结直肠癌中潜在的S-棕榈酰化蛋白质组学分析

Proteomic analysis of potential S-palmitoylation in colorectal cancer

目的 通过质谱鉴定分析结直肠癌中S-棕榈酰化蛋白,为寻找临床治疗结直肠癌的新靶点提供依据.方法 选取2022年12月至2023年3月吉林大学第二医院获取的11例患者的结直肠癌组织(其中男7例,女4例),同时与结直肠癌细胞系进行酰基-生物素基交换(ABE)后进行质谱鉴定,分析潜在S-棕榈酰化蛋白并进行蛋白质印迹法(Western blot)验证.两组间比较采用配对样本t检验.结果 在人结直肠癌组织和SW480、SW620细胞系中共同含有潜在的S-棕榈酰化位点的蛋白有21个,这些蛋白经基因本体(GO)和通路Pathway分析与免疫调节密切相关;Western blot验证了磷脂爬行酶1(PLSCR1)和细胞骨架相关蛋白4(CKAP4)是S-棕榈酰化修饰的;在人结直肠癌组织 CKAP4(0.693±0.092、1.162±0.003、0.771±0.012、1.683±0.085、1.144±0.266)CKAP4 总蛋白水平低于癌旁组织(2.306±0.231、1.471±0.055、1.201±0.01、1.978±0.031、2.107±0.035),差异有统计学意义(t=11.260、9.744、15.260、5.398、6.221,P<0.05);而 PLSCR1(3.185±0.047、1.305±0.153、2.131±0.0752、2.542±0.106)总蛋白水平高于癌旁组织(0.833±0.0529、1.038±0.057、1.477±0.095、2.108±0.034),差异有统计学意义(t=21.372、28.770、13.559、11.460,P<0.05).结论 结直肠癌中含有潜在的S-棕榈酰化修饰蛋白,这些蛋白可能通过调节免疫功能而影响结直肠癌的增殖.

Objective To identify S-palmitoyl protein in colon cancer by mass spectrometry,and to provide theoretical basis for finding a new target for clinical treatment of colorectal cancer.Methods Colorectal cancer tissues of 11 patients(7 males and 4 females)obtained from the Second Hospital of Jilin University from December 2022 to March 2023 were selected.At the same time,acyl-biotinyl exchange(ABE)was performed with colorectal cancer cell lines for identification by mass spectrometry,and the po-tential S-palmitoylation proteins were analyzed and verified by Western blotting.Paired sample t test was used for comparison between the two groups.Results There were 21 proteins in human colorectal cancer tissues and SW480 and SW620 cell lines that shared potential S-palmitoylation sites,and these proteins were closely related to immune regulation by gene ontology(GO)and Pathway analysis.Western blotting confirmed that phospholipid scramblase 1(PLSCR1)and cytoskeleton-associated protein 4(CKAP4)were S-palmitoylation.The total CKAP4 protein level in human colorectal cancer tissues(0.693±0.092,1.162±0.003,0.771±0.012,1.683±0.085,1.144±0.266)was significantly lower than that in adja-cent tissues(2.306±0.231,1.471±0.055,1.201)±0.01,1.978±0.031,2.107±0.035)(t=11.260,9.744,15.260,5.398,6.221,P<0.05).The total protein level of PLSCR1(3.185±0.047,1.305±0.153,2.131±0.0752,2.542±0.106)was significantly higher than that in para-cancerous tis-sues(0.833±0.0529,1.038±0.057,1.477±0.095,2.108±0.034)(t=21.372,28.770,13.559,11.460,P<0.05).Conclusion Colorectal cancer contains potential S-palmitoylation modified proteins that may influence the proliferation of colorectal cancer by modulating immune function.