- 作者: Se Jin Jeon; Jung Eun Seo; Sung-Il Yang; Ji Woong Choi; David G Wells; Chan Young Shin; Kwang Ho Ko
- 作者服務機構: Department of Pharmacology, College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea.
- 中文摘要: --
- 英文摘要:
Background: Fragile X syndrome (FXS), the most commonly inherited mental retardation and single gene
cause of autistic spectrum disorder, occurs when the Fmr1 gene is mutated. The product of
Fmr1, fragile X linked mental retardation protein (FMRP) is widely expressed in HeLa cells,
however the roles of FMRP within HeLa cells were not elucidated, yet. Interacting with a
diverse range of mRNAs related to cellular survival regulatory signals, understanding the
functions of FMRP in cellular context would provide better insights into the role of this
interesting protein in FXS. Using HeLa cells treated with etoposide as a model, we tried to
determine whether FMRP could play a role in cell survival.
Methods: Apoptotic cell death was induced by etoposide treatment on Hela cells. After we
transiently modulated FMRP expression (silencing or enhancing) by using molecular
biotechnological methods such as small hairpin RNA virus-induced knock down and
overexpression using transfection with FMRP expression vectors, cellular viability
was measured using propidium iodide staining, TUNEL staining, and FACS analysis
along with the level of activation of PI3K-Akt pathway by Western blot. Expression
level of FMRP and apoptotic regulator BcL-xL was analyzed by Western blot, RTPCR
and immunocytochemistry.
Results: An increased FMRP expression was measured in etoposide-treated HeLa cells, which
was induced by PI3K-Akt activation. Without FMRP expression, cellular defence
mechanism via PI3K-Akt-Bcl-xL was weakened and resulted in an augmented cell
- 3 -
death by etoposide. In addition, FMRP over-expression lead to the activation of PI3KAkt
signalling pathway as well as increased FMRP and BcL-xL expression, which
culminates with the increased cell survival in etoposide-treated HeLa cells.
Conclusions: Taken together, these results suggest that FMRP expression is an essential part of
cellular survival mechanisms through the modulation of PI3K, Akt, and Bcl-xL signal
pathways. - 中文關鍵字: --
- 英文關鍵字: --