The Expression Of MiR-92a-1in Human Plasma And Feces For Colorectal Cancer Screening

BackgroundColorectal cancer(CRC) is a kind of common cancer in China. The incidence rate of CRC is the second or third in developed countries. In China, the incidence rate of CRC is growing while the life level improving, especially in large cities. Colorectal adenoma is the most common precancerous lesion of CRC. The doctors and researchers pay much attention to the screening of CRC. If we can diagnose and treat the CRC in early stage, the patients are likely to have better and longer life. At the same time, we can reduce the social medical burden. Mature miRNAs is a class of small, non-coding RNAs that regulate gene expression, ranging from18to24nucleotides in length. MiRNAs are incorporated into the RNA interference (RNAi) effector complex, RISC, and target specific messenger RNAs for translational repression or mRNA cleavage. So, miRNAs can regulate the growth, differentiation and apoptosis of the cells. In recently studies, the expression of miR-92a-1is different with statistical significance between the nonnal and the patients with CRC or CRA. MiR-92a-1is likely to be a potential marker for the diagnosis of CRC.ObjectiveThis study is to explore the feasibility of the expression of miR-92a-1in human plasma and feces samples as noninvasive screening tool for colorectal cancer and precancerous lesions.Material and MethodsFrom August2011to October2011, We selected113patients who admitted to the first affiliated hospital of Zhengzhou University, including60cases of colorectal cancer and30normal controls and23colorectal adenoma, and All specimens were confirmed histologically, as for30cases of normal controls, all colonoscopy were negative. Feces and plasma samples were collected before colonoscopy or surgery from the83patients, then sent to the laboratory immediately and prepared,and then preserved in-80℃refrigerator. And miR-92a-1were extracted with Ultrapure RNA Kit and analyzed by quantitative reverse transcription-PCR (qRT-PCR). The results of the experiment were processed by statistical software SPSS17.0and GraphPad Prism5, and each group rate compared by Mann-Whitney U test. The test results signify statistically with P<0.05.Results1. In human plasma samples of CRC patients and patients with adenoma, the sensitivity of miR-92a-1were85.00%(51/60) and73.91%(17/23), respectively. The specificity of healthy controls was23.33%(7/30).(Cut-off=1.22)2. In feces samples of CRC patients and patients with adenoma, the sensitivity of miR-92a-1were31.67%(19/60) and26.09%(6/23), respectively. The specificity of healthy controls was10.00%(3/30).(Cut-off=1.14)3. MiR-92a-1in both human plasma and feces samples, the sensitivity of miR-92a-1were88.33%(53/60) and82.61%(19/23).respectively. The specificity of healthy controls was73.33%(22/30)ConclusionAs a feasible tumor diagnostic marker, the expression of miR-92a-1in human plasma and feces samples is sensitive, specific and noninvasive alternative for colorectal cancer screening.