Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2004-9-2
pubmed:abstractText
Replicative senescence/crisis is thought to act as a tumor suppressor mechanism. Although recent data indicate that normal human cells cannot be converted into cancer cells without telomerase, the original concept of senescence as a tumor suppressor mechanism is that senescence/crisis would act to limit the growth of telomerase-negative tumors. We show here that this concept is valid when oncogene-expressing human and bovine cells are introduced into immunodeficient mice using tissue reconstruction techniques, as opposed to conventional subcutaneous injection. Primary human and bovine adrenocortical cells were transduced with retroviruses encoding Ha-Ras(G12V) and SV40 large T antigen and transplanted in immunodeficient mice using tissue reconstruction techniques. Transduced cells were fully malignant (invasive and metastatic) in this model. They had negligible telomerase activity both before transplantation and when recovered from tumors. When serially transplanted, tumors showed progressively slower growth, decreased invasion and metastasis, shortened telomeres, and morphological features of crisis. Whereas telomerase was not essential for malignant behavior, expression of human telomerase reverse transcriptase enabled cells from serially transplanted tumors that had ceased growth to reacquire tumorigenicity. Moreover, telomerase-negative oncogene-expressing cells were tumorigenic only when transplanted using tissue reconstruction techniques; human telomerase reverse transcriptase was required for cells to form tumors when cells were injected subcutaneously. This work provides a new model to study crisis in an in vivo setting and its effects on malignancy; despite having invasive and metastatic properties, cells are eventually driven into crisis by proliferation in the absence of a telomere maintenance mechanism.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
64
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6144-51
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:15342398-Adrenal Cortex, pubmed-meshheading:15342398-Adrenal Cortex Neoplasms, pubmed-meshheading:15342398-Animals, pubmed-meshheading:15342398-Antigens, Polyomavirus Transforming, pubmed-meshheading:15342398-Cattle, pubmed-meshheading:15342398-Cell Division, pubmed-meshheading:15342398-Cell Transformation, Neoplastic, pubmed-meshheading:15342398-DNA-Binding Proteins, pubmed-meshheading:15342398-Female, pubmed-meshheading:15342398-Humans, pubmed-meshheading:15342398-Male, pubmed-meshheading:15342398-Mice, pubmed-meshheading:15342398-Mice, Inbred ICR, pubmed-meshheading:15342398-Mice, SCID, pubmed-meshheading:15342398-Neoplasm Transplantation, pubmed-meshheading:15342398-Telomerase, pubmed-meshheading:15342398-Telomere, pubmed-meshheading:15342398-Transduction, Genetic, pubmed-meshheading:15342398-Transplantation, Heterologous, pubmed-meshheading:15342398-ras Proteins
pubmed:year
2004
pubmed:articleTitle
Progressive loss of malignant behavior in telomerase-negative tumorigenic adrenocortical cells and restoration of tumorigenicity by human telomerase reverse transcriptase.
pubmed:affiliation
Department of Physiology, University of Texas Health Science Center, San Antonio, Texas 78245, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't