| Background and objectiveMicroRNAs are small nonprotein-coding, endogenous and have a length of19to22nucleotide sequences RNAs. It is predicted that miRNAs regulate approximately30%of human genes. Recent studies supported that miRNAs played very important roles in various biological processes including cell cycle progression, differentiation, apoptosis and tumorigenesis. It is reported that microRNAs regulate gene expression at the post-transcriptional level though binding to specific messenger RNAs (mRNAs) then leading to their degradation or translational repression of mRNAs. That act much like small interfering RNA. But how microRNAs exert its translational inhibition and mutation that detailed process are still ambiguous. Changes in the expression profiles of miRNAs have been observed in a variety of human tumors, including colorectal cancer. Current study show that some microRNAs may act as oncogenic or tumor suppressors in human CRC. Colorectal cancer (CRC) is one of the commonest cancer occurring all over the world. It is the third most and second leading cause of cancer death in the USA. In China, with the development of economy and the change of eating habit, the incidence of colorectal cancer among Chinese increases every year. It is still one of the most leading death cancer in our country. It is sported that adenoma is CRC’s precancerous lesions. So, it is very essential to further raise the diagnostic level for colorectal cancer early diagnosis. Compared with the traditional inspection, chick the expression of microRNAs in plasma, stool specimens or tissues show great advantages for CRC screening. This essay is to investigate the different levels of miR-144*in plasma of colorectal carcinoma(CRC), colorectal adenomas, and inflammatory bowel disease(IBD), preliminary exploration its role in colorectal cancer’s occurrence and development, provide a non-invasive method of diagnosis and prognosis for colorectal cancer.Materials and MethodSeparate collection plasma samples from55cases of CRC,30cases of adenomas,30cases of inflammatory bowel disease (IBD) and30normal volunteers, the Specimens were obtained from the patients in the First Affiliated Hospital of Zhengzhou University between Mar2010and Dec2011, plasma Specimens were taken from patients without pre-treatment; Separate collection the plasma specimens from43cases of Colorectal cancer postoperative after surgery7days,30cases after adenomas removal; when get the plasma specimens immediately stored it in the refrigerator under-70℃. All cases were confirmed by pathologic diagnosis.Before the experiment, using SDS pretreatment the plasma specimens then useing Trizol reagent for RNA extraction, obtained samples of purified plasma RNA. cDNA synthesis was performed using Fermentas Reverse Transcription System. The expression of miR-144*was determined by real-time quantitative RT-PCR. Statistical tests were done by using SPSS17.0statistical software. The level for a statistically significant difference was set at a=0.05for all the tests statistical analysis.Result:1. The expression of miR-144*in CRC plasma was significantly higher than non-carcinoma patients’. MiR-144*’s high expression associated with increased tumor size (p<0.001) and advanced pT stage (p=0.026). 2. In43cases of CRC plasma samples after7days, compared with preoperative,30cases with colorectal cancer surgery patients,27patients miR-144*expression was significantly reduced (p=0.021),13cases with palliative surgery miR-144*expression was no significant difference (p=0.230).3. Whether non-advanced adenoma or advanced adenoma, after the adenoma resection miR-144*expression was no significant change compared with before.Conclusion1. The expression of miR-144*in CRC plasma was high. MiR-144*’s high expression associated with tumor size and pT stage.2. After tumor resection, miR-144*’s expression is lower than the pre-operative’s.3. The expression of miR-144*in blood can be used as a means of non-invasive way of colorectal cancer screening. |
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