PMID- 2822232
OWN - NLM
STAT- MEDLINE
DCOM- 19871203
LR  - 20071114
IS  - 0008-5472 (Print)
IS  - 0008-5472 (Linking)
VI  - 47
IP  - 21
DP  - 1987 Nov 1
TI  - Characterization of the DIM series of BALB/c preneoplasms for mouse mammary tumor 
      virus-mediated oncogenesis.
PG  - 5707-14
AB  - The DIM series of preneoplasms, developed from the BALB/c mammary cell line 
      COMMA-D, and DIM-derived tumors were examined for evidence of mouse mammary tumor 
      virus (MMTV) involvement in the tumorigenic process. DIM tissues were shown to be 
      free of exogenous MMTV inasmuch as Southern blot analysis of DNAs extracted from 
      DIM preneoplasms and tumors showed the lack of a PstI-generated 4.2-kilobase 
      MMTV-gag-pol band. To examine the possibility of endogenous MMTV action via 
      enhancer insertion, DNAs from DIM preneoplasms and tumors were restricted with 
      EcoRI, BamHI, or SstI and subjected to Southern blot analysis using an MMTV-long 
      terminal repeat probe. The normal endogenous proviral content was detected in all 
      DIM tissues assayed; no new proviruses were found. To examine the possibility of 
      endogenous MMTV gene product oncogenesis, MMTV transcripts were quantified by 
      slot blot analysis and MMTV envelope proteins were assayed by immunohistochemical 
      staining of DIM tissue sections. While all DIM tissues expressed MMTV-long 
      terminal repeat transcripts, the level of expression did not correlate with 
      tumorigenicity. Most frequently, MMTV-env-containing sequences were more abundant 
      than the 1.6-kilobase long terminal repeat transcript, the latter being the most 
      promising candidate for a MMTV gene product mediating mammary tumorigenesis. 
      However, preneoplasms and tumors of only the DIM 4 line contained levels of MMTV 
      Mr 52,000 or 36,000 glycoproteins detectable by immunoperoxidase staining. 
      Electron microscopy did not reveal any virus particles in DIM 4 tissues. These 
      data do not substantiate MMTV as a causative agent in the formation of the DIM 
      preneoplasms or tumors. Thus while MMTV function may confuse the interpretation 
      of causative events in the formation of other preneoplasms and neoplasms, the DIM 
      preneoplasms represent a model system for the study of MMTV-independent 
      mechanisms.
FAU - Schwartz, M S
AU  - Schwartz MS
AD  - Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030.
FAU - Medina, D
AU  - Medina D
LA  - eng
GR  - CA-39017/CA/NCI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Cancer Res
JT  - Cancer research
JID - 2984705R
RN  - 0 (RNA, Viral)
SB  - IM
MH  - Animals
MH  - Female
MH  - Mammary Neoplasms, Experimental/*etiology
MH  - Mammary Tumor Virus, Mouse/*genetics
MH  - Mice
MH  - Mice, Inbred BALB C
MH  - Precancerous Conditions/*etiology
MH  - Proto-Oncogenes
MH  - Proviruses/genetics
MH  - RNA, Viral/*analysis
MH  - Repetitive Sequences, Nucleic Acid
MH  - Transcription, Genetic
EDAT- 1987/11/01 00:00
MHDA- 1987/11/01 00:01
CRDT- 1987/11/01 00:00
PHST- 1987/11/01 00:00 [pubmed]
PHST- 1987/11/01 00:01 [medline]
PHST- 1987/11/01 00:00 [entrez]
PST - ppublish
SO  - Cancer Res. 1987 Nov 1;47(21):5707-14.