scholarly journals Trichosanthin inhibits DNA methyltransferase and restores methylation-silenced gene expression in human cervical cancer cells

2012 ◽  
Vol 6 (4) ◽  
pp. 872-878 ◽  
Author(s):  
YILING HUANG ◽  
HUAMEI SONG ◽  
HUOJUN HU ◽  
LEI CUI ◽  
CHENGCHENG YOU ◽  
...  
2018 ◽  
Vol 2018 ◽  
pp. 1-21 ◽  
Author(s):  
Yu-Guo Yuan ◽  
Shimin Zhang ◽  
Ji-Yoon Hwang ◽  
Il-Keun Kong

Silver nanoparticles (AgNPs) are widely used metal nanoparticles in health care industries, particularly due to its unique physical, chemical, optical, and biological properties. It is used as an antibacterial, antiviral, antifungal, and anticancer agent. Camptothecin (CPT) and its derivatives function as inhibitors of topoisomerase and as potent anticancer agents against a variety of cancers. Nevertheless, the combined actions of CPT and AgNPs in apoptosis in human cervical cancer cells (HeLa) have not been elucidated. Hence, we investigated the synergistic combinatorial effect of CPT and AgNPs in human cervical cancer cells. We synthesized AgNPs using sinigrin as a reducing and stabilizing agent. The synthesized AgNPs were characterized using various analytical techniques. The anticancer effects of a combined treatment with CPT and AgNPs were evaluated using a series of cellular and biochemical assays. The expression of pro- and antiapoptotic genes was measured using real-time reverse transcription polymerase chain reaction. The findings from this study revealed that the combination of CPT and AgNPs treatment significantly inhibited cell viability and proliferation of HeLa cells. Moreover, the combination effect significantly increases the levels of oxidative stress markers and decreases antioxidative stress markers compared to single treatment. Further, the combined treatment upregulate various proapoptotic gene expression and downregulate antiapoptotic gene expression. Interestingly, the combined treatment modulates various cellular signaling molecules involved in cell survival, cytotoxicity, and apoptosis. Overall, these results suggest that CPT and AgNPs cause cell death by inducing the mitochondrial membrane permeability change and activation of caspase 9, 6, and 3. The synergistic cytotoxicity and apoptosis effect seems to be associated with increased ROS formation and depletion of antioxidant. Certainly, a combination of CPT and AgNPs could provide a beneficial effect in the treatment of cervical cancer compared with monotherapy.


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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