Design, Synthesis and Biological Evaluation of Novel Quinoline Derivatives as Potential Anti-Proliferative Agents Against PC-3 and KG-1 Cells

Background: Cancer is a major public health problem worldwide, and is the leading cause of death. The discovery and development of cancer therapeutic drugs have become the most urgent measure, which significantly benefited from the usage of small molecule compounds. The quinoline core possessed a vast number of biological activities that were found to be imperative. Objective: The aim is to design, synthesize and perform the biological evaluation of novel quinoline derivatives as potential anti-proliferative agents. Methods: Quinoline as a privileged scaffold was adopted to introduce diverse effective nitrogen heterocycles through different linkers. The synthesized compounds were spectroscopically characterized and evaluated for their anti-proliferative activity using the CCK8 assay. The mechanism of action was investigated by flow cytometry and the inhibitory activity against Pim-1 kinase was measured by mobility shift assay. Molecular docking analysis was performed to rationalize biochemical potency as well. Results: The majority of these quinolines displayed potent growth inhibitory effects, among which compounds 13e, 13f and 13h were the most effective ones, with GI50 values of 2.61/3.56, 4.73/4.88 and 4.68/2.98 μM, respectively. Structure-activity relationships indicated that both appropriate heterocycles at the C4 position of pyridine and suitable substituent at quinoline had a significant impact on improving activity. Compounds 13e and 24d exhibited moderate Pim-1 kinase inhibitory activity. Conclusion: In this study, three series of novel molecules bearing quinoline scaffold were designed, synthesized and evaluated for their in-vitro anti-proliferative activity. The most promising candidate, 13e, caused cell cycle arrest in a concentration-dependent manner and further induced apoptosis, which might represent a novel antiproliferative agent working through Pim-1 kinase inhibition to a certain extent.