基于RNA-seq分析黄曲霉毒素B1诱导大鼠肝癌的可变剪接事件

目的 探讨黄曲霉毒素B1（aflatoxin B1，AFB1）诱发大鼠致肝癌的可能机制及其阻断肝癌分子机制的可变剪接事件。方法 构建AFB1诱发大鼠致肝癌模型，提取大鼠肝组织总RNA，采用Illumina HiSeq 2000测序平台对大鼠肝组织进行RNA-seq测序，以大鼠基因组数据为参考，纳入目前已知的具有多种可变剪接存在的332个参考基因，鉴定和分析大鼠基因组的可变剪接基因，并对具有差异表达的可变剪接基因进行GO分类的生物过程（biological process，BP）富集分析。结果 RNA-seq测序结果显示，未成癌组与对照组有18个基因的可变剪接模式存在较大差异，差异基因主要富集在刺激反应功能上；成癌组与对照组有37个基因的可变剪接模式存在差异，差异基因主要富集在刺激反应和细胞增殖调节功能上；成癌组与未成癌组有32个基因的可变剪接模式存在明显差异，差异基因主要富集在细胞增殖调节功能上。成癌组发现7个与细胞增殖调节相关基因的可变剪接模式发生异常，其中成癌组、未成癌组和对照组IgfI、Carm1、Tcfe2a基因的可变剪接模式存在显著差异。结论 IgfI、Carm1、Tcfe2a基因的可变剪接改变可能在AFB1诱导大鼠肝癌形成过程中发挥重要作用。

Analysis of the alternative splicing events of AFB1-induced liver cancer in rats based on RNA-seq

Objective To explore the mechanism of aflatoxin B1（AFB1）-induced liver cancer in rats and the alternative splicing events that blocked the molecular mechanism of liver cancer. Methods Model of AFB1-induced liver cancer in rats was constructed， total RNA from rat liver tissue was extracted，and Illumina HiSeq 2000 sequencing platform was used to sequence RNA-seq  in rat liver tissue. Using rat genomic data as a reference，332 known reference genes with multiple  alternative splicing variants were currently included in the study. The rat genomic alternative splicing events were identified and analyzed， and biological process （BP）enrichment analysis for GO categorization of alternative spliced genes with differentially expressed was conducted. Results Compared with the control group，18 alternative splicing patterns of genes in the non-cancer group showed a big difference，and mainly enriched in the stimulatory response function. Compared with the control group，37 alternative splicing patterns of genes in the cancer group were different，and mainly enriched in the stimulation response and cell proliferation regulation function. Compared with the non-cancer group，the alternative splicing patterns of 32 genes in the cancer group were significantly different，mainly enriched in the cell proliferation regulation function. In the cancer group，7 splicing patterns of genes involved in cell proliferation regulation were found to be abnormal. The alternative splicing patterns of IgfI，Carm1，and Tcfe2a were significantly different between the cancer group，the non-cancer group，and the control group. Conclusion Alternative splicing changes of IgfI，Carm1，Tcfe2a may play an important role in AFB1-induced liver cancer formation in rats.