Linked Life Data

16818508

Source:http://linkedlifedata.com/resource/pubmed/id/16818508

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2006-7-4
pubmed:abstractText
Human malignant melanoma is a highly aggressive form of cancer; the 5-year survival rate in patients with stage III or IV disease is <5%. In patients with metastatic melanoma, systemic therapy becomes ineffective because of the high resistance of melanoma cells to various anticancer therapies. We have found previously that development of the drug resistance and metastatic phenotypes in breast cancer cells is associated with increased tissue transglutaminase (TG2) expression. In the study reported here, we investigated TG2 expression and its implications in metastatic melanoma. We found that metastatic melanoma cell lines expressed levels of TG2 up to 24-fold higher than levels in radial growth phase of primary melanoma cell lines. Activation of endogenous TG2 by the calcium ionophore A23187 induced a rapid and strong apoptotic response in A375 cells and A23187-induced apoptosis could be blocked by TG2-specific inhibitors. These findings indicated that activation of endogenous TG2 could serve as a strategy for inducing apoptosis in malignant melanomas. Importantly, tumor samples from patients with malignant melanomas showed strong expression of TG2, suggesting that TG2 expression is selectively up-regulated during advanced developmental stages of melanoma. We observed that 20% to 30% of TG2 protein was present on cell membranes in association with beta1 and beta5 integrins. This association of TG2 with cell surface integrins promoted strong attachment of A375 cells to fibronectin-coated surfaces, resulting in increased cell survival in serum-free medium. Inhibition of TG2 by small interfering RNA inhibited fibronectin-mediated cell attachment and cell survival functions in A375 cells. Overall, our results suggest that TG2 expression contributes to the development of chemoresistance in malignant melanoma cells by exploiting integrin-mediated cell survival signaling pathways.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1535-7163
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1493-503
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:16818508-Apoptosis, pubmed-meshheading:16818508-Cell Adhesion, pubmed-meshheading:16818508-Cell Line, Tumor, pubmed-meshheading:16818508-Cell Membrane, pubmed-meshheading:16818508-Cisplatin, pubmed-meshheading:16818508-Culture Media, Serum-Free, pubmed-meshheading:16818508-Dacarbazine, pubmed-meshheading:16818508-Disease Progression, pubmed-meshheading:16818508-Drug Resistance, Neoplasm, pubmed-meshheading:16818508-Fibronectins, pubmed-meshheading:16818508-Humans, pubmed-meshheading:16818508-Immunoprecipitation, pubmed-meshheading:16818508-Integrin beta Chains, pubmed-meshheading:16818508-Melanoma, pubmed-meshheading:16818508-RNA, Small Interfering, pubmed-meshheading:16818508-Signal Transduction, pubmed-meshheading:16818508-Survival Rate, pubmed-meshheading:16818508-Transglutaminases
pubmed:year
2006
pubmed:articleTitle
Implications of tissue transglutaminase expression in malignant melanoma.
pubmed:affiliation
Department of Experimental Therapeutics, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural