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Regulation of an H-ras-related transcript by parathyroid hormone in rat osteosarcoma cellsThe rat osteosarcoma cell line UMR 106-01 is a commonly used model system for the study of osteoblast function. However, it also expresses a phenotype characteristic of transformed cells. To test whether the latter could be accounted for by aberrant oncogene expression, we probed Northern blots of UMR and other osteoblastic cells with a panel of oncogene probes. These blots, when probed with a cDNA specific for v-H-ras, revealed a 7.0-kilobase (kb) H-ras-related transcript (designated HRRT) in UMR 106-01 cells that was not expressed in other osteoblastic cells. Osteoblast-enriched calvarial cells expressed the typical 1.1-kb H-ras mRNA, which was absent in UMR cells. Additionally, Western blots of lysates of UMR cells documented the presence of three proteins immunologically related to H-rasp21. To determine whether HRRT represented a recombinant retrovirus product, Northern blots were probed with a cDNA specific for the highly conserved gag-pol region of Moloney murine leukemia virus. These blots showed parallel cross-reactivity with an apparently identical transcript of 7.0 kb. The 7.0-kb transcripts detected by both v-H-ras and gag-pol probes declined to the same extent after treatment with concentrations of PTH known to inhibit proliferation of these cells. PTH regulated the abundance of HRRT in a time- and dose-dependent manner, with greatest repression of the transcript after 8 h of treatment with 10(-8) M PTH. The decrease in HRRT could not be completely accounted for by changes in transcriptional activity, as determined by nuclear run-on assays.(ABSTRACT TRUNCATED AT 250 WORDS).
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Scott, D. K.
(Pediatric Research Institute, Cardinal Glennon Children's Hospital, St. Louis University School of Medicine Missouri 63110)
Weaver, W. R.
Clohisy, J. C.
Brakenhoff, K. D.
Kahn, A. J.
Partridge, N. C.
Date Acquired
August 22, 2013
Publication Date
September 1, 1992
Publication Information
Publication: Molecular endocrinology (Baltimore, Md.)
Volume: 6
Issue: 9
ISSN: 0888-8809
Subject Category
Life Sciences (General)
Funding Number(s)
Distribution Limits
Non-NASA Center
NASA Discipline Cell Biology

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