siRNA沉默转酮醇酶样基因1下调人宫颈癌细胞HIF-1α表达及糖酵解关键酶活性

 目的：通过siRNA技术沉默宫颈癌细胞转酮醇酶样基因-1（TKTL1）后观察其在缺氧条件下低氧诱导因子1α（HIF-1α）表达水平及糖酵解途径中2个关键酶己糖激酶Ⅱ（HK-Ⅱ）和乳酸脱氢酶（LDH）活性的变化情况，旨在探讨肿瘤细胞TKTL1表达与糖酵解途径的关系。方法：用构建的靶向TKTL1基因siRNA干扰质粒载体转染HeLa细胞株，RT-PCR检测TKTL1 mRNA表达并结合转酮醇酶（TKT）活性测定判断其干扰效率；以未转染HeLa细胞为对照，进一步观察TKTL1沉默的癌细胞在缺氧条件下HIF-1α和HK-Ⅱ表达水平，以及HK-Ⅱ和LDH活性的变化。结果：siRNA沉默HeLa细胞TKTL1基因后TKTL1 mRNA表达下降,TKT活性显著降低（P<0.01），HIF-1α和HK-Ⅱ表达水平及HK-Ⅱ和LDH活性较对照组细胞均显著降低（P<0.01）。结论：沉默肿瘤细胞TKTL1基因能下调HIF-1α表达并降低糖酵解代谢关键酶活性，从而影响肿瘤细胞的恶性表型。  

Silencing of TKTL1 gene by siRNA down-regulates HIF-1α expression and activity of glycolytic key enzymes in human cervical cancer cells

AIM：To explore the relationship between the expression of transketolase-like gene 1 (TKTL1) and glycolysis metabolism in human cervical cells. METHODS：The changes of hypoxia-inducible factor 1α (HIF-1α) expression and the activity of glycolytic key enzymes, hexokinase Ⅱ (HK-Ⅱ) and lactate dehydrogenase (LDH), under hypoxia in human cervical cell line HeLa were observed after TKTL1 was knockdown by siRNA. The specific siRNA expression vector targeting TKTL1 gene was constructed, and the recombinant plasmid was transfected into HeLa cells. The effects of TKTL1 silencing were evaluated by detecting transketolase (TKT) activity and TKTL1 mRNA expression using RT-PCR. The changes of HIF-1α  expression and HK-Ⅱ expression, and HK-Ⅱ and LDH activity were also observed in transfected HeLa cells. RESULTS：The mRNA expression of TKTL1 and the activity of TKT decreased significantly (P<0.01) after TKTL1 silencing. Meanwhile, all HIF-1α  expression, HK-Ⅱexpression, and HK-Ⅱ and LDH activity decreased significantly compared with the untransfected cells (P<0.01). CONCLUSION：Silencing of TKTL1 gene in human cervical cancer cells by siRNA down-regulates HIF-1α expression and the activity of glycolytic key enzymes, thus changing the malignant phenotype of carcinoma cells.