ABSTRACT
Epidermal growth factor receptor (EGFR) is an important therapeutic target for the treatment of non-small cell lung cancer. A number of efficacious EGFR tyrosine kinase inhibitors have been developed. However, acquired drug resistance largely encumbered their clinical practicability. Therefore, there is an urgent need to develop new therapeutic regime. Herein, we designed and synthesized a set of EGFR-targeting small molecule PROTACs which showed promising efficacy. In particular, VHL-recruiting compound P3 showed potent anti-proliferative activity against HCC827 and H1975 cell lines with IC50 values of 0.83 and 203.01 nM, respectively. Furthermore, both EGFRdel19 and EGFRL858R/T790M could be significantly induced to be degraded under treatment of P3 with DC50 values of 0.51 and 126.2 nM, respectively. Compound P3 was able to dramatically suppress EGFR pathway signal transduction. Moreover, compound P3 could significantly induce cell apoptosis, arrest cell cycle and suppress cell colony formation. In addition, we identified that ubiquitination was indispensable in the degradation process, and found that the degradation was related to autophagy. Our work would provide an alternative approach for development of potentially effective EGFR degraders and give a new clue for investigation of PROTAC-induced protein degradation.
Subject(s)
Antineoplastic Agents/pharmacology , Protein Kinase Inhibitors/pharmacology , Proteolysis/drug effects , Purines/pharmacology , Adaptor Proteins, Signal Transducing/metabolism , Antineoplastic Agents/chemical synthesis , Apoptosis/drug effects , Autophagy/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Design , Drug Screening Assays, Antitumor , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/metabolism , G1 Phase Cell Cycle Checkpoints/drug effects , Humans , Lenalidomide/analogs & derivatives , Lenalidomide/pharmacology , Protein Kinase Inhibitors/chemical synthesis , Purines/chemical synthesis , Ubiquitin-Protein Ligases/metabolism , Ubiquitination/drug effects , Von Hippel-Lindau Tumor Suppressor Protein/metabolismABSTRACT
Reversibly altering endogenous protein levels are persistent issues. Herein, we designed photoswitchable azobenzene-proteolysis targeting chimeras (Azo-PROTACs) by including azobenzene moieties between ligands for the E3 ligase and the protein of interest. Azo-PROTACs are light-controlled small-molecule tools for protein knockdown in cells. The light-induced configuration change can switch the active state to induce protein degradation activity, which can be reversely controlled by light exposure in intact cells. We compared the protein degradation abilities of Azo-PROTACs with different configurations and linker lengths. Using the stable form with the best degradation ability against the BCR-ABL fusion and ABL proteins in myelogenous leukemia K562 cells, we showed that Azo-PROTAC combines the potent protein knockdown and facile cell uptake properties of the small-molecule PROTAC with a reversible photoswitchability, offering a promising chemical knockdown strategy based on the light-induced reversible on/off properties.
Subject(s)
Azo Compounds/pharmacology , Dasatinib/analogs & derivatives , Dasatinib/pharmacology , Lenalidomide/analogs & derivatives , Lenalidomide/pharmacology , Adaptor Proteins, Signal Transducing/metabolism , Azo Compounds/chemical synthesis , Azo Compounds/radiation effects , Cell Line, Tumor , Dasatinib/radiation effects , Fusion Proteins, bcr-abl/metabolism , Humans , Lenalidomide/radiation effects , Ligands , Proteolysis/drug effects , Stereoisomerism , Ubiquitin-Protein Ligases , Ubiquitination/drug effects , Ultraviolet RaysABSTRACT
Lenalidomide and its analogs have exhibited extensive anti-tumor, anti-inflammatory and immunomodulatory properties in pharmaceutical research. In this work, a series of novel thioether-containing lenalidomide analogs were designed and synthesized for biological evaluation. Lenalidomide showed significant anti-proliferative activity against the MM.1S cell line (IC50â¯=â¯50â¯nM) while it displayed no anti-proliferative activity against other treated tumor cell lines. Compared with lenalidomide, compound 3j exhibited preferable anti-proliferative activity against the MM.1S (IC50â¯=â¯1.1â¯nM), Mino (IC50â¯=â¯2.3â¯nM) and RPMI 8226â¯cell lines (IC50â¯=â¯5.5â¯nM). In addition, compound 3j displayed selective anti-proliferative activity against several tumor cell lines, including various B-NHL, MM and AML cell lines, and showed no cytotoxicity on the normal human cell line PBMC, suggesting a good safety profile. Following oral administration, compound 3j achieved a Cmax of 283â¯ng/mL at 0.83â¯h, and had a higher relative oral bioavailability value (Fâ¯=â¯39.2%) than that of CC-220 (Fâ¯=â¯22.8%), but its oral exposure in vivo was somewhat low (AUCâ¯=â¯755â¯hâ¯ng/mL). Furthermore, it was found that oral administration of compound 3j at dosages of 60â¯mg/kg could delay RPMI 8226 tumor growth in the female CB-17 SCID mice. The current work confirmed that installing thioether moiety at the 4-position of isoindolinone is an effective strategy for identifying new promising lenalidomide analogs with anti-tumor activities in preclinical study.