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“Purpose: To evaluate the nature of cyclin-dependent Dibutyryl-cAMP price kinase 5 (CDK5) hyperactivity in pancreatic cancer progression.\n\nExperimental Design: We used genetic, biochemical, and molecular biology methods to investigate the nature and function of overexpression of CDK5 and its activators p35 and p39

during the progression of pancreatic cancer.\n\nResults: Amplification of the CDK5 gene or either of its main activators, p35 and p39, was observed in 67% of human pancreatic ductal adenocarcinoma (PDAC). CDK5, p35, and p39 were rarely expressed in pancreatic ducts whereas more than 90% of PDACs had increased levels of CDK5 and p35. Increased levels of CDK5, p35, and p39 protein were observed in several pancreatic cancer cell lines. Inhibition of CDK5 kinase activity using GSK1120212 a CDK5 dominant-negative mutant or the drug roscovitine significantly decreased the migration and invasion of pancreatic cancer cells in vitro. Increased CDK5 kinase activity was also observed in immortalized human pancreatic nestin-expressing (HPNE) cells expressing a mutant form of K-Ras (G12D) compared with HPNE cells expressing native K-Ras. G12D K-Ras increased cleavage of p35 to p25, a stable and greater activator of CDK5,

thus implicating a role for CDK5 in early progression of PDAC. Inhibition of the signaling cascade downstream of mutant K-Ras (G12D) that involves mitogen-activated protein/extracellular signal-regulated kinase, phosphoinositide 3-kinase, or CDK5 decreased p25 protein levels.\n\nConclusion: These results suggest that mutant

K-Ras acts in concert with CDK5 and its activators to increase malignant progression, migration, and invasion of pancreatic cancer cells. Clin Cancer Res; 17(19); 6140-50. (C) 2011 AACR.”
“Measuring CA153 serum levels in the early breast cancer setting is not recommended by current ASCO guidelines. In this large single center study, we assess the prognostic value of preoperative (n = 3746), postoperative selleck screening library (n = 4049) and change in (n = 3252) CA15.3, also across different breast cancer phenotypes. Preoperative, postoperative and change in CA15.3 were all significant (p = 0.0348, p < 0.0001, p < 0.0001 respectively in multivariate analysis) predictors of distant metastasis free survival. For breast cancer specific survival, only postoperative and change in CA153 were significant predictors (p < 0.0001 both). Multivariate prognostic models did not improve by incorporating information on preoperative CA15.3, but did improve when introducing information on postoperative CA153 for distant metastasis (p = 0.0365) and on change in CA15.3 for breast cancer specific survival (p = 0.0291). Change in CA15.3 impacts on prognosis (distant metastasis) differently in different breast cancer phenotypes. A decrease in CA15.3 may be informative of improved prognosis in basal like and HER2 like breast cancer. (C) 2013 Elsevier Ltd. All rights reserved.