MiR-204-5p及其靶基因在乳头状甲状腺癌中的作用及机制研究

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. There are multiple differentially expressed miRNAs, which are closely related to the development of PTC, but its mechanism is not fully understood. In our previous work, we confirmed the low expression of miR-204-5p in PTC by bioinformatics analysis and in vitro experiments, and preliminarily predicted and screened its target genes. Based on the previous work, this project is intended to perform the following work: 1) further screen and validate the target genes of miR-204-5p; 2) study the effects of miR-204-5p and its target genes on PTC cell proliferation, migration, invasion, apoptosis, and epithelial-mesenchymal transition (EMT) in vitro; 3) bioinformatics analysis of the relationship between the expression of miR-204-5p as well as its target genes and PTC clinical characteristics; 4) explore the significance of miR-204-5p in serum and single nucleotide polymorphism (SNP) on the 3'untranslated region (3'UTR) binding site of its target genes as PTC biomarkers in populations.

乳头状甲状腺癌（PTC）是甲状腺癌最常见的分型，存在多个差异表达的miRNA，与PTC发生发展密切相关，但其作用机制尚不完全清楚。我们前期工作中通过生物信息学手段结合体外实验，已经证实了miR-204-5p在PTC中的低表达，确定为本研究的目标miRNA，并对其靶基因进行了初步预测和筛选。本项目基于前期工作基础，拟开展以下研究：1）进一步对miR-204-5p的靶基因进行筛选、验证；2）体外实验研究miR-204-5p及其靶基因对PTC细胞增殖、迁移、侵袭、凋亡、上皮-间充质转化（EMT）等功能的影响；3）生物信息学手段分析miR-204-5p及其靶基因的表达水平与PTC临床特征的关系；4）以人群为研究对象，探索血清miR-204-5p的表达水平及其与靶基因3'非编码区（3'UTR）结合位点的单核苷酸多态性（SNP）作为PTC生物标志物的意义。

乳头状甲状腺癌（papillary thyroid carcinoma, PTC）约占全部甲状腺癌的75-85%，尽管多数预后较好，但却是近年来发病率上升最快的肿瘤之一。miR-204-5p在多种肿瘤中发挥抑癌作用，在PTC中，仅有研究表明miR-204-5p可以通过靶向HMGB1、IGFBP5、BRD4和ZEB1发挥功能，研究尚不充分。在前期工作中，通过生物信息学方法及实验验证筛选并确定了miR-204-5p在PTC组织和细胞中的低表达。本研究进一步通过人群研究验证miR-204-5p在PTC患者血清中的差异表达情况；从血清和组织两个水平分析miR-204-5p的表达与患者临床特征的关系，明确其临床意义；在转录组和蛋白质组两个水平分析miR-204-5p对PTC细胞系基因表达的影响，并研究miR-204-5p及其靶基因对PTC细胞功能的影响，为PTC的发病机制及临床诊疗研究提供科学依据。结果发现，miR-204-5p在PTC组织、细胞和患者血清中均表达下调，提示其在PTC进程中发挥重要作用；miR-204-5p在PTC中具有抗肿瘤作用，能够抑制肿瘤细胞的增殖、集落形成、迁移和侵袭能力，并促进细胞凋亡；AP1S2是miR-204-5p的靶基因，沉默AP1S2在PTC中发挥抗肿瘤效应，包括抑制肿瘤细胞增殖、集落形成、迁移和侵袭能力，并诱发细胞G1期阻滞。