Relative quantification of AXIN2 mRNA expression in different pathological types of colorectal polyps

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.
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.
The data showed enhanced level of the expression of AXIN2 gene in the colonic polyps in comparison to the normal tissues (RQ>2), which was significantly upper in adenoma polyps compared to the hyperplastic group (P=0.015). Also, unlike the rectum, the AXIN2 gene activity in colon area was higher than normal tissue.
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.