Premium
Silencing of JMJD2B induces cell apoptosis via mitochondria‐mediated and death receptor‐mediated pathway activation in colorectal cancer
Author(s) -
Sun Bei Bei,
Fu Lin Na,
Wang Yun Qian,
Gao Qin Yan,
Xu Jie,
Cao Zhi Jun,
Chen Ying Xuan,
Fang Jing Yuan
Publication year - 2014
Publication title -
journal of digestive diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.684
H-Index - 51
eISSN - 1751-2980
pISSN - 1751-2972
DOI - 10.1111/1751-2980.12166
Subject(s) - gene silencing , microbiology and biotechnology , apoptosis , caspase , programmed cell death , biology , intrinsic apoptosis , chemistry , biochemistry , gene
Objective To investigate the molecular mechanism of colorectal cancer ( CRC ) cell apoptosis induced by the Jumonji domain containing 2B ( JMJD2B ) silencing. Methods Both HCT116 and LoVo CRC cell lines were used for analyses. Cell apoptosis after JMJD2B silencing was determined by flow cytometry. JC ‐1 fluorescence probe was applied to measure the mitochondrial outer membrane permeabilization by flow cytometry and fluorescence microscopy. Immunofluorescence was used to detect cytochrome C translocation from mitochondria to cytosol after JMJD2B silencing. The efficacy of JMJD2B silencing on the protein levels of Bcl‐2 family, caspase proteins, CCAAT /enhancer binding protein homologous protein ( CHOP ) and glucose‐regulated protein 78 ( GRP78 ) were detected by W estern blot. Results JMJD2B silencing induced CRC cell apoptosis via a decrease of the anti‐apoptotic gene Bcl‐2 family expression, leading to the translocation of Bak and Bax proteins and the promotion of mitochondrial membrane disruption, resulting in the release of cytochrome C from mitochondria and subsequent caspase‐9 and caspase‐3 cleavage. It also increased the amount of cleaved caspase‐8 involved in the death receptor‐related apoptotic pathway. Bcl‐2 homology 3 interacting‐domain death agonist (Bid), a specific caspase‐8 substrate involved in the Fas signaling pathway, subsequently induced cleavage via caspase‐8 activation. However, levels of CHOP and GRP78 remained unchanged after JMJD2B silencing. Conclusions JMJD2B silencing induced CRC cell apoptosis via both mitochondria‐related and death receptor‐related pathways. The cleavage of Bid activated by caspase‐8 might serve as a crosstalk mediator between these two pathways in CRC .