| Breast cancer is one of the major diseases threatening to women’s health in the world.Its morbidity is in the 2nd place in cancer disease worldwide,which still keeps rising.Pathological classification is very important to the diagnosis,therapy and prognosis judgments of breast cancer,and is a mature risk evaluation index on clinic.But recently,with rapid development of molecular biosciences,molecular classification of breast cancer gradually becomes a vital component of clinical diagnosis and therapy.As one of the molecular types,Triple Negative Breast Cancer,TNBC,is a kind of breast cancer,on the cell surface of which all of estrogen receptor(ER),progesterone receptor(PR)and human epidermal growth factor receptor(HER-2)show negative.This type has characteristics of early onset,more likely to local recurrence and distant metastasis,leading to bad prognosis.However,TNBC is not sensitive to endocrine therapy and targeted therapy,because they function by targeting ER,PR or HER-2.So,more and more researches are focusing on TNBC,to find effective methods to this medical problem.MicroRNAs are a class of endogenous,non-coding,small single chain RNAs,which generally exist in eukaryotic cells.They are highly conserved and modulate cell growth,proliferation,differentiation,apoptosis and metabolism by inhibiting the protein expression of the target gene,resulting in the progress of disease.In this research,after consulting reference,I selected miR-335 which is highly expressed in breast cancer tissues as my research object.To find out how miR-335 affects TNBC cells and its possible modulation mechanism,the research did the following experiments.Part 1 The Study of the Function of MiR-335 in MDA-MB-231 and HCC-1937 CellsObjectives To explore the effect of miR-335 to TNBC cell----MDA-MB-231 and HCC-1937 in cell proliferation,migration and invasion.Methods After contrived up-regulation/down-regulation of miR-335,MTT and monoclonal formation experiment was used to examine the effect of cell proliferation,wound healing test was used to examine the immigration ability,and Transwell test was used to test the change of invasion ability.Results In MDA-MB-231 and HCC-1937 cells,the up-regulation of miR-335 promoted cell proliferation,migration and invasion,and down-regulation resulted to converse results.Conclusions MiR-335 acts as oncogene in MDA-MB-231 and HCC-1937 cells,so it may be a candidate therapeutic target of TNBC.Part 2 The Target Gene of MiR-3 3 5 and Function MechanismObjectives Validate the target gene of miR-335 and speculate its possible function mechanism.Methods Target prediction was performed using the software,miR-walk,miR-base and Targetscan followed by Dual-luciferase reporter assay,Western Blot to validate the target.Results Dual-luciferase reporter assay confirmed ROCK1 is a target of miR-335.Western Blot showed miR-335 negatively regulated the expression of ROCK1 protein.Conclusions MiR-335 might suppressed proliferation,migration and invasion of MDA-MB-231 breast cancer cells and HCC-1937 breast cancer cells by targeting ROCK1... |
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