Inhibition of autophagy enhances cisplatin cytotoxicity through endoplasmic reticulum stress in human cervical cancer cells

2012 ◽  
Vol 314 (2) ◽  
pp. 232-243 ◽  
Author(s):  
Ye Xu ◽  
Huimei Yu ◽  
Hanjiao Qin ◽  
JinSong Kang ◽  
Chunyan Yu ◽  
...  
2018 ◽  
Vol 46 (1) ◽  
pp. 322-334 ◽  
Author(s):  
Chia-Liang Lin ◽  
Chien-Hsing Lee ◽  
Chien-Min Chen ◽  
Chun-Wen Cheng ◽  
Pei-Ni Chen ◽  
...  

Background/Aims: Protodioscin (PD) is a steroidal saponin with anti-cancer effects on a number of cancer cells, but the anti-tumor effects and mechanism of action of PD on human cervical cancer cells is unclear. Methods: We determined cell viability using the MTT assay. Cell death, mitochondrial membrane potential (MMP), intracellular reactive oxygen species (ROS) generation, and endoplasmic reticulum (ER) stress were measured on a flow cytometry. Caspase activation, ER stress, and MMP-dependent apoptosis proteins in cervical cancer cells in response to PD were determined by Western blot analysis. The ability of ATF4 binding to ChIP promoter was measured using the ChIP assay. Results: We demonstrated that PD inhibits cell viability, causes a loss of mitochondrial function, and induces apoptosis, as evidenced by up-regulation of caspase-8, -3, -9, -PARP, and Bax activation, and down-regulation of Bcl-2 expression. PD was shown to induce ROS and the ER stress pathway, including GRP78, p-eIF-2α, ATF4, and CHOP. Pre-treatment with NAC, a ROS production inhibitor, significantly reduced ER stress and apoptosis-related proteins induced by PD. Transfection of GRP78/CHOP-siRNA effectively inhibited PD-induced ER stress-dependent apoptosis. Moreover, treatment with PD significantly increased p38 and JNK activation. Co-administration of a JNK inhibitor (SP600125) or p38 inhibitor (SB203580) abolished cell death and ER stress effects during PD treatment. In addition, PD induced the expression of nuclear ATF4 and CHOP, as well as the binding ability of ATF4 to the CHOP promoter. Conclusion: Our results suggest that PD is a promising therapeutic agent for the treatment of human cervical cancer.


2018 ◽  
Vol 18 (3) ◽  
pp. 412-421 ◽  
Author(s):  
Madhumitha Kedhari Sundaram ◽  
Mohammad Zeeshan Ansari ◽  
Abdullah Al Mutery ◽  
Maryam Ashraf ◽  
Reem Nasab ◽  
...  

Introduction: Epidemiological studies indicate that diet rich in fruits and vegetables is associated with decreased cancer risk thereby indicating that dietary polyphenols can be potential chemo-preventive agents. The reversible nature of epigenetic modifications makes them a favorable target for cancer prevention. Polyphenols have been shown to reverse aberrant epigenetic patterns by targeting the regulatory enzymes, DNA methyltransferases (DNMTs) and histone deacetylases (HDACs). In vitro and in silico studies of DNMTs and HDACs were planned to examine genistein’s role as a natural epigenetic modifier in human cervical cancer cells, HeLa. Methods: Expression of the tumour suppressor genes (TSGs) [MGMT, RARβ, p21, E-cadherin, DAPK1] as well the methylation status of their promoters were examined alongwith the activity levels of DNMT and HDAC enzymes after treatment with genistein. Expression of DNMTs and HDACs was also studied. In-silico studies were performed to determine the interaction of genistein with DNMTs and HDACs. Results: Genistein treatment significantly reduced the expression and enzymatic activity of both DNMTs and HDACs in a time-dependent way. Molecular modeling data suggest that genistein can interact with various members of DNMT and HDAC families and support genistein mediated inhibition of their activity. Timedependent exposure of genistein reversed the promoter region methylation of the TSGs and re-established their expression. Conclusions: In this study, we find that genistein is able to reinstate the expression of the TSGs studied by inhibiting the action of DNMTs and HDACs. This shows that genistein could be an important arsenal in the development of epigenetic based cancer therapy.


2010 ◽  
Vol 49 (4) ◽  
pp. 419-424 ◽  
Author(s):  
Wei-Chun Chang ◽  
Ching-Hung Hsieh ◽  
Meen-Woon Hsiao ◽  
Wu-Chou Lin ◽  
Yao-Ching Hung ◽  
...  

2017 ◽  
Vol 22 (3) ◽  
pp. 357-369 ◽  
Author(s):  
Daiana G. Alvarez-Olmedo ◽  
Veronica S. Biaggio ◽  
Geremy A. Koumbadinga ◽  
Nidia N. Gómez ◽  
Chunhua Shi ◽  
...  

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