Research On The Relationship Between MiR-196a Family And Tumorigenesis And Development Of Glioma

Glioma is the most common and invasive tumor to human. Most glioma is malignant, grows rapidly with high recurrence rate. There is no good treatment for glioma at present and patients suffered from short survival time and high mortality rate. Try to explain signaling pathway on the molecular mechanism of glioma carcinogenesis and progression, identify the key factors in the signaling pathway, is still the focus on the glioma clinical and basic research.miRNAs (miRNAs) are short(21—25nt)non-coding RNAs, which act as an post-transcriptional regulation factor in the eukaryotic gene expression, By targeting3’untranslated regions(3’UTRs)of cognant mRNAs,miRNAs are involved in diverse biological processes,including cell proliferation, differentiation, apoptosis, metabolism, tumor metastasis. Recently, miRNA profiling studies have indicated that miRNA-196a is related with the occurrence and prognosis of several tumors. miR-196a may plays important roles in molecular genesis of cancers through targeting specific genes. Our preliminary work also revealed that miR-196a up-regulated in glioma cells and was related with the survive time and prognosis of glioma. MiR-196a has two mature sequence:5’-uagguaguuucauguuguuggg-3’(miR-196a),5’-cggcaacaagaaacugucugag-3’(miR-196a*). Four target genes including HOXCB, HMGA2, ANXA1and p27kipl of miRNA-196a had been found at present. We hypothesized that miR-196a may play important role in the signaling pathway of the tumorigenesis and development of glioma. The purpose of our research is try to find the key role of miR-196a in the pathway through anchoring its’ target genes.According to the preliminary work, we choose the glioma cell line U251which over expressed miR-196a as experimental material. We transfected the Chemically synthetic miR-196a mimics/miR-196a inhibitor into cells, simulated the upexpression/downregulation of miR-196a in cells, which may influence the activity of target-mRNA, downstream genes and related proteins. The experiment was divided into four groups (A:transfection of miR-196a*mimics B:transfection of miR-196a mimics C:transfection of miR-196a inbibitor D:blank control), we compared the proteins expression of the four groups through high throughput proteomic analysis, combined the bioinformatics information and find the miR-196a/miR-196a*target genes. We picked up the most likely gene for further validation.After analyses, we found848distinct proteins in the B, C, D group, and437protein coubld be included in further screening. Combined with the latest bioinformatic information, we found5potential target genes (EIF43C,HDGF,MTDH,SLC4A7,ANXA2) of miR-196a*,8potential target genes (ACLY,MTDH,SMARCA1,YWHAB,MARCKS,ANXA1,API5,CALD1) of miR-196a. According to the latest researches on miR-196a target genes, we choose ANXA1, ANXA2for further verification experiment. Our results confirmed that ANXA1is miR-196a target gene, and there was a high possibility that ANXA2is the target gene of miR-196a*The most common genetic alterations detected in gliomas are EGFR (Epidennal growth factor receptor) amplication, which involve in many biological signaling pathways including the PI3K/AKI signaling pathway. The variation of EGFR expression may influence the tumorigenesis and development of glioma. ANXA1serve as a substrate of EGFR, the interaction between the ANXA1and EGFR may influence many signaling pathway. We postulated a "miR-196a-up-regulae ANXA1EGFR-PI3K/AKI" signaling pathway for explaining the biological role of miR-196a in the molecular mechanism o f glioma tumorigenesis, and our hypothesis need further experimental validation...