Fan Guanglei, Bo Jingli, Wan Renming, Peng Mingya, Luan Yufen, Deng Minbin, Xu Longbao
Department of Nuclear Medicine, Changzhou Second People's Hospital, Nanjing Medical University , Changzhou, P.R. China .
Cancer Biother Radiopharm. 2015 May;30(4):160-8. doi: 10.1089/cbr.2014.1700. Epub 2015 Apr 8.
Hypoxia can stimulate (18)F-fluorodeoxyglucose ((18)F-FDG) uptake in cultured tumor cells. This study has investigated the effect of lentiviral vector-mediated RNA interference (RNAi) targeting hypoxia-inducible factor 1α (HIF-1α) on the changes in HIF-1 and glucose transporter 1 (Glut-1) expression, the cell growth, and the uptake of (18)F-FDG in the human pancreatic cancer cell line, Patu8988. Lentiviral RNAi vector targeting the HIF-1α gene (LV-HIF-1αRNAi) was constructed and used to treat cells at various concentrations (25-200 nM). The expression changes of HIF-1α and Glut-1 in hypoxic Patu8988 cells after RNAi treatment were determined using real time reverse transcription-polymerase chain reaction (real-time PCR). The inhibition rate of cell proliferation 48 hours after the addition of 10 μL of different concentrations of LV-HIF-1αRNAi (25-200 nM) was assayed using the MTT method. Meanwhile, the cell uptake of (18)F-FDG was also assessed. After RNAi transfection, the relative expression levels of HIF-1α mRNA and Glut-1 under hypoxia were reduced and the relative expression levels of HIF-1α protein also decreased. Compared with the control group, the inhibition rates of cell proliferation under different viral dosages were 5.98%, 15.65%, 26.42%, and 40.81%, respectively, positively correlated with the viral doses (r=0.558, p<0.05). Under hypoxia, Glut-1 mRNA expression in Patu8988 cells treated with 200 nM of LV-HIF-1αRNAi for 24, 48, and 72 hours, respectively, was positively correlated with the inhibition rate of cell proliferation (r=0.618, p<0.05) as well as the inhibition rate of (18)F-FDG uptake (r=0.664, p<0.05), while the latter two displayed a positive correlation with each other too (r=0.582, p<0.05). Under hypoxia, RNAi targeting HIF-1α significantly inhibited the expression of Glut-1 mRNA in Patu8988 pancreatic cancer cells and their uptake of (18)F-FDG. These results suggest that LV-HIF-1αRNAi may form a new treatment for pancreatic cancer, and the effectiveness of the treatment can be readily assessed with (18)F-FDG imaging.
缺氧可刺激培养的肿瘤细胞摄取（18）F-氟脱氧葡萄糖（（18）F-FDG）。本研究探讨了慢病毒载体介导的针对缺氧诱导因子1α（HIF-1α）的RNA干扰（RNAi）对人胰腺癌细胞系Patu8988中HIF-1和葡萄糖转运蛋白1（Glut-1）表达变化、细胞生长以及（18）F-FDG摄取的影响。构建了靶向HIF-1α基因的慢病毒RNAi载体（LV-HIF-1αRNAi），并用于以不同浓度（25 - 200 nM）处理细胞。RNAi处理后，采用实时逆转录聚合酶链反应（实时PCR）测定缺氧Patu8988细胞中HIF-1α和Glut-1的表达变化。使用MTT法测定加入10 μL不同浓度LV-HIF-1αRNAi（25 - 200 nM）48小时后细胞增殖的抑制率。同时，也评估了细胞对（18）F-FDG的摄取。RNAi转染后，缺氧条件下HIF-1α mRNA和Glut-1的相对表达水平降低，HIF-1α蛋白的相对表达水平也下降。与对照组相比，不同病毒剂量下细胞增殖的抑制率分别为5.98%、15.65%、26.42%和40.81%，与病毒剂量呈正相关（r = 0.558，p < 0.05）。在缺氧条件下，分别用200 nM LV-HIF-1αRNAi处理Patu8988细胞24、48和72小时后，Glut-1 mRNA表达与细胞增殖抑制率（r = 0.618，p < 0.05）以及（18）F-FDG摄取抑制率（r = 0.664，p < 0.05）呈正相关，而后两者之间也呈正相关（r = 0.582，p < 0.05）。在缺氧条件下，靶向HIF-1α的RNAi显著抑制了Patu8988胰腺癌细胞中Glut-1 mRNA的表达及其对（18）F-FDG的摄取。这些结果表明，LV-HIF-1αRNAi可能成为胰腺癌的一种新治疗方法，并且可以通过（18）F-FDG成像轻易评估该治疗的有效性。
