Fig. 6. Loss of ZFHX3 eliminated the inhibitory effect of ERβ on colony formation and MYC expression in prostate cancer cells and correlated with worse patient survival.

C4-2B (a, c) and LNCaP (b, d) cells were used for both colony formation assay (a, b) and MYC expression analysis (c, d). In colony formation assay, cells plated on 0.35% soft agar in phenol red-free medium were cultured, and colonies >100 µm were counted. MYC protein was detected by Western blotting. DPN was added to enhance the ERβ activity. e Transfection-mediated re-expression of ZFHX3 in the ZFHX3-null KO8 clone of C4-2B cells decreased MYC expression, as detected by Western blotting. f A model for how ZFHX3 is indispensable for ERβ to suppress cell proliferation and tumor growth in prostate cancer cells. In the presence of ZFHX3, ERβ interacts with ZFHX3 to repress the transcription of MYC and other oncogenes, but this repression is eliminated by the loss of ZFHX3. g, h Kaplan–Meier analysis of overall survival (g) and disease-free survival (h) of prostate cancer patients with different statuses of ZFHX3 and ESR2 expression. The n of a, b is 3. *P < 0.05; **P < 0.01; ns, not significant. ZFHX3, zinc-finger homeobox 3; ERβ, estrogen receptor beta; DPN, diarylpropionitrile