Phase II Study of Ramucirumab Plus Irinotecan Combination Therapy as Second-Line Treatment in Patients with Advanced Gastric Cancer: HGCSG1603.

Background: Ramucirumab is a human IgG1 monoclonal vascular endothelial growth factor receptor-2 antibody that inhibits tumor cell growth and affects the tumor cell microenvironment. We assessed the efficacy and safety of ramucirumab plus irinotecan combination therapy as second-line treatment in patients with previously treated advanced gastric cancer.

Materials And Methods: Patients with advanced gastric cancer refractory or intolerant to primary chemotherapy were included.

Identification of amphiphysin 1 as an endogenous substrate for CDKL5, a protein kinase associated with X-linked neurodevelopmental disorder.

Cyclin-dependent kinase-like 5 (CDKL5) is a Ser/Thr protein kinase predominantly expressed in brain and mutations of its gene are known to be associated with neurodevelopmental disorders such as X-linked West syndrome and Rett syndrome. However, the physiological substrates of CDKL5 that are directly linked to these neurodevelopmental disorders are currently unknown. In this study, we explored endogenous substrates for CDKL5 in mouse brain extracts fractionated by a liquid-phase isoelectric focusing.

Detection of protein kinase substrates in tissue extracts after separation by isoelectric focusing.

Here we report a simple and useful method to detect endogenous substrates of protein kinases. When crude tissue extracts were resolved by liquid-phase isoelectric focusing (MicroRotofor) and the separated protein fractions were phosphorylated by protein kinases such as Ca(2+)/calmodulin-dependent protein kinase I or cAMP-dependent protein kinase, various proteins in the different fractions were efficiently phosphorylated. Since a higher number of substrates could significantly be detected using the resolved fractions by MicroRotofor as compared to direct analysis of the original tissue extracts, our present method will be applicable to the screening of endogenous substrates for various protein kinases.

Cyclin-dependent kinase-like 5 binds and phosphorylates DNA methyltransferase 1.

DNA methyltransferase 1 (Dnmt1) is an enzyme that recognizes and methylates hemimethylated CpG after DNA replication to maintain methylation patterns. Although the N-terminal region of Dnmt1 is known to interact with various proteins, such as methyl-CpG-binding protein 2 (MeCP2), the associations of protein kinases with this region have not been reported. In the present study, we found that a 110-kDa protein kinase in mouse brain could bind to the N-terminal domain of Dnmt1.