tRNA剪切分子AS-tDR-770抑制CKAP2调控乳腺癌转移的机制研究

前期通过高通量测序并筛选获得一条差异低表达于乳腺癌、功能未知的tRNA来源小分子RNA片段AS-tDR-770（简称tRF）。预实验发现tRF显著低表达于乳腺癌组织，与肿瘤分期和淋巴结转移呈负相关。过表达tRF可抑制乳腺癌细胞侵袭转移等恶性行为。生信分析和实验提示CKAP2基因的3 ́UTR区域可与tRF直接结合；文献报道CKAP2与FAK-ERK信号通路相关，我们证实乳腺癌细胞ERK及下游基因表达亦可受tRF调控。故提出假说：tRF发挥竞争性内源RNA作用吸附CKAP2负向调控FAK-ERK信号通路抑制乳腺癌恶性进展。本课题拟体内外实验验证tRF抑制乳腺癌侵袭转移;阐明tRF竞争结合CKAP2抑制FAK-ERK通路的网络机制；评价tRF/CKAP2/FAK-ERK与乳腺癌临床病理特征关系。tRF在乳腺癌侵袭转移方面的功能机制未见报道，本项目为乳腺癌防治提供新思路及新靶标

AS-tDR-770, a tRNA derived fragment with unknown function, was identified from next-generation sequencing technology and specifically under-expression in breast cancer tissue. Previously, we found that the expression of AS-tDR-770 detected by qPCR was significantly low expression in breast cancer tissue.And it was negatively related with the TNM stage and. lymphatic metastasis.Besides, overexpression of AS-tDR-770 decreased the breast cancer cell ability of proliferation and metastasis. Bioinformatics analysis and our experiments confirmed that3 'UTR of CKAP2 gene can directly bind to AS-tDR-770. It has been reported that CKAP2 is associated with the FAK-ERK signaling pathway, and our data showed that the protein of ERK including its downstream gene expression in breast cancer cells may be regulated by AS-tDR-770. Therefore, we hypothesized that AS-tDR-770 may negatively regulate the FAK-ERK signaling pathway to inhibit the malignant progression of breast cancer by the adsorption of CKAP2 acting as competitive endogenous RNA. Our study intends to explore whether AS-tDR-770 can inhibit breast cancer invasion and metastasis in vivo and vitro experiments. Further more, We plan to clarify the network mechanism of AS-tDR-770 combined with CKAP2 competitively to inhibit the FAK-ERK pathway.Finally, the correlation between tRF/CKAP2/FAK-ERK and the clinicopathological characteristics of breast cancer will be evaluated in a large number of patients diagnosed with breast cancer. The function and mechanism of tRF promoting breast cancer proliferation and metastasis has not been reported. This project provides a new idea for determining whether tRF can be a potential target for clinical prevention and treatment.