After studying the biological activity of five new, metal-organic hybrid knotted molecules, termed metal-organic trefoil knots, M-TKs, researchers from NYU Abu Dhabi’s, NYUAD, found that these molecules can effectively deliver metals to cancer cells, potentially acting as a new category of anti-cancer agents.
In a study published in the journal, Chemical Science, NYUAD Research Scientists, Farah Benyettou and Thirumurugan Prakasam, from the Trabolsi Research Group, led by NYUAD Associate Professor of Chemistry, Ali Trabolsi, reported that these nanoscale, water-soluble M-TKs showed high potency in vitro against six cancer cell lines and in vivo in zebrafish embryos. Zebrafish-related studies were undertaken by NYUAD Postdoctoral Associate, Anjana Ramdas Nair, from the Sadler Lab.
The M-TKs, generated by the metal-templated self-assembly of a simple pair of chelating ligands were well-tolerated in vitro by non-cancer cells but were significantly more potent than cisplatin, a common chemotherapy medication, in both human cancer cells, including those that were cisplatin-resistant and in zebrafish embryos. In cultured cells, the M-TKs introduce reactive oxygen species, ROS, that damage the mitochondria of cancer cells, but not the nuclear DNA or the plasma membrane.
"The cytotoxicity and wide scope for the structural variation of the M-TKs indicate the potential of synthetic metal-organic knots as a new field of chemical space for pharmaceutical design and development," Trabolsi said, adding, "There is a significant promise for developing new cancer therapies that can complement the existing chemotherapy options that are currently used to treat nearly half of all cancer patients undergoing chemotherapy."
Benyettou said, "The M-TKs synthesised by Prakasam from the Trabolsi Research Group were found, in many cases, to have greater potency than what has been previously reported in cisplatin and other metal complexes."
"The main delivery routes were macropinocytosis and both caveolin - and clathrin-mediated endocytosis, which are more active in cancer cells than in normal cells. Cisplatin and other small molecules penetrate cells by diffusion, which is less cancer-selective in vitro. The researchers hypothesise that the molecules they have developed are less toxic to healthy cells because they are internalised less," Benyettou added.
In the next stage of developing the M-TKs, research efforts will focus on the mechanism of action of the M-TKs to determine whether their ROS-mediated toxicity involves specific intracellular targets.
Other NYUAD collaborators include fourth-year graduate PhD student, Tina Skorjanc, who contributed to the paper’s biological-related aspects.