Protein tyrosine kinases play a pivotal role in intracellular signal transduction pathways and oncogenic transformation. It is necessary to develop a simple, cost-effective, and sensitive kinase assay for study of protein kinases and discovery of kinase-target drugs. In this paper, we present a simple and sensitive method for homogeneous detection of protein kinase activity and screening of inhibitor by measuring surface charge change on the peptide-modified gold nanoparticles (GNPs) as kinase substrates. In this assay, Abl (Abelson murine leukemia viral oncogene) kinase was used as a model. In the presence of Abl kinase and ATP, the surface negative charge on GNPs significantly increases due to phosphorylation of the peptide-modified GNPs. The surface charge on the peptide-modified GNPs was measured by zeta potential analyzer. Under the optimum conditions, the zeta potential on the peptide-modified GNPs was linearly dependent on Abl kinase concentration, the linear range was from 1 to 40 nM and the detection limit was 1 nM. This method was used to evaluate the inhibition efficiency of inhibitors, and the obtained IC50 values were well in agreement with the results reported in the references. Furthermore, this method was successfully applied to determine Abl kinase activity in the cell lysates. Compared to current methods, this new method shows simplicity, short analysis time, high sensitivity, and will become a promising platform for kinase-related fundamental research and inhibitor screening.

ObjectivesThe aim of this study is to determine the correlation of pretreatment fluorine-18 fluorodeoxyglucose uptake with clinicopathological factors and its prognostic value in patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL).Patients and methodsA cohort of 162 patients with newly diagnosed DLBCL who had undergone pretreatment PET/computed tomography was retrospectively reviewed. The relationship of pretreatment maximum standard uptake value (SUVmax) with clinical factors, molecular markers, and efficacy was evaluated. The value of SUVmax in predicting progression-free survival (PFS) and overall survival was analyzed.ResultsIn all, 72.9% of the patients received R-CHOP treatment; the rest received CHOP chemotherapy. The median follow-up duration was 30 months (range, 4-124 months). The median SUVmax was 12.2 (range, 1.7-42.7). SUVmax between groups differed significantly with respect to each of International Prognostic Index (IPI) factors, except for age and performance status. High SUVmax was associated with high Ki-67 and Glut-3 protein expression, but not with Glut-1. Complete remission rate differed significantly between the low (SUV(max)9.0) and the high SUVmax (SUVmax>9.0) groups (91.7 vs. 61.1%, P=0.000). Patients with low SUVmax showed favorable survival (3-year PFS: 92.2 vs. 63.6%, P=0.000; 3-year overall survival: 95.5 vs. 78.3%, P=0.003). On multivariate analyses, SUVmax predicted PFS independent of revised-IPI (SUVmax: P=0.011, hazard ratio 4.784; revised-IPI: P=0.004, hazard ratio 2.551).ConclusionPretreatment SUVmax was associated with clinicopathological factors, efficacy, and survival outcome. A novel prognostic model on the basis of IPI score/pretreatment SUVmax might be useful for risk stratification of patients with newly diagnosed DLBCL Video abstract: http://links.lww.com/NMC/A55.

背景:肿瘤干细胞是肿瘤组织中—小部分具有自我更新、多向分化以及高度增殖能力的肿瘤细胞.研究发现表皮生长因子(EGF)可促进肿瘤干细胞增殖.目的:探讨EGF及其受体(EGFR)在结肠癌干细胞增殖调控中的作用.方法:结肠癌细胞株HT29、HCT116培养于无血清培养基中,以EGF、碱性成纤维细胞生长因子(bFGF)、胰岛素样生长因子(IGF)分别干预细胞.MTT法检测EGFR抑制剂吉非替尼对结肠癌细胞球细胞的增殖抑制作用,体外实验检测EGFR抑制剂吉非替尼、PD153035对细胞球形成的抑制作用,流式细胞术检测细胞凋亡.体内实验检测结肠癌细胞球和细胞株的成瘤能力,real-time PCR检测两者干细胞标记LGR5、Musashi-1和分化标记CK20表达.结果:EGF组HCT116细胞形成的细胞球数量显著高于空白对照、bFGF、IGF组(P＜0.05).吉非替尼能抑制HCT116细胞球细胞增殖和细胞球形成,并诱导细胞凋亡,作用呈浓度依赖性.HCT116细胞球成瘤时间较细胞株显著缩短,移植瘤体积显著增大(P＜0.05).LGR5、Musashi-1在细胞球中的表达显著高于细胞株,而CK20在细胞株中的表达显著高于细胞球(P＜0.05).结论:EGF对结肠癌细胞株HCT116、HT29形成细胞球具有促进作用.EGFR抑制剂可抑制结肠癌细胞球增殖并诱导细胞凋亡,相关作用可能与调控LGR5、Musashi-1和CK20表达有关.