選擇性剪接(Alternative splicing;AS)是特定pre-mRNA藉由不同方式將表現區(exons)納入或排除,為產生不同形式mRNA的過程。在本實驗中研究butyric acid在人類多型性神經膠母細胞瘤GBM8401細胞株對AS的影響。研究使用反轉錄酶連鎖反應及西方點墨法研究藥物對於AS的影響,及對AS相關訊息傳遞路徑的影響且使用流式細胞儀研究藥物對細胞週期的影響,進而探討藥物影響細胞凋亡的路徑。結果顯示butyric acid在GBM8401細胞株藉由增加hnRNPA1、hnRNPA2/B1、hnRNPC1/C2表現,及降低SRp20蛋白質表現量來調控AS:其改變BCL-X、HIPK3基因,增加BCL-XS、FIST凋亡的型式且在調控細胞訊息傳遞路徑上會增加PP1α的表現量來調控AS其蛋白質磷酸化的過程;在誘使細胞凋亡時,磷酸化JNK、磷酸化P38會增加,而磷酸化ERK隨著濃度增加而減少且會活化caspase 3造成PARP cleavage進而促進細胞凋亡;另外butyric acid使細胞週期停滯在G2/M phase,具有細胞週期的抑制效果,故可以推測butyric acid可能對於治療人類多型性神經膠母細胞瘤扮演一定的角色。
Alternative splicing is a process involving different exon selection of identical pre-mRNA molecules, thereby, expanding the proteomic complexity encoded by the genome. Butyric acid (BA) is the major short-chain fatty acid produced by fermentation of dietary fiber in the large bowel, it may be an important regulator of apoptosis in a number of cancer cells (1, 2). In this study, the alternative splicing pattern effects of BA on human GBM8401 cell lines were investigated. These were accomplished by examining the cell viability; alternative splicing mode using RT-PCR, Western blot, and cell cycle perturbation using cytometric methodology with various concentrations of BA. It was observed that BA changing the splicing patterns of BCL-X, HIPK3 genes and BA can modulate the alternative RNA splicing of many genes through increased expression of hnRNPA1, hnRNPA2/B1, hnRNPC1/C2 and decreased expression of SRp20 protein level in human GBM8401 cell lines; BA induced apoptosis via mechanisms that are dependent on caspase 3 and makes PARP cleavage; BA arrested the cell cycling at G2/M in cell cycle of the treated GBM8401cells.