Chen Xiao-Hong, Yu Ding-Li, Zhong Jiang-Tao, Zhou Shui-Hong, Fan Jun, Lu Zhong-Jie
Department of Otolaryngology, The Second Hospital of Jiaxing (The Second Affiliated Hospital, Jiaxing University), Jiaxing City, Zhejiang Province, 314000, People's Republic of China.
Department of Otolaryngology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310003, People's Republic of China.
Cancer Manag Res. 2021 Oct 27;13:8063-8076. doi: 10.2147/CMAR.S324754. eCollection 2021.
Hexokinase-II (HK-II) is the key enzyme in the first rate-limiting step of glycolysis that catalyzes the conversion of glucose to glucose-6-phosphate. Here, we examined the association between HK-II expression and radioresistance in laryngeal carcinoma and whether the inhibition of HK-II expression can enhance the radiosensitivity of these tumors.
The effects of HK-II small interfering RNA (siRNA) on the radiosensitivity of Tu212 cells were examined in vitro and in vivo in a mouse model. Cells were irradiated using a 6-MV linear accelerator. The cell viability, cell survival, proliferation, apoptosis, and cell cycle of Tu212 cells were evaluated using trypan blue staining, colony formation assays, CCK-8 assays, and flow cytometry, respectively. Oxygen consumption, lactic acid production, glucose consumption, and the ATP level of Tu212 cells were also examined. The expression of glycolytic and regulatory enzymes involved in the tricarboxylic acid cycle was assessed using Western blotting.
The HK-II siRNA and X-ray combination treatment led to a significantly greater reduction of cell viability, inhibition of cell survival and proliferation, increased apoptosis, and increased G2 phase arrest compared to either treatment alone (all, <0.01). HK-II siRNA increased the oxygen consumption rate of cells, significantly inhibited lactic acid production and glucose consumption, and significantly suppressed the upregulation of HK-II, pyruvate kinase M2 (PKM2), pyruvate dehydrogenase (PDH), phosphofructokinase platelet (PFKP), lactate dehydrogenase (LD), and citrate synthase (CS) (all, P<0.01).
The inhibition of HK-II by siRNA enhances the radiosensitivity of laryngeal carcinoma Tu212 cells by inhibiting glycolysis and partially inhibiting oxidative phosphorylation.
己糖激酶-II（HK-II）是糖酵解第一步限速反应中的关键酶，催化葡萄糖转化为葡萄糖-6-磷酸。在此，我们研究了HK-II表达与喉癌放射抗性之间的关联，以及抑制HK-II表达是否能增强这些肿瘤的放射敏感性。
在体外和小鼠模型体内研究HK-II小干扰RNA（siRNA）对Tu212细胞放射敏感性的影响。使用6兆伏直线加速器对细胞进行照射。分别采用台盼蓝染色、集落形成试验、CCK-8试验和流式细胞术评估Tu212细胞的细胞活力、细胞存活、增殖、凋亡和细胞周期。还检测了Tu212细胞的耗氧量、乳酸生成、葡萄糖消耗和ATP水平。采用蛋白质印迹法评估参与三羧酸循环的糖酵解酶和调节酶的表达。
与单独使用任何一种处理相比，HK-II siRNA与X射线联合处理导致细胞活力显著降低、细胞存活和增殖受到抑制、凋亡增加以及G2期阻滞增加（所有P值均<0.01）。HK-II siRNA提高了细胞的耗氧率，显著抑制了乳酸生成和葡萄糖消耗，并显著抑制了HK-II、丙酮酸激酶M2（PKM2）、丙酮酸脱氢酶（PDH）、血小板型磷酸果糖激酶（PFKP）、乳酸脱氢酶（LD）和柠檬酸合酶（CS）的上调（所有P值均<0.01）。
siRNA抑制HK-II可通过抑制糖酵解并部分抑制氧化磷酸化来增强喉癌Tu212细胞的放射敏感性。
