Identification of dinactin, a macrolide antibiotic, as a natural product-based small molecule targeting Wnt/β-catenin signaling pathway in cancer cells

• Published in: Cancer chemotherapy and pharmacology Vol. 84; no. 3; pp. 551 - 559
• Main Authors: Hussain, Aehtesham, Dar, Mohd Saleem, Bano, Nasima, Hossain, Md Mehedi, Basit, Rafia, Bhat, Aadil Qadir, Aga, Mushtaq A., Ali, Sabeena, Hassan, Qazi Parvaiz, Dar, Mohd Jamal
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2019; Springer Nature B.V
• Subjects: Anti-Bacterial Agents - pharmacology; Antibiotics; Antineoplastic Agents, Phytogenic - pharmacology; Apoptosis; Apoptosis - drug effects; Assaying; beta Catenin - genetics; beta Catenin - metabolism; Cancer; Cancer Research; Cell cycle; Cell Cycle - drug effects; Cell proliferation; Cell Proliferation - drug effects; Cell viability; Colorectal carcinoma; Cyclin D1; Flow cytometry; HCT116 Cells; Hep G2 Cells; Humans; Impact analysis; Lung carcinoma; Macrolides - pharmacology; Medicine; Medicine & Public Health; Natural products; Neoplasms - drug therapy; Neoplasms - pathology; Neuralgia; Oncology; Original Article; Pain; Pharmacology/Toxicology; Reactive Oxygen Species - metabolism; Salinomycin; Signal transduction; Signal Transduction - drug effects; Small Molecule Libraries - pharmacology; Western blotting; Wnt protein; Wnt1 Protein - genetics; Wnt1 Protein - metabolism; β-Catenin; Wnt/β-catenin signaling; HCT-116 and HepG2 cells; Antibiotic; Anti-cancer agents; Ionophore; Apoptosis
• ISSN: 0344-5704; 1432-0843
• DOI: 10.1007/s00280-019-03870-x

Purpose Despite the fact that hyper-activation of Wnt/β-catenin signaling pathway has been seen in many cancers, including liver, colorectal and lung carcinoma, no small molecule inhibitors are available that specifically target this pathway. In this study, we analyzed the impact of dinactin (DA), an antibiotic ionophore produced by Streptomyces  species, as an effective small molecule targeting Wnt/β-catenin signaling pathway in cancer cells. Methods We performed MTT assays to investigate cell viability and proliferation after exposure to small molecules. Protein expression analysis was carried out by western blotting. Top-Flash reporter assays were used to score for β-catenin signaling and cell cycle analysis was carried out by flow cytometry. Results In the first set of experiments, DA was seen to selectively inhibit the proliferation of HCT-116 and HepG2 cancer cells, unlike HEK-293 cells (a low tumorigenic cell line), in apoptosis-independent manner. Further, DA was seen to block the G1/S progression and decrease the expression of cyclin D1 in cancer cells. Since cyclin D1 is the downstream target gene of Wnt/β-catenin signaling, we examined the impact of DA on TCF-dependent β-catenin activity using Top-Flash reporter assay. Interestingly, DA significantly decreased Top-Flash activity at lower nano-molar concentrations when compared with salinomycin in HCT-116 and HepG2 cells. Conclusion We report the identification of dinactin as a natural product-based small molecule that effectively blocks the Wnt/β-catenin signaling pathway in cancer cells at nano-molar concentration. We anticipate that DA could be developed as a novel drug for anti-cancer therapy and for the management of neuropathic pain.