The association between eicosanoids and incident atrial fibrillation in the Framingham Heart Study.

Chronic inflammation is a continuous low-grade activation of the systemic immune response. Whereas downstream inflammatory markers are associated with atrial fibrillation (AF), upstream inflammatory effectors including eicosanoids are less studied. To examine the association between eicosanoids and incident AF. We used a liquid chromatography-mass spectrometry for the non-targeted measurement of 161 eicosanoids and eicosanoid-related metabolites in the Framingham Heart Study. The association of each eicosanoid and incident AF was assessed using Cox proportional hazards models and adjusted for AF risk factors, including age, sex, height, weight, systolic/diastolic blood pressure, current smoking, antihypertensive medication, diabetes, history of myocardial infarction and heart failure. False discovery rate (FDR) was used to adjust for multiple testing. Eicosanoids with FDR < 0.05 were considered significant. In total, 2676 AF-free individuals (mean age 66 ± 9 years, 56% females) were followed for mean 10.8 ± 3.4 years; 351 participants developed incident AF. Six eicosanoids were associated with incident AF after adjusting for multiple testing (FDR < 0.05). A joint score was built from the top eicosanoids weighted by their effect sizes, which was associated with incident AF (HR = 2.72, CI = 1.71-4.31, P = 2.1 × 10-5). In conclusion, six eicosanoids were associated with incident AF after adjusting for clinical risk factors for AF.

Expression of LC3B and FIP200/Atg17 in brain metastases of breast cancer.

BACKGROUND: Macroautophagy/autophagy is considered to play key roles in tumor cell evasion of therapy and establishment of metastases in breast cancer. High expression of LC3, a residual autophagy marker, in primary breast tumors has been associated with metastatic disease and poor outcome. FIP200/Atg17, a multi-functional pro-survival molecule required for autophagy, has been implicated in brain metastases in experimental models. However, expression of these proteins has not been examined in brain metastases from patients with breast cancer. METHODS: In this retrospective study, specimens from 44 patients with brain metastases of infiltrating ductal carcinoma of the breast (IDC), unpaired samples from 52 patients with primary IDC (primary-BC) and 16 matched-paired samples were analyzed for LC3 puncta, expression of FIP200/Atg17, and p62 staining. RESULTS: LC3-puncta+ tumor cells and FIP200/Atg17 expression were detected in greater than 90% of brain metastases but there were considerable intra- and inter-tumor differences in expression levels. High numbers of LC3-puncta+ tumor cells in brain metastases correlated with a significantly shorter survival time in triple-negative breast cancer. FIP200/Atg17 protein levels were significantly higher in metastases that subsequently recurred following therapy. The percentages of LC3 puncta+ tumor cells and FIP200/Atg17 protein expression levels, but not mRNA levels, were significantly higher in metastases than primary-BC. Meta-analysis of gene expression datasets revealed a significant correlation between higher FIP200(RB1CC1)/Atg17 mRNA levels in primary-BC tumors and shorter disease-free survival. CONCLUSIONS: These results support assessments of precision medicine-guided targeting of autophagy in treatment of brain metastases in breast cancer patients.

Variation in primary and culture-expanded cells derived from connective tissue progenitors in human bone marrow space, bone trabecular surface and adipose tissue.

BACKGROUND AIMS: Connective tissue progenitors (CTPs) embody the heterogeneous stem and progenitor cell populations present in native tissue. CTPs are essential to the formation and remodeling of connective tissue and represent key targets for tissue-engineering and cell-based therapies. To better understand and characterize CTPs, we aimed to compare the (i) concentration and prevalence, (ii) early in vitro biological behavior and (iii) expression of surface-markers and transcription factors among cells derived from marrow space (MS), trabecular surface (TS), and adipose tissues (AT). METHODS: Cancellous-bone and subcutaneous-adipose tissues were collected from 8 patients. Cells were isolated and cultured. Colony formation was assayed using Colonyze software based on ASTM standards. Cell concentration ([Cell]), CTP concentration ([CTP]) and CTP prevalence (PCTP) were determined. Attributes of culture-expanded cells were compared based on (i) effective proliferation rate and (ii) expression of surface-markers CD73, CD90, CD105, SSEA-4, SSEA-3, SSEA-1/CD15, Cripto-1, E-Cadherin/CD324, Ep-CAM/CD326, CD146, hyaluronan and transcription factors Oct3/4, Sox-2 and Nanog using flow cytometry. RESULTS: Mean [Cell], [CTP] and PCTP were significantly different between MS and TS samples (P = 0.03, P = 0.008 and P= 0.0003), respectively. AT-derived cells generated the highest mean total cell yield at day 6 of culture-4-fold greater than TS and more than 40-fold greater than MS per million cells plated. TS colonies grew with higher mean density than MS colonies (290 ± 11 versus 150 ± 11 cell per mm2; P = 0.0002). Expression of classical-mesenchymal stromal cell (MSC) markers was consistently recorded (>95%) from all tissue sources, whereas all the other markers were highly variable. CONCLUSIONS: The prevalence and biological potential of CTPs are different between patients and tissue sources and lack variation in classical MSC markers. Other markers are more likely to discriminate differences between cell populations in biological performance. Understanding the underlying reasons for variation in the concentration, prevalence, marker expression and biological potential of CTPs between patients and source tissues and determining the means of managing this variation will contribute to the rational development of cell-based clinical diagnostics and targeted cell-based therapies.

Macropinocytosis of Bevacizumab by Glioblastoma Cells in the Perivascular Niche Affects their Survival.

Purpose: Bevacizumab, a humanized monoclonal antibody to VEGF, is used routinely in the treatment of patients with recurrent glioblastoma (GBM). However, very little is known regarding the effects of bevacizumab on the cells in the perivascular space in tumors.Experimental Design: Established orthotopic xenograft and syngeneic models of GBM were used to determine entry of monoclonal anti-VEGF-A into, and uptake by cells in, the perivascular space. Based on the results, we examined CD133+ cells derived from GBM tumors in vitro Bevacizumab internalization, trafficking, and effects on cell survival were analyzed using multilabel confocal microscopy, immunoblotting, and cytotoxicity assays in the presence/absence of inhibitors.Results: In the GBM mouse models, administered anti-mouse-VEGF-A entered the perivascular tumor niche and was internalized by Sox2+/CD44+ tumor cells. In the perivascular tumor cells, bevacizumab was detected in the recycling compartment or the lysosomes, and increased autophagy was found. Bevacizumab was internalized rapidly by CD133+/Sox2+-GBM cells in vitro through macropinocytosis with a fraction being trafficked to a recycling compartment, independent of FcRn, and a fraction to lysosomes. Bevacizumab treatment of CD133+ GBM cells depleted VEGF-A and induced autophagy thereby improving cell survival. An inhibitor of lysosomal acidification decreased bevacizumab-induced autophagy and increased cell death. Inhibition of macropinocytosis increased cell death, suggesting macropinocytosis of bevacizumab promotes CD133+ cell survival.Conclusions: We demonstrate that bevacizumab is internalized by Sox2+/CD44+-GBM tumor cells residing in the perivascular tumor niche. Macropinocytosis of bevacizumab and trafficking to the lysosomes promotes CD133+ cell survival, as does the autophagy induced by bevacizumab depletion of VEGF-A. Clin Cancer Res; 23(22); 7059-71. ©2017 AACR.