Changes in mRNA expression between resistant and sensitive cell lines. Changes are expressed in mean percentage±s.e.m between BON-1/R and BON-1 and QGP-1/R (A) and QGP-1 (B). In addition to MTOR, mTORC1 component RAPTOR and mTORC2 component RICTOR expression was studied. Moreover, gene expression of AKT, encoding the mTOR upstream AKT, S6K1 and 4EBP1, encoding the mTOR downstream p70 ribosomal kinase 1 (S6K1) and eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1), respectively, was determined. In addition, BCL2, a gene encoding for anti-apoptotic protein B-cell leukaemia 2 (Bcl-2), and HIF1A, encoding the hypoxia-inducible factor 1-alpha protein (HIF-1 alpha) was used to study the overall effect on apoptosis and proliferation in the cell. Finally, expression of ERK1 and ERK2, two components of the MAPK-ERK pathway was determined. Differences were tested using Student's t-test. P<0.05, after Bonferroni correction for multiple testing, was considered significant (hatched bars).