1. Inhibition of malaria parasite growth by quinomycin A and its derivatives through DNA-intercalating activity
Hiroki Hayase, Nobumoto Watanabe, Chung Liang Lim, Toshihiko Nogawa, Keisuke Komatsuya, Kiyoshi Kita, Hiroyuki Osada Biosci Biotechnol Biochem. 2015;79(4):633-5. doi: 10.1080/09168451.2014.987205. Epub 2014 Dec 4.
Quinomycin A and its derivatives were identified as potent antimalarial (Plasmodium falciparum) agents in a screen of the RIKEN NPDepo chemical library. IC50 values of quinomycin A and UK-63,598 were approximately 100 times lower than that of the antimalarial drug chloroquine. This activity was mitigated by the addition of plasmid DNA, suggesting that these compounds act against parasites by intercalating into their DNA.
2. Quinomycin A targets Notch signaling pathway in pancreatic cancer stem cells
Sivapriya Ponnurangam, Prasad R Dandawate, Animesh Dhar, Ossama W Tawfik, Rajashri R Parab, Prabhu Dutt Mishra, Prafull Ranadive, Rajiv Sharma, Girish Mahajan, Shahid Umar, Scott J Weir, Aravind Sugumar, Roy A Jensen, Subhash B Padhye, Arun Balakrishnan, Shrikant Anant, Dharmalingam Subramaniam Oncotarget. 2016 Jan 19;7(3):3217-32. doi: 10.18632/oncotarget.6560.
Cancer stem cells (CSCs) appear to explain many aspects of the neoplastic evolution of tumors and likely account for enhanced therapeutic resistance following treatment. Dysregulated Notch signaling, which affects CSCs plays an important role in pancreatic cancer progression. We have determined the ability of Quinomycin to inhibit CSCs and the Notch signaling pathway. Quinomycin treatment resulted in significant inhibition of proliferation and colony formation in pancreatic cancer cell lines, but not in normal pancreatic epithelial cells. Moreover, Quinomycin affected pancreatosphere formation. The compound also decreased the expression of CSC marker proteins DCLK1, CD44, CD24 and EPCAM. In addition, flow cytometry studies demonstrated that Quinomycin reduced the number of DCLK1+ cells. Furthermore, levels of Notch 1-4 receptors, their ligands Jagged1, Jagged2, DLL1, DLL3, DLL4 and the downstream target protein Hes-1 were reduced. The γ-secretase complex proteins, Presenilin 1, Nicastrin, Pen2, and APH-1, required for Notch activation also exhibited decreased expression. Ectopic expression of the Notch Intracellular Domain (NICD) partially rescued the cells from Quinomycin mediated growth suppression. To determine the effect of Quinomycin on tumor growth in vivo, nude mice carrying tumor xenografts were administered Quinomycin intraperitoneally every day for 21 days. Treatment with the compound significantly inhibited tumor xenograft growth, coupled with significant reduction in the expression of CSC markers and Notch signaling proteins. Together, these data suggest that Quinomycin is a potent inhibitor of pancreatic cancer that targets the stem cells by inhibiting Notch signaling proteins.
3. Quinomycin A reduces cyst progression in polycystic kidney disease
Priyanka S Radadiya, Mackenzie M Thornton, Emily A Daniel, Jessica Y Idowu, Wei Wang, Brenda Magenheimer, Dharmalingam Subramaniam, Pamela V Tran, James P Calvet, Darren P Wallace, Madhulika Sharma FASEB J. 2021 May;35(5):e21533. doi: 10.1096/fj.202002490R.
Polycystic kidney disease (PKD) is a genetic disorder characterized by aberrant renal epithelial cell proliferation and formation and progressive growth of numerous fluid-filled cysts within the kidneys. Previously, we showed that there is elevated Notch signaling compared to normal renal epithelial cells and that Notch signaling contributes to the proliferation of cystic cells. Quinomycin A, a bis-intercalator peptide, has previously been shown to target the Notch signaling pathway and inhibit tumor growth in cancer. Here, we show that Quinomycin A decreased cell proliferation and cyst growth of human ADPKD cyst epithelial cells cultured within a 3D collagen gel. Treatment with Quinomycin A reduced kidney weight to body weight ratio and decreased renal cystic area and fibrosis in Pkd1RC/RC ; Pkd2+/- mice, an orthologous PKD mouse model. This was accompanied by reduced expression of Notch pathway proteins, RBPjk and HeyL and cell proliferation in kidneys of PKD mice. Quinomycin A treatments also normalized cilia length of cyst epithelial cells derived from the collecting ducts. This is the first study to demonstrate that Quinomycin A effectively inhibits PKD progression and suggests that Quinomycin A has potential therapeutic value for PKD patients.