Growth Hormone Protects the Intestine Preserving Radiotherapy Efficacy on Tumors: A Short-Term Study

Area of Science:

• Oncology
• Radiotherapy
• Gastroenterology

Background:

• Radiotherapy's efficacy is limited by severe gastrointestinal side effects, hindering treatment intensity and potentially leading to tumor resistance.
• Effective strategies to protect healthy bowel tissue during radiation therapy are crucial for improving patient outcomes and treatment effectiveness.

Purpose of the Study:

• To evaluate the protective impact of short-term growth hormone (GH) treatment on intestinal tissue during radiotherapy.
• To assess GH's effect on tumor response and compare its impact on intestinal versus tumor tissue.

Main Methods:

• Comparative analysis of intestinal and tumor tissues in tumor-bearing rats undergoing radiotherapy.
• Exogenous administration of growth hormone (GH) as a protective agent.
• Assessment of proliferation using Positron Emission Tomography and markers like Ki67, cyclin D3, and Proliferating Cell Nuclear Antigen.
• Measurement of intestinal villi and crypt length, and caspase-3 activity.

Main Results:

• GH treatment significantly improved intestinal recovery after radiation.
• GH increased proliferation in irradiated intestine but not in tumors, evidenced by increased villi and crypt length.
• GH significantly decreased apoptosis (caspase-3 activity) in the intestine, with no similar effect observed in tumors.

Conclusions:

• Short-term growth hormone (GH) administration protects the bowel during radiotherapy.
• GH promotes proliferation and reduces apoptosis in healthy intestinal tissue.
• GH treatment preserves the efficacy of radiotherapy against tumors.