dolichols and Lymphoma

The effect of different clinical conditions on urinary dolichols was studied in 219 hospital patients and in 24 pregnant women. Significantly increased urinary dolichol levels were found in patients with severe bacterial infections (mean +/- SEM, 37.5 +/- 8.0 micrograms/mmol creatinine, P less than 0.001), in patients with haematological or metastatic (23.3. +/- 5.1, P less than 0.05) as well as localised (15.4 +/- 1.8, P less than 0.01) malignancies and in pregnant women (22.2 +/- 1.8, P less than 0.001) as compared to healthy controls (6.6 +/- 0.4). These results show that urinary excretion of dolichols may be increased, not only in alcoholics and patients with some rare neurodegenerative storage diseases, but also in patients suffering from various other diseases.

Topics: Adult; Aged; Bacterial Infections; Dolichols; Female; Humans; Leukemia; Lymphoma; Male; Middle Aged; Neoplasms; Pregnancy

Thy-1 glycoprotein is a member of a class of proteins which are anchored to the plasma membrane via a covalently bound glycophospholipid. The biosynthesis and anchoring of Thy-1 were investigated in a family of wild-type and mutant (complementation groups A, B, C, E, and F) T lymphomas. The mutants all synthesize Thy-1 but fail to express it on the cell surface. Analysis of the size of D-[2-3H]mannose-labeled dolichol-linked oligosaccharides showed that the class E mutant is the only cell line which does not synthesize dolichol-P-P-Glc3Man9GlcNAc2. Turnover and possible secretion of Thy-1 by mutant T lymphoma cells were documented in D-[2-3H]mannose pulse-chase experiments. The turnover of [3H]Thy-1 for all wild-type cells is considerably slower than for the mutant cells. Class B and E cells release appreciably more [3H]Thy-1 than wild-type cells. Additional experiments were performed to determine the electrophoretic mobility and hydrophobicity of cell-associated and released forms of Thy-1 labeled overnight with [3H]mannose. All wild-type and class A, C, E, and F mutant cells contain a major Triton X-114 binding species of cell-associated [3H]Thy-1. All extracellular [3H]Thy-1 was almost exclusively hydrophilic. The presence of two Thy-1 anchor components, ethanolamine and palmitate, was investigated. Biosynthetic labeling with [3H]palmitic acid showed that all of the wild-type cells but none of the mutants incorporated this anchor precursor into Thy-1. In [3H]ethanolamine-labeling experiments, incorporation was detected in the Thy-1 of all wild-type cells and in two mutants, S1A-b and T1M1-c. Based on the above studies, the phenotype of Thy-1 negative T lymphoma mutants can be re-evaluated. In classes A and F, dolichol-linked oligosaccharides appear normal and no anchor is detected. In class B, dolichol-linked oligosaccharides appear normal, a partial anchor may be present, and a substantial amount of Thy-1 is released. In class C, dolichol-linked oligosaccharides appear normal and a partial anchor may be present. In class E, truncated dolichol-linked oligosaccharides are formed, no anchor is detected, but a substantial amount of newly synthesized Thy-1 is released. These observations are discussed with reference to the possibility that the lesions which characterize the mutants pertain to the biosynthesis of the glycophospholipid moiety of Thy-1.

Topics: Animals; Antigens, Surface; Cell Line; Dolichols; Electrophoresis, Polyacrylamide Gel; Ethanolamine; Ethanolamines; Kinetics; Lymphoma; Mannose; Mice; Mutation; Palmitic Acid; Palmitic Acids; Phenotype; T-Lymphocytes; Thy-1 Antigens; Tumor Cells, Cultured