Search results for "Tumor spheroid"

2016

AbstractMulticellular tumor spheroids (MCTSs) embedded in a matrix are re-emerging as a powerful alternative to monolayer-based cultures. The primary information gained from a three-dimensional model is the invasiveness of treatment-exposed MCTSs through the acquisition of light microscopy images. The amount and complexity of the acquired data and the bias arisen by their manual analysis are disadvantages calling for an automated, high-throughput analysis. We present a universal algorithm we developed with the scope of being robust enough to handle images of various qualities and various invasion profiles. The novelty and strength of our algorithm lie in: the introduction of a multi-step se…

2016

AbstractMulticellular tumor spheroids embedded in a matrix represent invaluable tools to analyze cell invasion. Spheroid sizes and invasiveness are the main observables easily measurable to evaluate effects of biological or pharmaceutical manipulations on invasion. They largely account for these 3-D platforms variability, leading to flaws in data interpretation. No method has been established yet that characterizes this variability and guarantees a reliable use of 3-D platforms. Spheroid initial/end sizes and invasiveness were systematically analyzed and compared in spheroids of U87MG cells generated by three different methods and embedded at different times in a collagen matrix. A normalit…

Semiautomatic growth analysis of multicellular tumor spheroids.

2011

Multicellular tumor spheroids (MCTS) are routinely employed as three-dimensional in vitro models to study tumor biology. Cultivation of MCTS in spinner flasks provides better growing conditions, especially with regard to the availability of nutrients and oxygen, when compared with microtiter plates. The main endpoint of drug response experiments is spheroid size. It is common practice to analyze spheroid size manually with a microscope and an ocular micrometer. This requires removal of some spheroids from the flask, which entails major limitations such as loss of MCTS and the risk of contamination. With this new approach, the authors present an efficient and highly reproducible method to an…

Changes in O2 Consumption of Multicellular Spheroids During Development of Necrosis

1985

Multicellular spheroids are spherical aggregates of cells that are supplied by diffusion of oxygen and substrates from the surrounding growth medium (Sutherland and Durand, 1976). Metabolic waste products are removed from the cells in these aggregates by diffusion into the growth medium. Cells within multicellular spheroids may be exposed to environmental conditions similar to those in tissue located between nutritive microvessels. Thus, tumor spheroids make it possible to study the impact of the tumor-specific micromilieu on cellular metabolism, cell cycle state, cellular viability or response to treatment. Factors in the microenvironment of tumor cells which may be relevant in this regard…

Influence of growth, measuring conditions, and cell types on oxygen tensions in multicell tumor spheroids determined by microelectrodes

1981

3.3 Glucose levels in microregions of multicellular EMT6/Ro tumor spheroids

1991

Three-dimensional cell cultures: from molecular mechanisms to clinical applications.

1997

This article reviews actual advances in the development and application of three-dimensional (3-D) cell culture systems. Recent therapeutically oriented studies include characterization of multicellular-mediated drug resistance, novel ways of quantifying hypoxia, and new approaches to more efficient immunotherapy. Recent progress toward understanding the development of necrosis in tumor spheroids has been made using novel spheroid models. 3-D cultures have been used for studies on molecular mechanisms involved in invasion and metastasis, with a major focus on the role of E-cadherin. Similarly, tumor angiogenesis and the significance of vascular endothelial growth factor have been investigat…

Oxygenation Status of Rhabdomyosarcoma Spheroids with Different Stages of Differentiation

1994

Multicellular tumor spheroids with regional heterogeneities of proliferation and substrate concentrations have been investigated recently to study the biological properties of small tumor nodules prior to onset of vascularization (for reviews see: Mueller-Klieser, 1987; Sutherland, 1988).

Glucose Diffusion Coefficients Determined from Concentration Profiles in Emt6 Tumor Spheroids Incubated in Radioactively Labeled L-Glucose

1994

In order to theoretically assess tissue energetic status, conditions for substance exchange need to be known. One group of parameters important in this context are diffusion coefficients of nutrients and metabolic waste products which may be assessed by incubating spheroids in a medium containing tracer amounts of the radioactively labeled substance in question, for a defined period of time. In previous studies, the overall amount of 14C-labeled substance taken up by the spheroids was measured by scintillation counters (e.g.[1]), or the concentration of 3H-labeled substance in the spheroid center was determined by autoradiography and grain counting (e.g. [4]). From a number of such measurem…