FEZF2 inhibits the growth of triple-negative breast cancer cells through EZH2/PD-L1 and enhances anti-tumor immunity in vivo.

Background: Triple-negative breast cancer (TNBC) is characterized by high aggressiveness, heterogeneity, and poor prognosis. Programmed cell death 1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors, a crucial type of immune checkpoint inhibitor therapy, have been proven to be a promising strategy for the TNBC treatment. Forebrain embryonic zinc finger 2 (FEZF2) is dysregulated in various cancers and participates in the tumor progression. However, its role and mechanism in TNBC remain unknown. Objectives: To investigate whether FEZF2 is involved in the progression of TNBC via EZH2/PD-L1 axis. Results: The expression of FEZF2 was downregulated in TNBC. Overexpression of FEZF2 reduced cell viability and enhanced cell apoptosis in both MDA-MB-231 and BT-549 cells. Meanwhile, upregulation of FEZF2 decreased the relative protein expression of EZH2 and PD-L1, which was restored by overexpression of EZH2 in both cells. Moreover, overexpression of PD-L1 neutralized the inhibitory effect of the FEZF2 overexpression on the cell viability in MDA-MB-231 and BT-549 cells. Furthermore, overexpression of FEZF2 reduced the tumor weight and volume, and increased numbers of CD8⁺ tumor-infiltrating lymphocytes in xenografted mice. Conclusion: Overexpression of FEZF2 inhibited the proliferation and enhanced the apoptosis of TNBC cells through EZH2/PD-L1 axis, as well as promoted anti-tumor immunity in vivo. [ABSTRACT FROM AUTHOR]