Figure 3.
OPB-31121 inhibited STAT3 phosphorylation and growth of subcutaneous tumors of cell lines in mice. (a) Dose-dependent tumor growth suppression in mice. HEL cells (4 × 107 cells/body) were subcutaneously inoculated into SCID mice. Oral administration of OPB-31121 or 5% gum arabic for control was started 14 days after inoculation when tumors had developed detectably. The average tumor volume of five mice was plotted with standard deviation. (b) STAT3 inhibition by OPB-31121 in mouse tumor. HEL cells were inoculated into SCID mice as in (a). After tumor development, 300 mg/kg OPB-31121 or 5% gum arabic was administered daily for 3 days. On the 4th day, tumors were resected and subjected to immunohistochemistry with anti-phospho-STAT3 antibody. (c) Summary of OPB-31121 effect on cell line tumors in mice.