Abstract 1868: Metabolic characterization of prostate cancer cell lines.
Authors: Moroz Ekaterina S. , Blasberg Ronald , Serganova Inna 
Published: August 2014

Purpose: The tumor microenvironment has a major impact on tumor growth and progression; the composition and characteristics of the tumor microenvironment is influenced by the metabolism of both tumor and stromal cells. In preparation to determining the effects of cell metabolism on the anti-tumor T cell immune response, we studied the metabolism of two murine prostate cell lines (RM1 and Myc-Cap) under different conditions. The long-term goal of our study is to assess what features of an abnormal tumor microenvironment negatively impact T cell tumor targeting and the activation of T cells in orthotopic prostate cancer models.

Methods: The metabolic profiles of the more aggressive rapidly growing RM1 and more moderate growing Myc-Cap cells were determined. A Seahorse XF96 Extracellular Flux Analyzer, which provides real-time measurements of the extracellular acidification rate (ECAR), was used to measure of glycolysis and lactate production, and the oxygen consumption rate (OCR), a measure of oxidative phosphorylation (OXPHOS). The effects of 24-hour glucose and glutamine deprivation were studied.

Results: Myc-Cap cells utilized significantly less glucose, produced much less acid (lactate) and had a low proliferation rate compared to RM1 cells. RM1 cells exhibit a higher rate of glycolysis and showed higher glycolytic capacity, whereas OCR (a measure of mitochondrial respiration) was lower in RM1 compared to Myc-Cap cells. The expression of glycolytic enzymes was comparable in both cell lines; RM1 cells demonstrated higher LDHA and lower expression of mitochondrial enzymes, as measured by Western blot.

For RM1, glucose withdrawal from the media resulted in reduced LDHA expression, a 77% decrease in lactate production (measured by ECAR), and a 50% decrease in OCR. Glutamine withdrawal resulted in a 35% decrease in ECAR, and an 82% decrease in OCR. Myc-Cap cells were slightly less affected by glucose withdrawal (slight change in LDHA expression, a 69% decrease in ECAR, and a 40% decrease in OCR), whereas glutamine withdrawal had a more profound effect on ECAR (75% decrease) and a similar effect on OCR (83% decrease). Glutamine withdrawal reduced the proliferation rate of both cell lines significantly more than glucose withdrawal.

Conclusions: Our data demonstrate a major difference in acid production (lactate) between the two cell lines (RM1&gt;Myc-Cap). RM1 cells are more glucose dependent, whereas Myc-Cap is more glutamine dependent. Understanding the metabolic differences between tumors and the impact of metabolism on the tumor microenvironment will provide specific targets that could enhance T cell therapy through a modification of the tumor microenvironment.

Citation Format: Ekaterina S. Moroz, Ronald Blasberg, Inna Serganova. Metabolic characterization of prostate cancer cell lines. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1868. doi:10.1158/1538-7445.AM2013-1868