ABSTRACT
As a recently discovered DNA repair enzyme, tyrosyl-DNA phosphodiesterase 1 (TDP1) removes topoisomerase IB (TOP1)-mediated DNA protein cross-links. Inhibiting TDP1 can potentiate the cytotoxicity of TOP1 inhibitors and overcome cancer cell resistance to TOP1 inhibitors. On the basis of our previous study, herein we report the synthesis of benzophenanthridinone derivatives as TOP1 and TDP1 inhibitors. Seven compounds (C2, C4, C5, C7, C8, C12, and C14) showed a robust TOP1 inhibitory activity (+++ or ++++), and four compounds (A13, C12, C13, and C26) showed a TDP1 inhibition (half-maximal inhibitory concentration values of 15 or 19 µM). We also show that the dual TOP1 and TDP1 inhibitor C12 induces both cellular TOP1cc, TDP1cc formation and DNA damage, resulting in cancer cell apoptosis at a sub-micromolar concentration. In addition, C12 showed an enhanced activity in drug-resistant MCF-7/TDP1 cancer cells and was synergistic with topotecan in both MCF-7 and MCF-7/TDP1 cells.
Subject(s)
Benzophenanthridines/chemistry , DNA Topoisomerases, Type I/metabolism , Phosphodiesterase Inhibitors/chemical synthesis , Phosphoric Diester Hydrolases/metabolism , Topoisomerase I Inhibitors/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Apoptosis/drug effects , Benzophenanthridines/metabolism , Benzophenanthridines/pharmacology , Benzophenanthridines/therapeutic use , Binding Sites , Cell Line, Tumor , Cell Survival/drug effects , DNA Damage/drug effects , DNA Topoisomerases, Type I/chemistry , Drug Resistance, Neoplasm/drug effects , Drug Screening Assays, Antitumor , Humans , Molecular Dynamics Simulation , Neoplasms/drug therapy , Phosphodiesterase Inhibitors/metabolism , Phosphodiesterase Inhibitors/pharmacology , Phosphodiesterase Inhibitors/therapeutic use , Phosphoric Diester Hydrolases/chemistry , Structure-Activity Relationship , Topoisomerase I Inhibitors/metabolism , Topoisomerase I Inhibitors/pharmacology , Topoisomerase I Inhibitors/therapeutic useABSTRACT
DNA topoisomerase IB (TOP1) regulates DNA topological structure in many cellular metabolic processes and is a validated target for development of antitumor agents. Our previous study revealed that the benzophenanthridone scaffold is a novel chemotype for the discovery of TOP1 inhibitors. In this work, a series of novel 5-aminoethyl substituted benzophenanthridone derivatives have been synthesized and evaluated for TOP1 inhibition and cytotoxicity. Compound 12 exhibits the most potent TOP1 inhibition (+++) and cytotoxicity in human cancer cell lines with GI50 values at nanomolar concentration range. 12 induces the cellular TOP1cc formation and DNA damage, resulting in HCT116â¯cell apoptosis. The pharmacokinetics, acute toxicity and antitumor efficiency in vivo of 12 were also studied.
Subject(s)
Antineoplastic Agents/pharmacokinetics , Benzophenanthridines/pharmacokinetics , Topoisomerase I Inhibitors/pharmacokinetics , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/metabolism , Antineoplastic Agents/therapeutic use , Apoptosis/drug effects , Benzophenanthridines/chemical synthesis , Benzophenanthridines/metabolism , Benzophenanthridines/therapeutic use , Breast Neoplasms/drug therapy , Cell Line, Tumor , DNA Damage/drug effects , DNA Topoisomerases, Type I/chemistry , DNA Topoisomerases, Type I/metabolism , Drug Screening Assays, Antitumor , Humans , Mice, Nude , Molecular Docking Simulation , Molecular Structure , Protein Binding , Structure-Activity Relationship , Topoisomerase I Inhibitors/chemical synthesis , Topoisomerase I Inhibitors/metabolism , Topoisomerase I Inhibitors/therapeutic use , Xenograft Model Antitumor AssaysABSTRACT
Tyrosyl-DNA phosphodiesterase 1 (TDP1) is a recently discovered enzyme repairing DNA lesions resulting from stalled topoisomerase IB (TOP1)-DNA covalent complex. Inhibiting TDP1 in conjunction with TOP1 inhibitors can boost the action of the latter. Herein, we report the discovery of the natural product oxynitidine scaffold as a novel chemotype for the development of TOP1 and TDP1 inhibitors. Three kinds of analogues, benzophenanthridinone, dihydrobenzophenanthridine, and benzophenanthridine derivatives, were synthesized and evaluated for both TOP1 and TDP1 inhibition and cytotoxicity. Analogue 19a showed high TOP1 inhibition (+++) and induced the formation of cellular TOP1cc and DNA damage, resulting in cancer cells apoptosis at nanomolar concentration range. In vivo studies indicated that 19a exhibits antitumor efficiency in HCT116 xenograft model. 41a exhibited additional TDP1 inhibition with IC50 value of 7 µM and synergistic effect with camptothecin in MCF-7 cells. This work will facilitate future efforts for the discovery of natural product-based TOP1 and TDP1 inhibitors.
Subject(s)
DNA Topoisomerases, Type I/metabolism , Drug Design , Phenanthridines/chemical synthesis , Phenanthridines/pharmacology , Phosphoric Diester Hydrolases/metabolism , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Chemistry Techniques, Synthetic , DNA Cleavage/drug effects , DNA Topoisomerases, Type I/chemistry , Humans , Models, Molecular , Phenanthridines/chemistry , Phosphodiesterase Inhibitors/chemical synthesis , Phosphodiesterase Inhibitors/chemistry , Phosphodiesterase Inhibitors/pharmacology , Phosphoric Diester Hydrolases/chemistry , Protein Conformation , Structure-Activity Relationship , Topoisomerase I Inhibitors/chemical synthesis , Topoisomerase I Inhibitors/chemistry , Topoisomerase I Inhibitors/pharmacologyABSTRACT
Porcine placenta is commonly used in Chinese as a traditional medicine. It has been reported by a number of researchers that the porcine placenta contains many compounds which have good health benefits. Response surface methodology (RSM) was applied to optimize the parameters of ultrasound power, ultrasound treat time, and extraction temperature on the extraction yield of porcine placenta water-soluble proteins (PPWP). The results indicated that, under optimum conditions of ultrasound power 257 w, extraction temperature at 49 °C for 7 min, the extraction yield of PPWP was 32.7 %, which was significantly higher than that of the conventional extraction method (CEM) of 15.0 %. The experimental data were fitted to a second-order polynomial equation using multiple regression analysis and the estimated model showed a high capacity of predicting the dependent variables. Although not significantly, the antioxidant activity of PPWP from ultrasound-assist-extraction (UAE) were higher than those from CEM, indicated that UAE had a positive effect or at least no negative effect on the bioactivity of PPWP.
