A Triangular Platinum(II) Multinuclear Complex with Cytotoxicity Towards Breast Cancer Stem Cells

Area of Science:

• Medicinal Chemistry
• Oncology
• Nanotechnology

Background:

• Multinuclear metal complexes represent a promising strategy for developing novel anticancer agents and drug delivery systems.
• Breast cancer stem cells (CSCs) are implicated in tumor recurrence and metastasis, making them critical therapeutic targets.

Purpose of the Study:

• To evaluate the potency of a novel triangular multinuclear platinum complex, designated Pt-3, against breast cancer stem cells (CSCs).
• To compare the efficacy of Pt-3 with established CSC-targeting agents and clinically used platinum drugs.

Main Methods:

• Synthesis and characterization of the trinuclear platinum(II) complex, Pt-3.
• In vitro assessment of Pt-3's selective toxicity towards breast CSCs, bulk breast cancer cells, and non-tumorigenic breast cells.
• Evaluation of Pt-3's effect on mammosphere formation, size, and viability.
• Investigation of Pt-3's mechanism of action, including cellular uptake, nuclear penetration, DNA damage induction, and apoptosis pathways.

Main Results:

• Pt-3 demonstrated selective toxicity towards breast CSCs compared to bulk cancer cells and normal breast cells.
• Pt-3 significantly inhibited mammosphere formation, size, and viability, outperforming salinomycin, cisplatin, and carboplatin.
• Mechanism studies revealed Pt-3 enters breast CSCs, damages genomic DNA, and induces caspase-dependent apoptosis.

Conclusions:

• Pt-3 is the first reported multinuclear platinum complex with selective activity against breast CSCs.
• This novel complex exhibits superior efficacy in targeting key characteristics of breast CSCs.
• Pt-3 holds potential as a novel therapeutic agent for breast cancer treatment, particularly for overcoming resistance mediated by CSCs.