The anticancer properties of iron core–gold shell nanoparticles in colorectal cancer cells
Received 7 May 2013
Accepted for publication 21 June 2013
Published 2 September 2013 Volume 2013:8(1) Pages 3321—3331
Checked for plagiarism Yes
Review by Single anonymous peer review
Peer reviewer comments 3
Ya-Na Wu,1 Ping-Ching Wu,1 Li-Xing Yang,1 Kyle R Ratinac,2 Pall Thordarson,4 Kristina A Jahn,2 Dong-Hwang Chen,3 Dar-Bin Shieh,1,5,6 Filip Braet2,7
1Institute of Oral Medicine and Department of Stomatology, National Cheng Kung University Hospital, College of Medicine, Tainan, Taiwan; 2Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, NSW, Australia; 3Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan; 4School of Chemistry, University of New South Wales, Sydney, NSW, Australia; 5Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan, Taiwan; 6Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan, Taiwan; 7School of Medical Sciences (Discipline of Anatomy and Histology), The Bosch Institute, University of Sydney, Sydney, NSW, Australia
Abstract: Previously, iron core–gold shell nanoparticles ([email protected]) have been shown to possess cancer-preferential cytotoxicity in oral and colorectal cancer (CRC) cells. However, CRC cell lines are less sensitive to [email protected] treatment when compared with oral cancer cell lines. In this research, [email protected] are found to decrease the cell viability of CRC cell lines, including Caco-2, HT-29, and SW480, through growth inhibition rather than the induction of cell death. The cytotoxicity induced by [email protected] in CRC cells uses different subcellular pathways to the mitochondria-mediated autophagy found in [email protected] oral cancer cells, OECM1. Interestingly, the Caco-2 cell line shows a similar response to OECM1 cells and is thus more sensitive to [email protected] treatment than the other CRC cell lines studied. We have investigated the underlying cell resistance mechanisms of [email protected] CRC cells. The resistance of CRC cells to [email protected] does not result from the total amount of [email protected] internalized. Instead, the different amounts of Fe and Au internalized appear to determine the different response to treatment with Fe-only nanoparticles in [email protected] CRC cells compared with the [email protected] OECM1 cells. The only moderately cytotoxic effect of [email protected] nanoparticles on CRC cells, when compared to the highly sensitive OECM1 cells, appears to arise from the CRC cells' relative insensitivity to Fe, as is demonstrated by our Fe-only treatments. This is a surprising outcome, given that Fe has thus far been considered to be the "active" component of [email protected] nanoparticles. Instead, we have found that the Au coatings, previously considered only as a passivating coating to protect the Fe cores from oxidation, significantly enhance the cytotoxicity of [email protected] in certain CRC cells. Therefore, we conclude that both the Fe and Au in these core–shell nanoparticles are essential for the anticancer properties observed in CRC cells.
Keywords: cancer therapy, Fe, gold-coated iron, nanoparticles, differential cytotoxicity
© 2013 The Author(s). This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.