Abstract
Osteosarcoma (OS) is the major type of primary bone tumor and is associated with a poor prognosis due to chemotherapy resistance. Accumulating evidence indicates that microRNAs (miRNAs/miRs) may influence the tumor progression of OS and cell sensitivity to chemotherapy. In the present study, a total of 7 patients with OS and 7 healthy volunteers were recruited. Reverse transcription‑quantitative polymerase chain reaction and ELISA were performed to determine the expression of miRNAs and mRNAs in the serum of participants. Furthermore, the biological function of miR‑22 and S100A11 was examined in MG‑63 cells using Cell Counting Kit‑8 assays, Transwell migration assays and western blot analysis to determine the effects on cell proliferation, migration and protein expression, respectively, while MG‑63 cell sensitivity to cisplatin was assessed by measuring cell viability following cisplatin treatment and calculating the half maximal inhibitory concentration (IC50). Additionally, the association between miR‑22 and S100 calcium‑binding protein A11 (S100A11) was validated using a luciferase reporter assay. The results demonstrated that miR‑22 expression was significantly reduced in patients with OS and the MG‑63 OS cell line, compared with healthy volunteers and the normal osteoblast hFOB 1.19 cell line, respectively, while the expression of S100A11 was negatively associated with miR‑22 levels in the MG‑63 cell line. Furthermore, overexpression of miR‑22 inhibited the proliferation and migratory ability of MG‑63 cells, and increased the sensitivity of MG‑63 cells to cisplatin treatment; however, overexpression of S100A11 partially attenuated the alterations in proliferation, migratory ability and chemosensitivity that were induced by miR‑22 overexpression. In addition, it was confirmed that S100A11 is a direct target gene of miR‑22 in MG‑63 cells. In conclusion, to the best of our knowledge, the present study is the first to demonstrate that miR‑22 may be a promising therapeutic target and may have potential as part of a combination treatment alongside chemotherapeutic agents for OS.