The study of methylation and single nucleotide polymorphisms of cancer-related genes in patients with early-stage ulcerative colitis

N-ethyl-N-nitrosourea (ENU)-induced C-terminal truncation of Runx3 results in autoimmune colitis associated with Th17/Treg imbalance

Inflammatory bowel disease (IBD) is a chronic and progressive inflammatory intestinal disease that affects people around the world. The primary cause of IBD is an imbalance in the host immune response to intestinal flora. Several human genes, including IL10, STAT3, IRGM, ATG16L1, NOD2 and RUNX3, are associated with inappropriate immune responses in IBD. It has been reported that homozygous Runx3-knockout (ko) mice spontaneously develop colitis. However, the high mortality rate in these mice within the first two weeks makes it challenging to study the role of Runx3 in colitis. To address this issue, a spontaneous colitis (SC) mouse model carrying a C-terminal truncated form of Runx3 with Tyr319stop point mutation has been generated. After weaning, SC mice developed spontaneous diarrhea and exhibited prominent enlargement of the colon, accompanied by severe inflammatory cell infiltration. Results of immunofluorescence staining showed massive CD4+ T cell infiltration in the inflammatory colon of SC mice. Colonic IL-17A mRNA expression and serum IL-17A level were increased in SC mice. CD4+ T cells from SC mice produced stronger IL-17A than those from wildtype mice in Th17-skewing conditions in vitro. In addition, the percentages of Foxp3+ Treg cells as well as the RORγt+Foxp3+ Treg subset, known for its role in suppressing Th17 response in the gut, were notably lower in colon lamina propria of SC mice than those in WT mice. Furthermore, transfer of total CD4+ T cells from SC mice, but not from wildtype mice, into Rag1-ko host mice resulted in severe autoimmune colitis. In conclusion, the C-terminal truncated Runx3 caused autoimmune colitis associated with Th17/Treg imbalance. The SC mouse model is a feasible approach to investigate the effect of immune response on spontaneous colitis.

A functional polymorphism within the distal promoter of RUNX3 confers risk of colorectal cancer

Background

Accumulating evidence has indicated that runt-related transcription factor 3 ( RUNX3) gene polymorphism (rs7528484) is associated with an alimentary system cancer risk. However, the role of rs7528484 in colorectal cancer is still unclear. The present study aimed to explore the association between rs7528484 and colorectal cancer susceptibility in a Chinese Han population.

Material and methods

We firstly investigated the effect of the polymorphism rs7528484 in distal promoter of RUNX3 polymorphism on colorectal cancer risk in a Chinese Han population comprising 427 colorectal cancer patients and 503 controls. We then carried out a phenotype–genotype association analysis to validate its influence on the adjacent gene RUNX3.

Results

Logistic regression analysis demonstrated that the T allele of rs7528484 was significantly associated with an increased risk for colorectal cancer occurrence in our case-control study (odds ratio = 1.33; 95% confidence interval = 1.09–1.65; P = 0.005). In stratified analysis, the susceptibility of colorectal cancer in the T allele carriers increased among the smokers, III and IV tumor stage, and at the rectum. Furthermore, the T allele was significantly correlated with lower expression of RUNX3 in vitro.

Conclusion

In summary, the current case-control and genotype–phenotype study provides convincing evidence that functional RUNX3 polymorphism (rs7528484) is related to colorectal cancer risk and is a plausible marker for the prediction of colorectal cancer.

The association between IL-1 family gene polymorphisms and colorectal cancer: A meta-analysis

BACKGROUND

Colorectal cancer (CRC) is a major public health problem given its high incidence and mortality. This study focuses on examining the associations between IL-1α, IL-1β, and IL-1RN polymorphisms and colorectal cancer susceptibility.

METHODS

A systematic literature search of PubMed, Embase, Web of Science, CNKI (China National Knowledge Infrastructure) and Wan Fang databases was conducted to identify relevant studies. Relevant data were extracted from the original included studies. The correlation was demonstrated based on the odds ratio (OR) and corresponding 95% confidence intervals (95% CIs). Publication bias was investigated by Egger's line regression test and Begg's funnel plot.

RESULTS

Eighteen independent studies involving 6218 cases and 10160 controls were eligible for this pooled analysis. Overall, the result revealed that the IL-1α rs3783553 polymorphism was significantly associated with an increased risk of CRC (G vs. C, OR = 1.02, 95% CI = 0.90-1.15, I² = 51%, P = 0.78; GG vs. CC, OR = 1.97, 95% CI = 1.04-3.74, I² = 70%, P = 0.04; GC vs. CC, OR = 1.75, 95% CI = 1.12-2.75, I² = 42%, P = 0.01; GG + GC vs. CC, OR = 1.85, 95% CI = 1.08-3.18, I² = 63%, P = 0.03; and GG vs. GC + CC, OR = 1.28, 95% CI = 1.04-1.58, I² = 39%, P = 0.02), and significance was also noted for IL-1RN VNTR under the dominant model (22 + 2L vs. LL, OR = 1.49, 95% CI = 1.01-2.19, I² = 77%, P = 0.045) and allelic contrast model (2 vs. L, OR = 1.28, 95% CI = 1.00-1.64, I² = 58.6%, P = 0.047). For IL-1β + 31C/T, significance was observed in the dominant model (CC + CT vs. TT, OR = 0.83, 95% CI = 0.69-0.99, I² = 52%, P = 0.034) and the heterozygous model (CT vs. TT, OR = 0.80, 95% CI = 0.65-0.98, I² = 60%, P = 0.04). For IL-1β + 511 C/T, a significant association was noted in four gene models (CT vs. TT, OR = 0.72, 95% CI = 0.63-0.83, I² = 0%, P < 0.001; CC + CT vs. TT, OR = 0.74, 95% CI = 0.65-0.84, I² = 0%, P < 0.001; CC vs. TT, OR = 0.77, 95% CI = 0.65-0.91, I² = 30.9%, P = 0.003; C vs. T, OR = 0.87, 95% CI = 0.80-0.95, I² = 38%, P = 0.001), but a significant relationship was not found in the recessive model (CC vs. CT + TT, OR = 1.09, 95% CI = 0.86-1.38, I² = 57.1%, P = 0.25). In addition, borderline statistical significance was noted between IL-1β + 3954 Ins/Del and CRC in the homozygous model, but no significance was identified for IL-1β + 3737 G/A, Il-1β + 1464 G/C, and IL-1RN + 2018 T/C under all five genetic models. In the subgroup analysis of ethnic groups, significant associations with CRC were found for IL-1β + 31 (CC vs. TT: OR = 0.82, 95% CI = 0.67-0.99, I² = 20.2%, P = 0.04; CT vs. TT: OR = 0.62, 95% CI = 0.47-0.82, I² = 0%, P < 0.001; CC + CT vs. TT: OR = 0.69, 95% CI = 0.55-0.87, I² = 29.7%, P = 0.001), IL-1β + 511 (CT vs. TT, OR = 0.65, 95% CI = 0.55-0.77, I² = 0%, P < 0.001; CC + CT vs. TT, OR = 0.67, 95% CI = 0.58-0.78, I² = 0%, P < 0.001; C vs. T, OR = 0.83, 95% CI = 0.75-0.92, I² = 49.6%, P < 0.001) and IL-1RN + 2018 T/C in the allelic contrast model (T vs. C, OR = 0.66, 95% CI = 0.44-0.98, I² = 0%, P = 0.04) among Asians but not in Caucasians. A significant association between IL-1β + 1464 G/C polymorphisms in Caucasians was observed under the recessive model (OR = 0.87, 95% CI = 0.77-0.98, I² = 45%, P = 0.03).

CONCLUSION

The current meta-analysis demonstrated that IL-1α rs3783553, IL-1β + 31C/T, IL-1β + 511C/T, and IL-1RN VNTR are critical genes for CRC susceptibility.

Single Nucleotide Polymorphisms in Colitis-Associated Colorectal Cancer: A Current Overview with Emphasis on the Role of the Associated Genes Products

Colitis-Associated Colorectal Cancer (CA-CRC) is one of the most severe complications of Inflammatory Bowel Disease (IBD) and constitutes the cause of death in 10-15% of patients. The risk ratio for carcinogenesis depends on numerous factors, such as the extent of intestinal inflammatory lesions and the duration of the disease. CA-CRC is a major problem of today's gastroenterology and colorectal surgery due to the fact that the incidence and prevalence of IBD are increasing. In this review, we discussed the current state of knowledge regarding genetic differences between sporadic CRC and CA-CRC, especially pertaining to the chromosomal instability mechanism (CIN). In order to explain CA-CRC molecular basis, we have analyzed the data from studies regarding the correlations between CA-CRC and the presence of Single Nucleotide Polymorphisms (SNPs). Further focus on the role of associated proteins has emphasized the role of NF-κB signaling as the main link between inflammation and carcinogenesis during the course of IBD.