Bcl-2 and Mn-SOD antisense oligodeoxynucleotides and a glutamine-enriched diet facilitate elimination of highly resistant B16 melanoma cells by tumor necrosis factor-alpha and chemotherapy.
Mitochondrial glutathione (mtGSH) depletion increases sensitivity of Bcl-2-overexpressing B16 melanoma (B16M)-F10 cells (high metastatic potential) to tumor necrosis factor-alpha (TNF-alpha)-induced oxidative stress and death in vitro. In vivo, mtGSH depletion in B16M-F10 cells was achieved by feeding mice (where the B16M-F10 grew as a solid tumor in the footpad) with an L-glutamine (L-Gln)-enriched diet, which promoted in the tumor cells an increase in glutaminase activity, accumulation of cytosolic L-glutamate, and competitive inhibition of GSH transport into mitochondria. L-Gln-adapted B16M-F10 cells, isolated using anti-Met-72 monoclonal antibodies and flow cytometry-coupled cell sorting, were injected into the portal vein to produce hepatic metastases. In l-Gln-adapted invasive (iB16M-Gln+) cells, isolated from the liver by the same methodology and treated with TNF-alpha and an antisense Bcl-2 oligodeoxynucleotide, viability decreased to approximately 12%. iB16M-Gln+ cell death associated with increased generation of O2*- and H2O2, opening of the mitochondrial permeability transition pore complex, and release of proapoptotic molecular signals. Activation of cell death mechanisms was prevented by GSH ester-induced mtGSH replenishment. The oxidative stress-resistant survivors showed an adaptive response that includes overexpression of manganese-containing superoxide dismutase (Mn-SOD) and catalase activities. By treating iB16M-Gln+ cells with a double anti- antisense therapy (Bcl-2 and SOD2 antisense oligodeoxynucleotides) and TNF-alpha, metastatic cell survival decreased to approximately 1%. Chemotherapy (taxol plus daunorubicin) easily removed this minimum percentage of survivors. This contribution identifies critical molecules that can be sequentially targeted to facilitate elimination of highly resistant metastatic cells.
Benlloch
María
M
Department of Physiology, University of Valencia, 17 Av. Blasco Ibañez, 46010 Valencia, Spain.
Mena
Salvador
S
Ferrer
Paula
P
Obrador
Elena
E
Asensi
Miguel
M
Pellicer
José A
JA
Carretero
Julian
J
Ortega
Angel
A
Estrela
José M
JM
D000821:Animal Feed; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D003131:Combined Modality Therapy; D004195:Disease Models, Animal; D019008:Drug Resistance, Neoplasm; D015316:Genetic Therapy; D005973:Glutamine / Q000494:pharmacology*; D005978:Glutathione / Q000378:metabolism; D008297:Male; D008545:Melanoma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008928:Mitochondria / Q000378:metabolism; D009368:Neoplasm Transplantation; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D018384:Oxidative Stress; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics*; D012983:Soft Tissue Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D000970:Antineoplastic Agents; D016376:Oligonucleotides, Antisense; D019253:Proto-Oncogene Proteins c-bcl-2; D014409:Tumor Necrosis Factor-alpha; D005973:Glutamine; D013482:Superoxide Dismutase; D005978:Glutathione