Outcome of Patients With Cardiac Sarcoidosis Who Received Cardiac Resynchronization Therapy: Comparison With Dilated Cardiomyopathy Patients.

INTRODUCTION: Cardiac resynchronization therapy (CRT) has been shown to be effective for patients with chronic heart failure; however, the efficacy of CRT in patients with cardiac sarcoidosis (CS) has not been established. METHODS: We compared the outcomes of patients with CS who received CRT to patients with dilated cardiomyopathy (DCM). The incidence of major adverse cerebral and cardiovascular events (MACCE) in 11 consecutive CS patients (8 females; mean age, 66 ± 8.0 years) who received CRT were compared with 29 DCM patients (9 females; mean age, 70 ± 8.9 years). RESULTS: Females and patients with previous right ventricular pacing were largely included in the comparison of CS and DCM patients (P < 0.05 and P < 0.0001, respectively). During the mean follow-up period (465 ± 383 days for CS and 729 ± 393 days for DCM), MACCE were evident in 9 patients (23%); specifically, 5 CS and 4 DCM patients developed MACCE (45% vs. 14%, P < 0.05), respectively. Kaplan-Meier survival analysis demonstrated that CS patients had a higher prevalence of MACCE than DCM patients (log rank = 6.306, P = 0.0120; and Wilcoxon = 7.1333, P = 0.0076). Based on univariate analysis, the etiology of CS was associated with MACCE. CONCLUSION: Our results suggest that the long-term outcome of CRT in patients with CS was very poor compared with DCM patients. Thus, caution should be exercised regarding the indication of CRT in patients with CS.

Mast Cells Play an Important Role in the Pathogenesis of Hyperglycemia-Induced Atrial Fibrillation.

BACKGROUND AND OBJECTIVES: Recently, it was reported that mast cells (MCs) could underlie the mechanisms of several cardiovascular diseases. However, the role of MCs in diabetes-induced atrial fibrillation (AF) has not been notably investigated. We tested the hypothesis that MC deficiency attenuates hyperglycemia-induced AF in mice. METHODS AND RESULTS: Mast cell-deficient W/W(v)  mice, and congenic +/+ littermates (WT) were divided into either the vehicle (VEH)-injection group or the streptozotocin (STZ)-injection group (MCKO-VEH, MCKO-STZ, WT-VEH, and WT-STZ groups). On day 28 of our studies, we observed that (1) STZ-induced hyperglycemia increased MC infiltration in the left atrium (LA) in WT mice (P < 0.01), (2) atrium isolated from the WT-STZ group showed inhomogeneous interstitial fibrosis, abundant infiltration of macrophages, and enhanced apoptosis compared to the WT-VEH group (P < 0.01, P < 0.01, P < 0.05, respectively). However, the changes observed in the WT-STZ group were significantly attenuated in the MCKO-STZ mice. In addition, we observed that (3) messenger RNA levels of tumor necrosis factor-α, monocyte chemoattractant protein-1, interleukin-1ß, transforming growth factor-ß, and collagen-1 in the LA were increased in the WT-STZ group, but not in the MCKO-STZ group, (4) STZ-induced hyperglycemia increased AF induction and prolonged interatrial conduction time in the WT mice, which were not observed in the MCKO mice, and that (5) hyperglycemia-enhanced atrial production of reactive oxygen species (ROS) was equally observed in the WT and MCKO mice. CONCLUSIONS: Our results suggest that MCs contribute to the pathogenesis of hyperglycemia-induced AF via enhancement of inflammation and fibrosis.

HIF-1alpha and HIF-2alpha have divergent roles in colon cancer.

Hypoxia-inducible factor (HIF)-1 and HIF-2 are heterodimeric transcription factors that mediate the cellular response to hypoxia. Their key regulatory subunits, HIF-1alpha and HIF-2alpha, are induced similarly by hypoxia, but their functional roles in cancer may be distinct and isoform-specific. SW480 colon cancer cells with stable expression of siRNA to HIF-1alpha or HIF-2alpha or both were established. HIF-1alpha-deficient cells displayed lower rates of proliferation and migration, but HIF-2alpha-deficient cells exhibited enhanced anchorage independent growth in a soft agar assay. Xenograft studies revealed that HIF-1alpha deficiency inhibited overall tumor growth, whereas deficiency of HIF-2alpha stimulated tumor growth. In human colon cancer tissues, expression of HIF-1alpha and to a lesser extent, HIF-2alpha, was linked to upregulation of VEGF and tumor angiogenesis. However, loss of expression of HIF-2alpha but not HIF-1alpha was strongly correlated with advanced tumor stage. DNA microarray analysis identified distinct sets of HIF-1alpha and HIF-2alpha target genes that may explain these phenotypic differences. Collectively, these findings suggest that HIF isoforms may have differing cellular functions in colon cancer. In particular, HIF-1alpha promoted the growth of SW480 colon cancer cells but HIF-2alpha appeared to restrain growth. Consequently, therapeutic approaches that target HIF may need to consider these isoform-specific properties.

Hoxc6 is overexpressed in gastrointestinal carcinoids and interacts with JunD to regulate tumor growth.

BACKGROUND & AIMS: The molecular alterations that underlie carcinoid tumor pathogenesis remain poorly defined. The homeobox gene HOXC6 was highly up-regulated in human gastrointestinal carcinoid tumors, and we sought to define its pathogenic role. METHODS: The functional and physical properties of Hoxc6 were investigated by establishing carcinoid cells that stably overexpressed Hoxc6 or were deficient in Hoxc6. Cellular proliferation assays, luciferase reporter assays, Western blotting, immunoprecipitation, DNA affinity precipitation, and DNA microarray studies were performed. RESULTS: Expression of Hoxc6 in cultured human BON1 carcinoid cells enhanced their proliferation, and knock-down of Hoxc6 inhibited their growth. Hoxc6 activated the oncogenic activator protein-1 signaling pathway through a physical interaction with JunD. Mutations in the homeodomain of Hoxc6 blocked this interaction and inhibited proliferation of carcinoid cells. Of note, Hoxc6 induced the expression of genes that characteristically are up-regulated in carcinoid tumors, including neurotensin and connective tissue growth factor. CONCLUSIONS: A novel molecular pathway has been identified that links Hoxc6 with oncogenic signaling through the activator protein-1 pathway in carcinoid tumorigenesis.

A case of Type-C Wolff-Parkinson-White syndrome with severe left ventricular dysfunction: Efficacy of catheter ablation.

The present case report describes a 59-year-old female with manifest Wolff-Parkinson-White syndrome and severe left ventricular (LV) dysfunction, however, there was no indication of heart palpitations. The polarity of delta is consistent with the features of the right anteroseptal accessory pathways (APs). The echocardiography showed a remarkable dyssynchrony of the LV wall motion. To circumvent the cardiac dysfunctions, radiofrequency catheter ablation (RFCA) was successfully performed to disconnect the AP. Thereafter, the dyssynchrony disappeared, and the clinical reports observed 6 months following RFCA showed that the LV ejection fraction had been improved from 13% up to 48%, in addition to the improvement in other parameters. The RFCA prevented her from receiving a cardiac resynchronization therapy defibrillator as well as a heart transplantation. .

Smad4 silencing in pancreatic cancer cell lines using stable RNA interference and gene expression profiles induced by transforming growth factor-beta.

The transforming growth factor-beta (TGF-beta)-Smad signaling pathway inhibits the growth of human epithelial cells and plays a role in tumor suppression. The Smad4 gene is mutated or deleted in 50% of pancreatic cancers. In this study, we succeeded in establishing Smad4 knockdown (S4KD) pancreatic cancer cell lines using the stable RNA interference (RNAi) method. Smad4 protein expression was reduced dramatically and TGF-beta-Smad signaling was markedly inhibited in the S4KD cell lines. The S4KD and control cells were stimulated with TGF-beta and analysed using a cDNA microarray that contained 3756 genes, in order to screen for target molecules downstream of TGF-beta. The microarray analysis revealed that 187 S4KD genes and 155 genes in the control cells were regulated immediately upon TGF-beta stimulation. Quantitative RT-PCR analysis on several of these genes produced results that corroborated the outcome of the microarray analysis. Most of the genes in the S4KD and control cells identified by the array differed, which suggests signaling pathways that differ according to Smad4 status. Of the identified genes, 246 have not been reported previously as genes that lie downstream of TGF-beta. Genes that are involved in cell proliferation, adhesion, and motility were found to be regulated differentially with respect to S4KD and control cells. Cell migration induced by TGF-beta was inhibited in the S4KD cells, which might be associated with a different regulation of integrin beta7. The knock down of a specific gene using stable RNAi appears to be a promising tool for analysing endogenous gene function.

Functional analysis of mutations within the kinase activation segment of B-Raf in human colorectal tumors.

Mutations in the B-Raf gene have been reported in a number of human cancers, including colorectal carcinoma. More than 80% of the B-Raf mutations were V599E. Although other mutations have been reported, their functional consequences were unclear. Here, we examined the effect of colon tumor-associated B-Raf mutations within the kinase activation segment, including V599E, on extracellular signal-regulated kinase (Erk) and nuclear factor kappaB (NFkappaB) signaling, and on the transformation of NIH3T3 fibroblasts. Among the six mutations examined, only the B-Raf V599E and K600E mutations greatly increased Erk and NFkappaB signaling, and the transformation of NIH3T3 cells. The B-Raf F594L mutation moderately elevated Erk signaling and NIH3T3 transformation, but did not significantly increase NFkappaB signaling. Although the basal kinase activity of the B-Raf T598I mutant was comparable with that of wild-type, its oncogenic Ras-induced kinase activity was decreased to 60% of wild-type activity. The B-Raf D593V and G595R mutants showed severely reduced kinase activity and affected neither NFkappaB signaling nor NIH3T3 transforming activity. These results suggest that the B-Raf activation segment mutations other than V599E reported in colorectal tumors do not necessarily contribute to carcinogenesis by increasing kinase and transforming activities.

Different effects of point mutations within the B-Raf glycine-rich loop in colorectal tumors on mitogen-activated protein/extracellular signal-regulated kinase kinase/extracellular signal-regulated kinase and nuclear factor kappaB pathway and cellular transformation.

Recently, mutations in the B-Raf gene have been identified in a variety of human cancers, such as melanoma and colorectal carcinoma, and more than 80% of the B-Raf mutations have been V599E. Although other mutations have been reported, their functional consequences are poorly understood. In our earlier study, we demonstrated that colon tumor-associated B-Raf mutations within the kinase activation segment are not necessarily associated with an increase in mitogen-activated protein/extracellular signal-regulated kinase kinase/extracellular signal-regulated kinase (MEK/Erk) or nuclear factor kappaB (NFkappaB) signaling activity or in NIH3T3-transforming ability. In this study, we examined the effect of colon tumor-associated mutations within the B-Raf glycine-rich loop (G loop) on MEK/Erk and NFkappaB signaling and on the transformation of NIH3T3 fibroblasts or IEC-6 intestinal epithelial cells. Of the six G loop mutations examined, only the B-Raf G468A significantly increased MEK/Erk and NFkappaB signaling and NIH3T3 transformation. Only this mutation induced transformed phenotypes of IEC-6 cells. In contrast, the B-Raf G468E mutation significantly decreased MEK/Erk signaling and NIH3T3 transformation and had no effect on NFkappaB signaling. The B-Raf F467C mutation moderately elevated MEK/Erk signaling and NIH3T3 transformation. The other three B-Raf mutations, R461I, I462S, and G463E, did not increase MEK/Erk or NFkappaB signaling or NIH3T3 transformation. Except for F467C, none of the tumors with B-Raf mutations examined in this study had K-Ras mutations. These results suggest that some of the B-Raf G loop mutations reported in colorectal tumors do not increase kinase or transforming activities but might contribute to carcinogenesis via other mechanisms or be irrelevant to carcinogenesis.

A case of anomalous origin of the left coronary artery from the pulmonary artery presenting with sudden cardiac arrest due to coronary artery steal generated by excessive exercise.

This case report describes a 43-year-old man who temporarily survived cardiac arrest that was prospectively related to ventricular fibrillation due to the anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA). Prior to admission to our hospital, he was asymptomatic for ALCAPA syndrome. Emergent coronary angiography revealed that the dilated right coronary artery was connected with extensive collateral vessels to the left coronary artery. The origin of the latter was in the pulmonary artery. Moreover, coronary steal phenomenon was identified by examining the pulmonary arterial blood oxygen saturation. The patient later died of acute decompensated acidosis. .

Bilateral spontaneous renal artery dissection.

Spontaneous renal artery dissection is a rare condition that precedes renal infarction. We describe a 48-year-old, normotensive healthy woman presenting with left flank pain of sudden onset. Enhanced abdominal computed tomography demonstrated a dissecting intimal flap of the left renal artery complicating renal infarction. Doppler ultrasonography, selective angiography, and intravascular ultrasound revealed a dissecting intimal flap, with a large false lumen and narrow true lumen, of the renal artery bilaterally. Conservative management was undertaken with anticoagulant and analgesic therapy, and the patient was discharged after an uneventful clinical course.

Colorimetric multiplexed immunoassay using specific aggregation of antigenic peptide-modified luminous nanoparticles.

A rapid immunoassay capable of detecting specific antibodies in one-step procedure is described. Antigenic peptides with cationic (KKKKC) or anionic (DDDDC) pentamer tail were immobilized on luminous nanospheres of 40 nm diameter (Ø) through cystamine and bifunctional linker molecules under various conditions. The numbers of each peptide anchored to a sphere were 5.0 x 10(2) and 0.8-3.8 x 10(3), respectively. A mixture of the antigenic peptides of FAK and c-Myc was immobilized to the spheres with red emission, while that of c-Myc and alpha-catenin was likewise to green spheres. Multiplexed immunoassay was easily achieved by adding the antibodies to a mixed dispersed solution of these spheres under appropriate conditions. Anti-FAK and anti-alpha-catenin antibodies formed aggregates with red and green emissions, respectively. On the other hand, the anti-c-Myc antibody formed aggregates emitting a yellow light. This system enabled us to differentiate three antibodies in one vessel from the definite differences in aggregate color.

TRAIL-induced cell death cooperates with IFN-gamma activation in the graft-versus-tumor effect against colon tumors.

The graft-versus-tumor (GVT) effect that occurs following allogeneic bone marrow transplantation (BMT) and donor lymphocyte infusion (DLI) is currently being subjected to intensive investigation because of clinical evidence for GVT efficacy against leukemia. In this report, we investigate the efficacy and molecular mechanisms of GVT against solid tumors, using a modification of the mouse parent-to-F1 BMT model. Mouse Colon26 cells in which tumor necrosis factor related apoptosis-inducing ligand (TRAIL) receptor expression was stably knocked down were transplanted to investigate the role of the TRAIL-TRAIL receptor system in the GVT effect. In addition, Fas ligand-(FasL) deficient mice on a C57BL6 (B6) background were used as donors, to determine the significance of the Fas-FasL system for the antitumor effect. The group that received B6 DLI followed by preconditioning with 950 rad irradiation underwent tumor reduction associated with the induction of IFN-gamma, TRAIL and tumor-cell apoptosis. In vitro cultured Colon26 cells were resistant to TRAIL but susceptible to the combination of IFN-gamma and TRAIL in a TRAIL-dose-dependent manner. The infusion of lymphocytes from FasL-defective donors reduced the tumor progression, although efficacy was decreased in the TRAIL receptor knockdown tumors but not in wild-type ones, compared with infusion of B6-derived lymphocytes. The findings indicate that GVT activity against subcutaneous colon tumors is efficiently induced by preconditioning with irradiation and allogeneic DLI, and that TRAIL and IFN-gamma act cooperatively in the antitumor effect.

Lamivudine treatment in a patient with hepatitis B virus reactivation after allogenic peripheral bone marrow transplantation.

We report the case of a 52-year-old woman with hepatitis B virus (HBV) reactivation during treatment for chronic graft vs. host disease (GVHD) after peripheral bone marrow transplantation (PBSCT) to treat chronic myelocytic leukemia. She was given cyclosporine and prednisolone orally to treat chronic GVHD after PBSCT. Liver dysfunction first developed 25 months after transplantation with the appearance of hepatitis B s antigen (HBsAg), hepatitis B e antigen (HBeAg), and elevation of HBV-DNA up to 4.5 log copies/ml. Retrospective examination of her serum before PBSCT proved negative for HBsAg and HBeAg, and positive for anti-HBsAg, anti-HBeAg, anti-hepatitis B core antigen, and HBV-DNA (2.7 log copies/ml), showing that she was in a state of occult HBV infection. Nucleotide sequences of the HBV genome obtained from her serum showed no core promoter mutations at nt 1762 and 1764 and no pre-core mutation at nt 1896. Polymerase chain reaction-restriction fragment length polymorphism showed that she was infected with HBV genotype B. The administration of lamivudine, a nucleoside analog, improved her liver function and reduced HBV-DNA replication. We conclude that antiviral agents, such as lamivudine, are effective for treating hepatitis B reactivation during immunosuppressive treatment, such as for GVHD. The administration of a nucleoside analog before transplantation should also be considered in the light of HBV genotypes and mutations, even if HBsAg was negative and the viral load was low before transplantation.

Proteomic analysis of the TGF-beta signaling pathway in pancreatic carcinoma cells using stable RNA interference to silence Smad4 expression.

Smad4 is a tumor-suppressor gene that is lost or mutated in 50% of pancreatic carcinomas. Smad4 is also an intracellular transmitter of transforming growth factor-beta (TGF-beta) signals. Although its tumor-suppressor function is presumed to reside in its capacity to mediate TGF-beta-induced growth inhibition, there seems to be a Smad4-independent TGF-beta signaling pathway. Here, we succeeded in establishing Smad4 knockdown (S4KD) pancreatic cancer cell lines using stable RNA interference. Smad4 protein expression and TGF-beta-Smad4 signaling were impaired in S4KD cells, and we compared the proteomic changes with TGF-beta stimulation using two-dimensional gel electrophoresis (2-DE) and mass spectrometry. We identified five proteins that were up-regulated and seven proteins that were down-regulated; 10 of them were novel targets for TGF-beta. These proteins function in processes such as cytoskeletal regulation, cell cycle, and oxidative stress. Introducing siRNA-mediated gene silencing into proteomics revealed a novel TGF-beta signal pathway that did not involve Smad4.