MicroRNA-150 agomir治疗三阴性乳腺癌及其机制研究

Triple negative breast cancer (TNBC) is ER, PR, HER-2 receptors all negative tumors. Nowdays, though patients with TNBC are mainly treated by chemotherapy, they easily become resistant to chemotherapy drugs. Previous studies have found that miR-150 acted as a tumor suppressor in the vast majority of tumors, involving the regulation of tumor proliferation, apoptosis, metastasis and so on. Therefore, upregulation of miR-150 through chemically synthesized and modified miRNA agonist may become a new strategy for antitumor therapy. Previously, we verified the low expression of miR-150 in TNBC, and found that upregualtion of miR-150 inhibited the proliferation of TNBC cells. This program will first analyze the relationship between miR-150 expression in samples of TNBC patients and the clinical and pathological features; Secondly, we will study the role of miR-150 agomir in the biological characteristics of TNBC including cell proliferation, apoptosis, invasion, etc; Finally, we will research the inhibitory effect of miR-150 on TNBC in vivo through subcutaneous tumor in mice experiments and mouse lung metastasis model. Through above researches, we will explore the feasibility of the treatment for TNBC by upregulation of miR-150 and the systematic mechanism of miR-150, which will provide new ideals and approaches to the treatment of TNBC.

三阴性乳腺癌（TNBC）是ER、PR、HER-2受体均阴性的肿瘤，目前临床以化疗为主，但TNBC患者易对化疗产生耐药。既往研究发现miR-150在绝大多数肿瘤中发挥抑癌作用，参与肿瘤增殖、凋亡、转移等调控。因此，利用化学合成和修饰的miRNA激动剂agomir调控miR-150表达可能成为抗肿瘤治疗的新策略。前期我们也发现miR-150在TNBC中低表达，上调miR-150表达抑制TNBC细胞的增殖。本课题将首先在TNBC患者标本中分析miR-150表达与临床病理特征的关系；其次，利用miR-150 agomir，研究其对TNBC细胞增殖、凋亡、侵袭等生物学特性的影响及其作用机制；最后，通过小鼠皮下成瘤试验和小鼠肺转移模型，体内水平研究miR-150对TNBC的抑制效果。通过以上研究，我们初步探讨上调miR-150表达治疗TNBC的可行性以及miR-150系统的作用机制，从而为TNBC的治疗提供新的思路和途径。

三阴性乳腺癌（TNBC）作为一类特殊的乳腺癌，具有肿瘤体积大、病理等级高和早期复发转移等特点，临床尚缺乏有效的治疗手段。既往研究显示MiR-150在多种实体肿瘤和血液系统肿瘤中扮演抑癌基因的角色，但其在TNBC中的表达、功能及作用机制仍未揭示。本研究通过RNA原位杂交检测了60例TNBC肿瘤组织中miR-150的表达，结果显示miR-150低表达与TNBC淋巴结转移和术后复发转移密切相关。体外的细胞试验发现miR-150激动剂（agomir）显著抑制了TNBC细胞的迁移；体裸鼠肺转移模型显示miR-150显著抑制TNBC的肺转移。高通量的芯片筛选结合2个生物数据库预测发现19个mRNA是潜在的作用靶点。进一步通过qRT-PCR、Western blot和报告基因实验，我们发现HMGA2是miR-150的直接作用靶点。临床标本检测发现HMGA2蛋白表达与淋巴结转移正相关，且与miR-150的表达显著负相关。最后，补救试验显示HMGA2过表达能够部分缓解miR-150抑制TNBC转移的作用。以上研究揭示miR-150在TNBC中低表达并发挥抑制转移的功能，其主要作用机制是下调靶基因HMGA2的mRNA和蛋白表达。MiR-150可能成为TNBC治疗的一个潜在靶点。