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Induction of differentiation in K‐562 leukemia cells by PMA and AD 198
Author(s) -
Barham Whitney Jo,
Lothstein Leonard
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.649.1
Subject(s) - cytotoxic t cell , protein kinase c , microbiology and biotechnology , myeloid leukemia , western blot , phorbol , chemistry , cellular differentiation , apoptosis , leukemia , biology , cancer research , kinase , immunology , biochemistry , in vitro , gene
Both the phorbol ester phorbol‐12‐myristate‐13‐acetate (PMA) and the anthracycline N ‐benzyladriamycin‐14‐valerate (AD 198) are protein kinase C (PKC) activators. Both act by binding to the C1b domain of PKC. PMA and AD 198 promote apoptosis in cells exposed to their respective cytotoxic doses. PMA promotes differentiation when administered at lower than cytotoxic levels. AD 198 may too induce differentiation when administered at non‐cytotoxic levels. K‐562 chronic myeloid leukemia cells were exposed to AD 198 at a non‐cytotoxic dose. Other cells were exposed to a non‐cytotoxic dose of PMA. Western blot analysis showed the level of expression of p21 in these samples, revealing significant p21 expression in the PMA treated cells, and no expression in the AD 198 treated cells. Reverse transcriptase polymerase chain reaction (RT‐PCR) was used to probe for differentiated cell specific RNAs including CD61, pdgf, and c‐myc. Significant amounts of both CD61 and pdgf were found in the PMA treated cells, but were not found in those treated with AD 198. C‐myc was absent in all samples. It was concluded that AD 198 does not induce differentiation as PMA does. Since AD 198 and PMA both increase PKC‐ ε expression, but only PMA promotes PKC‐ ε activation and nuclear localization (both implicated in differentiation), differential PKC‐ ε expression may account for this functional difference. Research funded by NIH NCI #CA 100093.