缺氧微环境下miR-296/Snail双向负反馈环路调控胰腺癌转移的机制研究

miRNA and epithelial-mesenchymal transition (EMT) plays an important role in hypoxia-induced tumor metastasis. Our previous study found that the expression of miR-296 in pancreatic cancer cells was downregulated under hypoxia condition, and hypoxia-induced EMT in promoting metastasis of pancreatic cancer cells, which is related to HIF-1α/Snail/E-cadherin axis. Through bioinformatics analysis, we speculate miR-296/Snail form a double negative feedback loop to regulate metastasis of pancreatic cancer cell under hypoxia condition. Through miRNA mimics/sponge, realtime PCR, Western Blot, luciferase reporter gene system, chromatin immunoprecipitation to clarify the direct and indirect mechanisms of miR-296 on Snail and negative feedback of Snail on miR-296; RNA interference to investigate the effect of HIF-1α on miR-296 expression; pancreatic cancer metastasis model in nude mice to confirm miR-296 in the treatment of pancreatic cancer metastasis. Our findings reveal miR-296/Snail form a double negative feedback loop to regulate the metastasis of pancreatic cancer under hypoxia condition for the first time, laying the foundation for clinical therapy based on microRNAs.

miRNA的表达改变和上皮间质转化（EMT）在缺氧诱导肿瘤转移中发挥重要作用。我们前期研究发现缺氧下调胰腺癌细胞中miR-296的表达，并诱导其发生EMT促进转移，其中HIF-1α/Snail/E-cadherin轴起关键作用。结合生物信息学，我们推测miR-296/Snail形成双向负反馈回路调控缺氧诱导的胰腺癌转移。本研究拟采用miRNA mimics/sponge、实时定量PCR、WB、荧光素酶报告基因系统、染色质免疫共沉淀阐明miR-296对Snail的直接和间接调控机制，以及Snail对miR-296的负反馈调控作用；RNA干扰沉默HIF-1α探讨其对miR-296表达的影响；动物实验初步证实miR-296对胰腺癌裸鼠移植模型转移的治疗作用。本研究结果将揭示缺氧微环境下miR-296/Snail双向负反馈环路调控胰腺癌转移的机制，为基于miRNA临床靶向治疗奠定基础。

miRNA的表达改变和上皮间质转化（EMT）在缺氧诱导肿瘤转移中发挥重要作用。本研究采用miR-296激动剂agomir/拮抗剂antagomir、实时定量PCR、WB、荧光素酶报告基因系统、染色质免疫共沉淀阐明miR-296对Snail的直接和间接调控机制，以及Snail对miR-296的负反馈调控作用；RNA干扰沉默HIF-1α探讨其对miR-296表达的影响；动物实验初步证实miR-296对胰腺癌裸鼠移植模型转移的治疗作用。本研究结果揭示了缺氧微环境下miR-296/Snail双向负反馈环路调控胰腺癌转移的机制，为基于miRNA临床靶向治疗奠定基础。