TNF-α -308 A allele is associated with an increased risk of distant metastasis in rectal cancer patients from Southwestern China

Low-Penetrance Susceptibility Variants in Colorectal Cancer-Current Outlook in the Field

Colorectal cancer (CRC) is one of the most frequent and mortality-causing neoplasia, with various distributions between populations. Strong hereditary predispositions are the causatives of a small percentage of CRC, and most cases have no transparent genetic background. This is a vast arena for exploring cancer low-susceptibility genetic variants. Nonetheless, the research that has been conducted to date has failed to deliver consistent conclusions and often features conflicting messages, causing chaos in this field. Therefore, we decided to organize the existing knowledge on this topic. We screened the PubMed and Google Scholar databases. We drew up markers by gene locus gathered by hallmark: oncogenes, tumor suppressor genes, genes involved in DNA damage repair, genes involved in metabolic pathways, genes involved in methylation, genes that modify the colonic microenvironment, and genes involved in the immune response. Low-penetration genetic variants increasing the risk of cancer are often population-specific, hence the urgent need for large-scale testing. Such endeavors can be successful only when financial decision-makers are united with social educators, medical specialists, genetic consultants, and the scientific community. Countries' policies should prioritize research on this subject regardless of cost because it is the best investment. In this review, we listed potential low-penetrance CRC susceptibility alleles whose role remains to be established.

Inherited variant in NFκB-1 promoter is associated with increased risk of IBD in an Algerian population and modulates SOX9 binding

BACKGROUND

The link between inflammation and cancer development was intensively studied in the last decade. To date, few studies explored the association between inflammatory genes and colorectal cancer (CRC) development.

AIM

The present study aimed to evaluate the implication of three single nucleotide polymorphisms (SNPs), rs28362491 ins/del -94 ATTG in NFκB1, rs6920220 (G/A) in TNFAIP3, and rs419598 (C/T) in IL1RN, which play a role in inflammation regulation in CRC development.

METHODS AND RESULTS

A case-control study was conducted on an Algerian cohort of 358 subjects (147 healthy people, 89 individuals affected by inflammatory bowel disease [IBD], and 122 CRC patients enrolled at the University Hospital Center Ben Badis of Constantine). SNPs genotyping was performed by allelic discrimination TaqMan assay. The rs28362491 ins/del heterozygous genotype in NFκB1 conferred an increased risk of IBD compared with ins/ins homozygous genotype, with an increase of twofold (OR = 2.34 [1.29-4.21]; 95% CI, 1.29-4.21, P value = 0.004). No significant association was detected for the other two variants. Dual-Luciferase Reporter Assay System performed in LoVo cells showed a significantly higher activity of the construct with ins allele of rs28362491 compared with the one harboring the del allele. Computational analysis nominated SOX9 as putative transcription factor (TF) with higher probability to bind the NFκB1 promoter at the SNP site, and we demonstrated in the in vitro assay that its overexpression modulates NFκB1 promoter activity in allele-specific manner.

CONCLUSION

We speculate that SOX9 may modulate the NFκB1 activity by binding its promoter at the SNP site in allelic specific manner.

Associations of tumor necrosis factor-α polymorphisms with the risk of colorectal cancer: a meta-analysis

Background: Recently, the roles of tumor necrosis factor-α (TNF-α) polymorphisms in colorectal cancer (CRC) were analyzed by some pilot studies, with inconsistent results. Therefore, we performed the present study to better assess the relationship between TNF-α polymorphisms and the risk of CRC.

Methods: Eligible studies were searched in PubMed, Medline, Embase and CNKI. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess correlations between TNF-α polymorphisms and CRC.

Results: A total of 22 studies were included for analyses. A significant association with the risk of CRC was detected for TNF-α -308 G/A (recessive model: P = 0.004, OR = 1.42, 95%CI 1.12–1.79) polymorphism in overall analyses. Further subgroup analyses based on ethnicity of participants revealed that TNF-α -238 G/A was significantly correlated with the risk of CRC in Caucasians (dominant model: P = 0.01, OR = 0.47, 95%CI 0.26–0.86; overdominant model: P = 0.01, OR = 2.27, 95%CI 1.20–4.30; allele model: P = 0.02, OR = 0.51, 95%CI 0.29–0.90), while -308 G/A polymorphism was significantly correlated with the risk of CRC in Asians (recessive model: P = 0.001, OR = 2.23, 95%CI 1.38–3.63).

Conclusions: Our findings indicated that TNF-α -238 G/A polymorphism may serve as a potential biological marker for CRC in Caucasians, and TNF-α -308 G/A polymorphism may serve as a potential biological marker for CRC in Asians.

The correlation between TNF-α-308 gene polymorphism and susceptibility to cervical cancer

Tumor necrosis factor-α (TNF-α) is closely related to the occurrence of human cancers. Cervical cancer seriously affects female health. Therefore, our study aimed to investigate the correlation between the polymorphism of TNF-α-308 gene and susceptibility to cervical cancer. Whole blood was collected from 142 patients with cervical cancer and 150 healthy controls. PCR-RFLP was used to detect the polymorphism of TNF-α-308 and the correlation between polymorphism of TNF-α-308 and the susceptibility to cervical cancer was analyzed. The three genotypes of TNF-α-308 were GG, GA and AA, and the distributions of genotypes of TNF-α-308 were consistent with Hardy-Weinberg equilibrium in both cervical cancer group and control group. There were no significant differences in genotype and allele frequency between cervical cancer group and healthy control group (P>0.05). A/A genotype increased the risk of cervical cancer by 1.46 times with 95% confidence interval of 0.32-6.67. Different genotypes were not associated with tumor type (P>0.05). Different genotypes are correlated with cervical cancer TNM stages, tumor differentiation and lymph node metastasis. Proportion of GA+AA genotype in TNM stage III+IV group, low differentiation group and lymph node metastasis group were 28.1, 29.0 and 29.8%, respectively, which were significantly higher than those in stage I+II group, moderate/high differentiation group and non-lymph node metastasis group (P<0.05). The results suggested that TNF-α-308 gene polymorphism is associated with the degree of malignancy of cervical cancer. Female patients with A allele have higher malignant degree of cervical cancer.