PKCz restrains cancer cell transformation by inhibiting nutrient stress-induced metabolic reprogramming

Tumor cells utilize the so-called Warburg effect to allow for rapid proliferation with glucose as the main nutrient. We show here that, although PKCz is critical for that effect, its deficiency promotes the plasticity necessary for nutrient-stressed cancer cells to reprogram their metabolism to utilize glutamine through the serine biosynthetic pathway, empowering them to survive and proliferate in the absence of glucose. We show that PKCz deficiency enhances glutamine utilization and expression of two key enzymes of the pathway, PGHDGH and PSAT1, in cells cultured in the absence of glucose. The loss of PKCz in mice results in enhanced intestinal tumorigenesis and increased levels of these two metabolic enzymes, while patients with low levels of PKCz have a poor prognosis. Taken together, this suggests that PKCz is a critical metabolic tumor suppressor.

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Ma L, Tao Y, Duran A, Llado V, Galvez A, Barger JF, Castilla EA, Chen J, Yajima T, Porollo A, Medvedovic M, Brill LM, Plas DR, Riedl SJ, Leitges M, Diaz-Meco MT, Richardson AD, Moscat J