Polycomb complex protein BMI-1 (BMI1) (BMI1)

Polycomb complex protein BMI-1, encoded by the BMI1 gene, is a core component of the Polycomb Repressive Complex 1 (PRC1), which plays a fundamental role in epigenetic gene silencing through histone H2A ubiquitination [1.1.2, 1.3.1]. It is a critical regulator of stem cell self-renewal in various tissues, including the hematopoietic and nervous systems, primarily by repressing the Ink4a/Arf locus that encodes the tumor suppressors p16INK4a and p14ARF [1.2.1, 1.3.1]. In oncology, BMI-1 is recognized as a potent oncogene that is frequently overexpressed in a wide range of malignancies, including leukemias and solid tumors like breast, lung, and pancreatic cancers [1.3.2, 1.4.1, 1.5.4]. Its overexpression promotes tumor growth, epithelial-mesenchymal transition, and chemoresistance by maintaining the cancer stem cell population and bypassing cellular senescence [1.4.1, 1.5.1]. Therapeutic strategies targeting BMI-1, such as small molecule inhibitors like PTC-596 and PTC-209, aim to reduce BMI-1 protein levels or disrupt its interaction within the PRC1 complex to reactivate silenced tumor suppressor genes [1.1.4, 1.3.4]. While promising, targeting BMI-1 presents challenges due to its essential role in normal adult stem cell maintenance, necessitating careful evaluation of potential toxicities [1.2.1, 1.3.1].

Other names

PCGF4 [1.2.1]RNF51 [1.2.1]FLVI2 [1.2.1]Polycomb group RING finger protein 4 [1.2.2]B lymphoma Mo-MLV insertion region 1 homolog [1.2.3]Murine leukemia viral (Bmi-1) oncogene homolog [1.2.3]

Inhibition of BMI1 protein expression or disruption of the Polycomb Repressive Complex 1 (PRC1) to reactivate silenced tumor suppressor genes [1.1.1, 1.3.4].