Example 20
240 cell lines representative of multiple cancer indications with known alterations in the MAPK pathway, including KRAS, NRAS, HRAS, NF1, EGFR, BRAF and CRAF mutations, were seeded overnight in 386-well plates, then treated with a 9-point dose response of exemplary MEK inhibitors (starting dose of 100 nM and 3-fold dilution) for 5 days. Cell viability was determined using a Cell Titer Glo (CTG) assay. Percent inhibition was calculated for all compounds utilizing staurosporine (1000 nM) treatment as a measure of maximal inhibition. IC50 and area under the curve (AUC) values were determined by fitting a variable slope, four parameters curve to the compound concentration to percent inhibition relationship.
Compared to RAS/RAF wild-type cell lines, increased sensitivity to MEK inhibitors, such as I-2, was observed in cell lines with KRAS, NRAS, BRAF Class I and III mutations, as well as CRAF-alterations (both CRAF mutations and fusions). Cell lines with mutations in PIK3CA, PTEN, NF1, EGFR and HRAS showed similar sensitivity to MEK inhibition to RAS/RAF wild-type cell lines.
