Caloric restriction modulates Mcl-1 expression and sensitizes lymphomas to BH3 mimetic in mice

Meynet O, Zunino B, Happo L, Pradelli LA, Chiche J, Jacquin MA, Mondragón L, Tanti JF, Taillan B, Garnier G, Reverso-Meinietti J, Mounier N, Michiels JF, Michalak EM, Carles M, Scott CL, Ricci JE

Blood 2013 Oct;122(14):2402-11

Abstract

PMID: 23966420

Caloric restriction (CR) is proposed to decrease tumorigenesis through a variety of mechanisms including effects on glycolysis. However, the understanding of how CR affects the response to cancer therapy is still rudimentary. Here, using the Eµ-Myc transgenic mouse model of B-cell lymphoma, we report that by reducing protein translation, CR can reduce expression of the prosurvival Bcl-2 family member Mcl-1 and sensitize lymphomas to ABT-737-induced death in vivo. By using Eµ-Myc lymphoma cells lacking p53, we showed that CR mimetics such as 2-deoxyglucose led to a decrease in Mcl-1 expression and sensitized lymphoma cells to ABT-737-induced death independently of p53. In keeping with this, Eµ-Myc lymphoma cells lacking the BH3-only proapoptotic members Noxa, Puma, or Bim were also sensitized by CR mimetics to ABT-737-induced death. Remarkably, neither the loss of both Puma and Noxa, the loss of both Puma and Bim, nor the loss of all three BH3-only proteins prevented sensitization to ABT-737 induced by CR mimetics. Thus, CR can influence Mcl-1 expression and sensitize cells to BH3 mimetic-induced apoptosis, independently of the main BH3-only proteins and of p53. Exploiting this may improve the efficiency of, or prevent resistance to, cancer therapy.