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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Apoptosis, Apoptosis Regulatory Proteins, Blotting, Western, Bone Neoplasms, Cell Proliferation, Drug Resistance, Neoplasm, Gene Expression Regulation, Neoplastic, Humans, MicroRNAs, Osteoblasts, Osteosarcoma, RNA, Messenger, RNA, Small Interfering, RNA-Binding Proteins, Real-Time Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, Signal Transduction, Transforming Growth Factor beta1, Tumor Cells, Cultured.
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Does tGF-β1-induced miR-202 mediate drug resistance by inhibiting apoptosis in human osteosarcoma? Context: A number of studies have demonstrated that microRNAs play a critical role in osteosarcoma progression, therapy and drug resistance. MicroRNA-202 has proven to be dysregulated in many human cancer studies. This study aimed to explore miR-202 contributions to drug resistance in osteosarcoma. miR-202 expression was measured by real-time PCR in patient tissues, cell lines or cells treated with TGF-β1, using siRNA to knock down the expression of Smad2, Smad3 and Smad4. miR-202 mimics, inhibitor and scramble siRNA were transfected into osteosarcoma cells to observe effects on cell apoptosis and drug resistance. Moreover, relationships of miR-202 level with PDCD4 were investigated by luciferase reporter assay, real-time PCR and Western blotting. We found that miR-202 is overexpressed in osteosarcoma tissues when compared with normal human osteoblasts and TGF-β1 can induce the expression of miR-202. Transfection of miR-202 mimics into osteosarcoma cell lines significantly promotes chemotherapy resistance by targeting PDCD4, a tumor suppressor which is involved in apoptosis. In contrast, transfection of miR-202 inhibitor enhances the drug sensitivity and apoptosis.
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This study provides new insights into miRNA-202 in osteosarcoma as a potential molecular target for chemotherapy. Final Decision: yes