Plicamycin

Plicamycin (Mithramycin A) is a selective specificity protein 1 (Sp1) inhibitor. Plicamycin inhibits the growth of various cancers by decreasing Sp1 protein. Plicamycin inhibits GSTM2 promoter activity and protein expression^[1][2]. IC50 & Target:Sp1 transcription factor^[1] In Vitro:Plicamycin (Mith) decreases Sp1 protein by inducing proteasome-dependent degradation, thereby suppressing cervical cancer growth through a DR5/caspase-8/Bid signaling pathway. Plicamycin inhibits HEp-2 and KB cell growth in a concentration-dependent manner after 48 h. Apoptotic cell death is qualitatively estimated by DAPI staining for nuclear condensation and fragmentation. Plicamycin leads to significant DNA fragmentation compared to untreated controls^[1].
Plicamycin (mithramycin A) (0-400 nM, 24 h) dose-dependently inhibited GSTM2 protein expression in BFTC 905 and 5637 cells; SP1 overexpression increased GSTM2 protein expression in BFTC 905 and 5637 cells^[2]. In Vivo:The antitumorigenic activity of Plicamycin (0.2 mg/kg/day) is determined in a xenograft model and observed reduction in tumor volume and weight. No significant mouse body weight loss is observed in Plicamycin-treatment groups, indicating that Plicamycin-associated toxicity is minimal. Plicamycin also increases TUNEL-positive cells in tumor xenografts. No notable intergroup differences are observed among organs, indicating no marked signs of systemic toxicity at the Plicamycin dose used in this study^[1].