Liu Wenbin, Yu Xinfang, Zhou Li, Li Jigang, Li Ming, Li Wei, Gao Feng
Department of Pathology, The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan 410006, People's Republic of China.
Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA.
Onco Targets Ther. 2020 Apr 16;13:3209-3221. doi: 10.2147/OTT.S243212. eCollection 2020.
Addiction to aerobic glycolysis is a common metabolic phenotype in human non-small cell lung cancer (NSCLC). The natural product Sinomenine (Sin) exhibits significant anti-tumor effects in various human cancers. However, the underlying mechanism remains elusive.
The inhibitory effect of Sin on NSCLC cells was determined by MTS and soft agar assays. The glycolysis efficacy of NSCLC cells was examined by glucose uptake and lactate production. The activation of Akt signaling and the protein level of hexokinases II (HK2) were examined by immunoblot (IB), qRT-PCR, and immunohistochemical staining (IHC). The in vivo anti-tumor effect of Sin was validated by the xenograft mouse model.
We showed that HK2 is highly expressed in NSCLC tissues and cell lines. Depletion of HK2 suppressed cell viability, anchorage-independent colony formation, and xenograft tumor growth. Sinomenine exhibited a profound inhibitory effect on NSCLC cells by reducing HK2-mediated glycolysis both in vitro and in vivo. Ectopic overexpression of HK2 compromised these anti-tumor efficacies in sinomenine-treated NSCLC cells. Moreover, we revealed that sinomenine decreased Akt activity, which caused the down-regulation of HK2-mediated glycolysis. Knockdown of Akt reduced HK2 protein level and impaired glycolysis. In contrast, overexpression of constitutively activated Akt1 reversed this phenotype.
This study suggests that targeting HK2-mediated aerobic glycolysis is required for sinomenine-mediated anti-tumor activity.
有氧糖酵解成瘾是人类非小细胞肺癌（NSCLC）中常见的代谢表型。天然产物青藤碱（Sin）在多种人类癌症中表现出显著的抗肿瘤作用。然而，其潜在机制仍不清楚。
通过MTS和软琼脂试验确定青藤碱对NSCLC细胞的抑制作用。通过葡萄糖摄取和乳酸生成检测NSCLC细胞的糖酵解效率。通过免疫印迹（IB）、qRT-PCR和免疫组织化学染色（IHC）检测Akt信号通路的激活和己糖激酶II（HK2）的蛋白水平。通过异种移植小鼠模型验证青藤碱的体内抗肿瘤作用。
我们发现HK2在NSCLC组织和细胞系中高表达。HK2的缺失抑制了细胞活力、非锚定依赖性集落形成和异种移植肿瘤生长。青藤碱在体外和体内均通过减少HK2介导的糖酵解对NSCLC细胞表现出显著的抑制作用。HK2的异位过表达削弱了青藤碱处理的NSCLC细胞中的这些抗肿瘤功效。此外，我们发现青藤碱降低了Akt活性，这导致HK2介导的糖酵解下调。敲低Akt降低了HK2蛋白水平并损害了糖酵解。相反，组成型激活的Akt1的过表达逆转了这种表型。
本研究表明，靶向HK2介导的有氧糖酵解是青藤碱介导的抗肿瘤活性所必需的。
