Transferrin Receptor-Mediated Iron Uptake Promotes Colon Tumorigenesis.

Area of Science:

• Oncology
• Molecular Biology
• Cancer Research

Background:

• Transferrin receptor (TFRC) regulates cellular iron uptake.
• High TFRC levels in iron-rich cancer cells and their role in cancer development are poorly understood.
• Adenomatous polyposis coli (APC) gene loss and beta-catenin activation are implicated in colorectal cancer.

Purpose of the Study:

• To elucidate the mechanism of TFRC regulation in colorectal cancer.
• To investigate the role of TFRC-mediated iron accumulation in cancer progression.
• To explore TFRC as a therapeutic target in colorectal cancer.

Main Methods:

• Investigated TFRC induction by APC loss and beta-catenin activation.
• Assessed TFRC's effect on tankyrase activity and beta-catenin signaling.
• Utilized TFRC disruption, iron chelation, and POLD1 knockdown models.
• Analyzed DNA replication stress, DNA damage response, and apoptosis.
• Evaluated therapeutic potential of combined iron chelators and DNA damaging agents.

Main Results:

• TFRC is induced by APC loss-driven beta-catenin activation in colorectal cancer.
• TFRC-mediated iron accumulation enhances tankyrase activity, potentiating beta-catenin signaling.
• TFRC disruption reduces iron levels and inhibits the beta-catenin/c-Myc/E2F/POLD1 axis.
• POLD1 knockdown, iron chelation, or TFRC disruption increases DNA damage and apoptosis, reducing tumor growth.
• Combined iron chelation and DNA damaging agents synergistically enhance anti-tumor effects.

Conclusions:

• TFRC-mediated iron import forms a feed-forward loop promoting colon cancer cell survival.
• Targeting TFRC or iron metabolism presents a promising therapeutic strategy for colorectal cancer.
• Understanding this iron-centric signaling pathway opens new avenues for cancer treatment.