Expression of MIZ-1-like (related) Protein in LungAdenocarcinomas

• Main Authors: Chia-Chi Fan, 范嘉琪
• Other Authors: Kuan-Chih Chow
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/87738452611540490932

碩士 === 國立中興大學 === 生物醫學研究所 === 97 === MIZ-1, a POZ-zinc finger transcriptional factor protein, regulates cell growth through activating or suppressing the transcription of cell cycle inhibitory proteins. To further illustrate the role of MIZ-1 in lung cancer, we generated a monoclonal antibody recognizing MIZ-1-like (related) (MIZ1L) protein and analyzed its expression pattern in lung adenocarcinomas. MIZ1L was detected in two forms, 70 kDa and 95 kDa, in lung cancer cell lines and in mouse organs in a tissue-specific fashion. In lung cancer specimens, MIZ1L was mainly identified as 95 kDa, whereas in non-tumor lung tissues, it was expressed as 70 kDa. Interestingly, MIZ1L expression was more frequently detected in non-tumor lung tissue than in lung tumor tissues. Results of immunocytochemistry and immunofluorescence confocal microscopy showed that MIZ1L was present in both cytoplasm and nucleus. Moreover, MIZ1L expression correlated with S phase progression and changed cellular localization under low serum stress. Immunoprecipitation assay displayed protein-protein interaction between MIZ1L and HSP90α, which guarded abnormal protein processing and maintained cell survival under environmental stress. Our results suggest that MIZ1L protein could be cleavage into two forms, 70 kDa and 95 kDa, and might play a role in restraining cancer growth by affecting S phase progression and stress responses.