CPP-Ts: a new intracellular calcium channel modulator and a promising tool for drug delivery in cancer cells

Area of Science:

• Toxicology
• Cardiology
• Biotechnology
• Molecular Biology

Background:

• Scorpion envenoming is a global health issue, with cardiac complications causing significant mortality.
• Cardiac dysfunction is a primary cause of death in scorpion sting victims.
• The specific mechanisms of scorpion venom-induced cardiotoxicity are not fully understood.

Purpose of the Study:

• To identify and characterize novel toxins in Tityus serrulatus venom.
• To investigate the effects of a newly identified toxin on cardiomyocyte function.
• To explore the potential of this toxin as a nuclear-targeting drug delivery system for cancer therapy.

Main Methods:

• Isolation and characterization of a novel toxin, CPP-Ts, from Tityus serrulatus venom.
• Assessment of CPP-Ts's effect on intracellular calcium release in cardiomyocytes via nuclear InsP3R activation.
• Evaluation of a synthetic CPP-Ts sub-peptide for nuclear targeting in cancer cell lines.

Main Results:

• Identification of CPP-Ts, the first Ca2+ channel toxin from Tityus serrulatus venom, characterized as a cell-penetrating peptide.
• CPP-Ts activates nuclear InsP3R in cardiomyocytes, leading to increased intracellular Ca2+ release and enhanced contraction frequency.
• A synthetic CPP-Ts sub-peptide (14-39) demonstrated nuclear-targeting capabilities in specific cancer cell lines without pharmacological activity.

Conclusions:

• Tityus serrulatus venom contains a novel subfamily of Ca2+ active toxins, exemplified by CPP-Ts.
• CPP-Ts represents a new class of toxins affecting cardiomyocyte contractility through nuclear calcium signaling.
• The nuclear-targeting property of CPP-Ts offers promising biotechnological applications for targeted cancer drug delivery systems.