脑胶质瘤细胞糖酵解表型特征及对细胞增殖与凋亡的影响

Characterization of glycolytic phenotype of SHG44 human glioma cells under hypoxic conditions and its association with cell proliferation and apoptosis

目的探讨胶质瘤细胞株SHG44糖酵解表型特征及对细胞增殖、凋亡的影响。方法通过化学模拟法(CoCl2)建立人脑胶质瘤细胞株SHG44体外缺氧模型。Realtime-PCR、Western blot分别检测HIF-1αmRNA、PDK1 mRNA、PKM2 mRNA、LDHAmRNA和蛋白的表达;生物发光法检测细胞内ATP值;酶法检测上清中乳酸含量;MTT法检测细胞增殖、流式细胞技术检测细胞凋亡。结果缺氧条件下,人脑胶质瘤SHG44细胞HIF-1α和糖酵解酶的mRNA和蛋白表达显著升高,细胞内ATP水平下降、细胞增殖能力减弱、细胞凋亡增加。结论缺氧能诱使肿瘤细胞出现糖酵解表型特征。肿瘤细胞增殖、凋亡与其代谢特征有关。

Objective To investigate the glycolytic phenotype of SHG44 human glioma cells under hypoxic conditions and the association between cell proliferation and apoptosis and the metabolic status. Methods An in vitro hypoxic cell model was established in SHG44 cells using CoCh. Real-time PCR and Western blotting were used to assess the expressions of hypoxia-inducible factor-1α （HIF-1α） and the enzymes involved in glycolysis including PDK1, PKM2, and LDHA. Intracellular ATP levels were measured by bioluminescence assay to assess the energy metabolic status of SHG44 cells. The viability and apoptosis of the ceils were examined using MTT assay and flow cytomel. , respectively. Results The cells in hypoxic culture showed obviously increased expressions of HIF-1α, LDHA, PDK1, and PKM2 at both the mRNA and protein levels as compared to those in normal cell culture. Hypoxia of the cells also resulted in a lowered cell proliferative activity and an increased apoptosis rate with lowered intraceUular ATP concentrations and elevated mitochondrial membrane potential. Conclusion Hypoxia can induce a glycolytic phenotype of tumor cells. The sensitivity of tumor cells to hypoxia-induced cell death is directly correlated with their metabolic status.