1. Melatonin induces apoptosis of colorectal cancer cells through HDAC4 nuclear import mediated by Ca MKII inactivation.
- Author
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Wei, Jia‐Yi, Li, Wan‐Ming, Zhou, Lin‐Lin, Lu, Qiu‐Nan, and He, Wei
- Subjects
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APOPTOSIS , *COLON cancer , *MELATONIN , *HISTONE deacetylase , *CANCER cell proliferation , *DEPHOSPHORYLATION - Abstract
Melatonin induces apoptosis in many different cancer cell lines, including colorectal cancer. However, the precise mechanisms involved remain largely unresolved. In this study, we provide evidence to reveal a new mechanism by which melatonin induces apoptosis of colorectal cancer LoVo cells. Melatonin at pharmacological concentrations significantly suppressed cell proliferation and induced apoptosis in a dose-dependent manner. The observed apoptosis was accompanied by the melatonin-induced dephosphorylation and nuclear import of histone deacetylase 4 ( HDAC4). Pretreatment with a HDAC4-specific si RNA effectively attenuated the melatonin-induced apoptosis, indicating that nuclear localization of HDAC4 is required for melatonin-induced apoptosis. Moreover, constitutively active Ca2+/calmodulin-dependent protein kinase II alpha ( Ca MKII α) abrogated the melatonin-induced HDAC4 nuclear import and apoptosis of LoVo cells. Furthermore, melatonin decreased H3 acetylation on bcl-2 promoter, leading to a reduction of bcl-2 expression, whereas constitutively active Ca MKII α(T286D) or HDAC4-specific si RNA abrogated the effect of melatonin. In conclusion, the present study provides evidence that melatonin-induced apoptosis in colorectal cancer LoVo cells largely depends on the nuclear import of HDAC4 and subsequent H3 deacetylation via the inactivation of Ca MKII α. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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