Histone H3 (K36M Mutant Specific) (E8N1L) Rabbit mAb #98399

Chondroblastoma is a rare type of benign tumor that is found at the rounded ends of the long bones in the arms and legs. More than 90% of chondroblastomas have been found to contain a heterozygous mutation in the H3F3A gene encoding the histone variant H3.3 (1). This mutation, a lysine to methionine amino acid substitution in codon 36 (K36M), inhibits at least two histone H3 lysine 36 methyltransferases, WHSC1 (MMSET) and SETD2, resulting in reduced global levels of histone H3 lysine 36 methylation (1). Chondrocytes containing the histone H3 K36M mutation exhibit several hallmarks of cancer cells, including increased ability to form colonies, resistance to apoptosis, and defects in differentiation. Reduction of global methylation levels in chondrocytes, resulting from the K36M mutation, contributes to tumorigenesis by altering the expression of cancer-associated genes. The histone H3 K36M mutation is also found to promote sarcomagenesis by impairing the differentiation of mesenchymal progenitor cells, resulting in undifferentiated sarcomas (2). The K36M mutation alters the histone methylation landscape, resulting in a genome-wide gain in histone H3 lysine 27 methylation, redistribution of polycomb repressive complex 1, and derepression of its target genes known to block mesenchymal differentiation. Finally, the histone H3 K36M mutation is also found in 13% of HPV-negative head and neck squamous cell carcinomas, again contributing to tumorigenesis by altering global methylation levels of histone H3 lysine 36 (3).