Nujiangexanthone A (NJXA)为本课题组首次从怒江藤黄中分离的新化合物，前期研究发现NJXA能诱导HeLa细胞G0/G1周期阻滞，并下调hnRNPK(heterogeneous nuclear ribonucleoprotein K)蛋白的表达。文献报道hnRNPK蛋白与细胞周期密切相关，且其在多种肿瘤患者体内表达升高。为了阐明NJXA下调hnRNPK蛋白与抗肿瘤之间的关系，本项目计划通过CRISPR/Cas9介导的基因敲除及质粒过表达等技术，考察NJXA是否下调hnRNPK蛋白而发挥作用；进一步通过RT-PCR， Western blot等分子技术阐明NJXA下调该蛋白的作用机制；最后通过动物实验，验证NJXA下调hnRNPK蛋白抗肿瘤作用的机制。目前关于天然药物对hnRNPK蛋白的作用及机制罕有报道，本研究为以该蛋白为靶标的抗肿瘤中药及其活性成分的研究开拓了新领域。

Nujiangexanthone A (NJXA) is a novel compound isolated from Garcinia nujiangensis. Our previous study indicated that NJXA could induce G0/G1 cell cycle arrest in HeLa cell. Using two-dimensional gel electrophoresis, it was found that the expression of hnRNPK was down regulated in HeLa cells. HnRNPK is overexpressed in many human cancers and has been associated with a worse prognosis for patients. However, until now there is little report about the effect and mechanism of natural compounds on hnRNPK protein. In this proposal, we will study whether the anti-tumor effect of NJXA was induced by down regulation of hnRNPK based on cell death, cell cycle and other related biological methods; the mechanism of how NJXA down regulated the expression of hnRNPK protein will also be studied; at last, the in vivo experiment will be used to further elucidate how NJXA showed anti-tumor effect by down regulation of hnRNPK protein. The creativity of the researches can provide theoretical guidance for the comprehensive utilization of the compound, as well as lay a solid foundation for the development of new drugs with intellectual properties.