In vitro activity: 10058-F4 inhibits growth of leukemic cells and dimerization of Myc and Max. 10058-F4 induces cell-cycle arrest and apoptosis of AML cells. 10058-F4 arrests AML cells at G0/G1 phase, downregulates c-Myc expression and upregulated CDK inhibitors, p21 and p27. Meanwhile, 10058-F4 induces apoptosis through activation of mitochondrial pathway shown by downregulation of Bcl-2, upregulation of Bax, release of cytoplasmic cytochrome C, and cleavage of caspase 3, 7, and 9. Furthermore, 10058-F4 also induces myeloid differentiation, possibly through activation of multiple transcription factors. Similarly, 10058-F4-induced apoptosis and differentiation could also be observed in primary AML cells. 10058-F4 decreases c-Myc protein levels, inhibites proliferation of HepG2 cells likely through upregulation of cyclin-dependent kinase (cdk) inhibitor, p21WAF1 and lowers intracellular levels of [alpha]-fetoprotein (AFP). Treatment with 10058-F4 also downregulates human telomerase reverse transcriptase (hTERT) at the transcriptional level. In addition to inhibiting the proliferation of HepG2 cells, 10058-F4 enhances sensitivity to conventional chemotherapeutic agents, doxorubicin, 5-fluorouracil (5-FU) and cisplatin.

Kinase Assay: 10058-F4 is a c-Myc inhibitor that prevents c-Myc-Max dimerization and transactivation of c-Myc target gene expression.

Cell Assay: Cells, plated in 96-well plates (105/mL for cell lines and 5 × 105/mL for primary leukemic cells), are treated in triplicate with indicated concentrations of 10058-F4. At various time points, 20 μL 5 mg/mL MTT is added to each well. After incubation at 37°C for 3 hours, the MTT medium is removed and 100 μL DMSO lysis buffer is added. The number of viable cells is assessed by the percentage of absorbance of treated cells relative to that of solvent controls, using 570-nm wavelength on a spectrophotometer.