Tehran University Medical Journal

Background: Most of colorectal cancers (CRC) have originated from intestinal polyps. Evaluating of the expression level of genes that are involved in tumors growth and development, may consider as diagnostic factor of malignancy in the polyps. AXIN2 regulates the level of nuclear β-catenin in a negative-feedback loop there by being a negative regulator and target gene at the same time. The aims of current study were to examine the expression level of the AXIN2 in the colonic polyps and its linkage with the pathological features of the polyps.
Methods: In the present analytical-descriptive study, the investigated population was chosen from the cases with colonic polyps that referred to the Gastroenterology and Liver Diseases Research Center, Taleghani Hospital, Tehran, Iran, from October 2014 to April 2015. Forty four biopsy polyp samples and 10 normal tissue samples were collected, as well as the demographic and clinical properties of the patients and the expression level of AXIN2 gene was quantified by Real-time PCR. The outcomes were analyzed by the ABI Prism 7500 Sequence Detection System (SDS) software, version 2.1.0 (Applied Biosystems Inc., Foster City, CA, USA) and GraphPad Prism, version 3 (GraphPad Software Inc., La Jolla, CA, USA) Also, the expression changes of the intended gene in target groups were compared with the normal tissues using the 2^-ΔΔCt equation.

Conclusion: The results of the current study show that the expression pattern of AXIN2 gene, was markedly changed during the transformation of the normal tissue to polyp. The increased expression level of this gene could be applied as a diagnostic marker in dissociation of the adenoma polyps from hyperplastic ones. On the other hand, the location of the polyps modulates the AXIN2 gene function. Taking together, evaluating the changes of AXIN2, has a precise diagnostic value in the CRC related studies.

Background: Colorectal cancer is the second most common cancer in the world which is mainly caused by epigenetic and environmental factors. Among these epigenetic factors, gut microbiota is an important one. Although it has not been proved a unique group of bacteria correlated with colorectal cancer, these findings have generally demonstrated differences between healthy and disease gut microbiome in population. Actually, the identification and investigation of intestinal microbiota in early detection of colorectal cancer have been highlighted in new researches and studies. Herein, in the current study, we aimed to evaluate the number of selected gut bacteria including Lactobacillus and Escherichia coli and Prevotella in the fecal specimens of adenomatous polyposis patients, colorectal cancerous cases in compared to normal participants in terms of estimating important role of gut microbiota during colorectal cancer initiation and progression.
Methods: The current research was a case-control study. Fecal samples were provided from 31 healthy individuals, 42 adenomatous polyposis patients and 20 colorectal cancer cases that were referred to Taleghani Hospital, Tehran, Iran, from August 2016 to August 2017 for colorectal cancer screening tests. Fecal samples were collected to analyze intestinal bacteria including, Lactobacillus, Escherichia coli, and Prevotella by absolute quantitative real-time polymerase chain reaction (PCR). The number of these gut bacteria was precisely determined by this method of real-time PCR.
Results: Higher number of Prevotella with 24.6 CT number (P<0.005) and E.coli with 20.4 CT number (P<0.015) were achieved in colorectal cancer cases and adenomatous polyposis patients in contrast to samples from normal individuals. On the contrary, the opposite range was observed for the quantification of Lactobacillus and greater numbers of bacteria (CT=28.6) were detected in normal, compared to the colorectal cancer cases and adenomatous polyposis (P<0.001).
Conclusion: The gut microbiota composition of individuals with colorectal cancer and adenomatous polyposis differs from that of healthy individuals, and the higher numbers of pathogenic microbiota versus beneficial microbiota present in those with colorectal cancer and adenomatous polyposis. In contrast, healthy individuals have higher numbers of beneficial gut microbiota than pathogenic microbes. These findings need more experimental analysis and investigation to better clarify.