Figure 2

Characteristics of SBC5 R1 and SBC5 R10 cells. (A) MTS assays with everolimus in SBC5, SBC5 R1 and SBC5 R10 cells. Data are expressed as the mean ± SD from 3 independent experiments. (B) Differentially expressed genes between SBC5 parent and SBC5 resistant cells by Gene-chip analysis (Fold change >10, <-10). (C) RTK phosphorylation associated with everolimus resistance in SBC5 cells. Ten differentially expressed RTKs between SBC5 parent and SBC5 R1 cells by RTK array (Fold change >1.5, <0.8). Only p-EGFR was overexpressed in both SBC5 R1 and SBC5 R10 cells (1.82-fold and 1.55-fold, respectively). (D) Protein expressions of three candidate molecules in SCLC cells by Western blot analysis. p-EGFR, EGFR, MYC and SPP1 were elevated in the two everolimus-resistant SBC5 cells. (E) FISH analysis for MYC. Red signal indicates 8q24. Green signal indicates D8Z2 probe (8cen). No evidence of MYC overexpression was found.