Joint oxygen‐glucose deprivation as the cause of necrosis in a tumor analog

Abstract

The sandwich system was recently developed as an in vitro tumor analog. Like spheroids, sandwiches are organized, multicellular systems in which the interplay between diffusion and consumption leads to the formation of spatial gradients; a necrotic center and a viable cell border subsequently develop. Using sandwiches of the 9L and V79 cell lines, the effects of oxygen and glucose deprivation on the onset and formation of necrosis were investigated. The data indicate that in sandwiches necrosis is a result of a shortage of both substances. Complementary cell monolayer experiments to determine a number of consumption parameters were performed. On the basis of the data, we propose a joint oxygen-glucose deprivation model for V79 cell necrosis. It is assumed a cell dies when oxygen deprivation in conjunction with glucose deprivation lowers the cell's ATP production rate below a critical value. Interactions of the concentrations and consumptions of oxygen and glucose are analyzed theoretically; concentration profiles are obtained by numerically solving coupled non-linear integral equations arising from the diffusion equation. The predicted viable border widths are in good agreement with the observed values.

Variable presence of hypoxia in M006 human glioma spheroids and in spheroids and xenografts of clonally derived sublines

“…we propose that those spheroids that exhibit hypoxia adjacent to necrosis can be regarded as functioning as oxygen regulators. The death of cells in this case is readily understood in terms of the joint oxygen-glucose deprivation model (Hlatky et al 1988 (Allalunis-Turner et al, 1998); lending support to the hypothesis that those M006XLo spheroids that have a high oxygen tension adjacent to necrosis can be regarded as functioning as oxygen conformers that reduce their rate of oxygen consumption at relatively high oxygen tensions. In this case we hypothesize that throughout much of the spheroid rim the rate of oxygen consumption is minimal and the cells obtain most of their energy from glycolysis, and that cell death occurs when glucose becomes limiting.…”

“…x-hich leads to a much shorter diffusion distance for Glucose than for oxvgen. This xould require that well-oxy genated cells exentually die wxhen deprived of Glucose (Hlatky et al 1988). Another factor that might contribute to the obserx ations is the possible egress of toxic metabolites from xithin necrotic regions (Freyver.…”

Dorsal and Ventral Stimuli in Cell–Material Interactions: Effect on Cell Morphology

“…Nevertheless, it must be taken into account that permeability of the upper substrate is a critical issue in the design of the sandwich-like system, and using less permeable materials as upper substrates could lead to a gradient of cell death, from the centre to the periphery, as happens in tumors. In fact, sandwich-like cultures with limited diffusion has been studied as an approach to supplement multicellular spheroids as tumor analogues [34][35][36]. Important differences with 3D environment include the lack of isotropy, limitation of cell mobility to the x-y plane, mechanical properties of the substrates and absence of a physiological nanofibrillar environment (although this is somehow mimicked by the fibrillogenesis of fibronectin on PEA).…”

Necrotic core in EMT6/Ro tumour spheroids: Is it caused by an ATP deficit?

“…The hypothesis that the formation of necrotic regions is caused by a deficit in ATP production was adopted in a model of cell population growth in a tridimensional (sandwich) culture (Hlatky et al, 1988). More recently the cell energy metabolism, i.e.…”