The Effects And Underlying Mechanisms Of MiR-99a On The Migration And Invision In Human Glioma

Gliomas are the most common primary tumors of the Central Nervous System which account for 46% of intracranial tumors. The incidence of malignant gliomas is approximately 3~8 per 10,0000 individuals per year.With the development of clinic treatment strategy,such as neurosurgery navigation system or Fluorescent guided surgery,new bioalkylating agents, Stereotactic radiotherapy techniques and the developing gene therapy. Although there is a widespread use of Comprehensive therapy focus on operation, malignant gliomas can not be totally resected, because of invasive growth. Moreover, malignant gliomas cannot be cured by means of synthetic radiotherapy,chemotherapy and biotherapy. Even it cause serious toxic and side efffcts in the Central Nervous System,such as fearful radionecrosis and so on. the prognosis of patients with malignant glioma has not been changed significantly over the past several decades.Thus,the research on the pathogenesis and new therapeutic approaches of malignant gliomas become an advanced research hotspot in neurosurgical field.Hitherto ad,the etiological mechanism of malignant gliomas is not clear. it is considered that glioma is a disease of multiple gene aberration involved amplification and overexpression of oncogenes and mutation or deletion of tumor suppressor genes, which results in the deregulation of signaling transduction pathways, then the tumor cells escape from the normal growth regulation mechanism and present the malignant phenotype. MicroRNAs(miRNAs or miRs) is the largest family of noncoding RNA involved in gene silencing, which has 21-25 nucleotides in length. MicroRNAs can regulate negatively protein expression at the post-transcriptional level in a sequence specific manner through binding to the 3?UTRs(3?untranslated regions) of relevant target m RNA and triggering translation inhibition or target m RNA degradation. There are vast studies which demonstrate a series of abnormal expression of micro RNA,it associate with malignant phenotype of tumor cells by several regulation mechanism. some studis point out that more than 50% of micro RNA genes are located in cancer-associated genomic regions or in fragile sites of chromosomal regions. these indicate the association between micro RNA and glioma is real.MicroRNA-99 a acts as a tumor suppressor gene and knochdown gene in several tumors,which participate in the biological process such as cell proliferation, differentiation and apotosis.Even so,there is no relevant reseach about micro RNA in glioma,which target gene relate to tumor cell growth,which signal path refer to tumor cell metabolism,or whther overexpression of micro RNA-99 a can inhibit tumor cell growth.therefore,we will attach more importance on the function and mechanism between micro RNA and glioma.This study is divided to 3 parts:1.The glioma cell model is set up by means of Recombination Three-plasmid Lentiviral Vectors in glioma cell line of LN229, hsa-miR-99 a mimics and hsa-miR-99 a inhibitor are imported in LN229 respectively and detect the actual transfection efficiency.2.After transfection with hsa-miR-99 a mimics and hsa-miR-99 a inhibitor into glioma cell line of LN229, the change of biological characteristics of glioma cells including proliferation activity, invasive ability and migration ability are investigated in vitro.3.By bioinformatics analysis, some potential target genes of microRNA-99 A are obtained and identified by luciferase reporter assay. Then, the mechanism of micro RNA-99 A regulating glioma cell growth and invasion may be preliminary clarified.4.Glioma cell line LN229 intracranial glioma model is established in nude mice which is treated with hsa-miR-99 a mimics and hsa-miR-99 a inhibitor and the growth rate and size of glioma tumor in vivo are compared with control group,a series of immunohistochemical analysis are executed to analysis the association between target gene expression and tumor cell proliferation activity, invasive ability and migration ability.The conclusion drawing from the present study is as follows:1.we can effectively change the expression of glioma cell line LN229.2.The changed glioma cells have different proliferation activity, invasive ability and migration ability.3.In the experient of LN229 intracranial glioma model,there are similar phenotype compared with the experient in vivo.