RESUMO
Background: Colorectal cancer (CRC) has been often the main reason for dying worldwide. Many factors are implicated in the progress of colorectal carcinoma, one of the chiefs of which is DNA methylation. Insulin-like growth factor-binding protein 3 (IGFBP3) and twist homolog 1 (TWIST1) genes have already been studied and are potential biomarkers for early colorectal diagnosis. Therefore, we designed this research to assess the levels of methylation of these genes in stool specimens of patients with CRC. Materials and Methods: A whole of 80 specimens containing 40 stool specimens from CRC patients and 40 specimens from healthy individuals as a control group was investigated. DNA was extracted using the bisulfate method and methylation of the candidate genes was assessed using methylation-sensitive high-resolution melting method. Differences in the methylation levels between CRC patients and controls were assessed by statistical analysis. Results: Our study showed significant hypomethylation in both IGFBP3 and TWIST1 promoters in patients' samples compared with normal individuals and notably the promoter hypomethylation found in these genes appeared to occur simultaneously (P < 0.0001 and P < 0.0025, respectively). Meantime, hypomethylation of these genes had not any significant connection with medical results. Conclusion: Our results propose that the IGFBP3 and TWIST1 genes' methylation status can serve as potential biomarkers for early CRC diagnosis. However, more studies are still necessary to better appreciate the methylation pattern of these two genes in CRC and to prove their effects on protein levels.
RESUMO
Background: Colorectal cancer (CRC) is still considered one of the prevalent cancers worldwide. Investigation of potential biomarkers for early detection of CRC is essential for the effective management of patients using therapeutic strategies. Considering that, this study was aimed to examine the changes in lncRNA FOXD2-AS1 expression through colorectal tumorigenesis. Methods: Fifty CRC tumor tissues and fifty adjacent normal tissue samples were prepared and involved in the current study. Total RNA was extracted from the samples and then reverse transcribed to complementary DNA. Next, the expression levels of lncRNA FOXD2-AS1 were evaluated using real-time PCR in CRC samples compared to normal ones. Also, receiver operating characteristic curve analysis was used to evaluate the diagnostic value of FOXD2-AS1 for CRC. Results: The obtained results showed that the expression level of FOXD2-AS1 gene was significantly (p<0.0001) up-regulated in tumor tissues compared to normal marginal tissues. Also, a significant correlation was observed between higher the expression of FOXD2-AS1and the differentiation of tumor cells. Furthermore, ROC curve analysis estimated an AUC value of 0.59 for FOXD2-AS1, suggesting its potential as a diagnostic target. Conclusion: Taken together, the current study implied that tissue-specific upregulation of lncRNA FOXD2-AS1 might be appropriate diagnostic biomarkers for CRC. Nonetheless, more studies are needed to validate these results and further illustrate FOXD2-AS1 function through colorectal tumorigenesis.
