Table 2. Inhibition of constitutive pSTAT3/1 and anchorage independent growth of HNSCC cell lines by C188-9.
| HNSCC Cell line | Constitutive pSTAT3 | Constitutive pSTAT1 | IC50 pSTAT3 | IC50 pSTAT1 | IC50 Cell growth (MTT) |
|---|---|---|---|---|---|
| SCC-35 | ++ | - | 22.8 ± 6.3 | NA | 10.8 ± 0.0 |
| SCC-61 | ++ | + | 21.5 ± 7.1 | 28.5 ± 0.9 | 14.8 ± 2,9 |
| UM-SCC-17B | ++ | ++ | 10.6 ± 0.7 | 19.1 ± 15.5 | 0.7 ± 0.6 |
| HN30 | +/− | +++ | 21.5 ± 8.3 | 5.0 ± 6.0 | 4.4 ± 0.1 |
Relative levels of pSTAT3 and pSTAT1 were indicated with negative and positive signs based on Luminex data shown in Supplementary Figure S1 based on their relative levels and whether these levels were above or below the levels in non-tumor line HEEpiC. Lysates from asynchronous cultures of SCC-35, SCC-61 and HN30 cells treated with DMSO or increasing doses (0/0.1/0.3/1/3/10/100 μM) of C188-9 for 36 hrs, assayed for pSTAT3/pSTAT1 and GAPDH by Luminex. GAPDH-normalized pSTAT3 or pSTAT1 values were divided by that for untreated cells and expressed in percentage. These values were plotted as a function of Log [M] compound, and IC50 values calculated using GraphPad. IC50s for inhibition of anchorage independent growth (Cell growth) was measured as described in methods and Legends of Figure 4C.