ζ-Stat trisodium (NSC37044 trisodium) is a potent and selective inhibitor of protein kinase C-ζ (PKC-ζ), exhibiting an IC50 of 5 μM. It effectively suppresses the proliferation of melanoma cell lines and promotes apoptosis. Moreover, ζ-Stat trisodium demonstrates notable antitumor activity in vitro.

APKCζ:5 μM (IC50)

ζ-Stat, administered at concentrations ranging from 0.1 to 20 μM, exhibits minimal inhibition (13%) of PKC-ι at the highest concentration (20 μM), but significantly inhibits PKC-ζ (51%) at a lower concentration of 5 μM. In studies conducted over three days, ζ-Stat demonstrates a dose-dependent reduction in cell proliferation in SK-MEL-2 and MeWo cell lines at concentrations between 0.1 and 10 μM. When combined with 5-FU, ζ-Stat, at concentrations of 7 or 10 μM over periods of 24 to 72 hours, significantly reduces the viability of LoVo CRC cells by more than 75%. Additionally, ζ-Stat at a concentration of 5 μM over three days markedly decreases levels of phosphorylated and total PKC-ζ, Bcl-2, and PARP, while increasing Caspase-3 and cleaved-PARP levels in SK-MEL-2 and MeWo cells. However, ζ-Stat shows no significant cytotoxicity at 5 μM over a duration of 1 to 10 hours in MEL-F-NEO, SK-MEL-2, and MeWo cells. Proliferation assays reveal a 47.7% reduction in SK-MEL-2 cells and a 50.6% decrease in MeWo cells at a concentration of 5 μM after three days, with a notable 19.3% inhibition in MEL-F-NEO cells at 10 μM. Western Blot analysis confirms the reduction in phosphorylated and total PKC-ζ levels in SK-MEL-2 and MeWo cells at a concentration of 5 μM.