CDK12 promotes tumorigenesis but induces vulnerability to therapies inhibiting folate one-carbon metabolism in breast cancer.

ABSTRACT: Cyclin-dependent kinase 12 (CDK12) overexpression is implicated in breast cancer, but whether it has a primary or only a cooperative tumorigenic role is unclear. Here, we show that transgenic CDK12 overexpression in the mouse mammary gland per se is sufficient to drive the emergence of multiple and multifocal tumors, while, in cooperation with known oncogenes or chemical carcinogens, it promotes earlier tumor onset and metastasis. Integrative transcriptomic, metabolomic and functional data revealed that enhanced glycolysis and hyperactivation of the serine-glycine-one- carbon network are metabolic hallmarks inherent to CDK12-induced tumorigenesis, which impose distinct metabolic dependencies in CDK12-transformed mammary epithelial cells. Consistently, in the retrospective analysis of adjuvant and neoadjuvant breast cancer patient cohorts and in prospective preclinical studies using primary-derived human breast tumor xenografts, CDK12-overexpressing breast cancers showed a more favorable disease course in response to methotrexate- based chemotherapy targeting CDK12-induced metabolic alterations, while appearing intrinsically refractory to other types of chemotherapy. Even more clinically relevant, in patients with hormone receptor-negative and lymph node-positive breast cancer who were randomized in an adjuvant phase III trial to 1-year low-dose metronomic methotrexate-based maintenance chemotherapy or no chemotherapy after standard adjuvant treatments, a high CDK12 status predicted a dramatic reduction in distant metastasis rate in the chemotherapy-treated vs. not-treated arm. Thus, by coupling tumor progression with metabolic reprogramming, CDK12 creates an actionable vulnerability for breast cancer therapy and might represent a suitable companion biomarker for targeted antimetabolite therapies in naturally occurring human breast cancers.

ORGANISM(S): Mus musculus Homo sapiens

PROVIDER: GSE189274 | GEO | 2022/02/22

REPOSITORIES: GEO