Premium
Melatonin‐induced increase in sensitivity of human hepatocellular carcinoma cells to sorafenib is associated with reactive oxygen species production and mitophagy
Author(s) -
PrietoDomínguez Néstor,
Ordóñez Raquel,
Fernández Anna,
MéndezBlanco Carolina,
Baulies Anna,
GarciaRuiz Carmen,
FernándezCheca José C.,
Mauriz José L.,
GonzálezGallego Javier
Publication year - 2016
Publication title -
journal of pineal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 131
eISSN - 1600-079X
pISSN - 0742-3098
DOI - 10.1111/jpi.12358
Subject(s) - sorafenib , mitophagy , melatonin , parkin , apoptosis , viability assay , biology , reactive oxygen species , hepatocellular carcinoma , cancer research , cell culture , chemistry , medicine , pharmacology , endocrinology , microbiology and biotechnology , biochemistry , autophagy , disease , parkinson's disease , genetics
Abstract Effects of sorafenib in hepatocellular carcinoma ( HCC ) are frequently transient due to tumor‐acquired resistance, a phenotype that could be targeted by other molecules to reduce this adaptive response. Because melatonin is known to exert antitumor effects in HCC cells, this study investigated whether and how melatonin reduces resistance to sorafenib. Susceptibility to sorafenib (10 nmol/L to 50 μmol/L) in the presence of melatonin (1 and 2 mmol/L) was assessed in HCC cell lines HepG2, HuH7, and Hep3B. Cell viability was reduced by sorafenib from 1 μmol/L in HepG2 or HuH7 cells, and 2.5 μmol/L in Hep3B cells. Co‐administration of melatonin and sorafenib exhibited a synergistic cytotoxic effect on HepG2 and HuH7 cells, while Hep3B cells displayed susceptibility to doses of sorafenib that had no effect when administrated alone. Co‐administration of 2.5 μmol/L sorafenib and 1 mmol/L melatonin induced apoptosis in Hep3B cells, increasing PARP hydrolysis and BAX expression. We also observed an early colocalization of mitochondria with lysosomes, correlating with the expression of mitophagy markers PINK 1 and Parkin and a reduction of mitofusin‐2 and mt DNA compared with sorafenib administration alone. Moreover, increased reactive oxygen species production and mitochondrial membrane depolarization were elicited by drug combination, suggesting their contribution to mitophagy induction. Interestingly, Parkin silencing by si RNA to impair mitophagy significantly reduced cell killing, PARP cleavage, and BAX expression. These results demonstrate that the pro‐oxidant capacity of melatonin and its impact on mitochondria stability and turnover via mitophagy increase sensitivity to the cytotoxic effect of sorafenib.