长非编码RNA AF070527抑制VEGF表达的分子机制及其在胃癌侵袭转移中的作用研究

lncRNA played important roles in gastric cancer metastasis. By previous experiments of micrornas chips and qRT-PCR, it was found lncRNA AF070527 was significantly low expression in gastric cancer. When AF070527 was overexpressed in SGC-7901 and BGC-823 cells, the proliferation and metastasis of these cells were significantly depressed, which indicated that AF070527 played important roles in gastric cancer progression. By bioinformatics, qRT-PCR and WB, it was found that VEGF may be the target gene of AF070527. Furthermore, by CHRIP-seq, mass spectrometric analysis and literature review, it was found that AF070527 combined with the nuclear factor RBP2, which inhibited the combine between RBP2 and VEGF promoter and lead to the low expression of VEGF. So we hypothesized that overexpressed AF070527 inhibited the expression of VEGF and finally lead to the low capacity of gastric cancer cell proliferation and metastasis. So this study intends to demonstrate the detail mechanism for AF070527 inhibiting gastric cancer metastasis, and provided new theoretical basis to the molecular mechanisms of gastric cancer proliferation and metastasis in lncRNA level.

lncRNA在胃癌的侵袭转移中发挥重要作用。我们前期通过基因芯片及qRT-PCR发现，在胃癌中lncRNA AF070527明显低表达。过表达AF070527后癌细胞的增殖及侵袭转移能力明显减弱，说明AF070527可能在胃癌的发生发展中发挥了重要作用。通过生物信息学、qRT-PCR及WB等实验发现，AF070527的靶基因可能是VEGF。进一步通过CHIRP-seq、质谱分析及文献复习发现，AF070527可能通过作用于核转录因子RBP2，间接抑制VEGF的表达。据此，我们提出以下假设：胃癌细胞中过表达AF070527，使其与RBP2竞争性结合，减少VEGF的表达，抑制胃癌细胞的增殖及侵袭转移。因此本课题拟通过相关分子生物学方法证实lncRNA AF070527通过抑制VEGF表达抑制胃癌的侵袭转移，为在lncRNA层面阐明胃癌发生发展的机制提供理论支持，并为胃癌的防治提供新靶点。

长链非编码RNA (lncRNA)在胃癌转移中发挥重要调节作用。本项目通过基因芯片及定量PCR发现，lncRNA AF070527在胃癌组织中显著低表达，进一步分析发现AF070527的表达与胃癌的淋巴结和远处转移呈负相关。通过慢病毒过表达的AF070527显著抑制了胃癌细胞的迁移能力，而对胃癌细胞的增殖能力无明显影响。原位杂交实验显示AF070527主要位于细胞浆，提示其主要在细胞浆内发挥功能。机制上，通过mRNA芯片筛选，发现过表达AF070527影响了p53、PI3K-Akt、Jak-STAT信号通路，提示AF070527可能通过影响这些信号通路调控胃癌细胞的迁移，为阐明AF070527调节胃癌转移的分子机制提供了线索。