Article,
Apoptosis in human liver carcinoma caused by gold nanoparticles in combination with carvedilol is mediated via modulation of MAPK/Akt/mTOR pathway and EGFR/FAAD proteins
INTERNATIONAL JOURNAL OF ONCOLOGY, 52 (1): 189-200 (2018)
DOI: 10.3892/ijo.2017.4179
Abstract
In cancers, apoptosis signaling pathways and cell survival and growth
pathways responsible for resistance to conventional treatments, such as
Pi3K/Akt/mTOR and mitogen-activated protein kinase (MAPK) become
dysregulated. Recently, alternative treatments to promote tumor cell
death have become important. The present study reports on the antitumor
and cytoprotective action of gold nanoparticles (GNPs) and carvedilol in
combination and in isolated application. Apoptosis was analyzed by
FITC/propidium iodide staining flow cytometry; caspase-3, caspase-8,
Bcl-2 and MAPK/ERK activity by immunofluorescence microscopy; gene
expression of proteins related to cell death as Akt, mTOR, EGFR, MDR1,
survivin, FADD and Apaf, by the real-time PCR; and western blot analysis
for MAPK/ERK, Akt and mTOR. Oxidative stress evaluation was performed by
reduced glutathione (GSH) and malondialdehyde (MDA) levels.
Intracellular GNPs targets were identified by transmission electron
microscopy. After exposure to a combination of GNPs (6.25 mu g/ml) and
carvedilol (3 mu M), death as promoted by apoptosis was detected using
flow cytometry, for expression of pro-apoptotic proteins FADD,
caspase-3, caspase-8 and sub-regulation of anti-apoptotic MAPK/ERK, Akt,
mTOR, EGFR and MDR1 resistance. Non-tumor cell cytoprotection with GSH
elevation and MDA reduction levels was detected. GNPs were identified
within the cell near to the nucleus when combined with carvedilol. The
combination of GNP and carvedilol promoted downregulation of
anti-apoptotic and drug resistance genes, over-regulation of
pro-apoptotic proteins in tumor cells, as well as cytoprotection of
non-tumor cells with reduction of apoptosis and oxidative stress.
