PAX9 G-四链体在口腔食管鳞状细胞癌细胞中的转录调控机制研究

PAX9是具有DNA结合配对结构域的转录因子，在口腔食管上皮的鳞状细胞分化和癌变中发挥重要作用，参与口腔食管鳞状细胞癌的发生发展，可能成为潜在的治疗靶点，然而其表达调控尚不清晰，有待深入研究。生物信息学提示PAX9启动子区和内含子区存在多条富G序列，并与多个转录调控因子的结合位点高度重合，推测会影响转录表达、可变剪切过程，在PAX9的转录表达过程中发挥着重要的作用与意义，然而具体的作用机制目前也尚不明确。申请者在前期研究中初步证实了其中四条序列在体外条件下能够形成G-四链体结构，并且有两条序列拥有非常高的热稳定性。本课题旨采用化学、分子、细胞生物学等技术，系统性得研究多条富G序列对PAX9基因表达的转录调控作用与机制，并以G-四链体为靶点探寻具有选择性识别功能的分子。这将有助于探究识别分子与G-四链体结构结合的机理，为新型识别分子调控基因表达活性的研究提供理论依据和实验基础。

PAX9 is a transcription factor of the PAX family characterized by a DNA-binding paired domain. Previous studies have suggested a potential role of PAX9 in squamous cell differentiation and carcinogenesis of the oro-oesophageal epithelium, and it participates in the development of oesophageal squamous cell carcinoma, which indicates that PAX9 may become a potential therapeutic target. However its expression regulation remains unclear, which needs further study. Bioinformatics analysis found that there are multiple G-rich sequences in the promoter region and introns, which are highly coincident with the binding sites of multiple transcription regulators; and may regulate the transcriptional expression and variable splicing of PAX9. It suggests that these G-rich sequences may play an important role in the transcription and expression of PAX9, but the specific mechanism is still unclear. In the previous study, the applicant preliminarily confirmed that four of these sequences could form G-quadruplex structures in vitro and some of them have very high thermal stability. Through the methods of chemistry, molecular biology, cell biology, etc., the purpose of our research is to systematically study the effect of multiple G-rich sequences on the expression regulation of PAX9 gene, and to explore small molecules with selective recognition with G-quadruplex as the target, which may lead to a better understanding of G-quadruplex ligands binding mechanism and play an important role in providing theoretical and experimental basis for the study of new gene expression regulating ligands.