The functional polymorphism in monocyte chemoattractant protein-1 gene increases susceptibility to gastric cancer

Relationship between the Monocyte Chemo-attractant Protein-1 gene rs1024611 A>G Polymorphism and Cancer Susceptibility: A Meta-analysis Involving 14,617 Subjects

BACKGROUND

Inflammatory and inducible chemokines are the hallmarks of malignancy. Monocyte chemo-attractant protein-1 (MCP-1) is a crucial chemokine implicated in infection and inflammation. Methods: We performed an updated meta-analysis of thirty independent case-control studies with 6,777 cancer cases and 7,840 controls to determine if the MCP-1 gene rs1024611 A > G variant is associated with the risk of cancer. Results: The G allele carriers of rs1024611 in the MCP-1 gene might have a null association with cancer risk in overall comparison. In a subgroup analysis by ethnicity, we identified a marked association between the MCP-1 G allele rs1024611 polymorphism and cancer risk in the Caucasian populations (GG vs. AA: OR = 1.72, 95% CI, 1.12-2.64, P = .013, and GG vs. AG/AA: OR = 1.82, 95% CI, 1.19-2.78, P = .006). The potential bias in literature selection was witnessed in this meta-analysis (G vs. A: P _Begg's =  0.187, P_Egger's =  0.049; and GG/GA vs. AA: P _Begg's =  0.069, P_Egger's =  0.024). The adjusted ORs and CIs of the nonparametric "trim-and-fill" method demonstrated the reliability of these findings. The outcome of heterogeneity analysis indicated that heterogeneity might be due to small sample sizes (<1000 subjects), cancer types (bladder cancer, other cancers), ethnicity (Asians), and population-based studies. However, the sensitivity analysis validated the reliability of the findings. Conclusion: In conclusion, this updated meta-analysis showed that the G carrier of the MCP-1 gene rs1024611 is associated with susceptibility to cancer in Caucasian.

Comparison of body condition score and other minimally invasive biomarkers between dogs with gastric carcinoma and dogs with chronic gastritis

OBJECTIVE To identify minimally invasive biomarkers to help differentiate dogs with gastric carcinoma from those with chronic gastritis. DESIGN Prospective study. ANIMALS 15 dogs with gastric carcinoma, 29 dogs with chronic gastritis, and 7 healthy dogs. PROCEDURES Dogs with clinical signs of upper gastrointestinal tract disease for > 14 days that underwent gastroscopy or necropsy for collection of gastric biopsy specimens for histologic evaluation were prospectively enrolled. Gastric carcinoma and chronic gastritis were diagnosed on the basis of histologic findings. Additionally, gastric biopsy specimens were collected endoscopically from 7 healthy (control) dogs while they were anesthetized for a routine neutering procedure. Prior to being anesthetized for gastroscopy or euthanized, all dogs underwent a physical examination, and a blood sample was collected for quantification of select serum biomarker concentrations. Histologic findings, body condition score (BCS), and serum biomarker concentrations were compared among the 3 groups. RESULTS Dogs with gastric carcinoma were significantly older and had a significantly lower BCS, lower serum folate concentration, and greater serum C-reactive protein (CRP) concentration, compared with dogs with chronic gastritis and control dogs. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that age > 8 years, BCS < 4, serum CRP concentration > 25 mg/L, and an abnormally low serum folate concentration might be useful noninvasive biomarkers for identification of dogs with gastric carcinoma. For underweight older dogs with signs of upper gastrointestinal tract disease and high serum CRP and low serum folate concentrations, gastric biopsy specimens should be obtained and evaluated so that a prompt definitive diagnosis can be made and appropriate treatment initiated.

Cytokine Regulation of Metastasis and Tumorigenicity

The human body combats infection and promotes wound healing through the remarkable process of inflammation. Inflammation is characterized by the recruitment of stromal cell activity including recruitment of immune cells and induction of angiogenesis. These cellular processes are regulated by a class of soluble molecules called cytokines. Based on function, cell target, and structure, cytokines are subdivided into several classes including: interleukins, chemokines, and lymphokines. While cytokines regulate normal physiological processes, chronic deregulation of cytokine expression and activity contributes to cancer in many ways. Gene polymorphisms of all types of cytokines are associated with risk of disease development. Deregulation RNA and protein expression of interleukins, chemokines, and lymphokines have been detected in many solid tumors and hematopoetic malignancies, correlating with poor patient prognosis. The current body of literature suggests that in some tumor types, interleukins and chemokines work against the human body by signaling to cancer cells and remodeling the local microenvironment to support the growth, survival, and invasion of primary tumors and enhance metastatic colonization. Some lymphokines are downregulated to suppress tumor progression by enhancing cytotoxic T cell activity and inhibiting tumor cell survival. In this review, we will describe the structure/function of several cytokine families and review our current understanding on the roles and mechanisms of cytokines in tumor progression. In addition, we will also discuss strategies for exploiting the expression and activity of cytokines in therapeutic intervention.

The 2518 A/G polymorphism in the MCP-1 gene and cancer risk: a meta-analysis

BACKGROUND

The 2518 A/G polymorphism in the MCP-1 gene has been extensively studied for associations with cancer; however, results from replication studies have been inconsistent. The aim of this investigation was to determine links with risk of cancer by meta-analysis.

METHODS

We searched Pubmed, Embase, CNKI, Weipu and Wanfang databases, covering all case-control studies until March, 2013. Statistical analyses were performed using the Revman 5.0 software.

RESULTS

A total of 11 case-control studies met our inclusion criteria, including 1,422 cases and 2,237 controls. The results indicated that the MCP-1 2518 gene polymorphism had no association with cancer risk overall (GG vs.GA+ AA: OR = 0.89, 95%CI = 0.61-1.28, P = 0.52). However, in the subgroup analysis by ethnicity, a decrease of cancer risk was found in Asian populations (GG vs.GA+ AA: OR = 0.79, 95%CI = 0.63-0.99, P = 0.04).

CONCLUSION

This meta-analysis suggested that the 2518A/G polymorphism of MCP-1 gene is associated with risk of cancer among Asian, but not in Caucasian populations.

Association between MCP-1 -2518A/G polymorphism and cancer risk: evidence from 19 case-control studies

Background

Single nucleotide polymorphisms (SNPs) may affect the development of diseases. The -2518A/G polymorphism in the regulatory region of the monocyte chemo-attractant protein-1 (MCP-1) gene has been reported to be associated with cancer risk. However, the results of previous studies were inconsistent. Therefore, we performed a meta-analysis to obtain a more precise estimation of the relationship between the -2518A/G polymorphism and cancer risk.

Methodology/Principal Findings

We performed a meta-analysis, including 4,162 cases and 5,173 controls, to evaluate the strength of the association between the −2518A/G polymorphism and cancer risk. Odds ratio (OR) and 95% confidence intervals (95% CIs) were used to assess the strength of association. Overall, the results indicated that the −2518A/G polymorphism was not statistically associated with cancer risk. However, sub-group analysis revealed that individuals with GG genotypes showed an increased risk of cancer in digestive system compared with carriers of the A allele (GG vs. AA: OR = 1.43, 95%CI = 1.05–1.96, P_{heterogeneity} = 0.08; GG vs. AG/AA: OR = 1.29, 95%CI = 1.02–1.64, P_{heterogeneity} = 0.14). In addition, the increased risk of GG genotype was also observed in Caucasians (GG vs. AG/AA: OR = 1.81, 95%CI = 1.10–2.96, P_{heterogeneity} = 0.02).

Conclusion

This meta-analysis suggests that the MCP-1 −2518A/G polymorphism may have some relation to digestive system cancer susceptibility or cancer development in Caucasian. Large-scale and well-designed case-control studies are needed to validate the findings.

Association of polymorphisms in the MCP-1 and CCR2 genes with the risk of cancer: a meta-analysis

Studies investigating the impact of polymorphisms on monocyte chemotactic protein-1 (MCP-1) and CC chemokine receptor 2 (CCR2) on the risk of cancer have reported inconsistent results. We performed a meta-analysis of 23 eligible studies to summarize the data describing the association between cancer risk and polymorphisms in MCP-1 A2518G and CCR2 V64I. Q-statistics and I(2) statistics were calculated to examine heterogeneity and summary odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated using a random effects model. Potential sources of heterogeneity were investigated via subgroup and sensitivity analyses, and publication biases were estimated. Overall, MCP-1 and CCR2 polymorphisms showed no significant associations with cancer risk (MCP-1-2518A/G, GG + GA vs. AA: OR=0.94, 95% CI=0.76-1.17; CCR2 V64I, AA+AG vs. GG: OR=1.27, 95% CI=0.87-1.86). However, strong evidence of heterogeneity was found among the investigated studies, and subgroup analyses were therefore conducted according to study location, cancer type, source of controls, and presence of deviation from the Hardy-Weinberg equilibrium (HWE). When the data were stratified by study location, the increased risk of cancer among A allele carriers of CCR2 V64I was observed only in studies conducted in Asian countries (AA+AG vs. GG: OR=1.65; 95% CI=1.25-2.18). This meta-analysis suggests that genetic polymorphisms of CCR2 V64I may influence the susceptibility of cancer in Asian countries. Further well-designed studies with larger sample sizes should be conducted.