Modification of Alternative Splicing of Mcl-1 Pre-mRNA: Role of Mcl-1S-Mediated Apoptosis in Basal Cell Carcinoma Cells

• Main Authors: Kuang-Ting Liu, 劉光庭
• Other Authors: Jeng-Jer Shieh
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/08313448612429266817

碩士 === 國立中興大學 === 醫學科技研究所 === 96 === Myeloid cell leukemia-1(Mcl-1, also named Mcl-1L), an anti-apoptotic protein of the Bcl-2 family, acts as a critical molecule in apoptotic control, preventing cell death by inhibiting cytochrome-C release and caspase activation. Mcl-1 transcripts can be alternatively spliced into Mcl-1S (short isoform), which resembles pro-apoptotic BH-3 only proteins and induces apoptosis. Many evidences reveal that over-expression of Mcl-1 may play a role in various human tumors and may serve as a target for cancer therapy. Basal cell carcinoma (BCC) is the most common malignant tumor of skin cancer. Mcl-1(Mcl-1L) is up-regulated by autocrined IL-6, then promotes tumorgenesis and protects against apoptosis in BCC cell line. Thus, we purpose that differential expression of Mcl-1L and/or Mcl-1S may exist between transformed BCC and primary keratinocytes. In addition, hight levels of expression of Mcl-1S by shifting the splicing pattern of Mcl-1 pre-mRNA from Mcl-1L to Mcl-1S may induce the apoptosis of BCC. In this study, first, we compared the expression level of Mcl-1 variants in the established BCC cell line and primary keratinocytes and showed the unbalances of mRNA and protein expression level of Mcl-1L /Mcl-1S in BCC cell line. Second, we evaluated the pro-apoptotic function of Mcl-1S and demonstrated that over-expression of Mcl-1S could mediate apoptosis of BCC cell line. Last, we demonstrated that Mcl-1 pre-mRNA could be specifically targeted by Mcl-1 antisense morpholino oligonucleotides what shifted the splicing pattern from Mcl-1L to Mcl-1S mRNA and protein, which resulted in increasing the level of pro-apoptotic Mcl-1S and decreasing the level of anti-apoptotic Mcl-1L. The shift of Mcl-1S splicing pattern could induce apoptosis in BCC cell line. Thus, here, we provided a novel strategy for cancer therapy by antisense morpholino oligonucleotides which induce apoptosis by changing the alternative splicing pattern of Mcl-1 pre-mRNA.