The Expression Of MiR-29c In Osteosarcoma And Its Regulating Effects On Proliferation And Metastasis Of Osteosarcoma Cell Line SOSP9607

Osteosarcoma is orphan malignant tumor derived from bones, characterized by early pulmonary metastatic potency and poor clinical prognosis. Pulmonary metastasis plays the key role of low survival rates of patients. MicroRNA, a class of small non-coding RNA molecules, can inhibit their target genes by post-transcriptional process, leading to some crucial effects on cell biological functions. It is widely accepted that several miRNAs could regulate the proliferation, invasion, migration, and apoptosis of some cancers.MiR-29 c, a member of miR-29 family, was showed down-regulated in several kinds of malignant tumors in some articles, and increasingly implicated in suppressive regulating the malignant progression of cancer cells. Preliminary study exhibited the aberrant expression of miR-29 c in osteosarcoma tissues and cell lines, predicting an inhibitory effect of miR-29 c on proliferation, invasion, and migration of osteosarcoma.Objective:The objective of this research is to unfold the aberrant expression of miR-29 c inosteosarcoma tissues and the different expression between the osteosarcoma cell lines with different metastatic potentials; to reveal the regulative function of miR-29 c in proliferation and metastasis of osteosarcoma cell lines aiming to provide the therotical foundation of molecular targeted therapy.Methods:1. Real-time PCR assay is applied to detect the expression of mi R-29 c in both osteosarcoma tissues and adjacent normal tissues and osteosarcoma cell lines with different metastatic potentials known as F5M2 and F4.2. Cell transient transfection by Lipofectamine2000 makes miR-29 c mimics and miR-29 c inhibitor infiltrating into F5M2 and F4 cell line respectively to establish the miR-29 c over-expressing and miR-29 c suppressing osteosarcoma cell models.3. Cell functioning experiments such as Transwell invasion and migration assay,MTT proliferation assay and flow cytometry detecting cell cycles and apoptosis were preformed to investigate the modulating effects of miR-29 c in proliferation and metastasis processes of osteosarcoma cell lines.Results:1. We found that the expression of miR-29 c is significantly down-regulated in osteosarcoma tissues compared with adjacent normal tissues and prominently lower in F5M2 cell lines which have high metastatic potential compared to F4 cell lines with low metastatic potency.2. miR-29 c over-expressing and mi R-29 c suppressing osteosarcoma cell models were well-established. miR-29 c expression level in F5M2/29 c mimics cells dramatically elevated and the expression levels of some target genes of miR-29 c significantly promoted in F4/29 c inhibitor cells indicated that both miR-29 c over-expressing and suppressing models were successfully prepared for further researches.3. MiR-29 c over-expressing F5M2 cell lines showed diminished ability in Transwell invasion and migration assay compared to negative controls and blank controls. WhilemiR-29 c suppressing F4 cell lines exerted promoting potency in Transwell invasion and migration assay compared to negative controls and blank controls. In MTT proliferation assay, Over-expression of miR-29 c inhibited the proliferation of F5M2 cell lines while down-regulation of miR-29 c made the F4 cell lines preforming elevated proliferating potentials.4. Detected by flow cytometry, cell cycles and apoptosis of both over-expression and repression of miR-29 c cell lines, showed no significant difference compared with negative and blank controls.Conclusions:1. The expression of miR-29 c is significantly down-regulated in osteosarcoma tissues in F5M2 cell lines which have high metastatic potential the expression of miR-29 c is prominently lower than F4 cell lines with low metastatic potency indicating the negative correlation between miR-29 c and metastatic potency of osteosarcoma.2. Mi R-29 c significantly suppresses cell invasion and proliferation by verifying the cell functions of osteosarcoma cell lines treated with both up and down regulated miR-29 c expression.3. MiR-29 c has no effect on cell cycle and apoptosis process in osteosarcoma cell lines SOSP9607.