Lack of association between interleukin-4 -524C>T polymorphism and colorectal cancer susceptibility

Associations of IL-4, IL-4R, IL-17A, and IL-17F Polymorphisms with Colorectal Cancer Risk: A Meta-Analysis, Meta-Regression, and Trial Sequential Analysis

Both interleukin (IL)-4 and IL-17 polymorphisms may be involved in the pathogenesis and progression of colorectal cancer (CRC). Herein, we designed a meta-analysis to assess the associations between IL-4, IL-4R, IL-17A, and IL-17F polymorphisms and CRC risk. Scopus, Web of Science, Cochrane Library, and PubMed databases were searched to retrieve articles published until October 21, 2021. We used crude odds ratio (OR) and 95% confidence interval assessing the association of the polymorphisms and CRC risk in 5 genetic models. Trial sequential analysis for the primary analyses was used to control random errors. Twenty-three studies (8: IL-4 rs2243250, 4: IL-4R rs1801275, 5: IL-17A rs2275913, and 6: IL-17F rs763780) were involved in the meta-analysis. The pooled OR (P-value) for the association between IL-4 rs2243250 polymorphism and the CRC risk was 1.11 (0.08), 1.27 (0.12), 1.07 (0.37), 1.09 (0.17), and 1.22 (0.12), for IL-4R rs1801275 polymorphism was 0.71 (0.18), 1.05 (0.76), 0.86 (0.37), 0.87 (0.41), and 0.69 (0.39), for IL-17A rs2275913 polymorphism was 1.83 (0.0003), 1.73 (0.06), 1.47 (<0.001), 1.61 (0.001), and 1.42 (0.15), and for IL-17F rs763780 polymorphism was 1.07 (0.48), 5.33 (0.02), 1.08 (0.49), 1.08 (0.47), and 8.42 (0.002) in allelic, homozygous, heterozygous, recessive, and dominant models, respectively. The G allele and GA genotype of IL-17A rs2275913 polymorphism and the CC genotype of IL-17F rs763780 polymorphism had an elevated risk in CRC cases. The ethnicity and genotyping method, sample size, control, and publication year were effective factors on the pooled results.

Possible Roles of Interleukin-4 and -13 and Their Receptors in Gastric and Colon Cancer

Interleukin (IL)-4 and -13 are structurally and functionally related cytokines sharing common receptor subunits. They regulate immune responses and, moreover, are involved in the pathogenesis of a variety of human neoplasms. Three different receptors have been described for IL-4, but only IL-4 receptor type II (IL-4Rα/IL-13Rα1) is expressed in solid tumors. While IL-13 can also bind to three different receptors, IL-13 receptor type I (IL-4Rα/IL-13Rα1/IL-13Rα2) and type II (IL-4Rα/IL-13Rα1) are expressed in solid tumors. After receptor binding, IL-4 and IL-13 can mediate tumor cell proliferation, survival, and metastasis in gastric or colon cancer. This review summarizes the results about the role of IL-4/IL-13 and their receptors in gastric and colon cancer.

Association of IL4, IL13, and IL4R polymorphisms with gastrointestinal cancer risk: A meta-analysis

Background

Previous studies have suggested that IL4, IL13, and IL4R are associated with serum IgE levels and allergies, and common variants of these genes may alter cancer risk. To clarify these associations, we conducted a meta-analysis to investigate the associations of IL4, IL13, and IL4R polymorphisms with gastrointestinal cancer risk.

Methods

We used 27 eligible case–control studies describing the associations of six polymorphisms of IL4, IL13, and IL4R with gastrointestinal cancer risk to calculate summary odds ratios (ORs) and 95% confidence intervals (CIs) using five different genetic models. The Q-statistic and I² statistic were calculated to examine heterogeneity.

Results

The IL4 rs2070874 T allele seems to be associated with an increased risk of gastrointestinal cancer (OR 1.11; 95% CI, 1.00–1.24 for T allele vs. C allele). This association was significant in studies conducted outside of Asia (OR 1.28; 95% CI, 1.03–1.58 for T allele vs. C allele) and in studies investigating the association with gastric cancer (OR 1.17; 95% CI, 1.03–1.34 for T allele vs. C allele). However, the IL4R rs1801275 heterozygote seems to be associated with a reduced risk of gastrointestinal cancer (OR 0.79; 95% CI, 0.65–0.96 for AG vs. AA). Other polymorphisms did not show any significant associations with gastrointestinal cancer risk in any of the genetic models and subgroup analyses.

Conclusions

Our results suggest that certain polymorphisms of IL4 and IL4R may affect susceptibility to gastrointestinal cancer. However, further studies are required to confirm these findings.

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This meta-analysis included 27 eligible case–control studies.

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IL4 rs2070874 T allele may increase the risk of gastrointestinal cancer.

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IL4R rs1801275 variant may reduce the risk of gastrointestinal cancer.

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Polymorphisms in IL4 and IL4R may affect susceptibility to gastrointestinal cancer.