Coculture with macrophages alters ferroptosis susceptibility of triple-negative cancer cells

Area of Science:

• Cancer biology
• Immunology
• Cell death mechanisms

Background:

• Cancer treatments like targeted drugs and immune checkpoint inhibitors face challenges with drug resistance.
• Ferroptosis, a form of programmed cell death driven by lipid peroxidation, is a promising new cancer therapy strategy.
• The tumor microenvironment, including cell-cell interactions, significantly impacts cancer treatment efficacy, but its effect on ferroptosis is unclear.

Purpose of the Study:

• To investigate the impact of macrophage-cancer cell interactions on ferroptosis induction.
• To understand how these interactions influence cancer cell sensitivity to ferroptosis inducers.

Main Methods:

• Co-culture experiments involving macrophages and cancer cells.
• Utilized transwell co-culture to allow paracrine signaling.
• Employed direct co-culture to facilitate cell-cell contact.
• Assessed ferroptosis sensitivity using ferroptosis inducers like RSL3.

Main Results:

• Macrophage-conditioned medium alone did not affect cancer cell ferroptosis sensitivity.
• Transwell co-culture, enabling secretion-mediated interactions, increased cancer cell sensitivity to ferroptosis inducers.
• Direct co-culture significantly enhanced cancer cell susceptibility to RSL3-induced ferroptosis.
• Macrophage co-culture upregulated intracellular ferrous ions and lipid peroxidation in cancer cells.

Conclusions:

• Direct cell-cell interactions between macrophages and cancer cells enhance ferroptosis sensitivity.
• This enhancement is mediated by increased intracellular iron and lipid peroxidation.
• Findings offer new insights into leveraging cell-cell interactions for effective ferroptosis-based cancer therapy.