34 research outputs found
Protein kinase C β ノ カジョウ ハツゲン ハ バルーン ショウガイゴ ノ ラット ケイドウミャク ノ ナイマク ヒコウ ヲ ソクシンスル
Vigorous restenosis is responsible for high failure rates of angioplasty in diabetic patients. Sinceprotein kinase C (PKC)β isoform activation is associated with vascular complications of diabetes, we havedetermined whether PKCβ isoform overexpression can stimulate growth and migration of vascular smoothmuscle cells (SMCs) and cause an acceleration of arterial intimal hyperplasia. Overexpression of PKCβ1(adv-PKCβ1) or β-galactosidase (adv-βgal) were achieved using replication-deficient adenovirus vectors incultured rat aortic SMCs and rat carotid arteries after balloon injury. Rat aortic SMCs infected with adv-PKCβ1 at 109 PFU/ml increased PKC activity and PKCβ1 isoform protein level by more than 10-fold comparedto adv-βgal infected SMCs at 4 days after infection. The growth and migration rates in PKCβ1 overexpressedSMCs were increased by 1.5- to 1.9-fold compared to adv-βgal infected SMCs. Protein levels ofPKCβ1 isoform in adv-PKCβ1 infected arteries were increased by 4.2- and 2.0-fold compared to non-infectedand adv-βgal infected arteries, respectively, at 7 days after adenovirus infection. Ratio of intima/media area,a marker of restenosis, were 0.26±0.08 and 0.54±0.14 (p<0.05) at 7 days after infection in adv-βgal and adv-PKCβ1 infected arteries, respectively. Thus, overexpression of PKCβ isoform can enhance vascular SMCsmigration and growth, causing an accelerated rate of intimal hyperplasia, and may involve the restenoticprocess after angioplasty in diabetic patients
Quantitative Values from Synthetic MRI Correlate with Breast Cancer Subtypes
The purpose of this study is to correlate quantitative T1, T2, and proton density (PD) values with breast cancer subtypes. Twenty-eight breast cancer patients underwent MRI of the breast including synthetic MRI. T1, T2, and PD values were correlated with Ki-67 and were compared between ER-positive and ER-negative cancers, and between Luminal A and Luminal B cancers. The effectiveness of T1, T2, and PD in differentiating the ER-negative from the ER-positive group and Luminal A from Luminal B cancers was evaluated using receiver operating characteristic analysis. Mean T2 relaxation of ER-negative cancers was significantly higher than that of ER-positive cancers (p < 0.05). The T1, T2, and PD values exhibited a strong positive correlation with Ki-67 (Pearson’s r = 0.75, 0.69, and 0.60 respectively; p < 0.001). Among ER-positive cancers, T1, T2, and PD values of Luminal A cancers were significantly lower than those of Luminal B cancers (p < 0.05). The area under the curve (AUC) of T2 for discriminating ER-negative from ER-positive cancers was 0.87 (95% CI: 0.69–0.97). The AUC of T1 for discriminating Luminal A from Luminal B cancers was 0.83 (95% CI: 0.61–0.95). In conclusion, quantitative values derived from synthetic MRI show potential for subtyping of invasive breast cancers
Optimization of prediction methods for risk assessment of pathogenic germline variants in the Japanese population
Predicting pathogenic germline variants (PGVs) in breast cancer patients is important for selecting optimal therapeutics and implementing risk reduction strategies. However, PGV risk factors and the performance of prediction methods in the Japanese population remain unclear. We investigated clinicopathological risk factors using the Tyrer-Cuzick (TC) breast cancer risk evaluation tool to predict BRCA PGVs in unselected Japanese breast cancer patients (n = 1, 995). Eleven breast cancer susceptibility genes were analyzed using target-capture sequencing in a previous study; the PGV prevalence in BRCA1, BRCA2, and PALB2 was 0.75%, 3.1%, and 0.45%, respectively. Significant associations were found between the presence of BRCA PGVs and early disease onset, number of familial cancer cases (up to third-degree relatives), triple-negative breast cancer patients under the age of 60, and ovarian cancer history (all P < .0001). In total, 816 patients (40.9%) satisfied the National Comprehensive Cancer Network (NCCN) guidelines for recommending multigene testing. The sensitivity and specificity of the NCCN criteria for discriminating PGV carriers from noncarriers were 71.3% and 60.7%, respectively. The TC model showed good discrimination for predicting BRCA PGVs (area under the curve, 0.75; 95% confidence interval, 0.69-0.81). Furthermore, use of the TC model with an optimized cutoff of TC score ≥0.16% in addition to the NCCN guidelines improved the predictive efficiency for high-risk groups (sensitivity, 77.2%; specificity, 54.8%; about 11 genes). Given the influence of ethnic differences on prediction, we consider that further studies are warranted to elucidate the role of environmental and genetic factors for realizing precise prediction
Overexpression of protein kinase C β isoform by adenoviral gene transfer accelerated intimal hyperplasia in rat carotid artery
Vigorous restenosis is responsible for high failure rates of angioplasty in diabetic patients. Sinceprotein kinase C (PKC)β isoform activation is associated with vascular complications of diabetes, we havedetermined whether PKCβ isoform overexpression can stimulate growth and migration of vascular smoothmuscle cells (SMCs) and cause an acceleration of arterial intimal hyperplasia. Overexpression of PKCβ1(adv-PKCβ1) or β-galactosidase (adv-βgal) were achieved using replication-deficient adenovirus vectors incultured rat aortic SMCs and rat carotid arteries after balloon injury. Rat aortic SMCs infected with adv-PKCβ1 at 109 PFU/ml increased PKC activity and PKCβ1 isoform protein level by more than 10-fold comparedto adv-βgal infected SMCs at 4 days after infection. The growth and migration rates in PKCβ1 overexpressedSMCs were increased by 1.5- to 1.9-fold compared to adv-βgal infected SMCs. Protein levels ofPKCβ1 isoform in adv-PKCβ1 infected arteries were increased by 4.2- and 2.0-fold compared to non-infectedand adv-βgal infected arteries, respectively, at 7 days after adenovirus infection. Ratio of intima/media area,a marker of restenosis, were 0.26±0.08 and 0.54±0.14 (p<0.05) at 7 days after infection in adv-βgal and adv-PKCβ1 infected arteries, respectively. Thus, overexpression of PKCβ isoform can enhance vascular SMCsmigration and growth, causing an accelerated rate of intimal hyperplasia, and may involve the restenoticprocess after angioplasty in diabetic patients
Evaluation of radiobromine-labeled 5-bromo-4\u27-thio-2\u27-deoxyuridine uptake in ACHN cells after treatment with 5-fluorouracil: comparison with 3H-FLT uptake.
Objectives: We have recently developed the radiobromine-labeled 5-bromo 4\u27-thio-2\u27-deoxyuridine (BTdU) as an imaigng agent for tumor proliferation. The aim of this study was to evaluate the potential usefulness of radiobromine-labeled BTdU as an imaging agent for detecting the early therapeutic effects of 5-fluorouracil (5-FU) compared with 3H-FLT uptake. \nMethods: The radiolabeling of BTdU with 77Br was achieved by a destannylation reaction of tributylstannyl precursor. 3H-FLT was commerically available. The cells of human renal cacinoma cell line, ACHN, were treated with various concentrations of 5-FU (0.01-300 µM). At 36 hr after 5-FU addition, double tracer cell uptake studies were performed. 2.0x10-2 MBq of 77Br-BTdU and 3.7x10-2 MBq of 3H-FLT were simaltaneously added to the cells and incubated for 15min, 30min, 60min. After 3 times washing, cells were lysed, and then the radioactivity and protein content were measured. \nResults: The radiochemical yield of 77Br-BTdU was about 40% and the radiochemical purity was more than 99%. Uptakes of 77Br-BTdU and 3H-FLT were increased with time. There was not significant differences between the uptake of 77Br-BTdU and that of 3H-FLT in control group at 60min (77Br-BTdU: 18.5 +- 2.0,3H-FLT: 20.3 +- 2.7 %ID/mg protein). Compared with control the uptake of 77Br-BTdU was significantlty decreased from 0.3 µM of 5-FU (One-way ANOVA with a post hoc Dunnett\u27s Multiple Comparison Test). However, the uptake of 3H-FLT was significantly decreased from 300 µM of 5-FU. These results suggest that 77Br-BTdU could detect the earlier effect of 5-FU compared with 3H-FLT. \nConclusions: Radiobromine-labeled BTdU is potentially useful as an imaging agent for detecting the early therapeutic effects of anticancer therapy with 5-FU in patients with renal cell carcinomaSNM 2011 Annual Meetin
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Mechanisms of Hepatocyte Growth Factor–Induced Retinal Endothelial Cell Migration and Growth
Purpose. Hepatocyte growth factor (HGF), also called scatter factor, stimulates growth and motility in nonocular endothelial cells and smooth muscle cells through its receptor c-Met. Recent reports suggest that HGF is increased in the serum and vitreous of patients with proliferative diabetic retinopathy and that smooth muscle cells and retinal pigment epithelial cells secrete HGF in the eye. However, little is known about HGF’s action in the retina. In this study, the activity, expression, and signaling pathways of HGF were investigated in bovine retinal microvascular endothelial cells (BRECs). Methods. Mitogenic and motogeneic effects of HGF on BRECs were examined using cell counts, thymidine uptake, and migration assays. MAP kinase (MAPK) phosphorylation was examined by Western blot analysis. Protein kinase C (PKC), MAPK, and PI3 kinase involvement were evaluated using selective inhibitors and activity assays. Expression of HGF and c-Met was evaluated by reverse transcription–polymerase chain reaction. Results. HGF and c-Met were both expressed in BRECs. HGF stimulated BREC growth in a time- and dose-dependent manner, observed at HGF concentrations of 5 ng/ml or more and maximal (410%) at 100 ng/ml (P 80-fold, P 20-fold, P < 0.001), respectively. MAPK phosphorylation was maintained for more than 2 hours. This response was inhibited 31% by 0.1 μm wortmannin and 76% by 30 μm LY294002, another PI3 kinase inhibitor. The non–isoform-selective PKC inhibitor GFX inhibited HGF-induced MAPK phosphorylation by only 15% at 5 μm. Combined PKC and PI3 kinase inhibition was additive (P < 0.05). Cell migration was inhibited 30% by wortmannin (P < 0.01) and 32% by GFX (P < 0.05), and again the effect was additive (P < 0.001). HGF-induced BREC growth was suppressed by PI3 kinase, PKC, or MAPK inhibition (all P < 0.01). HGF (50 ng/ml) stimulated PI3 kinase activity 347% (P < 0.001) and PKC activity 37% (P < 0.05). HGF-induced MAPK phosphorylation and mitogenesis were not inhibited by vascular endothelial growth factor (VEGF)–neutralizing antibody. Conclusions. HGF and its receptor are expressed in BREC, and HGF stimulates both BREC growth and migration at concentrations observed in the human eye with diabetic retinopathy. HGF signaling appears to involve activation of both PKC and PI3 kinase, inducing MAPK phosphorylation that is critical for migration and growth. However, VEGF does not appear to mediate these initial HGF effects. These results indicate that HGF could have a significant role in mediating retinal endothelial cell proliferation and migration in diabetic retinopathy, and they begin to elucidate the signal transduction pathway by which this action may occur
Drugs interacting with organic anion transporter-1 affect uptake of Tc-99m-mercaptoacetyl-triglycine (MAG3) in the human kidney: Therapeutic drug interaction in Tc-99m-MAG3 diagnosis of renal function and possible application of Tc-99m-MAG3 for drug development
IntroductionRenal uptake of Tc-99m-MG3 involves organic anion transporter (OAT). Treatment with drugs showing OAT affinity might interfere with renal uptake of Tc-99m-MAG3, leading to misinterpretation in Tc-99m-MAG3. This study was conducted to discuss a possible drug interference with Tc-99m-MAG3 diagnosis on OAT sites.MethodsRenal uptake and plasma clearance of Tc-99m-MAG3 were analyzed in healthy volunteers under control and OAT1 and OAT3 related drug treatment conditions. An in vitro uptake study using OAT1 or OAT3 expressing cells was also conducted.ResultsBoth PAH and probenecid treatment induced delays in Tc-99m-MAG3 clearance from blood, and reductions in the renal uptake clearance. As a result, the normalized effective renal plasma flow estimated from Tc-99m-MAG3 clearance was significantly underestimated, whereas the glomerular filtration rate estimated from plasma creatinine levels was unchanged. The transport activity of Tc-99m-MAG3 was higher in OAT1-expressing cells than in OAT3-expressing cells.ConclusionDrugs with OAT1 affinity affect the renal uptake of Tc-99m-MAG3 and blood clearance. This might cause misinterpretation of functional diagnosis of the kidney using Tc-99m-MAG3
Quantitative Values from Synthetic MRI Correlate with Breast Cancer Subtypes
The purpose of this study is to correlate quantitative T1, T2, and proton density (PD) values with breast cancer subtypes. Twenty-eight breast cancer patients underwent MRI of the breast including synthetic MRI. T1, T2, and PD values were correlated with Ki-67 and were compared between ER-positive and ER-negative cancers, and between Luminal A and Luminal B cancers. The effectiveness of T1, T2, and PD in differentiating the ER-negative from the ER-positive group and Luminal A from Luminal B cancers was evaluated using receiver operating characteristic analysis. Mean T2 relaxation of ER-negative cancers was significantly higher than that of ER-positive cancers (p < 0.05). The T1, T2, and PD values exhibited a strong positive correlation with Ki-67 (Pearson’s r = 0.75, 0.69, and 0.60 respectively; p < 0.001). Among ER-positive cancers, T1, T2, and PD values of Luminal A cancers were significantly lower than those of Luminal B cancers (p < 0.05). The area under the curve (AUC) of T2 for discriminating ER-negative from ER-positive cancers was 0.87 (95% CI: 0.69–0.97). The AUC of T1 for discriminating Luminal A from Luminal B cancers was 0.83 (95% CI: 0.61–0.95). In conclusion, quantitative values derived from synthetic MRI show potential for subtyping of invasive breast cancers.</p