RESUMO
The extracellular adenosine triphosphate (ATP) concentration is highly elevated in the tumor microenvironment (TME) and remains tightly regulated in normal tissues. Using phage display technology, we establish a method to identify an antibody that can bind to an antigen only in the presence of ATP. Crystallography analysis reveals that ATP bound in between the antibody-antigen interface serves as a switch for antigen binding. In a transgenic mouse model overexpressing the antigen systemically, the ATP switch antibody binds to the antigen in tumors with minimal binding in normal tissues and plasma and inhibits tumor growth. Thus, we demonstrate that elevated extracellular ATP concentration can be exploited to specifically target the TME, giving therapeutic antibodies the ability to overcome on-target off-tumor toxicity.
Assuntos
Trifosfato de Adenosina/metabolismo , Anticorpos/metabolismo , Espaço Extracelular/metabolismo , Animais , Humanos , Camundongos , Microambiente TumoralRESUMO
Osimertinib is the only EGFR-tyrosine kinase inhibitor (TKI) capable of overcoming EGFR-T790M-mutated NSCLC, but osimertinib-resistant EGFR triple mutations (Del19/T790M/C797S or L858R/T790M/C797S) have been reported. Although allosteric EGFR TKIs (e.g., EAI-045) that potentially overcome L858R/T790M/C797S have been identified, there are no effective inhibitors against Del19/T790M/C797S. In this study, we identified CH7233163 as having the potential to overcome EGFR-Del19/T790M/C797S. CH7233163 showed potent antitumor activities against tumor with EGFR-Del19/T790M/C797S in vitro and in vivo In addition to EGFR-Del19/T790M/C797S, the characterization assays showed that CH7233163 more selectively inhibits various types of EGFR mutants (e.g., L858R/T790M/C797S, L858R/T790M, Del19/T790M, Del19, and L858R) over wild type. Furthermore, crystal structure analysis suggested that CH7233163 is a noncovalent ATP-competitive inhibitor for EGFR-Del19/T790M/C797S that utilizes multiple interactions with the EGFR's αC-helix-in conformation to achieve potent inhibitory activity and mutant selectivity. Therefore, we conclude that CH7233163 is a potentially effective therapy for osimertinib-resistant patients, especially in cases of EGFR-Del19/T790M/C797S.
Assuntos
Acrilamidas/farmacologia , Compostos de Anilina/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Mutação , Inibidores de Proteínas Quinases/farmacologia , Alelos , Substituição de Aminoácidos , Animais , Ligação Competitiva , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Receptores ErbB/metabolismo , Perfilação da Expressão Gênica , Humanos , Camundongos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Inibidores de Proteínas Quinases/química , Deleção de Sequência , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Human N-acetyltransferase 10 (NAT10) is known to be a lysine acetyltransferase that targets microtubules and histones and plays an important role in cell division. NAT10 is highly expressed in malignant tumors, and is also a promising target for therapies against laminopathies and premature aging. Here we report that NAT10 is an ATP-dependent RNA acetyltransferase responsible for formation of N(4)-acetylcytidine (ac(4)C) at position 1842 in the terminal helix of mammalian 18 S rRNA. RNAi-mediated knockdown of NAT10 resulted in growth retardation of human cells, and this was accompanied by high-level accumulation of the 30 S precursor of 18 S rRNA, suggesting that ac(4)C1842 formation catalyzed by NAT10 is involved in rRNA processing and ribosome biogenesis.