Conclusions
Our data reveal a novel amplification effect, i.e., stromal cell-derived FGF7 promotes epithelial cell proliferation and stromal cell phenotype, ultimately inducing IPP formation. Targeting FGF7 can significantly reduce epithelial to stromal transition and provide a potential therapeutic target for BPH progression.
Methods
Clinical data analysis was performed to analyze the association between IPP and long-term complications in patients with BPH. RNA sequencing was performed on prostate tissues (IPP or not). Stromal cells were obtained from IPP-derived primary cultures to explore the molecular mechanism of IPP formation. Cell proliferation was evaluated by a CCK-8 assay. Multiple proteins in the signaling pathway were assessed using Western blot.
Results
First, we confirmed that IPP is a prognostic factor for long-term complications in patients with BPH. Then, we observed that FGF7 was upregulated in both IPP tissues and IPP primary stromal cells through immunohistochemistry, Western blot, and quantitative real-time PCR. Furthermore, FGF7 was significantly upregulated in high IPP-grade prostate tissues. The coculture experiments showed that the downregulation of FGF7 in IPP-derived stromal cells inhibited the proliferation and migration of the prostate epithelial cells. Additionally, FGF7 was bound to FGFR2 to induce the epithelial-mesenchymal transition process through binding to FGFR2. RNA sequencing analysis also revealed the activation of the MAPK/ERK1/2 signaling pathway. The MAPK/ERK1/2 was downregulated by a specific inhibitor affecting the FGF7 stimulation in vitro. Conclusions: Our data reveal a novel amplification effect, i.e., stromal cell-derived FGF7 promotes epithelial cell proliferation and stromal cell phenotype, ultimately inducing IPP formation. Targeting FGF7 can significantly reduce epithelial to stromal transition and provide a potential therapeutic target for BPH progression.