Malic enzyme and malate dehydrogenase activities in rat tracheal epithelial cells during the progression of neoplasia
Malic enzyme and malate dehydrogenase (MDH) activities were radio-metrically assayed in digitonin fractionated normal primary cultures (NPC), preneoplastic selected primary cultures (SPC) and tumor-derived primary cultures (TPC) of rat tracheal epithelial cells. Carcinogen-altered SPC and TPC select...
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Published in | Cancer letters Vol. 28; no. 1; pp. 35 - 42 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Shannon
Elsevier Ireland Ltd
01.08.1985
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | Malic enzyme and malate dehydrogenase (MDH) activities were radio-metrically assayed in digitonin fractionated normal primary cultures (NPC), preneoplastic selected primary cultures (SPC) and tumor-derived primary cultures (TPC) of rat tracheal epithelial cells. Carcinogen-altered SPC and TPC selectively grow in the absence of pyruvate, which is required by NPC for survival. Mitochondrial-containing particulate fractions from TPC and especially SPC had markedly higher levels of NADP
+-dependent malic enzyme than NPC in the presence or absence of pyruvate. This suggests that induction of mitochondrial malic enzyme activity occurs early in the progression of neoplasia. Malic enzyme activities in the soluble fractions from the various populations were not distinctly different. In contrast, particulate-bound MDH activity was higher in NPC and SPC than TPC in most cases, indicating a decrease in this enzyme late in tumorigenesis. |
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ISSN: | 0304-3835 1872-7980 |
DOI: | 10.1016/0304-3835(85)90089-8 |