Reversible G1 arrest of a human lung epithelial cell line by staurosporine

✍ Scribed by Yuan Lin; Francis J. Chrest; Edward W. Gabrielson

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 873 KB
• Volume: 152
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041520325

✦ Synopsis

Staurosporine, a rnicrobial-derived protein kinase inhibitor, reversibly blocked non-synchronized, replicatingcultures of the human lung epithelial cell line EKVX in the G1 phase of cell cycle and inhibited DNA synthesis and cell replication. The mechanism of this cell-cycle arrest in EKVX cells by staurosporine was likely due to inhibition of protein kinase C (PKC) because: 1 ) dose-dependent inhibition of DNA synthesis occurred at levels of staurosporinc that inhibit phosphorylation of PKC subslrate, 2) inhibition of DNA synthesis was also seen after treatment with another PKC inhibitor H7, hut not by the chemically similar HA1 004, which has a relative inhibitory specificity for CAMP-dependent protein kinasc, and 3) the DNA synthesis was not inhibited by specific tyrosine kinase inhibitors Cenistein and Lavendustin A at concentrations that inhibit tyrosine kinase activity. Removal of staurosporinc from cell culture medid resulted in a rebound in PKC activity and synchronized DNA synthesis in FKVX cultures. The reversibility of the inhibition was noted even after 5 days of treatment with staurosporine, and DNA synthesis remained synchronized for at least two rounds of cell replication after removal of staurosporine. Flow cytometric analysis confirmed that more than 90% of the cell population was blocked in the G, phase after cells were treated with staurosporine for 24 h. Agents such as staurosporine may be useful for synchronizing cell populations to study cell-cycle specific biochemical events important for the regulation of cell rcplication in the EKVX cell line. Q 1992 WiIey-Liss. Inc.