J Korean Cancer Assoc.  2000 Apr;32(2):270-278.

Phorbol Ester Induced - Apoptosis Mediated by Activating Serine Protease ( s ) and Caspase - 3 / CPP32 in SNU - 16 Human Gastric Cancer Cell Line

• Park IC
• Park MJ
• Choe TB
• Jang JJ
• Hong SI
• Lee SH

Abstract

PURPOSE: Protein kinase C (PKC) is a family of phospholipid dependent serine/threonine protein kinases that have important role in differentiation, development and tumor promotion. PKC also has been reported to be implicated in the induction of apoptosis in a number of studies, but the efforts to define a role for PKC in the induction of apoptosis have been complicated by conflicting reports.
MATERIALS AND METHODS
To determine the effect of phorbol 12-myristate 13-acetate (PMA) on the induction of apoptosis, DNA fragmentation was detected by agarose gel electrophoresis and morphological changes of apoptotic cells were detected by Hoechst 33258 staining. For the detection of caspase-3/CPP32 activity, we used the enzyme substrate Ac-DEVD-pNa and anti- D4-GDI antibody.
RESULTS
In the present study, PMA, a PKC activator, induced apoptosis in SNU-16 human gastric cancer cell line, whose apoptosis was significantly inhibited by the PKC inhibitor, chelerythrine chloride. The caspase-3/CPP32 protease activity was increased in PMA-induced apoptosis. Furthermore, 4-(2-aminoethyl) benzenesulfonyl fluoride (AEBSF), a serine profease inhibitor, also significantly suppressed PMA-induced cell death in an upstream of caspase-3/CPP32.
CONCLUSION
These findings indicate that PMA induces apoptotic cell death in the SNU-16 adenocarcinoma cells through PKC activation, which activates AEBSF-sensitive serine proteases and caspase-3/CPP32. Therefore, our results suggest that PKC would be a potential target for induction of apoptosis.

Keyword

Apoptosis; Protein kinase C; Phorbol ester; Caspase; Serine protease; Stomach cancer cell line

MeSH Terms

Adenocarcinoma
Apoptosis*
Bisbenzimidazole
Cell Death
Cell Line*
DNA Fragmentation
Electrophoresis, Agar Gel
Fluorides
Humans*
Protein Kinase C
Protein Kinases
Serine Proteases*
Serine*
Stomach Neoplasms*
Bisbenzimidazole
Fluorides
Protein Kinase C
Protein Kinases
Serine
Serine Proteases