CHEMBL5733239

HER2 Exon 20 YVMA Insertion Mutation: A compound's ability in selectively inhibiting Her2 exon 20 YVMA insertion mutations can be assessed using Ba/F3 cells, a murine pro-B cell line, which have been transduced with Her2 Exon20 YVMA insertions. An expression vector, pLVX-IRES puro (Clontech) coding for human EGFR exon 20 insertions YVMA (A775_G776ins YVMA), was transfected into HEK293 cells by the Trans-Lentiviral ORF Packaging System (Thermo Scientific), to produce virus encoding EGFR exon 20 insertions. Ba/F3 (DSMZ) cells maintained in RPMI 1640 medium supplemented with 10% fetal bovine serum, 200 μM L-glutamine/200 μg/mL penicillin/200 μg/mL streptomycin (Life Technology) and 10 ng/mL IL-3 (R&D system), were infected by EGFR Exon20 virus and subsequently selected by puromycin (Life Technology) selection and IL-3 depletion. Ba/F3 cells expressing Her2 Exon20 YVMA insertions (named Ba/F3-Her2 Exon20 YVMA) can proliferate in the absence of IL-3. The anti-proliferative activity of compounds was determined as follows: BaF3-Her2 Exon20 YVMA cells seeded in 96 well plates (2500 cells/well) were treated with test compound (dissolved in DMSO) at a series of concentrations (4-fold dilution, top concentration: 10,000 nM). The plates were incubated for 72 h in a 37° C. incubator with 5% CO2, and the number of viable cells in each well were measured indirectly by CellTiter 96® Aqueous One Solution Cell Proliferation Assay (Promega; this assay is a colorimetric method for determining the number of viable cells through measurement of their metabolic activity by detection of enzymatic conversion of tetrazolium salts into blue formazan derivatives). Reagent (20 μL) was added into each well, and the plates were returned to the incubator for 2 h. The absorbance in each well was then measured at 490 nm using an Envision plate reader (Perkin Elmer). IC50 values were calculated by determining the concentration of compound required to decrease the MTS signal by 50% comparing to the DMSO control in best-fit curves using Microsoft XLfit software or Accelrys Pipeline Pilot.