Vitamin B6 metabolism in Morris hepatomas.

Thanassi, John W.; Nutter, Louise M.; Meisler, Natalie T.; Commers, Patricia A.; Chiu, Jessie

doi:10.1016/s0021-9258(19)69617-1

Cited by 28 publications

(10 citation statements)

References 53 publications

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“…Buffalo and Sprague-Dawley Crl:CD(SD)BD strain rats were from Microbiological Associates and Canadian Breeding Laboratories, respectively. Morris hepatoma 7777 was grown in the hind legs of recipient animals as described previously (Thanassi et al, 1981).…”

Section: Methodsmentioning

confidence: 99%

“…Thin-Layer Chromatographic Separation of Pyridoxine and Pyridoxal. Cytosolic extracts of liver and hepatoma were prepared as described previously (Thanassi et al, 1981). Aliquots (15 i±L) were incubated in capped 1.5-mL Eppendorf tubes in 0.17 M Tris buffer (pH 8.0) containing 2.75 mM [4'-3H] pyridoxine (1.36 X 106 cpm) and 1 mM 4'-deoxypyridoxine (total volume 50 uL).…”

Section: Methodsmentioning

confidence: 99%

“…Purification of Pyridoxine-(Pyridoxamine-) 5'-phosphate Oxidase from Rat Liver. Oxidase activity was measured at 37 °C by the 2,4-dinitrophenylhydrazine procedure developed by Wada & Snell (1961) with modifications as previously described (Meisler & Thanassi, 1980;Thanassi et al, 1981). The purification was based on methods described by Kazarinoff & McCormick (1975) and Merrill et al (1979) for purification of the rabbit liver enzyme.…”

Section: Methodsmentioning

confidence: 99%

“…The procedures were modifications of those described by Engvall & Perlmann (1972). Liver and tumor cytosols were prepared as described previously (Thanassi et al, 1981) except that 3 instead of 9 volumes of 0.25 M sucrose was used in the preparation of the initial homogenate. Cytosols were dialyzed against 50 mM sodium carbonate buffer, pH 9.6.…”

Section: Methodsmentioning

confidence: 99%

“…We have previously found that two poorly differentiated Morris hepatomas lack pyridoxine-(pyridoxamine-) 5'phosphate oxidase activity (Thanassi et al, 1981). In addition, we have reported that there appears to be an oncodevelop- mental correlation between oxidase activity and the degree of differentiation in a series of Morris hepatomas (Meisler et al, 1982).…”

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confidence: 95%

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Absence of pyridoxine- (pyridoxamine-) 5'-phosphate oxidase in Morris hepatoma 7777

Nutter¹,

Meisler²,

Thanassi³

1983

Biochemistry

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Morris hepatoma 7777 previously has been shown to have no detectable pyridoxine- (pyridoxamine-) 5'-phosphate oxidase activity [Thanassi, J. W., Nutter, L. M., Meisler, N. T., Commers, P., & Chiu, J.-F. (1981) J. Biol. Chem. 256, 3370-3375]. In order to determine if this enzyme was missing in the hepatoma, we purified rat liver oxidase and raised antibodies to it in rabbits. Final purification of rat liver oxidase for use as an antigen was accomplished by affinity chromatography and gel electrophoresis. The rat liver enzyme is similar to rabbit liver oxidase [Kazarinoff, M. N., & McCormick, D. B. (1975) J. Biol. Chem. 250, 3436-3442] having two noncovalently linked subunits with molecular weights in the range of 25 000-28 000. Evidence indicating that inactive enzyme was simultaneously purified with native enzyme was obtained. The IgG fraction was purified from the serum of a rabbit that had been immunized with rat liver oxidase. This was used in the development of ELISA and immunoblot analyses for the presence of antigenically active pyridoxine- (pyridoxamine-) 5'-phosphate oxidase in cytosolic preparations from normal rat liver and Morris hepatoma 7777. The results indicated that there was no immunologically detectable oxidase protein in the tumor. An alternate pathway of pyridoxal 5'-phosphate synthesis, involving oxidation of pyridoxine to pyridoxal followed by phosphorylation, was ruled out. The implications of these findings with respect to acquisition of nutrients by tumors are discussed.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 95%

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Absence of pyridoxine- (pyridoxamine-) 5'-phosphate oxidase in Morris hepatoma 7777

Nutter¹,

Meisler²,

Thanassi³

1983

Biochemistry

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Abnormal vitamin B6 status in childhood leukemia

Pais

Vanous

Hollins

et al. 1990

Cancer

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Vitamin B6 is involved in many biological processes of potential relevance to carcinogenesis and tumor growth, including DNA synthesis and maintenance of immunocompetence, yet very little information exists on B6 nutritional status in childhood leukemia. Using a radioenzymatic assay, the authors measured plasma pyridoxal 5'-phosphate (PLP), the biologically active form of B6, in 11 newly diagnosed untreated children with leukemia and 11 age-matched controls. The children with leukemia had significantly lower PLP levels than the controls. In 26 additional leukemia patients and 26 additional controls, a high-performance liquid chromatography assay also demonstrated lower plasma PLP levels in childhood leukemia compared with controls. These differences were significant for both acute lymphoblastic leukemia (ALL) and for acute nonlymphoblastic leukemia (ANLL). The PLP values did not correlate with indices of leukemia cell burden, but did correlate with reported B6 intake, suggesting that illness-related diet changes are at least partially responsible for the low PLP levels. Before any chemotherapy, overall nutritional status was suboptimal in 53% of ALL cases and 57% of ANLL cases. Newly diagnosed children with leukemia have suboptimal overall nutrition as well as suboptimal vitamin B6 status.

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Vitamin B6 and Cancer

Fortmeyer

1990

Nutrients and Cancer Prevention

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Vitamin B6 metabolism in Morris hepatomas.

Cited by 28 publications

References 53 publications

Absence of pyridoxine- (pyridoxamine-) 5'-phosphate oxidase in Morris hepatoma 7777

Absence of pyridoxine- (pyridoxamine-) 5'-phosphate oxidase in Morris hepatoma 7777

Abnormal vitamin B6 status in childhood leukemia

Vitamin B6 and Cancer

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