HAMLET cytotoxicity in colorectal cancer cell models with different mutation status in Vitro

Abstract

HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) is a proteolipid complex of partially unfolded α-lactalbumin and several oleate residues. Its efficacy as a selective killer of tumor cells has been documented in vitro and in vivo in several animal models [1]. HAMLET interacts with multiple tumor cell compartments, affecting cell morphology, metabolism, proteasome function, chromatin structure and cell viability [2]. Colorectal cancer is one of the most frequent malignancies worldwide, being second in males and third in females for its frequency and ranking fourth and third for cancer-related deaths among males and females, respectively [3]. KRAS and BRAF are major oncogenic drivers of colorectal cancer (CRC) [4]. The aim of this study was to evaluate antitumoral activity of the HAMLET complex on three different CRC cell lines (LoVo, WiDr, Caco-2) with different mutation status (KRAS/BRAF, wild type). HAMLET complex was prepared using controlled temperature (partial protein unfold) combined with mixing/shaking with olein acid additive (acid incorporation in protein structure) [5]. Cytotoxicity of complex (metabolic activity and viability of the cells) was evaluated using 6 h exposition and different concentration in compliance with MTT and clonogenic assay protocols. The results suggest that HAMLET affects cell metabolism, this effect is severe and at the same time irreparable for cells, leading to cell death. The complex exhibits cytotoxicity in dose-response manner against all cell lines. However, BRAF mutant cells seems to be more resistant to HAMLET in comparison to KRAS mutants and wild type cells. HAMLET has anticancer potency for CRC in in vitro model.