Citations

Background and Study Aims. Endoscopic placement of self-expanding metal stents (SEMSs) is indicated for palliation of inoperable malignant biliary obstruction. A fully covered biliary SEMS (WallFlex Biliary RX Boston Scientific, Natick, USA) was assessed for palliation of extrahepatic malignant biliary obstruction.Patients and Methods. 58 patients were included in this prospective, multicenter series conducted under an FDA-approved IDE. Main outcome measurements included (1) absence of stent occlusion within six months or until death, whichever occurred first and (2) technical success, need for reintervention, bilirubin levels, stent patency, time to stent occlusion, and adverse events.Results. Technical success was achieved in 98% (57/58), with demonstrated acute removability in two patients. Adequate clinical palliation until completion of followup was achievedin 98% (54/55) ofevaluablepatients, with 1 reintervention due to stent obstruction after 142 days. Mean total bilirubin decreased from 8.9 mg/dL to 1.2 mg/dL at 1 month. Device-related adverse events were limited and included 2 cases of cholecystitis. One stent migrated following radiation therapy.Conclusions. The WallFlex Biliary fully covered stent yielded technically successful placement with uncomplicated acute removal where required, appropriate reduction in bilirubin levels, and low rates of stent migration and occlusion. This SEMS allows successful palliation of malignant extrahepatic biliary obstruction.

Abstract Purpose: The limited supply of oxygen and nutrients is thought to result in rigorous selection of cells that will eventually form the tumor. Experimental Design: Nupr1 expression pattern was analyzed in human tissue microarray (TMA) and correlated with survival time of the patient. Microarray analysis was conducted on MiaPaCa2 cells subjected to metabolic stress in Nupr1-silenced conditions. DNA repair and cell cycle–associated gene expression was confirmed by real-time quantitative PCR (qRT-PCR). Nupr1 and AURKA protective role were analyzed using RNA interference (RNAi) silencing or overexpression. DNA damage and autophagy were analyzed by Western blot analysis and immunofluorescence. Results: We showed that both Nupr1 and HIF1α are coexpressed in human pancreatic ductal adenocarcinoma (PDAC) samples and negatively correlate with survival time. PDAC-derived cells submitted to hypoxia and/or glucose starvation induce DNA damage–dependent cell death concomitantly to the overexpression of stress protein Nupr1. Affymetrix-based transcriptoma analysis reveals that Nupr1 knockdown enhances DNA damage and alters the expression of several genes involved in DNA repair and cell-cycle progression. Expression of some of these genes is common to hypoxia and glucose starvation, such as Aurka gene, suggesting that Nupr1 overexpression counteracts the transcriptional changes occurring under metabolic stress. The molecular mechanism by which hypoxia and glucose starvation induce cell death involves autophagy-associated, but not caspase-dependent, cell death. Finally, we have found that AURKA expression is partially regulated by Nupr1 and plays a major role in this response. Conclusions: Our data reveal that Nupr1 is involved in a defense mechanism that promotes pancreatic cancer cell survival when exposed to metabolic stress. Clin Cancer Res; 18(19); 5234–46. ©2012 AACR.

Abstract In this study we demonstrate that gain of HER-2/Neu expression in human breast cancer xenografts harboring constitutive active Raf-1 induces Aurora-A over-expression that ultimately drives the transition from a luminal to a highly invasive basal-like phenotype. Over-expression of Aurora-A was induced by phosphorylation and protein stabilization by HER-2/Neu rather than increased Aurora-A gene expression. Moreover, Aurora-A stabilization induced an increase of HER-2/Neu expression in breast cancer cells defining a novel positive feed-back loop between Aurora-A and HER-2/Neu oncogenic signaling pathways. Basal-like tumor cells over-expressing Aurora-A and HER-2/Neu underwent to loss of CD24 surface receptor, expressed epithelial to mesenchymal transition (EMT) markers and acquired stem cell-like properties such as mammospheres formation and self-renewal. Pharmacologic inhibition of HER-2/Neu signaling pathway with lapatinib in cancer cells over-expressing Aurora-A demonstrated that Aurora-A was downstream to HER-2/Neu in the development of EMT and stemness. To determine whether Aurora-A induced a cancer stem cell-like phenotype through development of chromosomal instability and tumor cell phenotypic heterogeneity, we performed a SKY analysis on the breast cancer cell lines employed in this study. Our results demonstrate that invasive breast cancer cells harboring a basal-like phenotype did not develop higher chromosomal instability compared to luminal non-invasive cancer cells, signifying that Aurora-A has a direct effect on the development of basal-like breast cancer cells with stemness properties. Importantly, pharmacologic inhibition of Aurora-A kinase activity with the small molecule MLN8237 restored CD24 expression and reversed EMT leading to the re-establishment of a luminal phenotype and suppression of distant metastases. Our findings implicate for the first time the mitotic kinase Aurora-A in the development and maintenance of CD24 negative basal-like tumor stem cells responsible for breast cancer recurrence and progression. These observations have also important implications for the development of molecular targeted therapies to inhibit Aurora-A kinase activity and stemness improving the overall survival of breast cancer patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 328. doi:1538-7445.AM2012-328

Abstract Background: We recently reported a 49% RECIST response rate in conjunction with a phase 2 clinical trial of the multi-targeted kinase inhibitor pazopanib in differentiated thyroid cancers (DTC; Lancet Oncology 2010, 11:962-72), prompting a search for synergistic pazopanib-containing doublets in thyroid cancer cell lines. Methods and Results: Among all explored pazopanib-containing combinations, paclitaxel and pazopanib produced the greatest combined cytotoxic effects (continuous exposure pazopanib, 24 h paclitaxel; Combination Index, CI, at IC90=0.3). Interestingly, analogous synergy resulted when combining pazopanib with other antimicrotubule agents including other taxanes (docetaxel), Vinca alkyloids (vincristine) and epothilones (ixabepilone) – suggesting a class effect. Further, we found this combination to be synergistic in multiple cancer cell lines including DTC, medullary and anaplastic thyroid cancer lines, and in the A549 lung cancer line. In pursuit of underlying mechanism(s), we noted that the combination produced a greater fraction of cells in G2/M phase of the cell cycle and increased apoptosis in comparison to paclitaxel alone, prompting us to examine whether pazopanib might potentiate the effects of paclitaxel on mitosis. Analysis of cell fate resulting from pazopanib and paclitaxel alone and in combination using time-lapsed video microscopy demonstrated that as low as 2.5 μM pazopanib augmented paclitaxel-induce mitotic catastrophe by 2.4 fold, while inducing no appreciable cell death alone. As pazopanib is somewhat promiscuous in inhibition of kinases, we hypothesized that observed combined effects with antimicrotubule agents might be attributed to its inhibition of cell cycle by targeting CDKs or mitosis by targeting aurora kinases. Inhibition of CDKs 1 and 2 required pazopanib concentrations 1000-times those required to inhibit its primary kinase targets, VEGF-Rs; whereas aurora kinases A and B were inhibited at much lower concentrations (IC50s, 500-1000 nM). Hence, we pursued shRNA aurora A knockdown experiments: potentiation of pazopanib effects were observed in knockdown clones, suggesting that pazopanib single-agent effects are at least in part mediated via aurora A inhibition. Moreover, augmentation of paclitaxel effects were achieved in knockdown clones that rivaled those observed for the pazopanib/paclitaxel combination. Additionally, pazopanib/paclitaxel synergy was reduced in aurora A knockdown clones (CI at IC80: vector<0.5, knockdown clones >1.0), indicating that aurora A inhibition by pazopanib is contributory to paclitaxel/pazopanib synergy. Conclusions: Pazopanib combines with antimicrotubule agents to produce cytotoxic synergy associated with augmentation of mitotic catastrophe that appears at least in part mediated by its ability to inhibit aurora kinases. Supported in part by CA125750. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3597. doi:10.1158/1538-7445.AM2011-3597

Background —The width of the vena contracta (VC-W), the smallest area of regurgitant flow, reflects the degree of valvular regurgitation and is measurable by color Doppler imaging, but this method has not been validated in aortic regurgitation (AR). Methods and Results —We prospectively examined 79 patients with isolated AR and 80 patients without regurgitation. The VC-W was measured from the long-axis parasternal view and compared with 2 simultaneous reference methods (quantitative Doppler and 2D echocardiography). In patients without regurgitation, the agreement between methods was excellent. In patients with AR, good correlations (all P <0.0001) were obtained between VC-W and effective regurgitant orifice (ERO) area and regurgitant volume recorded by quantitative Doppler ( r =0.89 and 0.90, respectively) and 2D echocardiographic ( r =0.90 and 0.89, respectively) methods. These correlations were similar with eccentric or central jets (all P >0.60). The other methods used showed good correlations of VC-W with aortographic grading of AR (n=8, r =0.82, P =0.01), with the proximal flow convergence method (n=53, r =0.85, P <0.0001), and with left ventricular end-diastolic volume ( r =0.81, P <0.0001). Sensitivity and specificity of VC-W ≥6 mm for diagnosing severe AR (ERO ≥30 mm 2 ) were 95% and 90%, respectively. Conclusions —For assessment of the degree of AR, VC-W shows good correlations with simultaneous quantitative measures (regardless of jet direction), shows good correlations with other methods of assessment of AR, and provides a high diagnostic value for severe AR. VC-W is a simple, reliable method that can be used clinically as part of comprehensive Doppler echocardiographic assessment of AR.

Background —Noninvasive assessment of diastolic filling by Doppler echocardiography provides important information about left ventricular (LV) status in selected subsets of patients. This study was designed to assess whether mitral annular velocities as assessed by tissue Doppler imaging are associated with invasive measures of diastolic LV performance and whether additional information is gained over traditional Doppler variables. Methods and Results —One hundred consecutive patients referred for cardiac catheterization underwent simultaneous Doppler interrogation. Invasive measurements of LV pressures were obtained with micromanometer-tipped catheters, and the mean LV diastolic pressure (M-LVDP) was used as a surrogate for mean left atrial pressure. Doppler signals from the mitral inflow, pulmonary venous inflow, and TDI of the mitral annulus were obtained. Isolated parameters of transmitral flow correlated with M-LVDP only when ejection fraction <50%. The ratio of mitral velocity to early diastolic velocity of the mitral annulus (E/E′) showed a better correlation with M-LVDP than did other Doppler variables for all levels of systolic function. E/E′ <8 accurately predicted normal M-LVDP, and E/E′ >15 identified increased M-LVDP. Wide variability was present in those with E/E′ of 8 to 15. A subset of those patients with E/E′ 8 to 15 could be further defined by use of other Doppler data. Conclusions —The combination of tissue Doppler imaging of the mitral annulus and mitral inflow velocity curves provides better estimates of LV filling pressures than other methods (pulmonary vein, preload reduction). However, accurate prediction of filling pressures for an individual patient requires a stepwise approach incorporating all available data.

Background —Functional mitral regurgitation (FMR) occurs with a structurally normal valve as a complication of systolic left ventricular dysfunction (LVD). Determinants of degree of FMR are poorly defined; thus, mechanistic therapeutic approaches to FMR are hindered. Methods and Results —In a prospective study of 21 control subjects and 128 patients with LVD (defined as ejection fraction <50%, mean 31±9%) in sinus rhythm, we quantified simultaneously by echocardiography the effective regurgitant orifice (ERO) of FMR by using 2 methods: mitral deformation (valve and annulus) and left ventricular (LV) global (volumes, stress, function, and sphericity) and local (papillary muscle displacements and regional wall motion index) remodeling. A wide range of ERO (15±14 mm 2 , 0 to 87 mm 2 ) was observed, unrelated to ejection fraction ( P =0.32). The major determinant of ERO was mitral deformation, ie, systolic valvular tenting and annular contraction in univariate ( r =0.74 and r =−0.61, respectively; both P <0.0001) and multivariate (both P <0.0001) analyses, independent of global LV remodeling. Systolic valvular tenting was strongly determined by local LV alterations, particularly apical ( r =0.75) and posterior ( r =0.70) displacement of papillary muscle, with confirmation in multivariate analysis (both P <0.0001), independent of LV volumes, function, and sphericity. Conclusions —The presence and degree of FMR complicating LVD are unrelated to the severity of LVD. Local LV remodeling (apical and posterior displacement of papillary muscles) leads to excess valvular tenting independent of global LV remodeling. In turn, excess tenting and loss of systolic annular contraction are associated with larger EROs. These determinants of FMR warrant consideration for specific approaches to the treatment of FMR complicating LVD.

Background Transesophageal echocardiography (TEE) is the diagnostic modality of choice for visualizing the left atrial appendage (LAA). This study defined the morphology of the LAA in normal autopsy specimen hearts and considered the implications of these findings for TEE studies. Methods and Results Five hundred normal autopsy hearts were reviewed (25 male and 25 female subjects from each decade for 10 decades). LAA length, width, orifice size, and number of lobes were recorded. Number of lobes was compared between sexes with the rank sum test and regressed against age. Mean length, width, and orifice size increased with age, up to age 20 years, in both sexes. Rates were significantly different between sexes for LAA size ( P =.011) and width ( P =.006). After age 20, statistically significant but clinically insignificant age-related changes were observed. Fifty-four percent of LAAs had two lobes (range, 1 to 4), with no age or sex differences. Lobes exist in different planes of the heart. Most pectinate muscles were ≥1 mm in width. Pectinate muscles <1 mm (2.6% of cases) were seen in only the first and last decades. Conclusions Age- and sex-related differences in LAA dimensions exist. These differences and the existence of multilobed appendages are important in the accurate TEE evaluation of LAA. Because lobes exist in different planes, imaging must be done in multiple planes to visualize the entire LAA.