空肠弯曲杆菌诱导的结直肠癌的转录组学分析

Transcriptome Analysis of Campylobacter jejuni-Induced Colorectal Cancer

【目的】探究空肠弯曲杆菌(C.jejuni)的致癌机制。【方法】将18只雌性的C57BL/6 Apc^(Min/+)小鼠随机分为C.jejuni感染组9只和空白对照组9只。采用灌胃C.jejuni和葡聚糖硫酸盐共同诱导Apc^(Min/+)小鼠产生结直肠癌。实验终点时,取各组小鼠结直肠组织解剖计数肿瘤个数,分别提取C.jejuni组4只小鼠和空白对照组3只小鼠的结直肠肿瘤和癌旁组织RNA,采用RNA-seq技术进行转录组学测序,筛选出差异表达基因后进行GO富集分析和KEGG通路富集分析。【结果】与对照组相比,C.jejuni感染组肿瘤发生率显著增高(P<0.01),显示造模成功。RNA-seq测序结果显示,C.jejuni感染组的肿瘤组织跟两个对照组相比,分别有394个和501个差异表达基因(变化>4倍;P<0.05)。GO富集分析差异基因主要富集在多种免疫反应的调控和激活途径、多种蛋白质转运和受体结合途径。KEGG通路富集分析癌症相关通路和代谢途径较显著。上述差异表达基因中,有17个基因在两次对照中均有出现,经过筛选,得到14个“核心”差异表达基因。在进一步的qRT-PCR验证中,有9个基因表达差异显著,其中有3个基因(Gm1987、Saxo1和Plekhs1)表达上调,6个基因(Lrp2、Serpina3c、Fabp4、Tmem52、Lrrn4和Upk3b)表达下调。【结论】本研究指出了9个可能在C.jejuni诱导的结直肠癌的发生发展中起到了重要且独特作用的宿主基因,为后续研究C.jejuni导致结直肠癌的机制提供了新的方向和思路。

【Objective】To explore the carcinogenic mechanism of Campylobacter jejuni.【Methods】Eighteen female C57BL/6 Apc^(Min/+) mice were randomly divided into the C.jejuni-infected group and the non-infection control group,each group with nine mice.Colorectal cancer of Apc^(Min/+) mice was induced by dextran sulfate sodium and gavage of C.jejuni(or PBS as a control).At the end of the experiment,the number of tumors in colorectal tissues of mice in each group was counted,and RNA was extracted from colorectal tumors,along with para-cancer tissues as controls.Transcriptome sequencing was performed by RNA-Seq technology,and data were analyzed for differentially expressed genes(DEGs).Further,selected DEGs were subjected to GO(gene ontology)enrichment analysis and KEGG pathway enrichment analysis.【Results】Compared with that of the non-infection control group,the incidence of tumor in C.jejuni-infected group was significantly higher(P<0.01),which indicated the success of recreating the C.jejuni-induced CRC model.RNA-seq results showed that there were 394 and 501 DEGs(fold change>4 and P<0.05)in the C.jejuni-infected group compared with the two control groups,respectively.In GO enrichment analysis,DEGs were mainly enriched in immune response regulation and activation pathways,multiple protein transport pathways and receptor binding pathways.Cancer-related pathways and met⁃abolic pathways were significant enriched in KEGG pathway enrichment analysis.Among these DEGs,17 genes were found in comparisons with both control groups.The 17 genes were further selected,resulting in 14“core”DEGs.In further validation of qRT-PCR,9 genes were significantly differentially expressed,among which 3 genes were up-regulated(Gm1987,Saxo1 and Plekhs1)and 6 were down-regulated(Lrp2,Serpina3c,Fabp4,Tmem52,Lrrn4 and Upk3b).【Conclusion】This study emphasizes 9 host genes that may play important and unique roles in the occurrence and development of colorectal cancer induced by C.jejuni,which provides new insights for further studies on the carcinogenic mechanism of C.jejuni.