Total Cellular ATP Production Changes With Primary Substrate in MCF7 Breast Cancer Cells.

Cancer growth is predicted to require substantial rates of substrate catabolism and ATP turnover to drive unrestricted biosynthesis and cell growth. While substrate limitation can dramatically alter cell behavior, the effects of substrate limitation on total cellular ATP production rate is poorly understood. Here, we show that MCF7 breast cancer cells, given different combinations of the common cell culture substrates glucose, glutamine, and pyruvate, display ATP production rates 1.6-fold higher than when cells are limited to each individual substrate. This increase occurred mainly through faster oxidative ATP production, with little to no increase in glycolytic ATP production. In comparison, non-transformed C2C12 myoblast cells show no change in ATP production rate when substrates are limited. In MCF7 cells, glutamine allows unexpected access to oxidative capacity that pyruvate, also a strictly oxidized substrate, does not. Pyruvate, when added with other exogenous substrates, increases substrate-driven oxidative ATP production, by increasing both ATP supply and demand. Overall, we find that MCF7 cells are highly flexible with respect to maintaining total cellular ATP production under different substrate-limited conditions, over an acute (within minutes) timeframe that is unlikely to result from more protracted (hours or more) transcription-driven changes to metabolic enzyme expression. The near-identical ATP production rates maintained by MCF7 and C2C12 cells given single substrates reveal a potential difficulty in using substrate limitation to selectively starve cancer cells of ATP. In contrast, the higher ATP production rate conferred by mixed substrates in MCF7 cells remains a potentially exploitable difference.

Relationship of Burnout and Engagement to Pharmacy Students' Perception of Their Academic Ability.

Objective. To assess burnout and engagement in first- and second-year Doctor of Pharmacy (PharmD) students and to investigate their relationships to students' perception of their academic ability. Methods. An online survey that included three validated scales was administered in May 2017 to first- and second-year pharmacy students enrolled in didactic coursework at Touro University California College of Pharmacy. The Maslach Burnout Inventory was used to assess burnout and the Utrecht Work Engagement Scale was used to measure student engagement. To characterize academic ability, Academic Self-Perception, a subscale of the School Attitude Assessment Survey-Revised, was used. Regression analysis was performed using statistical software. Results. One hundred sixty-two students (81.4% response rate) completed the survey. Emotional exhaustion and professional inefficacy were negatively correlated with students' academic self-perception. Dedication was positively correlated with academic self-perception. Conclusion. In pharmacy students completing the didactic portion of the PharmD curriculum, various engagement and burnout parameters correlated with academic self-perception.