Linked Life Data

17640716

Source:http://linkedlifedata.com/resource/pubmed/id/17640716

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2007-9-24
pubmed:abstractText
Tumor-associated macrophages (TAMs) may elicit contrasting effects on tumor growth, depending on their biological activities. Macrophages use arginine either to synthesize nitric oxide (NO) through the inducible NO synthase (iNOS) or to produce ornithine through arginase activity. Although the effects of NO are primarily cytotoxic, production of ornithine may promote tumor cell proliferation. Thus, iNOS/arginase balance in TAMs may be crucial in tumor progression. The aim of this study was (a) to explore iNOS and arginase expression in TAMs associated with human melanoma at different stages of tumor progression and (b) to explore whether melanoma cells influence iNOS and/or arginase expression in TAMs under basal condition and in the presence of interferon gamma and/or lipopolysaccharide. Immunohistochemical analyses performed on tissue sections from in situ melanoma, invasive melanoma of different pT categories, and metastatic melanoma revealed that (a) the percentage of iNOS-positive TAMs was significantly higher in in situ and thin melanomas in comparison with more advanced, thicker tumors; (b) the percentage of arginase-positive TAMs did not change among the pT categories analyzed; and (c) the percentage of iNOS-positive TAMs was greater than that of arginase-positive TAMs in peritumoral and intratumoral locations of thin melanomas (pT1). Moreover, by the use of an in vitro experimental protocol represented by B16 murine melanoma cells cocultivated with inflammatory macrophages, we found that melanoma cells stimulate iNOS expression and NO production in macrophages. In conclusion, our in vivo and in vitro results suggest that, mainly in early melanoma lesions, iNOS prevails over arginase in TAMs, a phenomenon possibly stimulated by contact with tumor cells. However, macrophages stimulated by murine melanoma cells secreted a level of NO compatible with an antitumor activity only in the presence of interferon gamma.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0046-8177
pubmed:author
pubmed:issnType
Print
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1516-25
pubmed:meshHeading
pubmed-meshheading:17640716-Adult, pubmed-meshheading:17640716-Aged, pubmed-meshheading:17640716-Aged, 80 and over, pubmed-meshheading:17640716-Animals, pubmed-meshheading:17640716-Antigens, CD, pubmed-meshheading:17640716-Antigens, Differentiation, Myelomonocytic, pubmed-meshheading:17640716-Arginase, pubmed-meshheading:17640716-Arginine, pubmed-meshheading:17640716-Cell Line, Tumor, pubmed-meshheading:17640716-Female, pubmed-meshheading:17640716-Humans, pubmed-meshheading:17640716-Macrophages, pubmed-meshheading:17640716-Male, pubmed-meshheading:17640716-Melanoma, pubmed-meshheading:17640716-Mice, pubmed-meshheading:17640716-Middle Aged, pubmed-meshheading:17640716-Nitric Oxide Synthase Type II, pubmed-meshheading:17640716-Polymerase Chain Reaction, pubmed-meshheading:17640716-RNA, Messenger, pubmed-meshheading:17640716-Retrospective Studies, pubmed-meshheading:17640716-Skin Neoplasms
pubmed:year
2007
pubmed:articleTitle
Arginine metabolism in tumor-associated macrophages in cutaneous malignant melanoma: evidence from human and experimental tumors.
pubmed:affiliation
Dipartimento di Patologia Umana ed Oncologia, Università di Firenze, Florence 50134, Italy. daniela.massi@unifi.it
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't