Recently, Chandler and colleagues (35) demonstrated that mice with one allele of BAF250a deleted do not get cancer, but when bred to a mouse with a mutation in PI3K, they develop ovarian clear cell cancer, establishing this as an excellent model for these cancers. They found that PI3K leads to the dissociation of BAF complexes from the interleukin-6 (IL-6) promoter, relieving its repression and leading to high levels of IL-6 production in the murine cancers. Treating the mice with PI3K inhibitors leads to reduction in tumor growth. IL-6 is also produced from human cancers and appears to contribute to their growth. The mechanism by which PI3K inactivates BAF on the IL-6 promoter is unclear.
