Induction of lung cancer stem-like cells by chronic exposure to carbon nanotubes.
Luanpitpong S; Wang L; Manke A; Barr J; Rojanasakul Y
Cancer Res 2013 Apr; 73(8)(Suppl 1):3752
Our previous studies have shown that chronic exposure to single-walled carbon nanotubes (SWCNTs) induces malignant transformation of human lung epithelial cells. Most solid tumors including lung cancer cells are believed to contain poorly differentiated cancer stem-like cells (CSCs) that initiate tumorigenesis and confer resistance to chemotherapy. In this study we investigated whether SWCNT-transformed lung epithelial cells present CSC traits. Similar to human non-small cell lung cancer H460 cells, SWCNT-transformed lung epithelial BEAS-2B cells but not its passage-matched control cells formed tumor spheres in stem cell-selective conditions, indicating the existence of lung CSCs. Lung CSCs have previously been reported to reside in the side population (SP) of parental lung cancer cells. Analysis of SP fractions based on the ability of SP to efflux Hoechst 33342 dye to generate a Hoechst blue-red profile revealed that the SWCNT-transformed cells and H460 cells have high SP fractions, while passage-matched control cells showed no SP, thus confirming the existence of CSC population in SWCNT-transformed and H460 cells. Compared with the corresponding parental cells, the SP cells of SWCNT-transformed and H460 cells acquired apoptosis resistance to various chemotherapy including antimycin A, cisplatin, doxorubicin and etoposide. Together, our results indicate the ability of SWCNT to transform human lung epithelial cells and induce CSCs which could represent a novel mechanism of carcinogenesis induced by CNTs.
Exposure-limits; Lung; Lung-cancer; Cancer; Nanotechnology; Humans; Cell-function; Cellular-function; Tumors; Chemotherapy; Carcinogenesis
Cancer Research. Proceedings of the AACR 104th Annual Meeting, April 6-10, 2013, Washington, DC