Visualization of the metastatic process by green fluorescent protein expression

Area of Science:

• Oncology
• Molecular Biology
• Biotechnology

Background:

• Cancer metastasis is a complex process involving multiple steps.
• Visualizing metastasis in real-time is crucial for understanding its progression.
• Green fluorescent protein (GFP) offers a powerful tool for live imaging.

Purpose of the Study:

• To visualize and compare cancer metastasis patterns in vivo.
• To utilize GFP expression for tracking cancer cell dissemination.
• To investigate the influence of initial metastatic steps on overall progression.

Main Methods:

• Human lung adenocarcinoma cells (Anip 973) were transfected with GFP.
• Stable GFP-expressing cells were used in two metastasis models in nude mice: surgical orthotopic implantation (SOI) and intravenous injection.
• Metastasis was detected and analyzed by GFP expression in live and fresh tissues at 4 and 8 weeks post-treatment.

Main Results:

• SOI model showed lymphogenous and direct seeding metastasis in various locations, including pulmonary hilum, lymph nodes, mediastinum, and contralateral pleura.
• Intravenous injection model resulted in widespread lung metastases, with some spreading to the brain and other organs.
• Dormant lung metastases were observed up to 8 weeks after intravenous injection.
• Distinct metastatic patterns were observed between the two models, visualized by GFP.

Conclusions:

• GFP visualization effectively tracks cancer cell dissemination and metastasis in vivo.
• The route of cancer cell entry significantly influences metastatic patterns and progression.
• Initial steps of the metastatic cascade play a critical role in subsequent metastasis development.