MALAT-1 is Associated with the Doxorubicin Resistance in U-2OS Osteosarcoma Cells

Abstract

Chang Liu,1,2,* Xuesong Han,1,* Bo Li,2,* Shaobin Huang,1 Zhong Zhou,1 Zhiwei Wang,2 Wanming Wang1 1Department of Orthopedics, The 900th Hospital of Joint Logistic Support Force, Fuzhou, Fujian Province, 350025, People’s Republic of China; 2Department of Orthopedics, Changhai Hospital Affiliated to the Naval Medical University, Shanghai, 200433, People’s Republic of China*These authors contributed equally to this workCorrespondence: Wanming WangDepartment of Orthopedics, The 900th Hospital of Joint Logistic Support Force, 156 North Xi-er Huan Road, Gulou District, Fuzhou, Fujian Province, 350025, People’s Republic of ChinaTel [phone]Email [email protected] WangDepartment of Orthopedics, Changhai Hospital Affiliated to the Naval Medical University, 168 Changhai Road, Yangpu District, Shanghai, 200433, People’s Republic of ChinaTel [phone]Email [email protected]: Our study aimed to investigate the relationship between MALAT-1 (metastasis-associated lung adenocarcinoma transcript 1) expression and the chemotherapy drug resistance in osteosarcoma.Methods: The U-2OS osteosarcoma cell line was selected for the experiment. The cells were treated with methotrexate, doxorubicin, cisplatin, and ifosfamide, respectively. RT-PCR was applied to detect the MALAT-1 expression in cells. The doxorubicin-resistant cell line was constructed. The cells were divided into doxorubicin-sensitivity group (DS/shCtrl), doxorubicin-resistance group (DR/shCtrl) and shMALAT1-doxorubicin-resistance group (DR/shMALAT1). The colony formation assay and 5-ethynyl-2ʹ-deoxyuridine (EdU) assay were used to detect cell proliferation. PI staining was used to detect the cell cycle. Transwell assay and wound healing assay were used to observe the migration and invasion ability. Annexin V-FITC assay was used to detect cell apoptosis. Western blot was used to detect the protein expression and potential mechanism. The impacts of MALAT-1 expression were verified in vivo.Results: The MALAT-1 was upregulated in the doxorubicin-resistant U-2OS osteosarcoma cells. Downregulating MALAT-1 in the doxorubicin-resistant cells inhibited the proliferation, migration, and invasiveness, increased the ratio of cells in the G0/G1 phase, promoted apoptosis. In the doxorubicin-resistant U-2OS cells, the extracellular regulated protein kinases (ERK) phosphorylation was declined, which could be reversed by downregulating MALAT-1. In vivo assay indicated that the growth of doxorubicin-resistant solid osteosarcoma could be suppressed by downregulating MALAT-1.Conclusion: Our study provides evidence that doxorubicin may upregulate MALAT-1 in osteosarcoma. Downregulating MALAT-1 in the doxorubicin resistance U-2OS cells could reverse the resistance and may improve chemotherapeutic efficiency. Some conclusions in previous literature may be one-sided.Keywords: osteosarcoma, doxorubicin, long noncoding RNA, MALAT-1, chemotherapy resistance, extracellular regulated protein kinases

Keywords

• osteosarcoma
• doxorubicin
• long noncoding rna
• malat-1
• chemotherapy resistance
• extracellular regulated protein kinases