Genetic polymorphism rs3760396 of the chemokine (C-C motif) ligand 2 gene (CCL2) associated with the susceptibility of lung cancer in a pathological subtype-specific manner in Han-ancestry Chinese: a case control study

Polymorphism rs1801516 (G > A) in the ATM gene is not associated with overall cancer risk: an updated meta-analysis

OBJECTIVE

The ataxia telangiectasia mutated (ATM) gene contains a functional single nucleotide polymorphism (SNP) rs1801516 (G > A) that may be associated with cancer risk. This meta-analysis aimed to interrogate the relationship between rs1801516 and cancer occurrence and disease etiology.

METHODS

We retrieved and identified the available case-control studies that met the inclusion criteria from the PubMed, Web of Science, and Embase databases. Odds ratio (OR) and 95% confidence intervals (CIs) were used to measure the association between rs1801516 and cancer risk. Additionally, we performed sensitivity, subgroup, and publication bias analyses.

RESULTS

After inclusion criteria were met, the meta-analysis included 29 studies, with 9,453 cancer patients (cases) and 14,646 controls. No association was found between rs1801516 and cancer risk (pooled OR = 0.911; 95% CI, 0.740-1.123). Concordantly, no association was found between rs1801516 and cancer risk after subgroup analysis by source of controls, cancer type, or ethnicity, which confirmed the finding of the dominant model that this SNP is not involved in the occurrence of cancer.

CONCLUSIONS

Through this meta-analysis, we found no association between rs1801516 and cancer occurrence as a risk factor. These data provide useful information for future case-control studies on cancer etiology.

Association Between Monocyte Chemotactic Protein 1 Variants and Age-Related Macular Degeneration Onset Among Chinese People

Background

We assessed the potential association between monocyte chemotactic protein 1 (MCP-1) variants (rs1024611 and rs3760396) and age-related macular degeneration (AMD) susceptibility among Chinese Han people.

Material/Methods

Our research included 129 AMD patients and 131 healthy controls. Genotyping for MCP-1 variants was performed in the 2 groups, and genotype and allele distributions were checked between groups by χ² analysis. Odds ratio (OR) and 95% confidence interval (CI) reflected the potential association between MCP-1 variants and AMD risk. The linkage disequilibrium of polymorphisms was detected using Haploview.

Results

Significant differences in rs1024611 genotype distributions were detected between the 2 groups, and homozygous carriers with GG genotype had higher AMD incidence (P<0.05, OR=2.650, 95% CI=1.127–6.231). The rs1024611 G allele frequency was significantly higher in AMD patients, suggesting that the G allele promotes AMD onset (P<0.05, OR=1.447, 95% CI=1.013–2.068). Strong linkage disequilibrium was found between rs1024611 and rs3760396, and haplotype A_rs1024611–C_rs3760396 was significantly associated with decreased risk of AMD (P=0.001, OR=0.502, 95% CI=0.335–0.752).

Conclusions

MCP-1 rs1024611 variant appears to contribute to risk of AMD in the Chinese Han population, and the interaction of MCP-1 polymorphisms may also influence individual susceptibility to AMD.

MiR-1-3p inhibits the proliferation and invasion of bladder cancer cells by suppressing CCL2 expression

We attempted to analyze the effects of miR-1-3p and CCL2 on the proliferation, migration, and invasion of bladder cancer cells. A total of 18 pairs of bladder cancer tissues with corresponding adjacent tissues and the 6 cases of normal tissues were collected. The expressions of miR-1-3p and CCL2 in the cancer tissues were evaluated using quantitative real-time polymerase chain reaction and western blot. The relationship between miR-1-3p and CCL2 was assessed using luciferase reporter assay. The UM-UC-3 bladder cancer cells were transfected with CCL2 small interfering RNA and miR-1-3p mimics. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, colony formation assay, wound healing assay, Transwell assay, and the flow cytometry test were used to detect the proliferation, migration, invasion, and apoptosis of bladder cancer cells. Bladder cancer tissues had lower levels of miR-1-3p but higher levels of CCL2 than normal tissues ( p < 0.05). The transfection of miR-1-3p mimics and CCL2 small interfering RNA remarkably suppressed cell proliferation and invasion and promoted apoptosis of cells ( p < 0.05). Results of the luciferase reporter gene assay demonstrated that miR-1-3p targeted CCL2. MiR-1-3p suppresses the proliferation and invasion of urinary bladder cancer cells by targeting CCL2.

Identifying reproducible cancer-associated highly expressed genes with important functional significances using multiple datasets

Identifying differentially expressed (DE) genes between cancer and normal tissues is of basic importance for studying cancer mechanisms. However, current methods, such as the commonly used Significance Analysis of Microarrays (SAM), are biased to genes with low expression levels. Recently, we proposed an algorithm, named the pairwise difference (PD) algorithm, to identify highly expressed DE genes based on reproducibility evaluation of top-ranked expression differences between paired technical replicates of cells under two experimental conditions. In this study, we extended the application of the algorithm to the identification of DE genes between two types of tissue samples (biological replicates) based on several independent datasets or sub-datasets of a dataset, by constructing multiple paired average gene expression profiles for the two types of samples. Using multiple datasets for lung and esophageal cancers, we demonstrated that PD could identify many DE genes highly expressed in both cancer and normal tissues that tended to be missed by the commonly used SAM. These highly expressed DE genes, including many housekeeping genes, were significantly enriched in many conservative pathways, such as ribosome, proteasome, phagosome and TNF signaling pathways with important functional significances in oncogenesis.