RESUMO
Estrogen receptor alpha gene (ESR1) mutations occur frequently in ER-positive metastatic breast cancer, and confer clinical resistance to aromatase inhibitors. Expression of the ESR1 Y537S mutation induced an epithelial-mesenchymal transition (EMT) with cells exhibiting enhanced migration and invasion potential in vitro. When small subpopulations of Y537S ESR1 mutant cells were injected along with WT parental cells, tumor growth was enhanced with mutant cells becoming the predominant population in distant metastases. Y537S mutant primary xenograft tumors were resistant to the antiestrogen tamoxifen (Tam) as well as to estradiol (E2) withdrawal. Y537S ESR1 mutant primary tumors metastasized efficiently in the absence of E2; however, Tam treatment significantly inhibited metastasis to distant sites. We identified a nine-gene expression signature, which predicted clinical outcomes of ER-positive breast cancer patients, as well as breast cancer metastasis to the lung. Androgen receptor (AR) protein levels were increased in mutant models, and the AR agonist dihydrotestosterone significantly inhibited estrogen-regulated gene expression, EMT, and distant metastasis in vivo, suggesting that AR may play a role in distant metastatic progression of ESR1 mutant tumors.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Receptor alfa de Estrogênio/genética , Receptores Androgênicos/genética , Tamoxifeno/farmacologia , Animais , Inibidores da Aromatase/farmacologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Di-Hidrotestosterona/farmacologia , Estradiol/metabolismo , Estrogênios/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Mutação/genética , Metástase Neoplásica , Receptores Androgênicos/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Tak-242 (resatorvid), a Toll-like Receptor 4 (TLR4) inhibitor, has been identified as a potent suppressor of innate inflammation. As a strategy to target Tak-242 to select tissue, four TLR4-inactive prodrugs were synthesized for activation via two different release mechanisms. Two nitrobenzyl Tak-242 prodrugs released the parent drug upon exposure to the exogenous enzyme nitroreductase, while the two propargyl prodrugs were converted to Tak-242 in the presence of Pd0.