Protein Kinase C Activity in Human Leukemia Cell Lines with Reference to Sensitivity to Antineoplastic Agents

SUGAWARA, S., KUMANO, N., SAIJO, Y., SUZUKI, S., NUMATA, Y., SATO, G. and MOTOMIYA, M. Protein Kinase C Activity in Human Leukemia Cell Lines with Reference to Sensitivity to Antineoplastic Agents. Tohoku J. Exp. Med., 1992, 168 (2), 393-396- Protein kinase C (PKC) regulates many cellular processes. In view of its possible relevance to the drug resistance, the levels of PKC activity were assessed in human leukemia cell lines with reference to the sensitivity to antineoplastic agents. K562/ADM exhibited approximately 2-fold higher levels of PKC activity as compared with the parental K562. After a 1-hr preincubation with Adriamycin (ADM) (0.5, 1, 10μM), PKC activity in K562 tended to increase dose-dependently, while no substantial alteration was found in K562/ADM. Cisplatin (CDDP) or etoposide was of no effect. The activity in THP-1/E was slightly lower than THP-1, and the basal level stayed unchanged with any one of the above durgs. These results suggest that in K562 increase in PKC activity with ADM may play a role in the process of acquisition of resistance.- protein kinase C; antineoplastic agents; human leukemia cell lines; drug resistance