Inhibition of caspase-9 activity in cisplatin-resistant head and neck squamous cell carcinoma

Nihon Jibiinkoka Gakkai kaiho
Daisuke KuwaharaIzumi Koizuka

Abstract

We have previously reported that cisplatin induces caspase-9 activation in head and neck squamous cell carcinoma cells (HNSCCs) in vitro, and the use of a specific inhibitor of caspase-9 blocks cisplatin-induced apoptosis in HNSCCs. Our purpose here was to determine whether HNSCCs selected for resistance to cisplatin fail to exhibit caspase-9 activation in response to cisplatin. Cisplatin-resistant HNSCCs (CRHNSCCs) were selected for growth in the presence of cisplatin. Following cisplatin treatment, no protelyzed caspase-9 subunits were detected in the CRHNSCCs, whereas proteolytic degradation of procaspase-9 was observed in parental cisplatin-sensitive HNSCCs (CSHNSCCs). Using a direct enzymatic assay measuring cleavage of the synthetic peptide substrate (LEHD-AFC), caspase-9 activity in cisplatin-treated CRHNSCCs was less than that in cisplatin-treated CSHNSCCs. Because caspase-9 activation requires the release of mitochondorial cytochrome c (Cyt c) into the cytoplasm, we determined the level of cytoplasmic Cyt c in response to cisplatin treatment. Interestingly, following cisplatin treatment, the same extent of increase in cytoplasmic Cyt c was evident and the expression of Bcl-2 family proteins (Bcl-2 and Bcl-XL) remained ...Continue Reading

Citations

Mar 6, 2007·Critical Reviews in Oncology/hematology·David J Stewart

❮ Previous
Next ❯

Related Concepts

Related Feeds

Apoptotic Caspases

Apoptotic caspases belong to the protease enzyme family and are known to play an essential role in inflammation and programmed cell death. Here is the latest research.

Apoptosis

Apoptosis is a specific process that leads to programmed cell death through the activation of an evolutionary conserved intracellular pathway leading to pathognomic cellular changes distinct from cellular necrosis

Carcinoma, Squamous Cell

Basal cell carcinoma is a form of malignant skin cancer found on the head and neck regions and has low rates of metastasis. Discover the latest research on basal cell carcinoma here.

BCL-2 Family Proteins

BLC-2 family proteins are a group that share the same homologous BH domain. They play many different roles including pro-survival signals, mitochondria-mediated apoptosis and removal or damaged cells. They are often regulated by phosphorylation, affecting their catalytic activity. Here is the latest research on BCL-2 family proteins.

Related Papers

American Journal of Physiology. Cell Physiology
Bok Hee ChoiYong-Geun Kwak
Cellular Physiology and Biochemistry : International Journal of Experimental Cellular Physiology, Biochemistry, and Pharmacology
Hitomi KamiyaTomoyuki Nishizaki
© 2022 Meta ULC. All rights reserved