Pyruvate blocks expression of sensitivity to antimycin A and chloramphenicol

Abstract

Selectivity in Chinese hamster cells with antimycin A and chloramphenicol depends on a metabolic balance which can be modulated by varying the level of exogenous pyruvate. The effects of both inhibitors are most clearly seen in pyruvate-free nutrients. Addition of 1 mM pyruvate in plating assays shifts dose-response curves for antimycin A or chloramphenicol to higher concentration levels and reduces the differential in response between sensitive and resistant cells. In mass populations, growth inhibition by antimycin A is reduced by adding pyruvate, and growth curves for sensitive and resistant cells tend to converge. These observations show that responses to antimitochondrial drugs can be conditioned by extrinsic factors and indicate the need for further definition of selective systems.

An Essential Role of the Mitochondrial Electron Transport Chain in Cell Proliferation Is to Enable Aspartate Synthesis

“…It has long been appreciated that human cells with ETC dysfunction can proliferate when cultured in media containing supra-physiological concentrations of pyruvate (Harris, 1980). Remarkably, pyruvate even enables the proliferation of cells that have deleterious mutations in their mitochondrial DNA or lack it altogether (143B ρ 0 cells) (King and Attardi, 1989).…”

“…Remarkably, pyruvate even enables the proliferation of cells that have deleterious mutations in their mitochondrial DNA or lack it altogether (143B ρ 0 cells) (King and Attardi, 1989). Pyruvate has been hypothesized to act as a biosynthetic substrate or to maintain the cellular redox state in cells with ETC dysfunction via reduction by lactate dehydrogenase, which helps regenerate the NAD + that is lost upon ETC inhibition (Harris, 1980; Wilkins et al, 2014). The NAD + made through pyruvate reduction should facilitate glycolytic flux and thus ATP production in cells lacking ETC function, but the key metabolic consequence of pyruvate addition that allows such cells to proliferate is unclear.…”

“…Interestingly, it has long been known that human cells lacking a functional ETC can proliferate if cultured in supra-physiological concentrations of pyruvate (King and Attardi, 1989). While pyruvate can serve as a biosynthetic substrate or affect the redox state of the cell by promoting the regeneration of NAD + (Harris, 1980; Howell and Sager, 1979), why it reverses the suppressive effects of ETC inhibition on cell proliferation is unknown.…”

Targeting Metabolism for Cancer Therapy

“…However, subsequent work determined that despite engaging in aerobic glycolysis, cancer cells consume oxygen at levels comparable to normal tissue (Weinhouse, 1956; Zu and Guppy, 2004). Moreover, inhibitors of cellular respiration block proliferation, suggesting that most cancer cells require respiration in order to proliferate (Harris, 1980; Howell and Sager, 1979; Kroll et al, 1983; Loffer and Schneider, 1982; Zhang et al, 2014b). Respiration is also needed for tumor initiation, as tumor cells with impaired oxidative phosphorylation due to depletion of mitochondrial DNA (mtDNA) exhibit increased tumor latency upon subcutaneous transplantation.…”

Genetics of the mammalian oxidative phosphorylation system: characterization of a new oligomycin-resistant Chinese hamster ovary cell line.

“…When cells are exposed to an inhibitor of oxidative phosphorylation, such as oligomycin, energy must be derived exclusively from glycolysis. Because the rate of glycolysis is slower when galactose is used as a carbon source than when glucose is used, cells are more sensitive to such inhibitors in medium containing galactose (7,27), chloramphenicol (53), and antimycin (25). As shown in Fig.…”