Measurement of Low Levels of Oxygen and Their Effect on Respiration in Cell Suspensions Maintained in an Open System

Marshall, R. S.; Koch, Cameron J.; Rauth, Andrew M.

doi:10.2307/3576973

Cited by 25 publications

(14 citation statements)

References 10 publications

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“…This relationship was evident in cells injected immediately after treatment but was much more prominent when the populations were reoxygenated. The EME of cells exposed to hypoxia for 48 hr followed by 18 After 48 hr of hypoxic culture, 75% of the cells exhibited a G1 phase DNA content, while only 15% had S phase DNA content. Partial G1 phase synchronization has been previously reported in studies which have examined the effects ofhypoxia on progression of cells through the cell cycle (14,15,21).…”

Section: Resultsmentioning

confidence: 99%

“…The oxygen concentrations in both gas and aqueous phases of cultures continuously purged with this oxygen-deficient mixture were monitored by using an electronic sensor (18) to determine the degree of hypoxia that was established. The gas phase quickly developed an oxygen tension comparable to that ofthe delivered mixture, while the depletion ofoxygen from the culture medium was more gradual.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Hypoxia induces DNA overreplication and enhances metastatic potential of murine tumor cells.

Young

Marshall

Hill

1988

Proc. Natl. Acad. Sci. U.S.A.

337

212

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Cultured cells subjected to oxygen deprivation have been shown to undergo anomalous DNA synthesis, which can result in DNA overreplication and the generation of cellular variants [Rice, G. C., Hoy, C. & Schimke, R. T. (1986) Proc. Natl. Arad. Sci. USA 83,[5978][5979][5980][5981][5982]. In the present study, murine tumor cells were exposed to severe hypoxia and then tested for their ability to form experimental metastases. Upon reoxygenation, cells transiently, yet dramatically, increased their metastatic potential. Flow cytometric analysis confirmed that hypoxia and reoxygenation induced cell cycle perturbations and DNA overreplication in these tumor cell lines. Fibrosarcoma cells with overreplicated DNA isolated by fluorescence-activated cell sorting proved to be highly metasiatic, although cells with 2-4 times the haploid DNA content in populations treated with hypoxia were also markedly

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Hypoxia induces DNA overreplication and enhances metastatic potential of murine tumor cells.

Young

Marshall

Hill

1988

Proc. Natl. Acad. Sci. U.S.A.

337

212

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“…Since the cells can be expected to consume some of the oxygen and hence influence the level of oxygen to which they are exposed, a Clark-type polarographic electrode (Marshall et al, 1986) was used to measure O 2 concentration in the cell-containing medium. A glass vial and stopper, into which an extra hole was cut to accommodate the oxygen sensor, was prepared as above.…”

Section: Oxygen Measurementsmentioning

confidence: 99%

A quantitative analysis of the reduction in oxygen levels required to induce up-regulation of vascular endothelial growth factor (VEGF) mRNA in cervical cancer cell lines

Chiarotto

Hill

1999

Br J Cancer

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Regions of hypoxia, or low oxygen tension, are known to exist within tumours (Raleigh et al, 1996;Brown and Giaccia, 1998;Dewhirst, 1998). Since radiotherapy and some forms of chemotherapy are less effective at killing cancer cells in hypoxic environments, much effort has been directed toward identifying tumours containing such regions. Measurement of oxygen tension by needle electrodes in lymph node metastasis of cancer of the head and neck found that radiation was less effective at inducing regression when the lymph nodes were hypoxic (Gatenby et al, 1988) and such measurements have been reported to identify patients with poor locoregional tumour control (Nordsmark et al, 1996). Similar work in advanced cancer of the uterine cervix (Hockel et al, 1993(Hockel et al, , 1996Fyles et al, 1998;Hockel and Vaupel, 1998) showed that increased levels of hypoxia in the primary tumour mass correlated with poorer treatment outcome. These results suggested that hypoxia in cervical cancers correlated with a greater likelihood of both local failure and nodal metastasis. Metastases were also found to be more frequent in patients with the most hypoxic soft tissue sarcoma of the extremities (Brizel et al, 1996). Furthermore, exposure of cancer cells to hypoxia (Young et al, 1988;Jang and Hill, 1997) and hypoxia-induced increases in vascular endothelial growth factor (VEGF) secretion have been associated with an increased metastatic ability (Danielsen and Rofstad, 1998).VEGF is the most selective vascular endothelial cell mitogen known . In cancer cells, the four VEGF isoforms which have been most frequently described contain 121, 165, 189 and 206 amino acids (Tischer et al, 1991). In some studies, increased intra-tumoural VEGF mRNA and protein has been associated with poor prognosis (Berger et al, 1995;Toi et al, 1995), increased metastasis Takahashi et al, 1995), and increased microvessel density Toi et al, 1995;Fontini et al, 1997). Antibodies directed towards VEGF can inhibit angiogenesis and the proliferation of cancer cells in vivo (Kim et al, 1993;Kondo et al, 1993). Cancer cells constitutively produce VEGF and can up-regulate its expression under hypoxic stress (Shweiki et al, 1992) via the transcription factor hypoxia-inducible factor 1 (Forsythe et al, 1996) and by stabilization of the mRNA (Levy et al, 1996(Levy et al, , 1998. The qualitative relationship between oxygen level and VEGF up-regulation has been examined in a variety of different tumour systems but has not been quantitatively documented in most of the studies performed (Shweiki et al, 1992;Minchenko et al, 1994;Leith and Michelson, 1995;Mukhapadhyay et al, 1995). The purpose of the present work was to examine the relationship between VEGF mRNA level and oxygen concentration in detail and to determine the extent of its variation between different tumour cells of similar histopathological type. Cell lines derived from human cancer of the uterine cervix were chosen for the study based on the abundance of clinical data relating tumour A quantitative analysis ...

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“…Cells cease proliferation when exposed to extreme hypoxia (Born et al, 1976;Shrieve et al, 1983;Heacock and Sutherland, 1986), glucose deprivation (Alpen and Mendonca, 1986), or low pH levels (Ceccarini and Eagle, 1971). The effect of oxygen concentration upon cellular oxygen consumption rates has been studied extensively (Froese, 1962;Marshall et al, 1986). The oxygen consumption rate is independent of oxygen concentration until very low oxygen levels are reached ( lo4 ppm) a t which point the oxygen consumption rate decreases with decreasing oxygen concentration.…”

Section: Q 1992 Wiicv-lis Incmentioning

confidence: 99%

“…It contains a glass stir bar and a custom ground ceramic fitting t o hold the sensor in place and seal the system. Performance data for the electrode and the amplifier under conditions of low oxygen tension are given by Marshall et al (1986). The electrode reading was calibrated to the oxygen concentration in the medium using two methods, a novel method described by Koch (personal communication) and the commonly used method of oxygen depletion by known amounts of NADH (Robinson and Cooper, 1970).…”

Section: Oxygen Consumption Rate Measurementsmentioning

confidence: 99%

Variations in tumor cell growth rates and metabolism with oxygen concentration, glucose concentration, and extracellular pH

Casciari

Sotirchos

Sutherland

1992

Journal Cellular Physiology

307

270

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Tumors and multicellular tumor spheroids can develop gradients in oxygen concentration, glucose concentration, and extracellular pH as they grow. In order to calculate these gradients and assess their impact on tumor growth, it is necessary to quantify the effect of these variables on tumor cell metabolism and growth. In this work, the oxygen consumption rates, glucose consumption rates, and growth rates of EMT6/Ro mouse mammary tumor cells were measured at a variety of oxygen concentrations, glucose concentrations, and extracellular pH levels. At an extracellular pH of 7.25, the oxygen consumption rate of EMT6/Ro cells increased by nearly a factor of 2 as the glucose concentration was decreased from 5.5 mM to 0.4 mM. This effect of glucose concentration on oxygen consumption rate, however, was slight at an extracellular pH of 6.95 and disappeared completely at an extracellular pH of 6.60. The glucose consumption rate of EMT6/Ro cells increased by roughly 40% when the oxygen concentration was reduced from 0.21 mM to 0.023 mM and decreased by roughly 60% when the extracellular pH was decreased from 7.25 to 6.95. The growth rate of EMT6/Ro cells decreased with decreasing oxygen concentration and extracellular pH; however, severe conditions were required to stop cell growth (0.0082 mM oxygen and an extracellular pH of 6.60). Empirical correlations were developed from these data to express EMT6/Ro cell growth rates, oxygen consumption rates, and glucose consumption rates, as functions of oxygen concentration, glucose concentration, and extracellular pH. These empirical correlations make it possible to mathematically model the gradients in oxygen concentration, glucose concentration, and extracellular pH in EMT6/Ro multicellular spheroids by solution of the diffusion/reaction equations. Computations such as these, along with oxygen and pH microelectrode measurements in EMT6/Ro multicellular spheroids, indicated that nutrient concentration and pH levels in the inner regions of spheroids were low enough to cause significant changes in nutrient consumption rates and cell growth rates. However, pH and oxygen concentrations measured or calculated in EMT6/Ro spheroids where quiescent cells have been observed were not low enough to cause the cessation of cell growth, indicating that the observed quiescence must have been due to factors other than acidic pH, oxygen depletion, or glucose depletion.

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Measurement of Low Levels of Oxygen and Their Effect on Respiration in Cell Suspensions Maintained in an Open System

Cited by 25 publications

References 10 publications

Hypoxia induces DNA overreplication and enhances metastatic potential of murine tumor cells.

Hypoxia induces DNA overreplication and enhances metastatic potential of murine tumor cells.

A quantitative analysis of the reduction in oxygen levels required to induce up-regulation of vascular endothelial growth factor (VEGF) mRNA in cervical cancer cell lines

Variations in tumor cell growth rates and metabolism with oxygen concentration, glucose concentration, and extracellular pH

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