The histochemical G6PDH reaction but not the LDH reaction with neotetrazolium is suitable for the oxygen sensitivity test to detect cancer cellsP Griffini, E Vigorelli, GN Jonges and CJ Van Noorden Academic Medical Center, Department of Cell Biology and Histology, University of Amsterdam, The Netherlands. We used the oxygen sensitivity of the histochemical reaction to detect glucose-6-phosphate dehydrogenase (G6PDH) activity based on neotetrazolium (NT) reduction to discriminate cancer cells from normal cells. Formazan generation was strongly reduced in normal but not in malignant cells when the incubation was performed in oxygen instead of nitrogen. Competition for reductive equivalents between NT and oxygen via superoxide dismutase (SOD) has been suggested. Since SOD activity is usually decreased in cancer cells, NT reduction would not be hampered in these cells. We tested this hypothesis by demonstrating NAD- dependent lactate dehydrogenase (LDH) activity instead of NADP- dependent G6PDH activity in normal rat liver and colon, in human colon carcinoma, and in experimentally induced metastases of colon carcinoma in rat livers. Reactions for both enzymes were determined cytophotometrically in an atmosphere of pure oxygen or nitrogen. G6PDH acted as described previously, showing distinct activity in cancer cells but strongly reduced activity in normal cells after incubation in oxygen, but this was not the case with LDH because formazan was also generated in normal tissue in oxygen. It appeared that after 5 min of incubation at 37 degrees C the residual activity of G6PDH in an atmosphere of oxygen compared with nitrogen was 0% in normal liver tissue and 15% in normal colon epithelium, whereas in colon carcinoma and in colon carcinoma metastasis in liver it was 48% and 33%, respectively. The residual activity of LDH in oxygen was 30% in normal female rat liver, 75% in normal male rat liver, and 38% in normal colon epithelium, whereas the residual activity in colon carcinoma and metastases in liver was 54% and 24%, respectively. These experiments clearly indicate that the oxygen sensitivity phenomenon is not solely an effect of competition for reducing equivalents between NT and oxygen via SOD, because NADPH generated by G6PDH and NADH generated by LDH have a similar redox potential. Apparently the system is more complex. The role of specifically NADPH-converting cellular systems such as NADPH-cytochrome P450 reductase was excluded because incubations in the presence of exogenous NADPH as substrate for these systems revealed oxygen sensitivity. Involvement of NADPH-dependent lipid peroxidation in the oxygen sensitivity test is discussed.
Volume 42,
Issue 10,
pp. 1355-1363,
10/01/1994
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W. M. Frederiks, H. Vreeling-Sindelarova, and C. J.F. Van Noorden Loss of Peroxisomes Causes Oxygen Insensitivity of the Histochemical Assay of Glucose-6-Phosphate Dehydrogenase Activity to Detect Cancer Cells J. Histochem. Cytochem., February 1, 2007; 55(2): 175 - 181. [Abstract] [Full Text] [PDF] |
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J. S.S.G. De Jong, W. M. Frederiks, and C. J.F. Van Noorden Oxygen Insensitivity of the Histochemical Assay of Glucose-6-phosphate Dehydrogenase Activity for the Detection of (Pre)Neoplasm in Rat Liver J. Histochem. Cytochem., May 1, 2001; 49(5): 565 - 572. [Abstract] [Full Text] |
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B. E. M. Van Driel, T. M. Van Gulik, P. D. J. Sturm, G. J. A. Offerhaus, D. J. Gouma, and C. J. F. Van Noorden Differential Diagnosis of Chronic Pancreatitis and Pancreatic Cancer in Brush Cytology Specimens Cancer Res., November 1, 1999; 59(22): 5732 - 5736. [Abstract] [Full Text] [PDF] |
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B. E.M. Van Driel and C. J.F. Van Noorden Oxygen Insensitivity of the Histochemical Assay of Glucose-6-Phosphate Dehydrogenase Activity for the Discrimination Between Nonmalignant and Malignant Cells J. Histochem. Cytochem., May 1, 1999; 47(5): 575 - 582. [Abstract] [Full Text] |
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