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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1984-8-20
pubmed:abstractText
We used an unique model, human medullary thyroid carcinoma (MTC) in culture (the TT line), to study features of neuroendocrine-related biochemistry in relationship to growth, differentiation, and tumor progression. Tumor tissues from patients with virulent MTC contain a very heterogeneous distribution of cells staining for calcitonin (CT) and have a high ratio of intracellular L-dopa decarboxylase activity (DDC) to CT. We found, in a culture line of MTC derived from a patient with virulent disease, that the degree of the inverse relationship between DDC and CT and the heterogeneous cellular distribution of CT probably relate to the rate of cellular growth and the biochemical set of individual cell clones. During exponential growth of the parent TT cell line, intracellular DDC and CT varied. DDC increased by 70% and CT decreased by 40%. Single time-point measurements in 54 cell clones or highly enriched cell populations revealed a more dramatic variability for CT (15-fold) than for DDC (5-fold). During growth of the clones having the highest and lowest CT measurements, respectively, inverse dynamics between DDC and CT were again found. However, each clone maintained a distinct range of CT during the entire growth curve, with a 2- to 4-fold difference in CT between the two clones throughout. In the low producing CT clone, ratios between DDC and CT rose to greater than 1.0 during growth, a very high value found before this study only in MTC tissues from patients with virulent disease. Immunohistochemical staining for CT of parent cells and clones grown on embryonic chick skin revealed increased cellular heterogeneity for CT distribution during growth. The TT line provides a powerful tool to study neuroendocrine related biochemical events in relationship to growth, differentiation, and tumor progression in MTC. Our in vitro findings in the TT line well explain observations made previously in patients. We conclude that: (1) DDC, a neural property of MTC, is an early differentiation marker as compared to CT and that the differentiation status of MTC cells varies inversely with cell growth rate; and (2) in patients with MTC, the virulence of the tumor probably varies inversely with differentiation status. The inverse ratio of DDC to CT is probably determined in MTC by the proportion of rapidly growing cells and numbers of cell clones which have a poor ability for maturation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-972X
pubmed:author
pubmed:issnType
Print
pubmed:volume
59
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
338-43
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Human medullary thyroid carcinoma in culture provides a model relating growth dynamics, endocrine cell differentiation, and tumor progression.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't