Determining the LC50 of a Novel MetAP Inhibitor in Lung Carcinoma Cells

Abstract

The rise of multi‐drug resistant bacterial infections grows at an alarming rate, thus necessitating the discovery of new antibiotics and antimicrobials. Dr. Omonike Olaleye, a colleague from Texas State University, discovered 75 compound inhibitors against Methionine aminopeptidase (MetAP) after a high‐throughput screen. MetAP is a universally conserved, essential protein that removes the initial methionine from a newly synthesized polypeptide, which allows for further modification to form a completed protein; studies have indicated that MetAP deletion is lethal. Interestingly, MetAP is conserved across species, and prokaryotic and eukaryotic MetAP are dissimilar enough to make MetAP an attractive potential therapeutic target. This project is currently focused on a compound (UST‐001) efficacious in inhibiting Mycobacterium tuberculosis; however, the effect on mammalian cells is unknown. Relative toxicities must be determined before further tests can be conducted. We determined the in‐vitro LC50 of UST‐001 on a human lung carcinoma (H1299) line to be 3.2μM by using a combination of an MTT assay and flow cytometry. However, because the H1299s are a cancerous and thus drug resistant line, the experimental calculated value may not be representative of the MetAP inhibitor's toxicity in a non‐cancerous cell line. We plan to overcome this limitation in the future by using a primary lung cell line, and to compare the relative toxicities between both cell lines. The data gathered from this project will facilitate further research in determining whether or not this UST‐001 will be a viable clinical candidate.