Scorpion venom HDP analog AKFK-IsCT1 shows potent, safer anti-breast cancer activity

Developing effective treatments for aggressive cancers like breast cancer, particularly triple-negative breast cancer (TNBC), remains a significant challenge due to its high metastatic potential and limited targeted therapies. Host Defense Peptides (HDPs), derived from the innate immune system, offer a promising avenue for anticancer therapy due to their membrane-disrupting properties. However, their clinical utility is often hampered by non-specific cytotoxicity towards healthy cells. This study addresses this gap by engineering a scorpion venom-derived HDP to enhance its selectivity and potency against cancer cells.

Researchers investigated the structure-activity relationship of the scorpion venom-derived HDP IsCT1 and its rationally designed analogs. The lead compound, AKFK-IsCT1, was tested for its antitumor activity and cytotoxicity against breast cancer models (in vitro) and nontumorigenic cells. Its efficacy was further evaluated in a triple-negative breast cancer mouse model (in vivo). The study also explored synergistic effects when AKFK-IsCT1 was combined with photodynamic therapy using hypericin.

The engineered HDP analog, AKFK-IsCT1, emerged as a lead compound, demonstrating potent antitumor activity while significantly reducing cytotoxicity toward nontumorigenic cells. Researchers found that an optimal balance of positive charge and helical conformation in AKFK-IsCT1 was more critical for anticancer efficacy than charge alone. When combined with photodynamic therapy using hypericin, AKFK-IsCT1 displayed remarkable synergistic effects. This synergy enabled a substantial dose reduction of both agents, suggesting a path to improved tolerability. In a triple-negative breast cancer mouse model, AKFK-IsCT1 treatment effectively reduced tumor burden and elicited immune-associated responses, highlighting its potential as a selective and multifunctional therapeutic.

AKFK-IsCT1 treatment in a triple-negative breast cancer mouse model reduced tumor burden and elicited immune-associated responses, supporting its potential as a selective and multifunctional therapeutic strategy.