16 research outputs found
Rho-associated kinase signalling and the cancer microenvironment: novel biological implications and therapeutic opportunities
Antitumor activity of UCN-01 in carcinomas of the head and neck is associated with altered expression of cyclin D3 and p27KIP1.
Altered and deregulated cyclin-dependent kinase (cdk) activity is now believed to play a major role in the pathogenesis of head and neck squamous cell carcinomas (HNSCC), thus providing a suitable cellular target for therapeutic intervention. UCN-01 (7-hydroxy-staurosporine), a known protein kinase C and cdk modulator, demonstrates antiproliferative and antitumor properties in many experimental tumor models and may represent a potential candidate to test in HNSCC. In this study, UCN-01 displayed potent antiproliferative properties (IC50 of ∼17–80 nm) in HNSCC cells. Cell cycle analysis revealed that UCN-01 treatment of HNSCC cells for 24 h leads to a G1 block with a concomitant loss of cells in S and G2-M and the emerging sub-G1 cell population, confirmed to be apoptotic by terminal deoxynucleotidyl transferase-mediated nick end labeling analysis. Additional in vitro studies demonstrated a G1 arrest that was preceded by depletion in cyclin D3, elevation of p21WAF1 and p27KIP1 leading to a loss in activity of G1 cdks (cdk2, cdk4), and reduction in pRb phosphorylation. Antitumor properties of UCN-01 were also assessed in vivo by treating HN12 xenografts (7.5 mg/kg/i.p./daily) with UCN-01 for 5 consecutive days. Total sustained abolition of tumor growth (P < 0.00001) was obtained with only one cycle of UCN-01 treatment. Terminal deoxynucleotidyl transferase-mediated nick end labeling staining of xenograft samples revealed a higher incidence of apoptosis in treated tissues when compared with control. Additional tissue analysis demonstrated that elevated p27KIP1 with minimal increase in p21WAF1 and reduced cyclin D3 levels were readily detected in those animals treated with UCN-01, similar to those observed in HNSCC cells. Thus, UCN-01 exhibits both in vitro and in vivo antitumor properties in HNSCC models, and these effects are associated with a decrease in cyclin D3 and an increase in p27KIP1 protein levels, thus providing appropriate surrogate markers to follow treatment efficacy in vivo and, therefore, a suitable drug candidate for treating HNSCC patients
The 6-minute pegboard and ring test is correlated with upper extremity activity of daily living in chronic obstructive pulmonary disease
Kenichi Takeda,1 Yuji Kawasaki,2 Kazumasa Yoshida,3 Yoji Nishida,3 Tomoya Harada,1 Kosuke Yamaguchi,2 Shizuka Ito,1 Kiyoshi Hashimoto,1 Shingo Matsumoto,1 Akira Yamasaki,1 Tadashi Igishi,1 Eiji Shimizu1 1Division of Medical Oncology and Molecular Respirology, Department of Multidisciplinary Internal Medicine, Tottori University, Yonago, Japan; 2Department of Regional Medicine, Faculty of Medicine, Tottori University, Yonago, Japan; 3Department of Rehabilitation Medicine, Yoka Hospital, Yabu, Japan Background: Upper-extremity exercise is for pulmonary rehabilitation. The 6-minute pegboard and ring test (6PBRT) was developed to evaluate arm exercise capacity in patients with chronic obstructive pulmonary disease (COPD). The purpose of this study was to characterize the 6PBRT and evaluate its relationship with upper-extremity activities of daily living (ADLs) in COPD patients. Methods: Twenty outpatients with mild to very severe COPD underwent the 6PBRT and spirometry, and their maximal inspiratory and expiratory pressures and grip strength were measured. For the 6PBRT, subjects were asked to move as many rings as possible in 6 minutes, and the score was the number of moved rings during the 6-minute period. Upper-extremity ADLs were evaluated with the upper extremity activities subdomain of the modified Pulmonary Functional Status and Dyspnea Questionnaire. Upper-extremity ADLs were also measured objectively by using a wrist accelerometer every day for 1 week. Results: There was a positive correlation between 6PBRT score and inspiratory capacity (r = 0.71, P < 0.001), inspiratory capacity/total lung capacity predicted (r = 0.68, P < 0.01), and forced vial capacity (r = 0.57, P < 0.01). There was also a positive correlation between 6PBRT score and accelerometer count (r = 0.54, P < 0.05) and a negative correlation between 6PBRT score and arm activity score (ρ = -0.49, P < 0.05). Conclusion: The 6PBRT may be a predictive test to maintain and improve upper-extremity ADL during pulmonary rehabilitation in patients with COPD. Keywords: pulmonary rehabilitation, inspiratory capacity, COPD, wrist accelerometer, modified Pulmonary Functional Status and Dyspnea Questionnair
Role of Src in C3 transient receptor potential channel function and evidence for a heterogeneous makeup of receptor- and store-operated Ca(2+) entry channels
Receptor-operated Ca(2+) entry (ROCE) and store-operated Ca(2+) entry (SOCE) are known to be inhibited by tyrosine kinase inhibitors and activation of C-type transient receptor potential channel (TRPC) isoform 3 (TRPC3), a cation channel thought to be involved in SOCE and/or ROCE, was recently shown to depend on src tyrosine kinase activity. What is not known is the step at which src acts on TRPC3 and whether the role for tyrosine kinases in ROCE or SOCE is a general phenomenon. Using in vitro and in cell protein-protein interaction assays we now report that src phosphorylates TRPC3 at Y226 and that formation of phospho-Y226 is essential for TRPC3 activation. This requirement is unique for TRPC3 because (i) mutation of the cognate tyrosines of the closely related TRPC6 and TRPC7 had no effect; (ii) TRPC6 and TRPC7 were activated in src-, yes-, and fyn-deficient cells; and (iii) src, but not yes or fyn, rescued TRPC3 activation in src-, yes-, and fyn-deficient cells. The Src homology 2 domain of src was found to interact with either the N or the C termini of all TRPCs, suggesting that other tyrosine kinases may play a role in ion fluxes mediated by TRPCs other than TRPC3. A side-by-side comparison of the effects of genistein (a general tyrosine kinase inhibitor) on endogenous ROCE and SOCE in mouse fibroblasts, HEK and COS-7 cells, and ROCE in HEK cells mediated by TRPC3, TRPC6, TRPC7, and TRPC5 showed differences that argue for ROCE and SOCE channels to be heterogeneous