Laryngeal Squamous Carcinoma Mirna Expression Changes And Mir - 125 For Laryngeal Hep B - 2 Research On The Effects Of Cell Proliferation

Part one Comprehensive expression profiling of microRNAs in laryngeal squamous cell carcinoma and screening of target genesBackground. MicroRNAs (miRNAs) are non-coding RNAs involved in post-transcriptional regulation of gene expression in cancer and, provide new perspectives on the development of laryngeal squamous cell carcinoma (LSCC).Methods. Laser capture microdissection was applied to isolate a homogeneous group of cells from six LSCC samples. miRNA expression of six pairs of LSCC and adjacent normal tissues was screened using miRNA array. The results of miRNA array analysis were validated in48pairs of LSCC and adjacent normal tissues using quantitative real time-PCR. The putative target genes were predicted using three on-line bioinformation software programs and their expression of mRNA were detected via quantitative real time-PCR in24pairs of LSCC.Results. Twenty-nine differentially expressed miRNAs were detected in the six pairs of LSCC, of which six were confirmed, including upregulation of miR-21, miR-93, miR-205, and miR-708and downregulation of miR-125b and miR-145using qRT-PCR.25putative target genes were predicted using three on-line software programs and their mRNA expression of ten target genes were confirmed in large cohort samples.Conclusion. These differentially expressed miRNAs may play a major role in tumorigenesis and progression in LSCC and offer new angles for further investigations into the function of miRNAs.Part two overexpression of miR-125b suppress proliferation via targeting EIF2C2Background. Uncontrolled proliferation is one of major character in malignancy. Deregulation of cell circle leads to unregular proliferation in tumor cells. The second part aims at that overexpression of miR-125b affects proliferation in Hep-2cell line and molecular mechanism.Method. To construct Hep-2-miR-125b cell line which can overexpress miR-125b stably and Hep-2-vector blank cell line with lentiviral vector. The proliferation of cell was detected using prolieferation WST-1kit, and cell circle and apoptosis was checked with flow cytometry. In vivo Hep-2-miR-125b and Hep-2-vector cells were injected into two group of NOD/SCID mouse separately and compared their growth. Dual luciferase Reporter assay tested whether EIF2C2was one of target genes of miR-125b, and mRNA expression and protein level were detected in two cell lines.Result. Hep-2-miR-125b cell can express high level miR-125b stably. Overexpression of miR-125b can suppress the proliferation of Hep-2and the growth of tumor in NOD/SCID mouse. The cell circle was arrested at G0-G1phase and apoptosis had no difference in two cell lines. miR-125b targeted EIF2C2via dual luciferase reporter assay and both mRNA expression and protein level were all decreased in Hep-2-miR-125b cell line.Conlusion. Up-regulation of miR-125b in Hep-2cell line could suppress the proliferation in vitro and in vivo through targeting EIF2C2gene. miR-125b may be a target in gene therapy of LSCC in the future.