Jingzhou Hospital Affiliated to Yangtze University, No.26 Chuyuan Avenue, Jingzhou District, Jingzhou City, 434020, Hubei Province, China.
Mol Biotechnol. 2024 Oct;66(10):2985-2994. doi: 10.1007/s12033-023-00914-9. Epub 2023 Oct 18.
Protein tyrosine phosphatase receptor type C (PTPRC) is reported to function as an oncogenic role in various cancer. However, the studies on the roles of PTPRC in osteosarcoma (OS) are limited. This study aimed to explore the potentials of PTPRC in OS. mRNA levels were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Protein expression was detected by western blot. Lysosome biogenesis was determined using immunofluorescence. The binding sites of transcription factor EB (TFEB) on the promoter of ferritin heavy chain 1 (FTH1) were predicted by the online dataset JASPAR and confirmed by luciferase and chromatin immunoprecipitation (ChIP) assays. Cell death was determined using propidium iodide (PI) and TdT-mediated dUTP nick-end labeling (TUNEL) staining. The results showed that PTPRC was significantly overexpressed in OS tissues and cells. PTPRC knockdown promoted the phosphorylation and nuclear translocation of TFEB. Moreover, PTPRC knockdown markedly promoted lysosome biogenesis and the accumulation of ferrous ion (Fe), whereas decreased the release of glutathione (GSH). Besides, PTPRC knockdown significantly promoted autophagy and downregulated mRNA expression of FTH1 and ferritin light chain (FTL). Additionally, TFEB transcriptionally inactivated FTH1. PTPRC knockdown significantly promoted the ferroptosis of OS cells, which was markedly alleviated by TFEB shRNA. Taken together, PTPRC knockdown-mediated TFEB phosphorylation and translocation dramatically promoted lysosome biogenesis, ferritinophagy, as well as the ferroptosis of OS cells via regulating FTH1/FTL signaling. Therefore, PTPRC/TFEB/FTH1 signaling may be a potential target for OS.
蛋白酪氨酸磷酸酯酶受体 C（PTPRC）在多种癌症中被报道具有致癌作用。然而，关于 PTPRC 在骨肉瘤（OS）中的作用的研究有限。本研究旨在探索 PTPRC 在 OS 中的潜力。通过逆转录定量聚合酶链反应（RT-qPCR）检测 mRNA 水平。通过蛋白质印迹法检测蛋白表达。通过免疫荧光法测定溶酶体生物发生。通过在线数据集 JASPAR 预测转录因子 EB（TFEB）在铁蛋白重链 1（FTH1）启动子上的结合位点，并通过荧光素酶和染色质免疫沉淀（ChIP）实验进行验证。通过碘化丙啶（PI）和 TdT 介导的 dUTP 缺口末端标记（TUNEL）染色测定细胞死亡。结果表明，PTPRC 在 OS 组织和细胞中显著过表达。PTPRC 敲低促进了 TFEB 的磷酸化和核易位。此外，PTPRC 敲低显著促进了溶酶体生物发生和亚铁离子（Fe）的积累，而降低了谷胱甘肽（GSH）的释放。此外，PTPRC 敲低显著促进了自噬，并下调了 FTH1 和铁蛋白轻链（FTL）的 mRNA 表达。此外，TFEB 转录失活了 FTH1。PTPRC 敲低显著促进了 OS 细胞的铁死亡，TFEB shRNA 显著减轻了这一作用。总之，PTPRC 敲低介导的 TFEB 磷酸化和易位通过调节 FTH1/FTL 信号显著促进了 OS 细胞的溶酶体生物发生、铁蛋白自噬和铁死亡。因此，PTPRC/TFEB/FTH1 信号可能是 OS 的一个潜在靶点。
