In vitro activity: SH5-07 is a hydroxamic acid analog of BP-1-102. SH5-07 dose-dependently inhibits Stat3 activity with an IC50 of 3.9±0.6 μM in in vitro assay. It preferentially inhibits Stat3:Stat3 DNA-binding activity, ahead of inhibiting Stat1:Stat3 activity, with minimal effects on Stat1:Stat1 activity. SH5-07 binds Stat3, disrupts Stat3 association with growth factor receptor, and thereby inhibits Stat3 phosphorylation. It induces antitumor cell effects against malignant cells harboring constitutively-active Stat3. SH5-07 inhibits the expression of known Stat3-regulated genes. Bcl-2, Bcl-xL, c-Myc, Survivin, Cyclin D1 and Mcl-1 expression is reduced in response to 24 h, 5 μM SH5-07 treatment.

Kinase Assay: SH5-07 is a hydroxamic acid based Stat3 inhibitor with an IC50 of 3.9±0.6 μM in in vitro assay.

Cell Assay: Cells are treated with 0-8 μM agent for 24-48 h. For cell cycle profile analysis, cells are harvested and fixed with 70% ice-cold ethanol and stained with propidium iodide (PI). For apoptosis analysis, cells are collected and stained with FITC-Annexin V using Apoptosis Detection Kit. Both the DNA content of cells and the Annexin V-positive cells are analyzed by FACScan flow cytometer. Cell cycle phase distribution is analyzed using the Cell-Fit program. Data acquisition is gated to exclude cell doublets