Description
Drug resistance invariably limits the clinical efficacy of targeted therapy with kinase inhibitors against cancer. We found that targeted therapy with BRAF, ALK, or EGFR inhibitors induces a complex network of secreted signals in drug-stressed melanoma and lung adenocarcinoma cells. This therapy-induced secretome (TIS) stimulates the outgrowth, infiltration and metastasis of drug-resistant cancer clones in the tumour. Additionally, the TIS supports the survival of drug-sensitive cells, contributing to incomplete tumour regression. We used transcriptomic analysis of sensitive tumour cells and xenograft tumours treated with vehicle, vemurafenib, or crizotinib to identify the transcriptional drivers and to dissect the TIS in melanoma (A375, Colo800, UACC62) and lung adenocarcinoma (H3122). In addition, we utilize cell type–specific mRNA purification by translating ribosome affinity purification (TRAP) to identify pathways that are up-regulated in resistant cells (A375R) in response to the regressing tumour microenvironment. Overall design: Analysis of the response of drug sensitive melanoma and lung adenocarcinoma cells to pharmacological inhibition of their driver oncogene and gene expression analysis of drug resistant cancer cells responding to different tumor microenvironments.