Spheroids of FAP-Positive Cell Lines as a Model for Screening Drugs That Affect FAP Expression

Area of Science:

• Oncology
• Cell Biology
• Biochemistry

Background:

• Fibroblast Activation Protein (FAP) is a promising therapeutic target due to its expression in tumor microenvironments.
• Research on FAP's therapeutic potential is hindered by in vivo restrictions and challenges in standardizing heterogeneous cancer-associated fibroblast cultures.

Purpose of the Study:

• To develop a reliable and convenient model for studying Fibroblast Activation Protein (FAP) expression.
• To investigate factors influencing FAP expression in a controlled in vitro setting.
• To establish a platform for high-throughput drug screening targeting FAP.

Main Methods:

• Utilized 3D spheroids derived from FAP-positive cell lines as an in vitro model.
• Exposed spheroids to various factors including TGFβ, pH changes, hypoxia, and starvation.
• Quantified FAP expression changes using confocal microscopy.

Main Results:

• 3D spheroids demonstrated robust and reproducible FAP expression, outperforming monolayer cultures.
• FAP expression was upregulated by TGFβ.
• FAP expression was independent of pH but downregulated by hypoxia and starvation.

Conclusions:

• 3D spheroids provide a practical and effective model for studying FAP expression dynamics.
• The proposed model can be instrumental in large-scale high-throughput screening of drugs targeting FAP.
• This approach may overcome limitations associated with in vivo studies and heterogeneous primary cell cultures.