miR-150作为大肠癌特异性敏感性生物标志物的探索及靶向药物治疗基础研究

The existing treatment system could not effectively improve the prognosis of patients with colorectal cancer(CRC), so we need to find and verify new biomarkers with high specificity and high sensitivity and also elucidate the relevant targeted drug mechanism. We have found that "high expression of miR-150 down-regulates target gene c-myb and improves the prognosis of patients with CRC". Based on the finding, first, we plan to elucidate the specificity and sensitivity of miR-150 in the diagnosis of several common tumors through a large sample of clinical detection, and the effect of miR-150 on the growth of different tumor cells was confirmed by cell and animal experiments. Second, miR-150 will be encapsulated with two carriers (ligand-targeted polypeptide nanocarrier HKP and lipid carrier). We will clarify the c-myb changes of genomics and epigenetics, using immunoprecipitation, pyrophosphate sequencing and other technologies. We will also clarify the molecular chaperones（ACF7） and molecular signaling pathways which possibly affect the c-myb’s epigenetic characteristics and expression. Finally, miR-150 and c-myb intestinal epithelial knockout mice will be constructed to verify its mechanism. The above findings help to promote the transformation from miRNA related basic research to clinical application, and promote the development of individualized and precise treatment of CRC.

现有诊疗体系不能有效改善大肠癌（CRC）患者预后，遂亟需发现、验证新型特异性敏感性生物标记物并阐明相关靶向药物机制。我们在前期发现“高表达miR-150下调靶基因c-myb并改善CRC患者预后”基础上，首先拟通过临床大样本检测明确miR-150在常见肿瘤中诊断特异性及敏感性，并通过细胞、动物实验明确miR-150对不同肿瘤细胞生长的影响。其次，在前期已有基础上制备两种载体（配体靶向型多肽纳米载体HKP、脂质载体）包裹的miR-150小核苷酸药物并通过基因组学、表观遗传学利用免疫共沉淀、焦磷酸测序等技术厘清miR-150可能使c-myb改变的表观遗传特征，寻找及验证可能影响c-myb表达和功能的分子伴侣（ACF7）及信号通路。最后，构建miR-150及c-myb肠上皮敲除小鼠验证其作用机制。以上发现有助于推动miRNA相关基础研究成果向临床转化，推进CRC个体化精准治疗体系建立。

课题组前期研究表明c-myb是miR-150的重要调控靶基因。本项目挖掘数据库信息，分别分析了miR-150在乳腺癌、肝癌、肺癌、胃癌、结肠癌、直肠癌共6种癌症2510例患者肿瘤组织中表达，发现miR-150在结肠癌与直肠癌的癌组织中表达显著降低，在胃癌与肺癌中表达增高，但无显著性，在乳腺癌中低表达但无显著性。分析了c-myb在乳腺癌、肝癌、肺癌、胃癌、结肠癌、直肠癌共6种癌症3158例患者肿瘤组织中表达，发现c-myb在肺癌组织中较正常组织表达降低，在其余5种癌组织中的表达均高于正常组织。以上数据说明miR-150/c-myb轴可作为 CRC 特异性生物标记物，可用作结直肠癌的诊断因子指导临床。 机制研究方面，本项目明确了miR-150/c-myb/c-fos调控结直肠癌生长和转移的机制研究，miR-150纳米药物通过miR-150/DNMT3a/TLE1/β-Catenin抑制肿瘤生长的表观遗传作用，DNMT1调节miR-150/IGF2BP1/m6A SRF信号在CRC进展中的致癌作用。小核酸药物研究方面，构建安全稳定的miR-150 载体复合物药物，验证其抗肿瘤效应，完成成药性基础研究。发现并验证了新型药物载体层状双氢氧化物LDH（水滑石）治疗CRC的基础和临床应用研究，已经申请发明专利及医疗器械注册证，临床试验治疗效果显著。下一步计划扩大癌症治疗种类，为其成为实体瘤新疗法积累有效临床数据。