Identification Of Differential Proteins In Invasive And Non-Invasive Submucosal Colorectal Carcinoma

With the improvement of people's living standard and the change of diet habit, the incidence of colorectal cancer(CRC) trend to ascend straightly in our country. The good therapeutic effect and early detection are closely related to this cancer. Survival rate in 5 years of early CRC was over 90% if was given immediate and appropriate treatment, some patients could have long-time survival. With rapid development and the increasing popularity of colonoscopies,endoscopic minimally invasive treatment has become a quick and effective way to treat early CRC. Endoscopic invasive treatments such as endoscopic submucosal dissection (ESD) or endoscopic mucosal resection (EMR) are ideal methods, but not appropriate in all patients. When CRC with invasive submucosa, because submucosa was rich of lymphatic and blood vessels, even with endoscopic complete resection, there were still at least 29% cases with metastasis to lymphonodus. These cases were especially suitable for operation with lymph-node dissection.Pathology classification is the guide of CRC treatment. Recently Vienna classification has variously categories provide a good basis for differentiated recommendations on how to be further diagnostic and therapeutic measures. This pathologic diagnosis is depend on tissues by endoscopic biopsy. However, those biopsy tissues by biopsy forceps were usually not deep enough to reach the submucusa., so it was not easy to diagnose whether the tumor had invaded submucosa. Judging whether CRC had submucosal invasion obtained by endoscopic biopsy, whether had metastatic lymphonodus, it was not able to known whether CRC had invaded the submucosa. That means these tissues obtained by endoscopic biopsy and by surgical excision were different, the former was less and superficial, these little tissues were not provided evidence with the diagnose of CRC invasion, were unable to provide recommendations of endoscopic mucosal resection or surgical excision with lymph-node dissection.In our study using proteomic technology, we analyzed differentially expressed proteins in CRC with or without submucosal invasion, and so as to find some biomarker of CRC pathological classification. We hope it can give a reference to select a better treatment using endoscopic mucosal resection or surgical excision. And even provide some new theraputic targets in futrue biotherapy.Animal models were made by N-methyl-N-nitrosourea (MNU) enema; then these rars were randomly divided into two groups by Vienna revised classification: submucosal invasion and no submucosal invasion; Using two - dimensional fluorescence difference gel electrophoresis(DIGE) and matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) we selected some different proteins between submucosal invasion and without submucosal invasion group; and gave further study by molecular biological methods on these different expressing proteins'transcription and translation.DIGE is a progress in quantitative proteomics. Compared with traditional 2DE, DIGE could provide more accurate qualitative and quantitative analyses. We got 1640-1880 differently expressed proteins by DIGE in CRC of submucosal invasion and no submucosal invasion. The condition of T-test Value<0.001 and Average Ratio>2.0, there were 5 proteins between submucosal invasion and no submucosal invasion. These 5 proteins were all significantly different with normal colorectal mucosa, and similar increasing and decreasing tendency with different expression. We found there were 3 upregulated expression proteins in submucosal invasion compared with non-submucosal invasion: Transgelin,Peptidylprolyl isomerase A and Tropomyosin1, alpha isoform d;2 downregulated expression proteins in submucosal invasion: carbonic anhydrase 2 and an unnamed protein identified by MALDI-TOF-MS,We selected 2 proteins from the 5 proteins identified from proteomics, they were CAâ…¡and Transgelin which were downregulated and upregulated in submucosa invasion, and gave them a further study by molecular biology. The results showed that: in the CRC with submucosa invasion, CAâ…¡a nd Transgelin in transcription and translation were similar with the results of proteomics.Our studies showed that there were at least 5 proteins in the inbret strain rats model of CRC with submucosa invasion and non-submucosa invasion: Transgelin,Peptidylprolyl isomerase A,Tropomyosin1,CAâ…¡et al. These proteins could be specific biomarker to identify submucosal invasion in the judgement of early CRC.