Mir-9 Exhibits Impact On Propagation Of Ovarian Cancer Cell By Targeting Nf-κb1

[Background and Aims] Nuclear factor kappaB is a kind of important intranuclear transcription factor, it acts as a second passenger in many signal pathways, therefore has important roles in the process of cell inflammatory reaction, immune reaction, cell apoptosis, and tumorigenesis. P50/p65 is the most common form of NF-κB heterodimer, NF-κB1 coding a 105kd protein (p105), which can be processed into a 50kd protein (p50). MicroRNAs are recently found small nocoding-RNAs which can post-transcriptionlly inhibit genes expression by complete ly or non-completely binding to 3'untranslated region (3'UTR) of its target mRNAs. In this research we found that NF-κB1 up-regulated in ovarian cancer cells, then we demonstrated that miR-9 can directly regulates the expression of NF-κB1, and furthermore study the effects of the phenotype of on ovarian cancer cells.[Methods] In this research we first analysis the different expression on mRNA level of NF-κB1 of ovarian cancer in contrast to its normal control ovarian tissue by means of semi-quantitative RT-PCR. Specific microRNA which can target NF-κB1, the miR-9, was achieved on the target gene prediction webset, and then its direct regulatory roles on the expression of NF-κB1 were terrified by using of EGFP fluorescence reporter vector system. Semi-quantitative RT-PCR and Western blot were performed to test the NF-κB1 expression discrepancy on mRNA and protein levels, after transfected with pcDNA3B/pri-9 and its negative control, paralleled with another test which transfected with miR-9 ASO and its control oligo. Furthermore the proliferation activity of ES-2 cell was determined by MTT and clone formation assay.[Results] NF-κB1 is up-regulated in gastric cancer tissues than in corresponding normal tissues. EGFP fluorescence reporter vector system confirmed that miR-9 directly inhibits NF-κB1 gene expression by binding to its 3'UTR. Over-expression of miR-9 in ovarian cancer cell line ES-2 cells results a down regulate of NF-κB1 expression in both mRNA and protein levels, and a reduced proliferation activity of ES-2 cells. Our tests also suggest that transfected with miR-9 ASO results a high level of NF-κB1 mRNA and its protein p105/p50, and furthermore an increased proliferation activity of ES-2 cells. [Conclusions] NF-κB1 transcription factors regulate a variety of promoters through specific DNA-binding sites, and is aberrantly activated in most cancer, thus increase the activity of cancer cells.over-expression of miR-9 can directly inhibit the expression of NF-κB1 in cancer cells, and the cell activity was reduced. In this study we reduce the activity of cancer cell by making use of over-expression miR-9 to inhibit NF-κB1; the results may have meaning for exploring new way to treat ovarian cancer.