Discovery of Novel Quinazoline Derivatives as Potent Antitumor Agents

Abstract

In this work, we designed and synthesized a novel series of quinazoline derivatives 6-19 and then evaluated their broad-spectrum antitumor activity against MGC-803, MCF-7, PC-9, A549, and H1975, respectively. Most of them demonstrated low micromolar cytotoxicity towards five tested cell lines. In particular, compound 18 exhibited nanomolar level inhibitory activity against MGC-803 cells with an IC₅₀ value of 0.85 μM, indicating approximately a 32-fold selectivity against GES-1 (IC₅₀ = 26.75 μM). Further preclinical evaluation showed that compound 18 remarkably inhibited the migration of MGC-803 cells, induced cell cycle arrest at G2/M, and induced MGC-803 apoptosis, resulting in decreasing the expression of both Bcl-2 and Mcl-1, and up-regulating the expression of both Bax and cleaved PARP. No death or obvious pathological damage was observed in mice by acute toxicity assay. The in vivo antitumor evaluation suggested that compound 18 significantly decreased the average tumor volume and tumor weight without any effect on body weight, which is better than 5-Fu. Therefore, compound 18 can be used as a lead compound for the further development of antitumor drugs in the future.

Keywords: antitumor; apoptosis; cell cycle; migration; quinazoline.

Figure 1

FDA approved quinazoline derivatives for cancer therapy.

Scheme 1

Synthesis of compounds 6–19. Reagents and conditions: (i) EtOH, room temperature, 5 h; (ii) POCl₃, 90 °C, 5 h; (iii) EtOH, room temperature, overnight.

Figure 2

The effect of compound 18 on the migration of MGC-803 cells. (A) The structure of compound 18; (B) The effect of 18 on the cell viability of selected cancer cells with different concentrations for 72 h by MTT method; (C,D) The effect of 18 at 1 µM on the migration of MGC-803 cells in a wound healing assay; (E,F) The effect of 18 on the migration of MGC-803 cells for 48 h in a transwell assay. ** p < 0.01, *** p < 0.001 compared to control group.

Figure 3

The effect of compound 18 on the apoptosis of MGC-803 cells. (A,B) MGC-803 cells were treated with compound 18 at the indicated concentrations for 48 h, which was then analyzed by using Annexin V-FITC/PI double staining through flow cytometry.

Figure 4

The effect of compound 18 on apoptosis-related proteins in MGC-803 cells. (A–E) Expression and quantitative analysis of cleaved-PARP, Mcl-1, Bcl-2, and Bax in MGC-803 cells treated with compound 18 at the different concentrations for 48 h. 0.001 < ** p < 0.01, *** p < 0.001, and **** p < 0.0001 compared to the control group.

Figure 5

The effect of compound 18 on cell cycle distribution of MGC-803 cells. (A) MGC-803 cells were treated with compound 18 at the indicated concentrations for 48 h, which was then analyzed by flow cytometry; (B) Column chart of the cell cycle distribution of MGC-803 cells.

Figure 6

The safety evaluation of compound 18. (A) Body weight of male mice-time; (B) Body weight of female mice-time; (C) The histological changes in mice were analyzed by HE staining (magnification: ×100).

Figure 7

The in vivo anti-proliferative effect of 18 on the gastric cancer xenograft model. (A) The effect of compound 18 (25 mg/kg) on body weight, with 5-Fu (10 mg/kg) used as the control; (B) The effect of compound 18 (25 mg/kg) on the tumor weight, with 5-Fu (10 mg/kg) used as the control; (C) The effect of compound 18 (25 mg/kg) on the tumor volume, with 5-Fu (10 mg/kg) used as the control.