The incidence of aggressive neuroendocrine prostate cancers (NEPC) related to androgen-deprivation therapy (ADT) is rising. NEPC is still poorly understood, such as its neuroendocrine differentiation (NED) and angiogenic phenotypes. Here we reveal that NED and angiogenesis are molecularly connected through EZH2 (enhancer of zeste homolog 2). NED and angiogenesis are both regulated by ADT-activated CREB (cAMP response element-binding protein) that in turn enhances EZH2 activity. We also uncover anti-angiogenic factor TSP1 (thrombospondin-1, THBS1) as a direct target of EZH2 epigenetic repression. TSP1 is downregulated in advanced prostate cancer patient samples and negatively correlates with NE markers and EZH2. Furthermore, castration activates the CREB/EZH2 axis, concordantly affecting TSP1, angiogenesis and NE phenotypes in tumor xenografts. Notably, repressing CREB inhibits the CREB/EZH2 axis, tumor growth, NED, and angiogenesis in vivo. Taken together, we elucidate a new critical pathway, consisting of CREB/EZH2/TSP1, underlying ADT-enhanced NED and angiogenesis during prostate cancer progression.
Significance: Although the majority of cancer-related deaths are consequences of metastatic dissemination, the molecular and cellular forces that drive tumor cell dispersion are still poorly understood. To help identify new regulators that play critical roles in these processes, we screened for human kinases that are important for continued survival of metastatic cells. One kinase identified from these screens, the G-protein–coupled receptor kinase 3 (GRK3; or β-adrenergic receptor kinase 2), was found to have a key role in promoting prostate tumor growth and metastasis in mouse models through enhancing angiogenesis. Notably, GRK3 is overexpressed in human prostate metastatic tumors. Further studies on GRK3 and its pathways promise to expand our knowledge of cancer metastasis and also yield new cancer therapeutic targets.
CDKL2 promotes epithelial-mesenchymal transition and breast cancer progression CDKL2 promotes epithelial-mesenchymal transition and breast cancer progression
• Through unbiased kinome cDNA screening, we have identified creatine kinase brain-type (CKB) as a critical negative regulator of epithelial-mesenchymal transition . • CKB is expressed significantly lower in tumors than in normal tissues and its downregulation correlates with poor prognosis in several solid cancer types. • Its ectopic expression blocks, while its silencing promotes, AKT activation and prostate cancer progression. • CKB physically sequestrates AKT from interacting with mTORC2 complex. • We have also mapped the CKB and AKT interaction domains and further pinpointed a small fragment of 84aa on C-terminus of CKB protein as the key element in blocking AKT activation and Epithelial-mesenchymal transition.