| MicroRNAs are a group of small RNA molecules, which are widely present in eukaryotic organisms. The length of microRNAs are about 16-22nt. They can inhibit target protein expression by combine with the 3’UTR region of the mRNA, thus affect the biological functions. Since being discovered in 1993, researchers pay more and more concerns on them. It has been confirmed that miRNAs take part in many physiological processes, such as cell differentiation, cell proliferation and apoptosis, organism devolopment and many other biological processes. And they are not only involved in physiological processes, the functions they perform during many diseases are also conducted extensive and in-depth exploration in recent years. With the discovery of stable serum microRNAs, serum microRNAs expression profiles serve as biomarkers for tumors and many other major diseases have become a hot topic in this field recent years. Actually, not only in the serum, microRNAs are also stable in other body fluids, such as urine, sweat, saliva, etc, and these microRNAs are expected to be good diagnose biomarkers under certain conditions. This paper aims to study the application of body fluid microRNAs as biomarkers in case of efficacy prediction of interferon a treating hepatitis B patients and diagnosis of kidney injury and the role of microRNA play during lung cancer development in case of miR-203 targeting SRC.Hepatitis B is a widespread infectious disease, the treatment of chronic hepatitis B is a big problem since it has extensive patients, being difficult to cure and easy to relapse. At present, the major anti-virus medicine using for treating chronic hepatitis B are nucleoside analogues and interferon a. The former is designed for depressing the reproduction of virus, which has a good anti-virus effect in short term and has little side effects. But it is easy to produce drug resistance with long-term treating, and easy to relapse. The latter is a classical anti-virus medicine with an anti-virus effect by regulating autoimmunity. It has a stable anti-virus effect, and doesn’t produce drug resistance, not easy to relapse, but the efficacy depends on individuals. Only 40% population are sensitive to interferon a, and it also has many side effects. Therefore, for interferon a, it is helpful to find a sensitive and specific biomarker predicting the efficacy before treatment. This part of research is focus on searching for serum miRNAs which can be used to predict the efficacy of interferon a treating hepatitis B patients in order to guide clinical treatment. On the basis of previous study, we are trying to find a microRNA expression profiles using for predicting the efficacy of interferon a treating hepatitis B patients. We collected 108 cases of hepatitis B serum, and dividing them into effective and ineffective groups by tracking the blood biochemical indicators. Using microRNA arrays screening out the differential expressed miRNAs and validate the results with real-time fluorescence quantitative PCR. We found that miR-99a is differential expressed in the two groups, and the area under ROC curve is 0.74.Besides serum, other body fluids also contain stable miRNAs. But studies focus on other body fluids derived miRNAs serve as biomarkers are few. Among all kinds of the body fluids, urine is quite easy to collect, without damage to patients and has close relationship with kidney, therefore it is expect to become an ideal media for kidney disease diagnosis. Renal disease occurence is always accompanied with renal injury. Mild renal injury with little syptoms is hardly being paid attention by patients, which will become a latent danger for major renal disease. Therefore, early diagnosis of renal injury is very important. At present, creatinine and urine volume are the mainly clinical diagnosis standard index. But they are not so perfect since they are easy to be affected by many factors, which results in the low specificity and making it difficult to make a unified standard. So looking for a sensitive and specific biomarker for early renal injury diagnose is very necessary, and it will benefit patients for taking effective measures to timely treatment. This part of research aims at screening out ideal urine microRNAs as biomarkers for renal injury, in order to provide reference for clinical diagnosis for renal injury. By ischemia reperfusion and intraperitoneal injection of streptozotocin (STZ), we made mouse model for acute and chronic renal injury, respectively. The model was identified by histological pathology. Then we detected the expression of several kidney specific miRNAs in serum, urine and renal tissues. We found miR-lOa and miR-30d can be used as a good biomarker for renal injury. It is more sensitive than BUN method. We also collected the urine samples of focal segmental glomerulosclerosis (FSGS) patients, and detect miR-lOa and miR-30d levels in the samples. We found they are significantly elevated in the patients’urine compared with normal controls, which further validate that miR-lOa and miR-30d are very good biomarkers for kidney injury diagnosing.Besides serving as biomarkers, microRNAs also play important roles in the process of tumor progression. Lung cancer is the leading cause of death related to tumor in the world.The mortality rate ranks the first place among all the malignant tumors. The current treatment methods are operation, radiotherapy and drug therapy. To develop effective antitumor agents is always the central issue of scientific community. Src is a non receptor protein tyrosine kinase. It is coding by oncogene c-Src, and plays an important role in tumor occurrence, development and metastasis. In vitro experiments show that the inhibition of Src is effective for lung cancer treating. By bioinformatics method, we found miR-203 can target to 4 binding sites in Src 3’untranslated (UTR) region. At the same time, we collect 6 pairs of lung cancer and normal tissues, and detect Src protein, mRNA and miR-203 expression level. We found in the lung cancer tissue, Src is remarkably highly expressed, its mRNA level doesn’t show obvious change, and miR-203 decrease obviously. By further analyzing, we found the expression level of Src and miR-203 show Pearson negative correlation. Then we prove miR-203 directly target to Src by luciferase assay, and miR-203 can affect A549 cell proliferation, migration and apoptosis. |
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