Department of Hand and Foot Surgery, The Affiliated Taizhou People's Hospital of Nanjing Medical University, Taizhou School of Clinical Medicine, Nanjing Medical University, Taizhou, China.
Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, China.
Cell Death Dis. 2024 May 20;15(5):346. doi: 10.1038/s41419-024-06722-6.
Exploring novel diagnostic and therapeutic biomarkers is extremely important for osteosarcoma. YME1 Like 1 ATPase (YME1L), locating in the mitochondrial inner membrane, is key in regulating mitochondrial plasticity and metabolic activity. Its expression and potential functions in osteosarcoma are studied in the present study. We show that YME1L mRNA and protein expression is significantly elevated in osteosarcoma tissues derived from different human patients. Moreover, its expression is upregulated in various primary and immortalized osteosarcoma cells. The Cancer Genome Atlas database results revealed that YME1L overexpression was correlated with poor overall survival and poor disease-specific survival in sarcoma patients. In primary and immortalized osteosarcoma cells, silencing of YME1L through lentiviral shRNA robustly inhibited cell viability, proliferation, and migration. Moreover, cell cycle arrest and apoptosis were detected in YME1L-silenced osteosarcoma cells. YME1L silencing impaired mitochondrial functions in osteosarcoma cells, causing mitochondrial depolarization, oxidative injury, lipid peroxidation and DNA damage as well as mitochondrial respiratory chain complex I activity inhibition and ATP depletion. Contrarily, forced YME1L overexpression exerted pro-cancerous activity and strengthened primary osteosarcoma cell proliferation and migration. YME1L is important for Akt-S6K activation in osteosarcoma cells. Phosphorylation of Akt and S6K was inhibited after YME1L silencing in primary osteosarcoma cells, but was strengthened with YME1L overexpression. Restoring Akt-mTOR activation by S473D constitutively active Akt1 mitigated YME1L shRNA-induced anti-osteosarcoma cell activity. Lastly, intratumoral injection of YME1L shRNA adeno-associated virus inhibited subcutaneous osteosarcoma xenograft growth in nude mice. YME1L depletion, mitochondrial dysfunction, oxidative injury, Akt-S6K inactivation, and apoptosis were detected in YME1L shRNA-treated osteosarcoma xenografts. Together, overexpressed YME1L promotes osteosarcoma cell growth, possibly by maintaining mitochondrial function and Akt-mTOR activation.
探索新的诊断和治疗生物标志物对骨肉瘤极为重要。YME1 样 1 ATP 酶（YME1L）位于线粒体的内膜，是调节线粒体可塑性和代谢活性的关键。本研究探讨了其在骨肉瘤中的表达和潜在功能。结果显示，YME1L mRNA 和蛋白在不同来源的骨肉瘤组织中表达显著上调。此外，在各种原代和永生化骨肉瘤细胞中，其表达也上调。癌症基因组图谱数据库结果表明，YME1L 过表达与肉瘤患者的总体生存率和疾病特异性生存率降低相关。在原代和永生化骨肉瘤细胞中，通过慢病毒 shRNA 沉默 YME1L 可显著抑制细胞活力、增殖和迁移。此外，在 YME1L 沉默的骨肉瘤细胞中检测到细胞周期停滞和细胞凋亡。YME1L 沉默抑制了骨肉瘤细胞的线粒体功能，导致线粒体去极化、氧化损伤、脂质过氧化和 DNA 损伤以及线粒体呼吸链复合物 I 活性抑制和 ATP 耗竭。相反，强制过表达 YME1L 可发挥致癌作用，并增强原代骨肉瘤细胞的增殖和迁移。YME1L 对骨肉瘤细胞中 Akt-S6K 的激活很重要。在原代骨肉瘤细胞中沉默 YME1L 后，Akt 和 S6K 的磷酸化被抑制，但过表达 YME1L 后则被增强。通过 S473D 组成型激活 Akt1 恢复 Akt-mTOR 激活可减轻 YME1L shRNA 诱导的抗骨肉瘤细胞活性。最后，在裸鼠中，通过肿瘤内注射 YME1L shRNA 腺相关病毒抑制皮下骨肉瘤异种移植瘤的生长。在 YME1L shRNA 处理的骨肉瘤异种移植瘤中检测到 YME1L 耗竭、线粒体功能障碍、氧化损伤、Akt-S6K 失活和细胞凋亡。总之，过表达的 YME1L 通过维持线粒体功能和 Akt-mTOR 激活促进骨肉瘤细胞生长。
