Teleocidin A2 inhibits human proteinase-activated receptor 2 signaling in tumor cells

Area of Science:

• Biochemistry
• Molecular Biology
• Cancer Research

Background:

• Enhanced expression of proteinase-activated receptor 2 (PAR2) is associated with cancer cell proliferation and migration.
• There is a significant need for potent and selective PAR2 inhibitors to target cancer progression.
• Previously, no potent and selective PAR2 antagonists have been reported.

Purpose of the Study:

• To characterize the natural product teleocidin A2 as a PAR2 antagonist.
• To evaluate the specificity and efficacy of teleocidin A2 in inhibiting PAR2-dependent cellular functions.
• To assess the potential of teleocidin A2 as an anti-cancer agent targeting PAR2.

Main Methods:

• Biochemical and cell-based assays were used to characterize teleocidin A2.
• PAR2-dependent intracellular Ca2+ mobilization was measured using tumor, endothelial, and epithelial cells.
• PAR2-mediated cell migration and actin cytoskeleton rearrangement were assessed in human breast adenocarcinoma cells (MDA-MB 231).

Main Results:

• Teleocidin A2 demonstrated PAR2 antagonism with IC50 values between 15-25 nmol/L against both peptide (SLIGKV-NH2) and trypsin-induced PAR2 activation.
• Teleocidin A2 exhibited high selectivity, with 10- to 20-fold higher concentrations required to inhibit PAR1 or P2Y receptors.
• In low nanomolar concentrations, teleocidin A2 effectively reversed PAR2-dependent cell migration and actin cytoskeleton rearrangement in MDA-MB 231 cells without affecting cell viability.

Conclusions:

• Teleocidin A2 is the first small molecule natural product identified as a potent PAR2 antagonist in the low nanomolar range.
• Teleocidin A2 possesses significant antimigratory activity against cancer cells by antagonizing PAR2.
• These findings highlight teleocidin A2 as a promising candidate for developing novel anti-cancer therapeutics targeting PAR2.