| Proteolysis-targeting chimeras(PROTACs)is a bifunctional chimera molecule which is composed of three parts: target protein ligand,E3 ligase ligand,and chemical linker.The chemical linker tethers the two functional ligands.The PROTACs can recruit both of the target protein and the E3 ligase at same time,and form a ternary complex.The target proteins are labeled with ubiquitination,and enter into the proteasome pathway to degrade the polyubiquitinated complex.As a bifunctional molecule,PROTACs works through the ubiquitin-proteasome pathway to degrade specific target proteins and regulate protein levels.It has shown great performance in improving drug resistance,affecting the activity of the non-enzymatic part in the protein,and developing non-druggable protein targets.So,it has very broad development prospectsand in the field of new drug discovery.In this paper,AR(Androgen Receptor)and NQO1(NAD(P)H quinone dehydrogenase 1)were used as the target proteins.We designed and synthesized PROTACs bifunctional small molecules which could potencially degrade the target protein.The biological activities of these small molecules were further explored,which provided an alternatry strategy for anti-cancer drugs development.1)Design,synthesis and biological activity evaluation of PROTACs targeting AR proteinAs a common malignant tumor in the urinary system,prostate cancer is a serious threat to human health.The mutation of AR protein plays a vital role in prostate cancer and castration-resistant prostate cancer(CRPC).The use of small molecule AR protein inhibitors often makes tumor tissues gradually resistant to drugs.The application of PROTACs technology to degrade AR protein has improved drug resistance and off-target toxicity to a certain extent.In this paper,two AR antagonists,four E3 ligase ligands and the different composition of the chemical linkers were used to design and synthesize the compound A001-A032.By testing their proliferation inhibition rate in VCa P cells,the compound A031 was screened out as the best one.In western blotting experiments,it was found that A031 induced AR protein degradation in a time-dependent manner,and the process of degradation relied on the ubiquitin-proteasome pathway.In wild-type AB zebrafish,A031 could inhibit the proliferation of VCa P xenograft tumors in vivo.On the basis of the similar efficacy to Enzalutamide(EZLA),the metabolic toxicity in vivo was 1/5 times than that of EZLA.In male SD rats,the peak concentration of A031 was 14366.2 ng/m L.And it had an appropriate half-life and clearance rate with the good blood concentration,which provided more basis of the PROTACs molecule as a targeted drug for the treatment of prostate cancer.2)Design,synthesis and biological activity evaluation of PROTACs targeting NQO1 proteinNQO1 is a kind of quinone oxidoreductase that has a “Janus” effect in cancer biology.It provides multiple layers of protection for normal cells against cancer.But it overexpressed in cancer cells,and promoted the process of proliferation,metastasis and drug resistance in tumor.Degrading NQO1 protein through PROTACs technology could inhibit the activity of NQO1,and prevented the growth and transformation of tumors.In this paper,NQO1 ligands,CRBN ligands and fatty amines with different carbon numbers were used to design and synthesize the compounds N001-N005.By testing their proliferation inhibition rate on He La cells and 7721 cells,the compound N005 with better activity was screened out.The He La cell lines were used to the further biological activity test.In the Annexin V-FITC/PI double staining experiment,N005 induced apoptosis in a concentration-dependent manner.In the experiment to verify the mechanism of action of N005,DIC(NQO1 inhibitor)was added,and cell viability was not affected.In Western blotting experiments,the NQO1 protein level was almost unchanged.Therefore,N005 didn’t have the NQO1-dependent cytotoxicity. |
