PVT1在骨肉瘤化疗中的耐药机制

The mechanism of PVT1 in chemotherapy resistance of osteosarcoma

[目的]探讨PVT1介导骨肉瘤化疗耐药的潜在机制。[方法]以2018年1月~2020年1月收治确诊为骨肉瘤顺铂耐药100例为耐药组,骨肉瘤顺铂敏感100例为敏感组。实时荧光定量PCR检测耐药组和敏感组骨肉瘤组织中PVT1的表达量。实时荧光定量PCR检测顺铂敏感细胞U2OS和HOS、顺铂耐药细胞U2OS/DDP和HOS/DDP的PVT1的表达量。敲低PVT1或质粒过表达PVT1后,检测上述细胞的凋亡水平和细胞活力,以及关键基因bcl2和mTOR的表达量。[结果]与顺铂敏感患者相比,顺铂耐药患者的癌症组织中观察到PVT1 mRNA水平显着升高(0.68±0.04 vs1.24±0.06,P <0.05)。顺铂耐药细胞U2OS/DDP和HOS/DDP中PVT1的表达量均分别高于非耐药U2OS和HOS细胞。敲低PVT1并用顺铂处理后,U2OS/DDP和HOS/DDP细胞的凋亡水平上升(0.32±0.04 vs 0.78±0.14,P <0.05;0.28±0.03 vs 0.81±0.20,P <0.05)、细胞活力水平下降(0.82±0.01 vs 0.39±0.02,P <0.05;0.83±0.02 vs0.50±0.03,P <0.05)。过表达PVT1并用顺铂处理后,U2OS/DDP和HOS/DDP细胞的凋亡水平下降(0.29±0.04 vs0.13±0.01,P <0.05;0.30±0.03 vs 0.09±0.02,P <0.05)、U2OS/DDP和HOS/DDP的细胞活力水平上升(0.79±0.03 vs 1.21±0.04,P <0.05;0.87±0.01 vs 1.43±0.01,P <0.05)、凋亡抑制因子bcl2和mTOR的表达水平上升。[结论]PVT1通过bcl2/mTOR信号途径促使骨肉瘤细胞U2OS和HOS抵抗顺铂的促凋亡作用(0.32±0.04 vs 0.78±0.14,P <0.05;0.28±0.03 vs 0.81±0.20,P <0.05)。

[Objective]To explore the potential mechanism of PVT1-mediated chemotherapy resistance of osteosarcoma.[Method]100 patients diagnosed with osteosarcoma-resistant cisplatin in our hospital from January 2018 to January 2020 were included in the drug-resistant group,and 100 patients with cisplatin-sensitive osteosarcoma were sensitive. The expression of PVT1 in osteosarcoma tissues of drug-resistant group and sensitive group was detected by real-time fluorescent quantitative PCR. The expressions of PVT1 in cisplatin-sensitive cells U2OS and HOS and cisplatin-resistant cells U2OS/DDP and HOS/DDP were detected by real-time fluorescent quantitative PCR. After PVT1 knockdown or plasmid overexpression of PVT1,apoptosis level and cell viability,as well as the expression levels of key genes Bcl2 and mTOR in these cells were detected.[Result]Compared with cisplatin-sensitive patients,PVT1 mRNA levels were significantly increased in cancer tissues of cisplatin-resistant patients(0. 68 ± 0. 04 vs 1. 24 ± 0. 06,P < 0. 05). The expression of PVT1 in cisplatin-resistant cells U2OS/DDP and HOS/DDP was higher than that in non-resistant U2OS and HOS cells,respectively. After knocking down PVT1 and treating with cisplatin,the apoptosis level of U2OS/DDP and HOS/DDP cells increased(0. 32 ± 0. 04 vs 0. 78 ±0. 14,P < 0. 05;0. 28 ± 0. 03 vs 0. 81 ± 0. 20,P < 0. 05) and the cell viability level decreased(0. 82 ± 0. 01 vs 0. 39 ± 0. 02,P < 0. 05;0. 83 ± 0. 02 vs 0. 50 ± 0. 03,P < 0. 05). After overexpression of PVT1 and treatment with cisplatin,apoptosis levels of U2OS/DDP and HOS/DDP cells were decreased(0. 29 ± 0. 04 vs 0. 13 ± 0. 01,P < 0. 05;0. 30 ± 0. 03 vs 0. 09 ± 0. 02,P <0. 05),cell viability levels of U2OS/DDP and HOS/DDP cells were increased(0. 79 ± 0. 03 vs 1. 21 ± 0. 04,P < 0. 05;0. 87 ±0. 01 vs 1. 43 ± 0. 01,P < 0. 05),and the expression levels of apoptosis inhibitors Bcl2 and mTOR were increased. [Conclusion]PVT1 promoted the anti-apoptotic effect of osteosarcoma cells U2OS and HOS against cisplatin through bcl2/mTOR signaling pathway(0. 32 ± 0. 04 vs 0. 78 ± 0. 14,P < 0. 05;0. 28 ± 0. 03 vs 0. 81 ± 0. 20,P < 0. 05).