IGF Discovery Offers Hope for Lymphedema Treatment

A newly identified cellular mechanism could pave the way for effective treatment of lymphedema, a chronic and painful swelling disorder with no current cure. The condition arises when the lymphatic system, responsible for transporting fluid through specialised vessels, is damaged. It may be congenital or caused by injury, but most commonly develops after breast cancer treatment involving lymph node removal. The resulting fluid build-up leads to persistent swelling, discomfort and increased infection risk.

Breakthrough in Lymphatic Vessel Growth

Researchers at Waipapa Taumata Rau, University of Auckland, have identified a cellular process that stimulates the growth of lymphatic vessels. The discovery was led by Dr Jonathan Astin, senior lecturer in molecular medicine and pathology. The team first observed the mechanism in zebrafish, a widely used model organism in biomedical research.

They found that insulin-like growth factor (IGF), a molecule long studied for its role in growth and development, significantly accelerates lymphatic vessel formation in zebrafish. This suggested potential for repairing damaged lymphatic networks.

Validation in Human Cells

To confirm relevance in humans, the team collaborated with Dr Justin Rustenhoven and other colleagues to culture human lymphatic cells in the laboratory. The results demonstrated that IGF can also instruct human lymphatic vessels to grow. This role of IGF in promoting lymphatic development had not been previously identified.

In Aotearoa New Zealand, around 20 per cent of women who undergo lymph node removal during breast cancer treatment develop lymphedema. The findings therefore offer a promising therapeutic pathway for a significant patient population.

Role of Zebrafish in Medical Research

Zebrafish were central to the study due to their rapid development and biological similarity to humans. Researchers can fluorescently label lymphatic vessels in fish, allowing real-time imaging of vessel growth in whole embryos without disrupting development. This enables faster and more precise observation of cellular processes.

Important Facts for Exams

• Lymphedema results from impaired lymphatic drainage and fluid accumulation.
• Insulin-like Growth Factor (IGF) regulates cell growth and development.
• Zebrafish are widely used in biomedical research due to genetic similarity to humans.
• Breast cancer treatment involving lymph node removal increases lymphedema risk.

Next Steps Towards Clinical Application

The next phase involves testing an IGF-based therapy in mouse models of lymphedema to assess safety and effectiveness. While researchers remain cautious, the discovery represents a significant step towards developing a targeted therapy for a painful and currently incurable condition.