RESUMO
The MEK1 and MEK2 inhibitor GSK1120212 is currently in phase II/III clinical development. To identify predictive biomarkers, sensitivity to GSK1120212 was profiled for 218 solid tumor cell lines and 81 hematologic malignancy cell lines. For solid tumors, RAF/RAS mutation was a strong predictor of sensitivity. Among RAF/RAS mutant lines, co-occurring PIK3CA/PTEN mutations conferred a cytostatic response instead of a cytotoxic response for colon cancer cells that have the biggest representation of the comutations. Among KRAS mutant cell lines, transcriptomics analysis showed that cell lines with an expression pattern suggestive of epithelial-to-mesenchymal transition were less sensitive to GSK1120212. In addition, a proportion of cell lines from certain tissue types not known to carry frequent RAF/RAS mutations also seemed to be sensitive to GSK1120212. Among these were breast cancer cell lines, with triple negative breast cancer cell lines being more sensitive than cell lines from other breast cancer subtypes. We identified a single gene DUSP6, whose expression was associated with sensitivity to GSK1120212 and lack of expression associated with resistance irrelevant of RAF/RAS status. Among hematologic cell lines, acute myeloid leukemia and chronic myeloid leukemia cell lines were particularly sensitive. Overall, this comprehensive predictive biomarker analysis identified additional efficacy biomarkers for GSK1120212 in RAF/RAS mutant solid tumors and expanded the indication for GSK1120212 to patients who could benefit from this therapy despite the RAF/RAS wild-type status of their tumors.
Assuntos
Biomarcadores Tumorais/genética , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 2/antagonistas & inibidores , Piridonas/farmacologia , Pirimidinonas/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Biomarcadores Tumorais/metabolismo , Western Blotting , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Fosfatase 6 de Especificidade Dupla/genética , Fosfatase 6 de Especificidade Dupla/metabolismo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HeLa , Humanos , MAP Quinase Quinase 1/genética , MAP Quinase Quinase 1/metabolismo , MAP Quinase Quinase 2/genética , MAP Quinase Quinase 2/metabolismo , Estrutura Molecular , Mutação , Análise de Sequência com Séries de Oligonucleotídeos , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Prognóstico , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Piridonas/química , Pirimidinonas/química , Transcriptoma , Quinases raf/genética , Quinases raf/metabolismo , Proteínas ras/genética , Proteínas ras/metabolismoRESUMO
Increasing evidence suggests that changes in the cellular microenvironment contribute to tumorigenesis, but the molecular basis of these alterations is not well understood. Although epigenetic modifications of the neoplastic cells in tumors have been firmly implicated in tumorigenesis, it is not known whether epigenetic modifications occur in the non-neoplastic stromal cells. To address this question in an unbiased and genome-wide manner, we developed a new method, methylation-specific digital karyotyping, and applied it to epithelial and myoepithelial cells, stromal fibroblasts from normal breast tissue, and in situ and invasive breast carcinomas. Our analyses showed that distinct epigenetic alterations occur in all three cell types during breast tumorigenesis in a tumor stage- and cell type-specific manner, suggesting that epigenetic changes have a role in the maintenance of the abnormal cellular microenvironment in breast cancer.
