Polycomb protein SUZ12 (SUZ12)

Polycomb protein SUZ12 is a core structural subunit of the Polycomb Repressive Complex 2 (PRC2), an essential epigenetic regulator that mediates gene silencing through the trimethylation of histone H3 at lysine 27 (H3K27me3) (UniProt Q15022; Wikipedia). SUZ12 is critical for the stability of the PRC2 complex and is required for the methyltransferase activity of its catalytic subunit, EZH2 (GeneCards; NIH 1.1.3). In many cancers, SUZ12 is overexpressed or involved in chromosomal translocations, such as the JAZF1-SUZ12 fusion in endometrial stromal sarcoma, leading to the repression of tumor suppressor genes and promoting cell proliferation, metastasis, and stemness (NIH 1.1.4; 1.2.2). Conversely, loss-of-function mutations in SUZ12 are associated with overgrowth syndromes like Imagawa-Matsumoto syndrome and certain malignancies like malignant peripheral nerve sheath tumors (MPNST) (NIH 1.3.1; 2.2.4). Therapeutic strategies targeting SUZ12 include small-molecule inhibitors of the PRC2 complex, such as EZH2 or EED inhibitors, and emerging proteolysis-targeting chimeras (PROTACs) that induce the degradation of the entire complex (NIH 2.3.3; AstraZeneca). While targeting SUZ12 offers significant potential for treating various cancers, challenges include the risk of secondary malignancies and the essential role of PRC2 in normal development and hematopoiesis (NIH 2.1.1; 2.4.4).

Other names

CHET9JJAZ1IMMASKIAA0160Suppressor of zeste 12 protein homologChromatin precipitated E2F target 9 proteinJoined to JAZF1 protein

SUZ12 acts as an essential scaffold for the PRC2 complex, enabling the catalytic activity of EZH2/EZH1. Drugs targeting this axis (inhibitors or degraders) disrupt the complex's ability to maintain H3K27me3 marks, leading to the reactivation of silenced tumor suppressor genes and inhibition of oncogenic pathways (NIH 1.2.3; 2.3.3).