Decoupled glucose- and glutamine-dependent orthogonal metabolic states independently sustain cancer cell survival
Cancer metabolism is often framed as dependence on cooperative glucose-glutamine fuels; however, whether distinct nutrients enforce discrete metabolic states remains unclear. Glucose utilization is often interpreted under Warburg physiology, involving accelerated glycolysis and clockwise TCA rotation to generate reducing equivalents; yet, emerging evidence suggests that glutamine, under certain conditions, can drive anaplerotic pathways independent of glycolysis, involving a counterclockwise TCA linked to massive lipid biosynthesis. Here, we sought to define how glucose and glutamine independently govern adaptive metabolic states, rather than functioning as cooperative co-fuels, in MDA-MB-231 breast cancer cells. Briefly, cells were cultured under four defined nutrient conditions—full (+Glc,+Gln), deficient (-Glc,-Gln), glucose-only, and glutamine-only—and applied transcriptomic, metabolomic, and lipidomic analyses to resolve nutrient-enforced transcriptional and metabolic states. Overall design: RNA-seq of MDA-MB-231 breast cancer cells cultured under four defined nutrient conditions—full (+Glc,+Gln), deficient (-Glc,-Gln), glucose-only, and glutamine-only—supported by evidence of  metabolomic, and lipidomic changes.