Search

To discover novel anticancer agents with potent and low toxicity, we designed and synthesized a range of new thiosemicarbazone-indole analogues based on lead compound 4 we reported previously. Most compounds displayed moderate to high anticancer activities against five tested tumor cells (PC3, EC109, DU-145, MGC803, MCF-7). Specifically, the represented compound 16f possessed strong antiproliferative potency and high selectivity toward PC3 cells with the IC 50 value of 0.054 μM, compared with normal WPMY-1 cells with the IC 50 value of 19.470 μM. Preliminary mechanism research indicated that compound 16f could significantly suppress prostate cancer cells (PC3, DU-145) growth and colony formation in a dose-dependent manner. Besides, derivative 16f induced G1/S cycle arrest and apoptosis, which may be related to ROS accumulation due to the activation of MAPK signaling pathway. Furthermore, molecule 16f could effectively inhibit tumor growth through a xenograft model bearing PC3 cells and had no evident toxicity in vivo. Overall, based on the biological activity evaluation, analogue 16f can be viewed as a potential lead compound for further development of novel anti-prostate cancer drug. Image 1 • New thiosemicarbazone-indole derivatives were designed and synthesized based on previous work. • Most compounds were more sensitive to prostate cancer PC3 cells in comparison to other cancer cells. • 16f exhibited stronger activity and better safety profile than 3-AP, DPC and lead 4. • 16f induced G1/S cycle arrest and apoptosis in prostate cancer cells (PC3, DU-145) via ROS accumulation. [ABSTRACT FROM AUTHOR]

In this paper, a series of thiosemicarbazone derivatives containing different aromatic heterocyclic groups were synthesized and the tridentate donor system of the lead compound was optimized. Most of the target compounds showed improved antiproliferative activity against MGC803 cells. SAR studies revealed that compound 5d displayed significant advantages in inhibition effect with an IC 50 value of 0.031 μM, and better selectivity between cancer and normal cells than 3-AP and DpC (about 15- and 5-fold improved respectively). Besides, compound 5d showed selective antiproliferative activity in not only other cancer cells but also different gastric cancer cell lines. In-depth mechanism studies showed that compound 5d could induce mitochondria-related apoptosis which might be related to the elevation of intracellular ROS level, and cause cell cycle arrest at S phase. Moreover, 5d could evidently suppress the cell migration and invasion by blocking the EMT (epithelial–mesenchymal transition) process. Consequently, our studies provided a lead optimization strategy of thiosemicarbazone derivatives which would contribute to discover high-efficiency and low-toxicity agents for the treatment of gastric cancer. Image 1 • The design and synthesis were based on lead optimization strategy. • 5d showed higher antiproliferative activity and lower toxicity than 3-AP and DpC. • 5d could induce cell apoptosis, and inhibit the migration and invasion of MGC803 cells. [ABSTRACT FROM AUTHOR]