Chen Jiangqiang, Chen Zuhui
Department of Traumatology, Tiantai People's Hospital, Tiantai, Zhejiang 317200, P.R. China.
Oncol Lett. 2020 Nov;20(5):173. doi: 10.3892/ol.2020.12033. Epub 2020 Aug 28.
Osteosarcoma is a malignant tumor derived from the skeletal system, often occurring in bone tissues, and it is the most common malignant tumor in the skeletal system, with more than 90% of cases being highly malignant. The present study was designed to explore the regulatory effects of microRNA (miR)-19a on the proliferation and apoptosis of osteosarcoma cells, and its influence on the activation of the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. The expression of miR-19a in adult SaOS-2 osteosarcoma cells was downregulated via lentiviral transfection, and the cells were divided into a control group, NC-inhibitor group and miR-19a-inhibitor group. The expression of miR-19a in each group was detected via quantitative polymerase Chain reaction (qPCR). Next, the cell proliferation and apoptosis levels in each group were detected via methyl thiazolyl tetrazolium (MTT) assay and flow cytometry, respectively, and the level of reactive oxygen species (ROS) in cells was further determined. Moreover, the expression levels of apoptosis-related proteins and JAK2/STAT3 signaling pathway-related proteins were detected through western blotting. The expression level of miR-19a in the miR-19a-inhibitor group was significantly lower than that in the control group and NC-inhibitor group (P<0.01). Downregulation of miR-19a significantly reduced the proliferation ability (P<0.01), increased the apoptosis level of SaOS-2 cells (P<0.01), and significantly increased the ROS level in cells (P<0.01). Downregulation of miR-19a also promote cleaved caspase-3/caspase-3 expression in the OS cells (P<0.01) and inhibited Bcl-2/Bax expression (P<0.01). Additionally, downregulation of miR-19a markedly lowered the protein expression levels of phosphorylated (p-)JAK2, p-STAT3 and myeloid cell leukemia-1 (Mcl-1) in the cells (P<0.01). To conclude, downregulation of miR-19a can inhibit the JAK2/STAT3 signaling pathway in SaOS-2 cells, promote the expression of apoptosis-related proteins, and increase the ROS level in cells, thereby promoting apoptosis and inhibiting cell proliferation.
骨肉瘤是一种起源于骨骼系统的恶性肿瘤，常发生于骨组织，是骨骼系统中最常见的恶性肿瘤，超过90%的病例具有高度恶性。本研究旨在探讨微小RNA（miR）-19a对骨肉瘤细胞增殖和凋亡的调控作用，及其对Janus激酶2（JAK2）/信号转导及转录激活因子3（STAT3）信号通路激活的影响。通过慢病毒转染下调成年SaOS-2骨肉瘤细胞中miR-19a的表达，并将细胞分为对照组、NC抑制剂组和miR-19a抑制剂组。通过定量聚合酶链反应（qPCR）检测每组中miR-19a的表达。接下来，分别通过甲基噻唑基四氮唑（MTT）法和流式细胞术检测每组细胞的增殖和凋亡水平，并进一步测定细胞中的活性氧（ROS）水平。此外，通过蛋白质免疫印迹法检测凋亡相关蛋白和JAK2/STAT3信号通路相关蛋白的表达水平。miR-19a抑制剂组中miR-19a的表达水平显著低于对照组和NC抑制剂组（P<0.01）。miR-19a的下调显著降低了增殖能力（P<0.01），增加了SaOS-2细胞的凋亡水平（P<0.01），并显著提高了细胞中的ROS水平（P<0.01）。miR-19a的下调还促进了骨肉瘤细胞中裂解的半胱天冬酶-3/半胱天冬酶-3的表达（P<0.01），并抑制了Bcl-2/Bax的表达（P<0.01）。此外，miR-19a的下调显著降低了细胞中磷酸化（p-）JAK2、p-STAT3和髓系细胞白血病-1（Mcl-1）的蛋白表达水平（P<0.01）。综上所述，miR-19a的下调可抑制SaOS-2细胞中的JAK2/STAT3信号通路，促进凋亡相关蛋白的表达，并增加细胞中的ROS水平，从而促进凋亡并抑制细胞增殖。
