PMID- 3029401
OWN - NLM
STAT- MEDLINE
DCOM- 19870422
LR  - 20200724
IS  - 0022-538X (Print)
IS  - 1098-5514 (Electronic)
IS  - 0022-538X (Linking)
VI  - 61
IP  - 4
DP  - 1987 Apr
TI  - Activation of int-1 and int-2 mammary oncogenes in hormone-dependent and 
      -independent mammary tumors of GR mice.
PG  - 1073-8
AB  - Mammary tumors in the GR mouse strain are caused by the expression of an 
      endogenous provirus of the mouse mammary tumor virus (MMTV). The tumors progress 
      from a hormone-dependent growth phase to autonomous, hormone-independent growth. 
      We studied proviral insertion of MMTV at the int-1 and int-2 mammary oncogenes 
      and the transcription of these genes during progression of a series of 
      transplanted mammary tumors. During the hormone-dependent phase, 6 of 15 
      transplanted tumors were positive for proviral insertion at int-1 or int-2 or 
      both. These tumors were oligoclonal with respect to the fraction of tumor cells 
      with novel int-1 and int-2 restriction fragments and, apparently, consisted of 
      different tumor cells with proviruses integrated at different oncogenes, 
      including genes that are not yet known. In 10 tumors we detected expression of 
      the int genes, indicating that most tumors contain minor populations of cells 
      with int-1 or int-2 activations. On transplantation the tumors remained 
      oligoclonal during the hormone-dependent phase. The hormone-independent variants 
      of the tumors emerged as clonal outgrowths of cells with MMTV proviruses that 
      could be traced back in the hormone-dependent tumors, but not always those of 
      cells that were positive for insertions near int-1 or int-2. The maintenance of 
      oligoclonality during the hormone-dependent phase suggests a growth-controlling 
      effect of different populations of cells on each other. The clonal, 
      hormone-independent tumors that arise later seem to be the result of mutations 
      that are unrelated to int activation.
FAU - Mester, J
AU  - Mester J
FAU - Wagenaar, E
AU  - Wagenaar E
FAU - Sluyser, M
AU  - Sluyser M
FAU - Nusse, R
AU  - Nusse R
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Virol
JT  - Journal of virology
JID - 0113724
RN  - EC 3.1.21.- (DNA Restriction Enzymes)
SB  - IM
MH  - Animals
MH  - Cell Division
MH  - DNA Restriction Enzymes
MH  - Female
MH  - *Genes, Viral
MH  - Mammary Neoplasms, Experimental/*microbiology/pathology
MH  - Mammary Tumor Virus, Mouse/*genetics
MH  - Mice
MH  - Mice, Inbred Strains
MH  - *Oncogenes
MH  - *Ovariectomy
MH  - Virus Activation
PMC - PMC254065
EDAT- 1987/04/01 00:00
MHDA- 1987/04/01 00:01
PMCR- 1987/04/01
CRDT- 1987/04/01 00:00
PHST- 1987/04/01 00:00 [pubmed]
PHST- 1987/04/01 00:01 [medline]
PHST- 1987/04/01 00:00 [entrez]
PHST- 1987/04/01 00:00 [pmc-release]
AID - 10.1128/JVI.61.4.1073-1078.1987 [doi]
PST - ppublish
SO  - J Virol. 1987 Apr;61(4):1073-8. doi: 10.1128/JVI.61.4.1073-1078.1987.