PIT-1 is a selective PIP3 antagonist that inhibits cancer cell survival and induces apoptosis by inhibiting PIP3-dependent PI3K/Akt signalling and the PH structural domain of Akt.

In breast cancer cell lines such as MCF-7, PIT-1 (10–100 μM, 24–48 h) induces apoptosis, reduces cell viability, and significantly downregulates the expression of Pit-1 target genes, including GH, PRL, and GHRHR. Additionally, PIT-1 upregulates pro-apoptotic genes such as Bax and activates caspase-3, suggesting PIT-1 induces apoptosis through a mitochondrial pathway[1].

In a breast cancer xenograft model using nude mice, PIT-1 (intraperitoneal injection) significantly inhibited tumor growth, reducing tumor volume by approximately 60% compared to the control group, with no apparent toxicity[1].