Breast cancer, the most common malignancy among women, affects one in eight women in the United States. Triple-negative breast cancer is an invasive subtype of breast cancer that lacks a biologically targeted therapy. The aim of this study was to investigate a possible treatment to this form of breast cancer, using MDA-MB-231 cells as a model triple-negative breast cancer cell line. Caffeine is considered a compound that possibly inhibits carcinogenesis in lung, skin and ovarian tumors. When combined with the chemotherapeutic agent cisplatin, caffeine has been reported to amplify cisplatin’s anti-cancerous effect in lung and bone cancers. However, this combination has not been tested on triple-negative breast cancers. It is possible that caffeine and cisplatin are useful in treatments for this breast cancer subtype. To test this hypothesis, this project uses cutting-edge microscopic imaging tools to non-invasively monitor shifts in cellular metabolic states. Cancer cells undergo the Warburg effect, a shift in metabolic behavior towards glycolysis (higher ratio of free NADH) and away from oxidative phosphorylation (lower ratio of free NADH) even in the presence of excess oxygen. This study incorporated Phasor Fluorescence Lifetime Imaging Microscopy (Phasor-FLIM) analysis to evaluate caffeine and cisplatin’s ability to revert a triple-negative cell line’s metabolic profile to that of a normally proliferating, or wild-type, cell. Phasor-FLIM was used to examine free and bound NADH levels, as NADH is an auto-fluorescent optical biomarker found in living cells. Free and bound NADH levels are calculated and used to evaluate the metabolic properties of SCRC-1041 human foreskin fibroblasts (control), MCF7 breast cancer cells (non-triple-negative), and MB231 triple-negative breast cancer cells after exposure to different concentrations of caffeine, specifically no treatment, 100 µM, and 500 µM. The SCRC-1041 and MCF7 cells showed no significant change in metabolism after caffeine treatment (p>0.05). The MB231 cells exhibited significant differences in free NADH fraction after treatment with 100 µM caffeine (p<0.01) and 500 µM caffeine (p<0.001). The study confirms that the higher the concentration of caffeine used to treat the MB231 cells, the lower the free NADH fraction. This indicates that in MB231 cells, caffeine induces a shift towards metabolism indicative of a wild-type cell. When the MB231 cells were treated with 500 µM caffeine with 20 µM cisplatin their metabolism shifted towards normal cellular metabolism (p< 0.001), although the magnitude of change in free NADH fraction was half that of cells treated with only caffeine (p< 0.001). Cisplatin directly interferes with the genetic sequence, and caffeine is known to act on the cell cycle through ATM/ATR kinases. Thus, the effect that cisplatin has on the cell could override or render caffeine’s effects useless.
This study showed that caffeine alone was more effective in shifting metabolism towards a normal cellular metabolism than cisplatin and caffeine combined. Overall, conclusions still suggest that caffeine, cisplatin, and their combined treatment reverse the metabolic profiles of cancerous cells to that of wildtype cells.
MEDICAL IMAGING & BIOMEDICAL DIAGNOSTICS
Author: Justin Wang
Status: Completed Work