PFDN5 plays a dual role in breast cancer and regulates tumor immune microenvironment: Insights from integrated bioinformatics analysis and experimental validation.

Background: Although the prognosis for patients with breast cancer has improved, breast cancer remains the leading cause of death for women worldwide. Prefoldin 5 (PFDN5), as a subunit of the prefoldin complex, plays a vital role in aiding the correct folding of newly synthesized proteins. However, the exact impact of PFDN5 on breast cancer development and its prognostic implications remain unclear.

Methods: We conducted bioinformatics analysis to investigate the correlation between PFDN5 and patient survival, as well as various clinicopathological characteristics in breast cancer. Additionally, various assays were employed to validate the biological functions of PFDN5 in breast cancer. Finally, RNA sequencing (RNA-seq) was utilized to investigate the molecular mechanisms associated with PFDN5.

Results: Compared to normal tissues, PFDN5 exhibited lower expression levels in breast cancer tissues, and lower expression of PFDN5 is associated with poorer prognosis. PFDN5 led to G2/M phase arrest in the cell cycle and reduced proliferative potential in breast cancer cells. However, PFDN5 also promoted migration and invasion of breast cancer cells. Also, RNA-seq analysis revealed an involvement of PFDN5 in the cell cycle and TGF-β signaling pathway. Furthermore, PFDN5 had a significant impact on tumor immune microenvironment by promoting macrophage polarization towards the M1 phenotype and exhibited a positive correlation with CD8 T cell infiltration levels.

Conclusions: PFDN5 plays a dual role in breast cancer and serves as a key factor in tumor immune microenvironment. Therefore, PFDN5 holds promise as a valuable biomarker for predicting both metastatic and prognosis in breast cancer.