Attenuating Smac mimetic compound 3-induced NF-kappaB activation by luteolin leads to synergistic cytotoxicity in cancer cells.
Smac mimetics are potential anticancer therapeutics selectively killing cancer cells through autocrine tumor necrosis factor (TNF)-mediated apoptosis pathway. Our recent study reveal that the Smac mimetic compound 3 (SMC3)-activated NF-kappaB protects cancer cells against apoptosis, thus blunting SMC3's anticancer activity. Based on our previous observations that the nutrient flavonoid luteolin potently blocks TNF-induced NF-kappaB activation in cancer cells, we investigated if the combination of SMC3 and luteolin would achieve a synergistic anticancer activity. The results show that luteolin had no effect on autocrine TNF but it effectively blocked SMC3-induced nuclear factor kappa B (NF-kappaB) activation and expression of anti-apoptotic NF-kappaB targets. When SMC3 and luteolin were combined in treating cancer cells derived from lung and liver tumors, the activation of TNF-dependent apoptosis was markedly sensitized and a synergistic cytotoxic effect was achieved. In addition, the SMC3 and luteolin co-treatment had marginal effect on immortalized normal human bronchial epithelial cells. The results suggest that combination of SMC3 and luteolin is an effective approach for improving the anticancer value of SMC3, which has implications in cancer prevention and therapy.
Bai
Lang
L
Molecular Biology and Lung Cancer Program, Lovelace Respiratory Research Institute, 2425 Ridgecrest DR. SE, Albuquerque, New Mexico 87108, USA.
Chen
Wenjie
W
Wang
Xia
X
Ju
Wei
W
Xu
Shanling
S
Lin
Yong
Y
D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins; D001980:Bronchi; D045744:Cell Line, Tumor; D004357:Drug Synergism; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000378:metabolism*; D008113:Liver Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D008175:Lung Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D047311:Luteolin / Q000494:pharmacology*; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000378:metabolism*; D018716:Molecular Mimicry; D016328:NF-kappa B / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D048069:Tumor Necrosis Factors / Q000378:metabolism*
D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; C412403:DIABLO protein, human; D047908:Intracellular Signaling Peptides and Proteins; D024101:Mitochondrial Proteins; D016328:NF-kappa B; D048069:Tumor Necrosis Factors; D047311:Luteolin