Abstract
Acquired cisplatin resistance is a common feature of tumours following cancer treatment with cisplatin and also of non-small cell lung cancer (H1299) and mesothelioma (P31) cell lines exposed to cisplatin. To elucidate the cellular basis of acquired cisplatin resistance, a comprehensive bioenergetic analysis was undertaken. We demonstrate that cellular oxygen consumption was significantly decreased in cisplatin resistant cells and that the reduction was primarily due to reduced mitochondrial activity as a result of reduced mitochondrial abundance. The differential mitochondrial abundance was supported by data showing reduced sirtuin 1 (SIRT1), peroxisome-proliferator activator receptor-γ co-activator 1-alpha (PGC1α), sirtuin 3 (SIRT3) and mitochondrial transcription factor A (TFAM) protein expression in resistant cells. Consistent with these data we observed increased reactive oxygen species (ROS) production and increased hypoxia inducible factor 1-alpha (HIF1α) stabilization in cisplatin resistant cells when compared to cisplatin sensitive controls. We also observed an increase in AMP kinase subunit α2 (AMPKα2) transcripts and protein expression in resistant H1299 cells. mRNA expression was also reduced for cisplatin resistant H1299 cells in these genes, however the pattern was not consistent in resistant P31 cells. There was very little change in DNA methylation of these genes, suggesting that the cells are not stably reprogrammed epigenetically. Taken together, our data demonstrate reduced oxidative metabolism, reduced mitochondrial abundance, potential for increased glycolytic flux and increased ROS production in acquired cisplatin resistant cells. This suggests that the metabolic changes are a result of reduced SIRT3 expression and increased HIF-1α stabilization.
Highlights
Altered metabolism is a hallmark of cancer [1] and while acquired genetic and molecular modifications have enabled cancers to survive the onslaught of various cancer therapies [2], understanding tumour cell metabolism is becoming increasingly more important
We report here for the first time, real-time cellular metabolism comparing and contrasting oxidative and glycolytic fluxes in cisplatin-resistant and parental H1299 and P31 cells
H1299 and P31 cells are greater than oxygen consumption rates in resistant cells
Summary
Altered metabolism is a hallmark of cancer [1] and while acquired genetic and molecular modifications have enabled cancers to survive the onslaught of various cancer therapies [2], understanding tumour cell metabolism is becoming increasingly more important. Cisplatin is a potent chemotherapeutic drug, used in the treatment of a variety of cancers but its usefulness is limited by the acquisition of resistance. Resistant cancers have been shown to adapt to long-term cisplatin treatment by decreasing their mitochondrial number [12, 13], oxygen consumption and glucose uptake [14] and exploiting these metabolic differences may prove important in overcoming chemo-resistance. Acquired cisplatin resistant nonsmall cell lung cancer (H1299) and mesothelioma (P31) cell lines demonstrate reduced sensitivity to cisplatininduced cell death when compared to their sensitive cell counterparts [15]. We decided to use these cells and apply comprehensive bioenergetics analyses to determine whether acquired cisplatin resistance was impacting mitochondrial function
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
