Modern cancer epidemiological research: genetic polymorphisms and environment

Filho, Victor Wünsch; Zago, Marco Antônio

doi:10.1590/s0034-89102005000300023

Cited by 17 publications

(4 citation statements)

References 31 publications

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“…Genetic polymorphism predisposes a person to cancer and is heavily dependent on environmental mutagens. The reason for this difference in research findings may be different types of races and geographical conditions, as well as differences in the type of life in each region (17). On the other hand, in the present study, the increase in the expres-sion of the miRNA146a gene in people with CRC has been observed in comparison with healthy subjects, and various studies have also shown similar results to this study.…”

Section: Discussionsupporting

confidence: 70%

Molecular Analysis of rs2910164 Polymorphism and its Association with TNF-α Gene Expression in Colorectal Cancer

Hamta

Tolooi

2021

Jentashapir J Cell Mol Biol

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Background: Colorectal cancer (CRC) is one of the most common malignant tumors in the world, which has been diagnosed as the third most common cancer and the third leading cause of death. This cancer before the age of 50 is uncommon, and its prognosis is controversial, with many studies reporting a worse prognosis than in older patients and others showing no difference. In addition to factors, including diet, environmental factors, somatic and hereditary mutations, genetic factors, including altered expression of some microRNAs and mutations in tumor necrosis factor-α (TNF-α) gene, may be involved in this cancer. Objectives: This study aimed to investigate the rs2910164 polymorphism from the miRNA146a gene and its association with the expression of TNF-α gene in CRC before and after the age of 50 for early diagnosis and treatment. Methods: In this study, 65 samples of cancerous lesions (37 cases over 50 years were considered the case group and 28 cases under 50 years were considered the control group) was collected from in an Iranian population. DNA was extracted from the samples, and rs2910164 polymorphism of the miRNA146a gene was investigated by PCR. Moreover, RNA was extracted from the samples, and the expression of the miRNA146a and TNF-α genes were evaluated. Finally, for data analysis, Epi Info software version 7.1.3.10 and MedCalc Version 19.2.0 were used. Results: The frequency of GG, GC, and CC genotypes from rs2910164 polymorphism of miRNA146a gene in the control group was 0.29, 0.46, and 0.25, respectively, but in the case group it was 0.54, 0.38, and 0.08, respectively. The results also showed that the expression of miRNA146a (P = 0.00006) and TNF-α (P = 0.009) genes was higher in the case group than the control group. Conclusions: Based on the results of this study, a significant correlation was found between GG genotype and rs2910164 polymorphism of miRNA146a gene and TNF-α gene expression in the CRC samples. Therefore, investigation of these factors may be helpful in patients over 50 years with CRC.

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Section: Discussionsupporting

confidence: 70%

Molecular Analysis of rs2910164 Polymorphism and its Association with TNF-α Gene Expression in Colorectal Cancer

Hamta

Tolooi

2021

Jentashapir J Cell Mol Biol

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“…Several studies suggest that single-nucleotide polymorphisms (SNPs) may influence gastric carcinogenesis and thus may be used as molecular biomarkers due to their relation to the individual genetic susceptibility and their involvement in a large variety of cellular mechanisms, such as inflammatory responses, cell cycle regulation, and metabolism [3,4].…”

Section: Introductionmentioning

confidence: 99%

Survivin -31C/G polymorphism and gastric cancer risk in a Brazilian population

2010

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Gastric cancer, despite its decline in incidence, remains a public health problem worldwide, especially in Brazil, where higher incidence indexes are still described. The Survivin gene codifies a multifunctional protein involved in the regulation of the cell cycle and inhibition of the apoptotic pathway, and a polymorphism (-31C/G) located in its promoter region is associated with gene regulation. In order to evaluate the correlation of this polymorphism with gastric cancer risk in a northern Brazil population, we sequenced a fragment containing the polymorphism in individuals with gastric cancer and controls. We observed no differences of alleles and genotype frequencies between cases and controls. However, G carriers of the tumor group had an increased relative risk of developing tumors of diffuse type (OR: 2.22-IC 95%: 0.4835-10.2137), localized in the antrum (OR: 2.16-IC 95%: 0.4811-9.6971) and in younger patients (<50 years-old) (OR: 3.65-IC 95%: 0.4012-33.2429), although with no statistical significance. Nevertheless, C carriers with a high D17S250 microsatellite instability (TP53 gene) show a higher risk to develop gastric tumors (P = 0.0453; OR: 4.1556-IC95%: 0.9716-17.7728), suggesting that the mutate TP53 gene may fail in control and inhibition of Survivin expression, favoring the gastric carcinogenesis. The present result suggests that the presence of the C allele of -31C/G Survivin promoter polymorphism in combination with D17S250 instability may be used as a risk factor for gastric cancer in our population. However, other studies based on a larger sample size are required to properly assess such hypothesis.

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“…Thus, a genomic control of ancestry in association studies is recommended, since the Brazilian population has a high rate of miscegenation. Consequently, ethnicity may cause differences among groups analyzed, and could lead to incorrect interpretations of the results [41,42].…”

Section: Discussionmentioning

confidence: 99%