Abstract |
In the present study, we examined the presence of deacetylases capable of producing free hexosamines, which we have shown earlier to be immunosuppressive against human natural killer (NK) cell-mediated cytotoxicity, from N-acetylhexosamines in human tumor cells. When human NK-resistant colon cancer cells (Colo-320DM) were incubated with acetyl-D-[1,6-3H(N)] glucosamine, a significant conversion to [3H] glucosamine occurred. Deacetylation was demonstrated as a change of the substrate radioactivity into free glucosamine trapped by a cation exchange resin, and this was subsequently confirmed by paper chromatography. This deacetylase activity was detected in other NK-resistant tumor cell lines, especially in freshly isolated human renal and breast cancer cells and testicular seminoma cells. However, no deacetylase activity was detected in NK-sensitive target cells such as K562, MOLT-4, or HL-60 cells. The ability to produce free hexosamines from N-acetylated aminosugars may provide a new mechanism for the escape of tumor cells from the attack of immune effector cells such as NK cells.
|
Authors | M Yagita, A Seppo, O Renkonen, E Saksela |
Journal | Cancer research
(Cancer Res)
Vol. 53
Issue 23
Pg. 5600-4
(Dec 01 1993)
ISSN: 0008-5472 [Print] United States |
PMID | 8242610
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
|
Chemical References |
- Hexosamines
- Immunosuppressive Agents
- Amidohydrolases
- Acetylglucosamine
|
Topics |
- Acetylglucosamine
(pharmacology)
- Amidohydrolases
(physiology)
- Cytotoxicity, Immunologic
- Hexosamines
(metabolism)
- Humans
- Immunosuppressive Agents
(metabolism, pharmacology)
- Killer Cells, Natural
(immunology)
- Mycoplasma
(enzymology)
- Neoplasms
(enzymology, immunology)
- Substrate Specificity
- Tumor Cells, Cultured
|