STUDY ON THE MECHANISM OF BASIC FIBROBLAST GROWTH FACTOR(bFGF)RELEASE INDUCED BY PHORBOL ESTER PMA
WANG Nan XU Yong Hua (Shanghai Institute of Cell Biology, Academia Sinica,Shanghai 200031 ,China)
Basic fibroblast growth factor (bFGF) is a strong mitogenic factor and inducer of angiogene-sis. It may play an important role in the growth of solid tumors. Whereas bFGF is known to act ex-tracellularly, the protein lacks a transient signal peptide. No defined mechanism for bFGF secretion has been characterized besides release from dead or injured cells. To explore molecular mechanism that modulates bFGF release, we treated CNE-2 cells with PMA for two days and found that the treatment increased bFGF gene expression in the cytoplasm and bFGF release significantly after 48 hours. This result suggests that protein kinase C is very likely to be involved in the bFGF release regulation. Our results have also shown that PKC-α activated by PMA in CNE-2 cells can phosphorylate bFGF(18KDa)in CNE-2 cells. The result suggests that PKC-α translo-cation and activation can phosphorylate bFGF in CNE-2 cells and increase bFGF release.