长链非编码RNA（lncRNA）在癌症进展中发挥重要作用，然而在甲状腺癌恶性增殖中的调控机制不明确。本课题组基于RNA-seq的方法在甲状腺乳头状癌中筛选出差异表达的LncRNA ENST00000556263.1。预实验证实下调ENST00000556263.1抑制了甲状腺癌细胞的增殖和侵袭转移，并导致细胞周期阻滞于G1/S期。机制研究证实ENST00000556263.1与转录因子c-Myc存在紧密结合并相互作用。本课题将进一步探索c-Myc参与ENST00000556263.1表达调控的作用方式，包括c-Myc与ENST00000556263.1的具体结合位点、调控方式，以及对下游细胞周期相关信号通路的影响。本课题预期将阐明c-Myc介导的ENST00000556263.1在甲状腺乳头状癌恶性增殖中的调控方式，为后续的转化研究提供理论基础和实验依据。

Long non-coding RNAs (lncRNA) are known to play critical roles in cancer progression. LncRNA ENST00000556263.1 was a recently identified papillary thyroid carcinoma(PTC)-related lncRNA, while its exact role in cancer remains elusive. Preliminary data indicate that ENST00000556263.1 could not only promote proliferation, migration and invasion of PTC cells, but also interact with c-Myc to regulate the process of cell cycle. So far the study of ENST00000556263.1 in PTC has not been reported. In this study, we aim to elucidate the biological function of ENST00000556263.1 in PTC, by overexpression or knockdown of Linc00673. To understand the binding sites and interactions between ENST00000556263.1 and c-Myc. And to explore the influnce of the ENST00000556263.1-c-Myc axis on cell cycle signaling pathway. Taken together, completion of our study will establish a novel carcinogenesis mechanism in PTC involving LncRNAs, and lay a foundation for finding novel molecular targets for diagnosis and therapy of thyroid carcinoma.