Head and neck cancer cell lines are resistant to mitochondrial-depolarization-induced apoptosis.
ORL J Otorhinolaryngol Relat Spec
; 70(4): 257-63, 2008.
Article
em En
| MEDLINE
| ID: mdl-18483464
ABSTRACT
PURPOSE:
Mitochondrial dysfunction has been linked to defects in the apoptotic pathway, and solid tumors, including head and neck squamous cell carcinoma (HNSCC), exhibit defects in apoptosis. Loss of mitochondrial membrane potential (DeltaPsim) is an early initiating event in the mitochondrial apoptotic pathway. We investigated the apoptotic response of 3 head and neck cancer cell lines treated with a mitochondrial-membrane-depolarizing agent, valinomycin, and studied the ability of depolarization to induce release of cytochrome c in these cell lines. EXPERIMENTALDESIGN:
HNSCC cell lines JHU-011, -012 and -019, and a leukemia control cell line HL-60 were assayed for DeltaPsim after valinomycin treatment by staining with mitochondrial-membrane-potential-specific probe JC-1 and stained with apoptosis-specific probe annexin-V to measure their rate of apoptosis by FACS. Western blotting was also applied to detect cytoplasmic cytochrome c release.RESULTS:
DeltaPsim in head and neck cell lines started to show slight loss of DeltaPsim, while HL-60 showed significant loss of DeltaPsim after 30 min of treatment. All cell lines demonstrated complete mitochondrial depolarization within 24 h, however, only the control cell line HL-60 underwent apoptosis. In addition, HNSCC cell lines did not demonstrate cytoplasmic cytochrome c release despite significant mitochondrial membrane depolarization, while HL-60 cell initiated apoptosis and cytochcrome c release after 24 h of treatment.CONCLUSIONS:
Head and neck cancer cell lines exhibit defects in mitochondrial-membrane-depolarization-induced apoptosis as well as impaired release of cytochrome c despite significant mitochondrial membrane depolarization. Proximal defects in the mitochondrial apoptosis pathway are a feature of HNSCC.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Carcinoma de Células Escamosas
/
Apoptose
/
Potencial da Membrana Mitocondrial
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Neoplasias de Cabeça e Pescoço
/
Mitocôndrias
Limite:
Humans
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article