RASA4,也称为Ras p21蛋白激活剂4,是一种重要的GTPase激活蛋白,属于GAP1家族,编码GTPase活化蛋白,用于小G蛋白。RASA4主要参与调节Ras-MAPK信号通路,抑制肿瘤生长。在多种癌症中,RASA4的表达水平与肿瘤的发生、发展和预后密切相关。
在宫颈癌中,RASA4的表达水平显著低于非癌组织。研究表明,RASA4可以抑制HIFα信号通路,从而抑制宫颈癌细胞的增殖[1]。在JMML中,RASA4的DNA甲基化水平升高,与患者的预后不良相关。RASA4的甲基化水平与临床参数、复发风险和PTPN11突变相关[2]。在结直肠癌中,RASA4的表达水平下调,其DNA甲基化水平升高。研究表明,SYNGAP1的表达上调可以抑制结直肠癌细胞的增殖,并通过Wnt/β-Catenin信号通路发挥作用[3]。在肺癌中,RASA4的表达水平上调,与患者的预后不良相关。研究表明,RASA4可以通过抑制MAPK信号通路和促进细胞周期停滞来抑制肺癌细胞的增殖[4]。
RASA4的基因位于小鼠染色体5上,其启动子区域存在一个Z/EG转基因的插入。该插入不影响RASA4的表达,但可以使细胞在Cre介导的重组后特异性表达EGFP蛋白[5]。在PEL中,RASA4基因的拷贝数减少,与患者的预后不良相关[6]。在孕妇中,RASA4的DNA甲基化水平与mRNA表达水平呈负相关。研究表明,DNA甲基化可能影响RASA4基因的表达[7]。在NSCLC中,RASA4的表达水平上调,与患者的预后不良相关。研究表明,RASA4可以通过抑制MAPK信号通路和促进细胞周期停滞来抑制NSCLC细胞的增殖[8]。
综上所述,RASA4在多种癌症中发挥重要作用,其表达水平与肿瘤的发生、发展和预后密切相关。RASA4可以通过抑制HIFα信号通路、MAPK信号通路和Wnt/β-Catenin信号通路来抑制肿瘤细胞的增殖。此外,RASA4的基因拷贝数和DNA甲基化水平也与肿瘤的发生和预后相关。因此,RASA4可能成为癌症治疗的新靶点。
参考文献:
1. Chen, Junying, Huang, Jinbing, Huang, Qiaoqiao, Chen, Erling, Xu, Wensheng. . RASA4 inhibits the HIFα signaling pathway to suppress proliferation of cervical cancer cells. In Bioengineered, 12, 10723-10733. doi:10.1080/21655979.2021.2002499. https://pubmed.ncbi.nlm.nih.gov/34752201/
2. Poetsch, Anna R, Lipka, Daniel B, Witte, Tania, Flotho, Christian, Plass, Christoph. 2014. RASA4 undergoes DNA hypermethylation in resistant juvenile myelomonocytic leukemia. In Epigenetics, 9, 1252-60. doi:10.4161/epi.29941. https://pubmed.ncbi.nlm.nih.gov/25147919/
3. Xiao, Yun, Zhu, Ying, Chen, Jiaojiao, Feng, Fei, Hou, Yanli. 2024. Overexpression of SYNGAP1 suppresses the proliferation of rectal adenocarcinoma via Wnt/β-Catenin signaling pathway. In Discover oncology, 15, 135. doi:10.1007/s12672-024-00997-z. https://pubmed.ncbi.nlm.nih.gov/38679635/
4. Li, Lili, Fan, Yichao, Huang, Xin, Huganir, Richard L, Tao, Qian. 2019. Tumor Suppression of Ras GTPase-Activating Protein RASA5 through Antagonizing Ras Signaling Perturbation in Carcinomas. In iScience, 21, 1-18. doi:10.1016/j.isci.2019.10.007. https://pubmed.ncbi.nlm.nih.gov/31654850/
5. Hsia, Te-Chun, Yu, Chien-Chih, Hsu, Shu-Chun, Lin, Jaung-Geng, Chung, Jing-Gung. 2015. cDNA microarray analysis of the effect of cantharidin on DNA damage, cell cycle and apoptosis-associated gene expression in NCI-H460 human lung cancer cells in vitro. In Molecular medicine reports, 12, 1030-42. doi:10.3892/mmr.2015.3538. https://pubmed.ncbi.nlm.nih.gov/25815777/
6. Colombo, Sophie, Kumasaka, Mayuko, Lobe, Corrinne, Larue, Lionel. . Genomic localization of the Z/EG transgene in the mouse genome. In Genesis (New York, N.Y. : 2000), 48, 96-100. doi:10.1002/dvg.20585. https://pubmed.ncbi.nlm.nih.gov/20014334/
7. Roy, Debasmita, Sin, Sang-Hoon, Damania, Blossom, Dittmer, Dirk P. 2011. Tumor suppressor genes FHIT and WWOX are deleted in primary effusion lymphoma (PEL) cell lines. In Blood, 118, e32-9. doi:10.1182/blood-2010-12-323659. https://pubmed.ncbi.nlm.nih.gov/21685375/
8. Harrison, Alan, Pentieva, Kristina, Ozaki, Mari, McNulty, Helene, Parle-McDermott, Anne. 2018. Assessment of candidate folate sensitive-differentially methylated regions in a randomised controlled trial of continued folic acid supplementation during the second and third trimesters of pregnancy. In Annals of human genetics, 83, 23-33. doi:10.1111/ahg.12281. https://pubmed.ncbi.nlm.nih.gov/30175844/