7-oxo Staurosporine is an antibiotic originally isolated from S. platensis with diverse biological activites. It inhibits PKC, PKA, phosphorylase kinase, EGFR, and c-Src in vitro (IC50s = 9, 26, 5, 200, and 800 nM, respectively). 7-oxo Staurosporine induces cell cycle arrest in the G2/M phase in human leukemia K562 cells with a minimal effective dose (MED) of 30 ng/ml. It is cytotoxic to P388 mouse leukemia cells that are resistant and susceptible to doxorubicin . 7-oxo Staurosporine inhibits growth of the mycelial, but not yeast form of C. albicans, C. krusei, C. tropicalis, and C. lusitaniae (MICs = 3.1-25 μg/ml). It increases sphingomyelin synthesis in CHO-K1 cells when used at a concentration of 50 nM.
K-252a is a staurosporine analog isolated from Nocardiopsis sp. soil fungi. K-252a inhibits protein kinase (IC50: 470 nM, 140 nM, 270 nM, and 1.7 nM for PKC, PKA, Ca2+ calmodulin-dependent kinase type II, and phosphorylase kinase, respectively).
K-252c is a staurosporine analog isolated from Nocardiopsis sp. and is a cell-permeable PKC inhibitor (IC50: 2.45 μM). K-252c also inhibits β-lactamase, chymotrypsin, and malate dehydrogenase. K-252c causes apoptosis in human chronic myelogenous leukemia cancer cells.
Co-treatment with Tanshinone IIB (TSB) significantly inhibits the DNA laddering, cytotoxicity and apoptosis of rat cortical neurons induced by staurosporine in a concentration-dependent manner; TSB also suppresses the elevated Bax protein and decreased bc