低氧诱导因子HIF-1α调控CX3CR1在胰腺癌细胞中的表达
Regulation of CX3CR1 expression in pancreatic cancer cells by hypoxia inducible factor 1α
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摘要:目的 以胰腺癌细胞株Patu8988为研究对象, 通过过表达和干扰低氧诱导因子(HIF-1α), 观察CX3CR1表达水平的变化, 并探讨CX3CR1在胰腺癌中的调控机制。方法 分别构建pcDNA3.1-HIF-1α过表达质粒和HIF-1α-siRNA, 转染胰腺癌细胞株Patu8988, 经Western blot、半定量PCR检测CX3CR1的表达情况。采用染色质免疫沉淀(chromatin immunoprecipitation, ChIP)、荧光素酶技术探查HIF-1α与CX3CR1启动子区的结合情况。结果 Patu8988转染pcDNA3.1-HIF-1α后CX3CR1的表达增加, 敲除HIF-1α后CX3CR1的表达减少。HIF-1α与CX3CR1启动子区的低氧反应元件直接结合, 并上调CX3CR1启动子的活性(P < 0.01)。结论 HIF-1α调控CX3CR1在胰腺癌细胞中的表达。Abstract:Objective This study aimed to investigate the effect of hypoxia inducible factor 1α(HIF-1α) expression on CX3CR1 and its regulatory mechanism in pancreatic cancer cell line Patu8988.Methods The highly expressed plasmid pcDNA3.1 HIF-1α and siRNA HIF-1α were initially constructed. After the plasmid was separately transfected to the pancreatic cancer cells, CX3CR1 and HIF-1α expressions were assayed by western blot analysis and real-time quantitative reverse transcriptase-polymerase chain reaction. The relationship between HIF-1α and CX3CR1 promoter was determined by chromatin immunoprecipitation and luciferase technology.Results The overexpressed HIF-1α could upregulate the CX3CR1 expression in pancreatic cancer cells. The CX3CR1 expression was significantly reduced when HIF-1 α was knocked down. Chromatin immunoprecipitation assay demonstrated that HIF-1α could be directly bound to the hypoxia-response element(5'-A/GCGTG-3') of the CX3CR1 promoter. This binding activity was significantly enhanced under hypoxic condition. CX3CR1 promoter-induced HIF-1α overexpression could significantly upregulate the expression of luciferase reporter genes in pancreatic cancer cells(P < 0.01).Conclusion HIF-1α could regulate CX3CR1 expression in pancreatic cancer cells.
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