EGFR-Targeted Hybrid Plasmonic Magnetic Nanoparticles Synergistically Induce Autophagy and Apoptosis in Non-Small Cell Lung Cancer Cells

Abstract

BackgroundThe epidermal growth factor receptor (EGFR) is overexpressed in 80% of non-small cell lung cancer (NSCLC) and is associated with poor survival. In recent years, EGFR-targeted inhibitors have been tested in the clinic for NSCLC. Despite the emergence of novel therapeutics and their application in cancer therapy, the overall survival rate of lung cancer patients remains 15%. To develop more effective therapies for lung cancer we have combined the anti-EGFR antibody (Clone 225) as a molecular therapeutic with hybrid plasmonic magnetic nanoparticles (NP) and tested on non-small cell lung cancer (NSCLC) cells.Methodology/Principal FindingsCell viability was determined by trypan-blue assay. Cellular protein expression was determined by Western blotting. C225-NPs were detected by electron microscopy and confocal microscopy, and EGFR expression using immunocytochemistry. C225-NP exhibited a strong and selective antitumor effect on EGFR-expressing NSCLC cells by inhibiting EGFR-mediated signal transduction and induced autophagy and apoptosis in tumor cells. Optical images showed specificity of interactions between C225-NP and EGFR-expressing NSCLC cells. No binding of C225-NP was observed for EGFR-null NSCLC cells. C225-NP exhibited higher efficiency in induction of cell killing in comparison with the same amount of free C225 antibody in tumor cells with different levels of EGFR expression. Furthermore, in contrast to C225-NP, free C225 antibody did not induce autophagy in cells. However, the therapeutic efficacy of C225-NP gradually approached the level of free antibodies as the amount of C225 antibody conjugated per nanoparticle was decreased. Finally, attaching C225 to NP was important for producing the enhanced tumor cell killing as addition of mixture of free C225 and NP did not demonstrate the same degree of cell killing activity.Conclusions/SignificanceWe demonstrated for the first time the molecular mechanism of C225-NP induced cytotoxic effects in lung cancer cells that are not characteristic for free molecular therapeutics thus increasing efficacy of therapy against NSCLC.

Gemcitabine versus Modified Gemcitabine: A Review of Several Promising Chemical Modifications

“…The EGFR was found to act as a strong prognostic indicator in head and neck, ovarian, cervical, bladder and oesophageal cancer. 97 The epidermal growth factor receptor (EGFR) is overexpressed in 80% of non-small cell lung cancer (NSCLC), 98 80-100% of human head and neck cancer cells, 14-91% of human breast cancer cells, and 30-50% of human pancreatic cancer cells. 95 Epidermal growth factor receptor (EGFR) is an important anti-cancer therapy target that is applicable to many cancer types.…”

“…In vitro uptake and cytotoxicity of EGF-GemC18-NPs realised with different human breast adenocarcinoma cell lines showed a correlation between EGFR density on the cell surface and cell uptake and toxicity. 86,98,100,101 In cell culture, EGF-GemC18-NPs uptake by tumour cells was correlated to the EGFR density, whereas the uptake of untargeted GemC18-NPs …”

Ferroferric oxide nanoparticles induce prosurvival autophagy in human blood cells by modulating the Beclin 1/Bcl-2/VPS34 complex

“…There are three major pathways to regulate autophagy initiation: (1) the mammalian target of rapamycin (mTOR) that negatively regulates autophagy; (2) the Beclin 1/VPS34/ Atg14 complex and (3) two ubiquitin-like conjugation processes that generate membrane-bound protein complexes, promoting the formation of LC3-conjugated autophagosome. 20 In our study, we found that inhibition of mTOR by Fe 3 mammalian homologous of yeast Atg6, which plays a key role in the process of autophagy. 21 In intact cells, Beclin 1 forms a complex with Bcl-2; therefore Bcl-2 acts as an inhibitor of autophagy.…”

“…1,2 Ferroferric oxide (Fe 3 O 4 ) nanoparticles (NPs) are one such material displaying great potential for medical application; however, recent studies have demonstrated that these NPs might induce apoptosis and other cell responses. 3 It was reported that Fe 3 O 4 NP-induced apoptosis depends on the cell type. As a drug carrier, these NPs display very limited toxicity to cancer cell lines such as cervical cancer cells, but induce cytotoxicity and apoptosis in non-small lung cancer cells.…”

“…As a drug carrier, these NPs display very limited toxicity to cancer cell lines such as cervical cancer cells, but induce cytotoxicity and apoptosis in non-small lung cancer cells. 3 Moreover, this activity is probably associated with the surface modifications. A recent study showed that polyacrylic acid-coated but not naked Fe 3 O 4 NPs induce apoptosis.…”