毛蕊异黄酮通过干预LncRNA-WDR7-7-Rab27B信号通路抑制乳腺癌细胞迁移侵袭作用的研究

Long non-coding RNAs (LncRNA), mRNA-like transcripts longer than 200nt, is involved in tumor invasion and metastasis via activation of downstream signaling pathways. Given our focus on metastasis of breast cancer, we here cover insights into the function of LncRNA-WDR7-7 that was downregulated by high concentration calycosin in ER-positive cells, as well as its target gene Rab27B. The mechanism of action of Rab27B is believed to be induction of exosome secretion and subsequent regulation of MAPK, AKT pathways, leading to migration and invasion of tumor cells. Moreover, our preliminary study suggested that selective regulation of Ras-p38 MAPK and PI3K/Akt signaling pathway is correlated with calycosin-mediated inhibitory effects in ER-positive breast cells. Therefore, we hypothesize that the LncRNA-WDR7-7-Rab27B pathwey, followed by regulation of MAPK and AKT signaling, may be responsible for calycosin-induced inhibition of metastasis. By transwell assays, scratch method, Western blot, qPCR, xenograft tumor growth and immunohistochemistry, our project will investigte the relationship among calycosin, LncRNA-WDR7-7 and Rab27B in breast cancer. The results will not only help to further ascertain calycosin-mediated signaling pathway, but also provide experimental foundation for calycosin's future clinical applications for ER-positive breast cancer.

长链非编码RNA(LncRNA)表达水平异常与肿瘤发生发展密切相关。本项目以癌细胞"侵袭"特性为切入点，以毛蕊异黄酮处理ER(+)乳腺癌细胞，筛选表达显著下调的LncRNA-WDR7-7及其靶基因Rab27B为研究对象。Rab27B可通过影响外泌体分泌，调节下游信号MAPK、AKT，促进肿瘤侵袭转移。结合本课题组前期实验基础，毛蕊异黄酮抑制乳腺癌细胞生长作用机制包括下游Ras-p38 MAPK、PI3K/Akt信号通路的调节，我们推测毛蕊异黄酮通过干预LncRNA-WDR7-7-Rab27B通路及其下游MAPK、AKT信号分子，抑制乳腺癌迁移侵袭。本项目拟通过细胞生物学、分子生物学和动物实验，检测LncRNA-WDR7-7、Rab27B在体内外的信号级联，探讨毛蕊异黄酮抗乳腺癌转移的信号转导通路及作用靶点，从而为乳腺癌治疗提供新的药物与靶点选择。

肿瘤侵袭转移是乳腺癌患者复发和死亡的主要原因。本项目以癌细胞“侵袭”特性为切入点，主要探讨植物雌激素毛蕊异黄酮对乳腺癌细胞迁移和侵袭能力的影响及可能机制。课题组研究表明，毛蕊异黄酮可同时抑制ER(+)与ER(-)人乳腺癌细胞迁移侵袭，并且该作用在高侵袭性ER(-)细胞中表现更为显著。进一步的细胞生物学、分子生物学和动物实验证明，毛蕊异黄酮在体内外均是通过下调Rab27B表达，抑制MAPK、Akt信号通路，降低β-catenin和VEGF水平，发挥抗肿瘤细胞转移的作用。另一方面，长链非编码RNA(LncRNA)表达水平异常与肿瘤发生发展密切相关，而课题组发现毛蕊异黄酮可下调ER(+)与ER(-)乳腺癌细胞中LncRNA-WDR7-7水平，抑制下游靶基因GRP30表达，影响MAPK、Akt等信号通路蛋白磷酸化水平，从而抑制肿瘤细胞增殖。据此，本项目的实验数据可为异黄酮类植物雌激素抗乳腺癌治疗研究提供新思路，并从肿瘤增殖、侵袭和转移多方面提供了新靶点。