Cell cycle effects of thaliblastine.

The non-myelotoxic antitumor drug thaliblastine (thalicarpine, NSC-68075, CAS-5373-42-21) has a novel chemical structure; it is a complex dimeric-type aporphine benzylisoquinoline alkaloid possessing antiproliferative and antitumor activities in experimental and clinical studies. In this study the effect of this drug on the cell cycle progression of ovarian tumor line O-342 and its cisplatin-resistant subline O-342/DDP was evaluated. As assessed by flow cytometric analysis, thaliblastine affected the cell cycle progression. In both lines, a comparable pattern of cell cycle arrest was found. Within the first 5 h of thaliblastine exposure, a G2/M block was observed; thereafter cell-cycle arrest in G1 became prominent, while S-phase cells finished DNA replication.