Ursolic Acid Impairs Cellular Lipid Homeostasis and Lysosomal Membrane Integrity in Breast Carcinoma Cells

Area of Science:

• Biochemistry
• Cell Biology
• Pharmacology

Background:

• Cancer remains a leading global cause of mortality, necessitating novel therapeutic approaches.
• Ursolic acid, a natural pentacyclic triterpene, exhibits anti-inflammatory and anti-neoplastic properties.
• Its anti-cancer mechanisms, including apoptosis induction and proliferation inhibition, are not fully elucidated.

Purpose of the Study:

• To identify the specific cellular targets of ursolic acid's anti-cancer activity.
• To elucidate the role of lysosomes in ursolic acid-induced cancer cell death.
• To explore combination therapies for enhanced anti-cancer effects.

Main Methods:

• Treatment of MCF7 breast cancer cells with ursolic acid.
• Analysis of lysosomal pH, cellular lipid profiles, and lysosomal membrane integrity.
• Assessment of lysosomal enzyme leakage into the cytosol.
• Evaluation of the autophagic pathway and cell death markers.
• Combination treatment with ursolic acid and cationic amphiphilic drugs.

Main Results:

• Ursolic acid treatment elevated lysosomal pH and altered lipid profiles in cancer cells.
• Lysosomal membrane permeabilization and enzyme leakage into the cytosol were observed.
• Lysosomal disruption preceded key apoptosis indicators, suggesting it's an early event.
• Impaired autophagic pathway function was noted, contributing to cancer cell death.
• Combined ursolic acid and cationic amphiphilic drug treatment significantly enhanced cell death.

Conclusions:

• Lysosomes are critical targets for the anti-cancer effects of ursolic acid.
• Ursolic acid induces cancer cell death via lysosomal membrane permeabilization and subsequent apoptosis.
• Disruption of lysosomal function and the autophagic pathway are key mechanisms.
• Combination therapy with cationic amphiphilic drugs potentiates ursolic acid's anti-cancer efficacy.