The Whitney Laboratory for Marine Bioscience
On March 9th, Elizabeth N. Kaweesa, a graduate student advised by Sandra Loesgen, Associate Professor of Chemistry, gave her Ph.D. defense seminar entitled “Screening and In Vitro Assessment of Cytotoxic Natural Products” and successfully earned her doctorate degree.
In Elizabeth’s dissertation projects, she has studied microbial metabolites as a source for new cancer drug leads. Natural products have been a source of cancer chemotherapeutics and cancer drug inspiration for several decades. Many anti-cancer drugs were first found in nature, for example the most-used anti-cancer drug paclitaxel also known as Taxol®, was found in trees, and the breast cancer drug doxorubicin was first found in a soil bacterium.
With the prevalence of increased cancer cases worldwide, there is a need to screen for potential cytotoxic compounds that can be developed into new chemotherapeutics. In Elizabeth’s thesis, extracts and pure compounds isolated from microbial sources were screened and tested across cancer cell lines to assess their cytotoxicity. Specifically, she studied the bacterial compound mensacarcin for its selective activity against aggressive skin cancers (melanoma). Mensacarcin is very effective in inducing cell death in melanoma cell lines while not affecting other tissues. This compound also overcomes cancer drug resistance in cancers resistant to the current FDA approved melanoma treatment option vemurafenib (Zelboraf®).
In collaboration with colleagues at Virginia Tech, Elizabeth was able to show inhibitory effects of mensacarcin on cell migration, an important feature to prevent spreading of highly metastatic melanoma cells to other tissues.
These are tremendous achievements in the area of cancer drug lead development and will pave the way for future studies.
In her work, Elizabeth utilized different chemistry techniques from isolating the metabolites, characterizing their molecular structures and assessment of their purity, to molecular biology techniques that screen for anti-cancer activity and mechanism of action using mammalian cancer cells.
The research has been published in five scientific publications with two more to come. After her successful defense, Elizabeth was presented with a ‘doctoral hat’ made by all Loesgen Lab members to honor and celebrate her work. On April 29 2021, she attended the first graduation ceremony held in person again at UF and was hooded by President Fuchs. The same day, she was hooded again at the Whitney Laboratory by her advisor with her family and colleagues in attendance.
Elizabeth will continue her academic career as an NIH IRACDA postdoctoral fellow at UIC, well deserved recognition of her scholarly work and her potential as a future leader in pharmaceutical chemistry!
Congratulations Elizabeth!
