Cells in the 6-good plate were observed directly under an inverted phase contrast microscope (magnification, 100). miR-504 were predicted using bioinformatics. p53 was confirmed to be a direct target of miR-504 using a luciferase reporter assay and western blot analysis revealed that miR-504 negatively regulated p53 expression at a molecular level. These results indicate that miR-504 contributes to cisplatin resistance in MG63 osteosarcoma cells by suppressing p53. miR-504 may therefore be a potential biomarker for cisplatin resistance in patients with osteosarcoma. (17) revealed that miR-140-5p regulated autophagy-mediated osteosarcoma chemoresistance by targeting high mobility group nucleosome binding domain name 5. Furthermore, Vanas (18) exhibited that miR-21 facilitated osteosarcoma cell proliferation and decreased cisplatin sensitivity by targeting sprouty RTK signaling antagonist 2. Additionally, Liu (19) decided that miR-200c suppressed cell proliferation and enhanced cisplatin sensitivity in osteosarcoma cells by targeting serine/threonine kinase 2. These studies provide evidence for the use of certain miRNAs as effective predictive markers for cisplatin resistance in osteosarcoma. p53 was the first tumor suppressor gene to be identified and is mutated in ~50% of osteosarcomas (20). The absence of normal p53 function serves an important role in tumor occurrence and progression, as p53 protein induces cell cycle arrest, apoptosis or the senescence of damaged or mutant cells to prevent their proliferation, which may otherwise promote tumor occurrence and progression (21C23). Zhao (24) demonstrated that Acarbose p53 overexpression increased chemosensitivity in multidrug-resistant osteosarcoma cell lines and Wu (25) revealed that p53 expression was a useful prognostic biomarker for the prediction of survival in patients with osteosarcoma. Previous studies have exhibited that specific miRNAs are involved in an additional p53-associated mechanism of Acarbose osteosarcoma suppression (26,27). He (28) decided that miR-34 suppressed osteosarcoma cell proliferation and invasion by targeting p53, whilst Zhang (29) decided that miR-29 induced osteosarcoma cell apoptosis via the activation of p53. miR-504 has been associated with several types of malignant tumor, particularly in association with cell proliferation and Acarbose apoptosis, with a previous study demonstrating that miR-504 is usually overexpressed in osteosarcoma (30). However, to the best of our knowledge, the specific role and mechanism of miR-504 in modulating cisplatin resistance in osteosarcoma cells is usually yet to be elucidated. The current study therefore aimed to clarify the role and mechanism of miR-504 in the modulation of cisplatin resistance in human osteosarcoma cells. The results of the present study verified that miR-504 promoted cell proliferation and contributed to cisplatin-induced apoptosis and cell cycle arrest in MG63 osteosarcoma cells, by targeting p53. These results indicate that miR-504 may be a novel Rabbit Polyclonal to NKX61 target for the reduction of cisplatin resistance. Materials and methods Tissue Acarbose samples, cell culture, lentivirus contamination and cell treatment Osteosarcoma tissues and adjacent normal tissues (n=10 pairs; 2C5 cm apart) were collected between September 2016 and May 2017 during routine therapeutic surgery at the Department of Orthopaedics at the First Affiliated Hospital of Wenzhou Medical University (Wenzhou, China). The human osteosarcoma tissues and pair-matched Acarbose adjacent normal tissues were subsequently used to compare the expression of miR-504 by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The role of miR-504 in osteosarcoma progression was subsequently analyzed by using MG63 cells. A total of 10 patients (range, 12C22 years of age), 4 male and 6 female, participated in the present study. Inclusion criteria were as follows: Patients with a pathological diagnosis of osteosarcoma, original site of osteosarcoma was the long bone of limbs, patients receiving surgical.