Risk factors associated with plasma omega-3 fatty acid levels in patients with suspected coronary artery disease.

INTRODUCTION: We sought to determine the associations between plasma eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels and various cardiovascular risk factors and with the use of fish oil supplements (FOS). PATIENTS AND METHODS: Patients with suspected coronary artery disease (CAD) undergoing cardiac catheterization (n=433) were studied. Serum fatty acid (FA) composition, the concentrations of lipids and biomarkers of oxidative stress, and dietary/lifestyle factors were measured. RESULTS: FOS use was associated with a higher plasma EPA+DHA levels (3.7±1.5 vs. 2.6±1.1%, p<0.0001). However, there was no relationship between FOS dose (mg/day) and EPA+DHA levels in 76 patients reporting FOS use (r=-0.21, p=0.07). Lower levels were inversely associated with risk factor profiles including lower ApoB100/ApoA1 ratios (p<0.001). DISCUSSION AND CONCLUSIONS: Higher EPA+DHA levels characterized patients with lower CAD risk. The lack of relations between FOS dose and plasma EPA+DHA levels likely reflects uncaptured variability in EPA+DHA content of supplements.

Enrichment of tumor-initiating breast cancer cells within a mammosphere-culture microdevice.

We report for the first time a microdevice that enables the selective enrichment, culture, and identification of tumor-initiating cells on native polydimethylsiloxane (PDMS). For nearly a decade, researchers have identified tumor-initiating breast cancer cells within heterogeneous populations of breast cancer cells by utilizing low-attachment serum-free culture conditions, which lead to the formation of spheroidal colonies (mammospheres) that are enriched for tumor-initiating cells. However, the utility of this assay has been limited by difficulties in combining this culture-plate-based technique with other cellular and molecular analyses. Integrating the mammosphere technique into a microsystem can enable it to be combined directly with a number of functions, such as cell sorting, drug screens, and molecular assays. In this work, we demonstrate mammosphere culture within a PDMS microdevice. We first prove that a native hydrophobic PDMS surface is as effective as commercial low-attachment plates at selectively promoting the formation of mammospheres. We then experimentally assess the PDMS microdevice. Time-lapse images of mammosphere formation within the microdevice show that mammospheres form from single cells or small clusters of cells. Following formation of the mammospheres, it is desirable to evaluate the cells within the spheroids for enrichment of tumor initiating cells. To perform assays such as this (which require the loading and rinsing of reagents) without flushing the cells (which are in suspension) from the device, the culture chamber is separated from a reagent reservoir by a commercially available microporous membrane, and thus reagents are exchanged between the reservoir and the culture chamber by diffusion only. Using this capability, we verify that the mammospheres are enriched for tumor initiating cells by staining aldehyde dehydrogenase activity, a cancer stem cell marker. To the best of our knowledge, this is the first assay that enables the direct observation of tumor-initiating cells within a suspended mammosphere.

Breast cancer stem cell enrichment and isolation by mammosphere culture and its potential diagnostic applications.

Emerging knowledge about cancer stem cells (CSCs) is raising attention about the need to provide a more precise and complete diagnosis including the molecular profile of a patient's CSCs. As opposed to simply treating the bulk of the tumor, a more complete diagnosis can lead to treatment regimens designed to eradicate CSCs from a patient. In this review the authors detail the application of the mammosphere assay in the study of breast CSCs. The authors then describe the potential transition of the mammosphere assay from the research laboratory to the clinic by leveraging microsystems technology, which enables the integration of multiple functions into a single automated device. To conclude the review, the authors project that future clinical devices will be capable of isolating circulating metastatic cells from patient blood, enriching the dangerous CSCs, and providing a molecular profile of the CSCs, thus arming physicians with the information to select a treatment program that combats CSCs.