McNair Scholars Research Journal
Abstract
Hyaluronan has been identified as a ligand for key receptors related to cancer cell growth and metastasis, such as CD44 and RHAMM (Misra et al. 2015). Analogs of cysteine deleted tachyplesin (CDT), an antimicrobial peptide, have shown effective anti-cancer properties against the A549 cancer cell line (Evans et al. 2016). It was hypothesized that the hyaluronan binding sequence could act as a coordination mechanism for the anti-cancer peptide contained within CDT. To enhance the efficacy of CDT, a shorter peptide analog was synthesized that contained only the sequence of the identified hyaluronan binding sequence (HA-CDT) and was tested on the A549 lung cancer cell line. In addition, two other shortened CDT analogs were synthesized and tested in both L- and D- forms. These experiments helped to determine which amino acids in the sequence contributed to the membranolytic process in the anticancer mechanism of CDT. HA-CDT exhibited reduced anti-cancer activity relative to CDT in both the D- and the L- form, while the longer analogs retained some activity. These results allow us to conclude that one or more key amino acids that are necessary for anti-cancer activity were removed from CDT in HA-CDT, and the hyaluronan sequence alone is too short for activity.