Interleukin (IL)-16, a multifunctional cytokine, plays a fundamental role in inflammatory diseases, as well as in the development and progression of tumors. Genetic variation in the DNA sequence of the IL-16 gene may lead to altered cytokine production and/or activity, and this variation may modulate an individual's susceptibility to both colorectal cancer (CRC) and gastric cancer (GC). To test this hypothesis, we investigated the association of IL-16 gene polymorphisms with serum levels of IL-16 and the risk of CRC and GC in a Chinese population. We analyzed single-nucleotide polymorphisms of the IL-16 gene in 596 cancer patients (376 patients with CRC and 220 patients with GC), and also in 480 age- and sex-matched controls using polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing methods. Serum IL-16 levels were measured by enzyme-linked immunosorbent assay. The rs11556218 T/G polymorphism of the IL-16 gene was significantly associated with the susceptibility to CRC and GC patients. Both male and female patients carrying the G allele had a significantly higher risk for developing CRC and GC compared with individuals carrying the T allele. Alternatively, women carrying the T allele (rs4072111 C/T) showed a decreased risk for CRC and GC compared with individuals carrying the C allele. In patients with CRC or GC, IL-16 serum levels were significantly higher than those in the healthy controls, although no significant association between IL-16 polymorphisms and serum levels of IL-16 was observed. Our data indicate that IL-16 polymorphisms may contribute to CRC and GC susceptibility.

Ferroptosis, a newly discovered form of iron-dependent regulated cell death, has been implicated in traumatic brain injury (TBI). MiR-212-5p has previously been reported to be downregulated in extracellular vesicles following TBI. To investigate whether miR-212-5p is involved in the ferroptotic neuronal death in TBI mice, we first examined the accumulation of malondialdehyde (MDA) and ferrous ion, and the expression of ferroptosis-related molecules at 6 h, 12 h, 24 h, 48 h and 72 h following controlled cortical impact (CCI) in mice. There was a significant upregulation in the expression of Gpx4 and Acsl4 at 6 h, Slc7a11 from 12 h to 72 h, and Nox2 and Sat1 from 6 h to 72 h post injury. Similarly, an upregulation in the expression of Gpx4 at 6 h, Nox2 from 6 h to 72 h, xCT from 12 h to 72 h, and Sat1 at 72 h after CCI was observed at the protein level. Interestingly, MDA and ferrous ion were increased whereas miR-212-5p was decreased in the CCI group compared to the sham group. Furthermore, we found that overexpression of miR-212-5p attenuated ferroptosis while downregulation of miR-212-5p promoted ferroptotic cell death partially by targeting prostaglandin-endoperoxide synthase-2 (Ptgs2) in HT-22 and Neuro-2a cell lines. In addition, administration of miR-212-5p in CCI mice significantly improved learning and spatial memory. Collectively, these findings indicate that miR-212-5p may protect against ferroptotic neuronal death in CCI mice partially by targeting Ptgs2.

BackgroundGenome-wide association studies have identified that genetic variants in 8q24 confer susceptibility to colorectal cancer (CRC). Recently, a novel lncRNA (PRNCR1) that located in the 8q24 was discovered. Single nucleotide polymorphisms (SNPs) in the lncRNAs may influence the process of splicing and stability of mRNA conformation, resulting in the modification of its interacting partners. We hypothesized that SNPs in the lncRNA PRNCR1 may be related to the risk of CRC.MethodsWe conducted a case–control study and genotyped five tag SNPs in the lncRNA PRNCR1 in 908 subjects including 313 cases with CRC and 595 control subjects using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) assay.ResultsIn overall analyses, we found that the rs13252298 and rs1456315 were associated with significantly decreased risks of CRC. In stratification analyses, we found that CRC patients carrying the rs1456315G were likely to have a tumor size of greater than 5 cm (G vs. A: adjusted OR = 1.56, 95% CI: 1.10-2.23). Additionally, patients with the rs7007694C and rs16901946G had decreased risks to develop poorly differentiated CRC, whereas patients with the rs1456315G had an increased risk to develop poorly differentiated CRC.ConclusionThese findings suggest that SNPs in the lncRNA PRNCR1 may contribute to susceptibility to CRC.

Emerging evidence has shown that miRNAs participate in human carcinogenesis as tumor suppressors or oncogenes. Single nucleotide polymorphism (SNP) which located in the pre-miRNA may affect the processing and then influence the expression of mature miRNA. Previous studies yielded conflicting results as to the association of two common polymorphisms in pre-miRNAs (i.e. hsa-miR-146 rs2910164 and hsa-miR-196a2 rs11614913) with breast cancer. To derive a more precise effect on the association between these polymorphisms and breast cancer risk, we conducted a meta-analysis. Through retrieving PubMed for the period up to May 2010, a total of four studies were identified with 3,007 cases and 3,718 controls for has-miR-146a rs2910164 polymorphism and with 3,287 cases and 4,298 controls for hsa-miR-196a2 rs11614913 polymorphism. We found that individuals carrying CC genotype of has-miR-196a2 rs11614913 polymorphism was associated with an increased breast cancer risk in homozygote comparison (OR = 1.30; 95% CI, 1.01-1.68), and dominant model (OR = 1.11; 95% CI, 1.01-1.23). However, no significant association between has-miR-146a rs2910164 polymorphism and breast cancer risk was observed in all comparison models tested. These findings suggest that has-miR-196a2 rs11614913 polymorphism may play crucial roles in breast cancer development.

These findings suggest that rs11614913 and rs2910164 polymorphisms may be associated with the etiology of CRC.

Inflammation is highly associated with colon carcinogenesis. Epigenetic mechanisms could play an important role in the initiation and progression of colon cancer. Curcumin, a dietary phytochemical, shows promising effects in suppressing colitis-associated colon cancer in azoxymethane-dextran sulfate sodium (AOM-DSS) mice. However, the potential epigenetic mechanisms of curcumin in colon cancer remain unknown. In this study, the anticancer effect of curcumin in suppressing colon cancer in an 18-week AOM-DSS colon cancer mouse model was confirmed. We identified lists of differentially expressed and differentially methylated genes in pairwise comparisons and several pathways involved in the potential anticancer effect of curcumin. These pathways include LPS/IL-1-mediated inhibition of RXR function, Nrf2-mediated oxidative stress response, production of NO and ROS in macrophages and IL-6 signaling. Among these genes, Tnf stood out with decreased DNA CpG methylation of Tnf in the AOM-DSS group and reversal of the AOM-DSS induced Tnf demethylation by curcumin. These observations in Tnf methylation correlated with increased and decreased Tnf expression in RNA-seq. The functional role of DNA methylation of Tnf was further confirmed by in vitro luciferase transcriptional activity assay. In addition, the DNA methylation level in a group of inflammatory genes was decreased in the AOM+DSS group but restored by curcumin and was validated by pyrosequencing. This study shows for the first time epigenomic changes in DNA CpG methylation in the inflammatory response from colitis-associated colon cancer and the reversal of their CpG methylation changes by curcumin. Future clinical epigenetic studies with curcumin in inflammation-associated colon cancer would be warranted.

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Growing evidence suggests that RAD51 plays a pivotal role in the repair of DNA double-strand breaks and the maintenance of genomic stability. A single nucleotide polymorphism, 135G/C, has been identified in the 5' untranslated region of the RAD51 gene and has been shown to influence gene transcription activity. Previous studies yielded conflicting results as to the association of 135G/C polymorphism with breast cancer. We aimed to assess the effect of 135G/C of RAD51 on breast cancer susceptibility with the use of a meta-analysis. We performed a meta-analysis of 21 published case-control studies up to April 2010. We found that the CC genotype was associated with a significantly increased risk of breast cancer when compared with the GG, CG, and CG/GG genotypes. Subgroup analyses showed that individuals carrying the CC genotype were associated with an elevated tumor risk in European populations and in sporadic breast cancer. After stratified analyses according to manuscript quality, the CC genotype was associated with a significantly increased risk of breast cancer compared with the CG genotype in studies of both higher and lower quality. However, significantly elevated risk was found in studies of higher quality, but not in studies of lower quality when homozygote and a recessive comparison model were tested. This meta-analysis indicates that RAD51 135G/C polymorphism may be identified as a susceptibility locus for breast cancer.