In vivo, P85 (200 mg/kg/day) and (-)-gossypol (15 mg/kg/day) could be safely injected intravenously over 5 days and enhanced radiation-related tumor control in an A549 xenograft model.
The short isoform p42 Ebp1, which is actual binding partner of ErbB3 has been implicated as a tumor suppressor with many binding partners such as Rb, HDAC2, Sin3A and the p85 subunit of PI3K with HSP70/CHIP, inhibiting its own antiproliferative activity or inhibiting PI3K activity.
At low nM concentrations, EHT 6706 exhibits highly potent antiproliferative activity on more than 60 human tumor cell lines, even those described as being drug resistant.
Mutating sst2-Y71 disabled sst2 to interact with p85 and somatostatin to inhibit PI3K, consequently abrogating sst2's ability to suppress cell survival and tumor growth.