on angiogenesis.

METHODS

Human umbilical vein endothelial cells (HUVECs) were treated with various concentrations of TF-SB. Cell viability was examined using the MTT assay. The scratch assay was used to detect the migration of HUVECs after treatment with TF-SB. The ability of HUVECs to form network structures in vitro was demonstrated using the tube formation assay. The chick embryo chorioallantoic membrane assay was performed to detect the in vivo anti-angiogenic effect. The expression of VEGF was measured by the enzyme-linked immunosorbent.

RESULTS

Results showed that TF-SB inhibited the proliferation and migration of HUVECs in a dose- dependent manner. Simultaneously, TF-SB significantly suppressed HUVEC angiogenesis in vitro and in vivo. Furthermore, VEGF was downregulated in both HUVECs and MHCC97-H cells after TF-SB treatment.

CONCLUSION

TF-SB could suppress the process of angiogenesis in vitro and in vivo. TF-SB potentially suppresses angiogenesis in HUVECs by regulating VEGF. These findings suggested that TF-SB may serve as a potent anti-angiogenic agent.

Targeted inhibition of mammalian target of rapamycin (mTOR) enhances radiosensitivity in pancreatic carcinoma cells

The mammalian target of rapamycin (mTOR) is a protein kinase that regulates protein translation, cell growth, and apoptosis. Rapamycin (RPM), a specific inhibitor of mTOR, exhibits potent and broad in vitro and in vivo antitumor activity against leukemia, breast cancer, and melanoma. Recent studies showing that RPM sensitizes cancers to chemotherapy and radiation therapy have attracted considerable attention. This study aimed to examine the radiosensitizing effect of RPM in vitro, as well as its mechanism of action. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and colony formation assay showed that 10 nmol/L to 15 nmol/L of RPM had a radiosensitizing effects on pancreatic carcinoma cells in vitro. Furthermore, a low dose of RPM induced autophagy and reduced the number of S-phase cells. When radiation treatment was combined with RPM, the PC-2 cell cycle arrested in the G2/M phase of the cell cycle. Complementary DNA (cDNA) microarray and reverse transcription polymerase chain reaction (RT-PCR) revealed that the expression of DDB1, RAD51, and XRCC5 were downregulated, whereas the expression of PCNA and ABCC4 were upregulated in PC-2 cells. The results demonstrated that RPM effectively enhanced the radiosensitivity of pancreatic carcinoma cells.