Anti-osteosarcoma Drugs Based On Thiazolone Molecular Inhibitors

Osteosarcoma is a kind of invasive bone cancer.About 60%of patients with malignant bone tumors are younger than 20 years old.At present,the cause of osteosarcoma is not clear,and the treatment is limited.The treatment of osteosarcoma usually uses the combination of drugs after surgery,but it does great harm to the patients with osteosarcoma,and the prognosis is very poor.Clinical data showed that the 5-year survival rate was less than 20%.Due to the numerous subtypes,complex pathogenesis and unknown targets of osteosarcoma,there is no targeted therapy for osteosarcoma on the market.Small molecule targeted therapy provides a means for the treatment of osteosarcoma.At present,there are many non osteosarcoma specific targeted drugs in different clinical trials,but these drugs still have some shortcomings,such as poor specificity.Therefore,in order to break through the bottleneck of clinical treatment of osteosarcoma,it is necessary to find new targeted drugs,explore related therapeutic targets,inhibit the growth and metastasis of osteosarcoma cells,and clarify the pathogenesis of osteosarcoma.Phenotypic screening is an important way to discover new drugs.Due to the unknown target of osteosarcoma cells,it is difficult to find new molecular entities by high-throughput screening based on target.Therefore,the discovery of new molecular entities through phenotypic screening is very important for the effective treatment of osteosarcoma.The condition of phenotypic screening is to have a large number of compound molecular libraries with structural diversity.Therefore,we found the thiazolidinone DYQ-01 through phenotypic screening of the molecular library of structural diversity compounds constructed in the laboratory,and identified it as a seedling compound(MNNG/HOS IC₅₀=321.9 n M).The study of structure-activity relationship mainly focused on improving the metabolic stability of thiazolidines in vivo.By adjusting the relative rigidity and solubility（Clog P and water solubility）,the water-soluble lead compound（R）-DYQ-64 was obtained.It has significant antitumor activity in vitro(MNNG/HOS IC₅₀=21.8 n M),pharmacodynamics in vivo and good pharmacokinetic characteristics.Compound（R）-DYQ-64 also significantly inhibited the migration of osteosarcoma cells in vitro.The preliminary study on the target of compound（R）-DYQ-64 also excluded p53 and myoferlin（myo F）as the target of the system.These results indicate that compound（R）-DYQ-64 may be a potential candidate for the treatment of osteosarcoma.This paper consists of five chapters.The first chapter introduces the following contents:1Osteosarcoma and its current treatment methods;2.Phenotypic screening and its important role in technical drug discovery;3.The important pharmacodynamic role of thiazolone skeleton and its challenges in drug development;4.The research idea and purpose of this paper.Chapter 2:through phenotypic screening,we found a class of thiazolone derivatives,which selectively showed good inhibitory activity on MNNG/HOS(IC₅₀=321.9 n M)cell lines in six osteosarcoma cell lines.Then,we identified compound DYQ-01 as a seedling compound,and obtained compound DYQ-07 by introducing a flexible long chain.The activity of compound DYQ-07 on MNNG/HOS cells was significantly increased(IC₅₀=33.1 n M).However,the stability of liver particles is not optimistic.Chapter 3:the structure of compound DYQ-07 was modified.The structure-activity relationship of compound DYQ-07 was studied by changing the electronic effect,rigidity and solubility of the compound,in order to improve the stability of compound liver particles and indirectly improve its oral utilization.At the same time,we also explored the synthesis method of the compound,and finally obtained the lead compound（R）-DYQ-64,which has good inhibitory effect on the proliferation of MNNG/HOS cell line in vitro(IC₅₀=21.8 n M),and has good optical stability,solubility and moderate stability of liver particles in vitro.Compound（R）-DYQ-64 could significantly inhibit the growth of human osteosarcoma in nude mice,and the TGI（tumor inhibition rate）was 52.9%,which was equivalent to that of sorafenib（TGI was 44.2%）.Interestingly,compound（R）-DYQ-64 had no significant effect on body weight and important organs of mice,indicating that it had little or no toxicity.Scratch test and invasion test showed that compound（R）-DYQ-64 could significantly inhibit the migration and invasion of osteosarcoma cells.Half of the compounds were metabolized to sulfone and sulfoxide at 0.5h.Through cell cycle experiment,it was verified that the lead compound could induce cell cycle arrest in G0/G1 phase.Finally,the target of compound（R）-DYQ-64 was preliminarily excluded,and it was confirmed that compound（R）-DYQ-64 did not target p53 and myo F reported in the literature.The fourth chapter is the summary and Prospect of the work.The fifth chapter is the experimental part.In conclusion,compound（R）-DYQ-64 has moderate liver microsphere stability,good solubility,good tumor growth inhibition and migration activity,and good pharmacokinetic properties.It can be used for further clinical research,indicating that this type of compound has great potential and research value,and provides a new possibility for the treatment of small molecule targeted osteosarcoma.