环状RNA-0000284介导miR-326调控FGF1在乳腺癌侵袭转移中的作用及分子机制

Breast cancer is the most common malignancy in women, and the main cause of death is invasion and metastasis, but the mechanism is still unknown. Circular RNA (circRNA), serves as a novel non-coding RNA, which is closely related to the development of tumor. The circ-0000284 molecular associated with invasion and metastasis of breast cancer was screened by high-throughput circRNA chip technology and its mechanism might be related to the binding with miR-326 to inhibit the expression of FGF1. Based on the preliminary study, the applicant aimed to explore the scientific problems as follows: (1) Cellular level: Analyze the role and mechanism of circ-0000284 mediating miR-326 to regulate FGF1 in invasion and metastasis of breast cancer. (2) In vivo level: Evaluate the effect of circ-0000284/miR-326/FGF1 pathway on invasion and metastasis of breast cancer. (3) Human tissue level: Verify the correlation between the expression of circ-0000284 and its target molecules and the prognosis of patients with breast cancer. This study intends to explore the regulatory network of invasion and metastasis of breast cancer based on circ-0000284/miR-326/FGF1 pathway from the multi-molecular perspective, thus providing new targets for clinical intervention in the treatment of breast cancer and improving the existing prevention strategies.

乳腺癌是女性最常见恶性肿瘤，侵袭转移为其主要致死原因，但机制尚不明了。环状RNA（circRNA）是一类新发现的非编码RNA，近期发现其与肿瘤发生发展密切相关。申请者前期通过高通量circRNA芯片筛选出与乳腺癌侵袭转移相关的circ-0000284分子，其机制可能与靶向结合miR-326抑制FGF1表达有关。基于上述研究基础，在本项目中我们拟通过：①细胞层面：解析circ-0000284介导miR-326调控FGF1影响乳腺癌侵袭转移的作用及机制；②动物层面：评估circ-0000284/miR-326/FGF1调控通路对乳腺癌侵袭转移的影响；③组织层面：验证circ-0000284及其靶控分子表达与患者预后的相关性。本项目拟从多分子视域挖掘基于circ-0000284/miR-326/FGF1信号轴介导的乳腺癌侵袭转移分子网络调控模式，为临床干预治疗乳腺癌提供新靶点，完善现有防治策略。

背景：环状RNA与多种肿瘤的侵袭以及进展密切相关。在我们前期的芯片研究结果提示环状RNA circ-0000284在乳腺癌组织中异常表达。但是其在乳腺癌中起何种作用以及作用机制尚未明确。研究方法：我们利用RT-qPCR技术检测circ-0000284在乳腺癌组织以及细胞系中的表达水平。并通过生物信息学分析以及荧光素酶报告基因的方法证实circ-0000284与miR-326直接相结合。进一步采用RNA沉默以及过表达的方法证实circ-0000284调节miR-326以及FGF1表达水平。结果：相较于正常乳腺组织以及乳腺上皮细胞circ-0000284在乳腺癌组织以及细胞株中均高表达，且表达程度的高低与淋巴结转移和临床分期呈正相关。我们利用transwell assay技术发现circ-0000284具有促进侵袭以及转移的功能，沉默circ-0000284表达能够抑制乳腺癌的侵袭以及转移。通过对其机制的研究，我们发现circ-0000284在乳腺癌细胞中发挥miRNA海绵的功能，通过吸附miR-326来减弱其对下游靶基因FGF1的抑制作用，从而促进乳腺癌的转移。结论：circ-0000284通过circ-0000284/miR-326/FGF1轴来促进乳腺癌的侵袭转移，为临床乳腺癌的诊断和治疗提供新的潜在靶点。