A modified tetrazolium reaction for identifying malignant cells from gastric and colonic cancer

Abstract

SUMMARY When non-malignant cells were reacted for glucose-6-phosphate dehydrogenase activity, with neotetrazolium chloride as the indicator of the activity, oxygen competed with the neotetrazolium and nullified the reaction. In contrast, about 30% of the activity was retained in malignant cells, in sections and in smears, from cancer of the stomach or colon. This could provide the basis of a qualitative (black-or-white) functional test for distinguishing malignant cells in these conditions.

Reaction rate studies of glucose-6-phosphate dehydrogenase activity in sections of rat liver using four tetrazolium salts

“…The diffusion of formazan observed in these studies with BPST and reflected in the low 'reaction rates' calculated from end point measurements (Table 2) make this salt unsuitable for quantitative analysis. The complex nature of the reaction curves obtained with Neotetrazolium may preclude its use in routine measurements though it will continue to have considerable value in studies on the effects of oxygen in different cells (Butcher, 1978a, I979;Ibrahim et al, 1983).…”

Development of oxygen insensitivity of the quantitative histochemical assay of G6PDH activity during colorectal carcinogenesis

“…8 Its activity can be demonstrated histochemically in tissue sections by using a tetrazolium salt as final electron acceptor. 9 Because G6PDH activity is usually high in any proliferating cell, and thus in normal proliferating cells as well as in cancer cells, 10 histochemical detection of its activity per se cannot be applied to make this distinction. When a particular tetrazolium salt, neotetrazolium (NT), is used in an atmosphere of oxygen, formazan production in normal tissue is almost completely prevented by oxygen, but not in the cells of cancer of the bronchus, 11 stomach, 10 colon, 10,12,13 or breast.…”

Prognostic estimation of survival of colorectal cancer patients with the quantitative histochemical assay of G6PDH activity and the multiparameter classification program CLASSIF1

“…When the histochemical reaction is performed with neotetrazolium as tetrazolium salt in the absence of oxygen in the incubation medium, formazan production gives a proper reflection of G6PDH activity in all cell types (10). However, in the presence of oxygen, formazan deposition is prevented in normal epithelia but not in cancerous epithelia of the colon (11)(12)(13), stomach (11), breast (14), and bronchus (15). This so-called oxygen insensitivity of cancer cells is developed in a gradual manner during the carcinogenetic process (13).…”