Abstract 6512: Label-free autofluorescence imaging reveals different metabolic responses to adverse growth conditions between normal and breast cancer cells lines
Authors: Junkins Katherine , Martinez Angel Perez , Rodgers Margaret , Phelan Shelley A. , Xu Min 
Published: April 2023

Cancer cells are metabolically distinct from normal cells, and can adapt differently to adverse growth conditions. We sought to compare normal MCF10A and Ras-transformed MCF10AT cells under various conditions (regular growth media, doxorubicin-treatment, and glucose-deprived media) by imaging endogenous cellular FAD and NADH fluorescence and comparing it to proliferation rates (measured by MTS assay) and chromatin structure (measured by Hoescht staining).

Under normal growth conditions, MCF10AT cells displayed similar levels of FAD and higher levels of mitochondrial NADH than MCF10A cells. Elevated NADH in MCF10AT cells seems to reflect the preference for anaerobic glycolysis rather than oxidative phosphorylation (the so-called Warburg effect). Our MTS data showed that doxorubicin treatment did not significantly affect MCF10AT cell proliferation but led to a modest reduction in cell proliferation in the normal cell line. Likewise, in MCF10AT cells, doxorubicin treatment led to an increase in FAD and a decrease in NADH. Conversely, in MCF10A cells, doxorubicin led to a decrease in FAD levels and an increase in mitochondrial NADH. These results suggest that the cancer line may be switching to oxidative phosphorylation to resist doxorubicin-induced toxicity, while the normal cells reduce oxidative phosphorylation with growth inhibition.

In contrast to the doxorubicin response, glucose deprivation produced significant growth inhibition and cell death in MCF10AT cells while having a modest growth-inhibitory effect on the normal line. Interestingly, low glucose decreased FAD and mitochondrial NADH in MCF10AT cells, suggesting that both aerobic and anaerobic respiration was reduced and consistent with the marked reduction in observed cell viability. In contrast, MCF10A cells showed a slight decrease in FAD and an increase in NADH, suggesting a decrease in oxidative phosphorylation consistent with the modest growth inhibition observed.

Finally, MCF10ATs displayed higher levels of Hoechst staining than MCF10A cells, consistent with a higher proportion of condensed chromatin observed in cancer cells. In addition, we found a larger increase in Hoechst staining in MCF10AT cells in response to both doxorubicin and low glucose, as compared to MCF10A cells. This data suggests that the chromatin state of the two lines is also differentially affected by these treatments.

In conclusion, label-free measurement of autofluorescence of cellular FAD and mitochondrial NADH reveals the different metabolic and chromatin responses to adverse growth conditions between cancer and non-cancer cells. These differences are associated with the different proliferation rates and may have important clinical implications for cancer risk stratification.

Citation Format: Katherine Junkins, Angel Perez Martinez, Margaret Rodgers, Shelley A. Phelan, Min Xu. Label-free autofluorescence imaging reveals different metabolic responses to adverse growth conditions between normal and breast cancer cells lines. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6512.