Photocrosslinkable Affibodies for Efficient Cancer Treatment and Proliferation Inhibition
AIChE Annual Meeting
2021
2021 Annual Meeting
Annual Student Conference
Undergraduate Student Poster Session: Food, Pharmaceutical, and Biotechnology
Monday, November 8, 2021 - 10:00am to 12:30pm
To combat these issues, we asked whether an engineered antibody-like protein, called an affibody, can be designed to not only increase permeation in solid tumor matrices but also crosslink a specific cell receptor to impart improved therapeutic efficacy as measured by sustained retention in the tumor bed with increased drug delivery and proliferation of cell growth.
First, recombinant protein engineering was utilized to create an affibody with a benzophenone modification (called N23BP) which provides the ability to covalently photocrosslink with overexpressed epidermal growth factor receptor (EGFR) upon exposure to near UV. This photocrosslinkability was confirmed in solution via SDS-PAGE. Retention in 4T1-cell tumor model spheroids was determined by photoluminescence. Next, N23BP was fused with cytosine deaminase (CodA) to give it the ability to convert prodrug 5-fluorocytosine to the anticancer drug 5-fluorouracil. The time and effectiveness of drug delivery in MDA-MB-468 cells was assessed using confocal microscopy, monitoring ERK activity, and MTT assay. Lastly, the inhibitory effects of N23BP covalently binding EGFR were explored by comparing it to Cetuximab, a commercial antibody which inhibits EGFR.
The research here shows the ability for sustained affibody expression throughout tumor models due the affibodyâs small size and ability to covalently bind EGFR. Furthermore, the affibody-enzyme N23BP-CodA shows promise of increasing drug delivery time to 48 hours as compared to a wild type non-photocrosslinkable affibody-enzyme or the antibody drug Cetuximab. Recently obtained results also show that photocrosslinking affibodies to cell receptors induces a significant decrease in cell growth and proliferation which could be used in the future as additional modalities for cancer therapy.