Discovery of new fluorescent thiazole\u2013pyrazoline derivatives as autophagy inducers by inhibiting mTOR activity in A549 human lung cancer cells

Baoxiang Zhao,Zhaoyang Wang,Dongfang Gao,Lu Zhang,Peng Wang,Yuan Chen,Yuxing Lin,Zhaomin Lin,Feng Kong,Junying Miao,Ming Zhang,Xuewen Zhou

doi:10.1038/s41419-020-02746-w

Abstract

A series of fluorescent thiazole–pyrazoline derivatives was synthesized and their structures were characterized by 1H NMR, 13C NMR, and HRMS. Biological evaluation demonstrated that these compounds could effectively inhibit the growth of human non-small cell lung cancer (NSCLC) A549 cells in a dose- and time-dependent manner in vitro and inhibit tumor growth in vivo. The structure–activity relationship (SAR) of the compounds was analyzed. Further mechanism research revealed they could induce autophagy and cell cycle arrest while had no influence on cell necrosis. Compound 5e inhibited the activity of mTOR via FKBP12, which could be reversed by 3BDO, an mTOR activator and autophagy inhibitor. Compound 5e inhibited growth, promoted autophagy of A549 cells in vivo. Moreover, compound 5e showed good selectivity with no influence on normal vascular endothelial cell growth and the normal chick embryo chorioallantoic membrane (CAM) capillary formation. Therefore, our research provides potential lead compounds for the development of new anticancer drugs against human lung cancer.

Highlights

Cancer is still a major global health concern and a leading cause of death all over the world
Thin-layer chromatography (TLC) was performed on silica gel 60 F254 plates (Merck KGaA) and column chromatography was conducted over silica gel. 1H NMR spectra were recorded on a Bruker Avance 400 (400 MHz) spectrometer or Bruker Avance 300 (300 MHz) spectrometer, using DMSO-d6 as solvent and tetramethylsilane as an internal standard
The cell density dramatically decreased and cells were elongated or formed triangle and arborization significantly treated for 48 h (Fig. 1a, an excerpt of Fig. S1)

Summary

Introduction

Cancer is still a major global health concern and a leading cause of death all over the world. Due to the nature of high quantum yield and readily synthetic process, some pyrazoline derivatives have been synthesized and used in fluorescence probes, for orientation[4], detecting cation[5,6,7,8], hydrazine[9,10], thiols[11,12,13], and DNA14 Their biological roles have been studied in insecticidal function[15,16,17], human monoamine oxidase activity inhibition[18,19], anti-inflammation[20,21,22], antimicrobial[23,24], analgesia[25].

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Results

Conclusion