HOXB13 interaction with MEIS1 modifies proliferation and gene expression in prostate cancer

Area of Science:

• Molecular Biology
• Cancer Research
• Genetics

Background:

• The germline mutation p.Gly84Glu (G84E) in HOXB13 is linked to prostate cancer (PCa), but the underlying mechanisms are unclear.
• HOXB13 mutations often occur in domains interacting with MEIS cofactors, suggesting a role in PCa pathogenesis.

Purpose of the Study:

• To investigate the biochemical and functional interactions between HOXB13 and MEIS in prostate cells.
• To determine how the HOXB13-MEIS complex influences PCa pathobiology and the G84E mutation's effect on this interaction.

Main Methods:

• Assessed HOXB13 and MEIS paralog expression using qPCR and immunoblot.
• Confirmed HOXB13-MEIS1 co-expression and interaction in prostate tissue and cell lines via IHC and co-IP.
• Evaluated PCa cell proliferation, transcriptional targets, and HOXB13 protein stability.

Main Results:

• HOXB13 and MEIS1 are co-expressed and interact in prostate cells, independent of the G84E mutation.
• MEIS1 knockdown augmented the inhibitory effect of HOXB13 knockdown on proliferation and abolished HOXB13-driven gene regulation.
• MEIS1 was found to stabilize the HOXB13 protein.

Conclusions:

• Functional HOXB13-MEIS1 interactions are evident in prostate cancer.
• MEIS1 may promote PCa by stabilizing HOXB13, enhancing cellular proliferation and gene regulation.
• The G84E mutation does not impair HOXB13 stability or its interaction with MEIS1.