PMID- 1655246
OWN - NLM
STAT- MEDLINE
DCOM- 19911029
LR  - 20071114
IS  - 0008-5472 (Print)
IS  - 0008-5472 (Linking)
VI  - 51
IP  - 19
DP  - 1991 Oct 1
TI  - Dietary restriction permits normal parturition and lactation but suppresses mouse 
      mammary tumor virus proviral transcription even after mammary involution.
PG  - 5123-8
AB  - Dietary restriction of C3H/Ou mice prevents development of spontaneous mammary 
      adenocarcinoma by suppressing mammary expression of the mouse mammary tumor virus 
      (MMTV) via a mechanism which may involve prolactin. In the present study, dietary 
      restriction of 40% was imposed for 16 weeks on nulliparous C3H/Ou mice, 
      interrupted by ad libitum consumption at mating and continued only during 
      pregnancy and lactation, with 40% energy restriction reimposed at the end of 
      lactation. The results show that mammary MMTV mRNA expression levels of chronic 
      energy intake restricted (CEIR) mice and ad libitum fed mice are similar and 
      elevated during early lactation, when all mice of both groups are being fed ad 
      libitum energy levels. In spite of this, and in marked contrast, when CEIR dams 
      are returned to 40% dietary restriction following the weaning of litters, mammary 
      MMTV transcription is suppressed to levels 4-5-fold less than those measured in 
      mammary glands from ad libitum fed controls. Within the 38 weeks of study, 73% of 
      ad libitum fed uniparous mice at risk and 11% of CEIR uniparous mice at risk 
      developed mammary tumors, yet mice of both dietary groups delivered and weaned 
      healthy litters with comparable efficiency. When dietary restriction is 
      maintained in CEIR mice during pregnancy and lactation, efficiency of conception 
      and litter size are reduced, and MMTV transcription is suppressed even during 
      lactation. Mean serum prolactin levels were not significantly different among 
      dietary groups. These findings show that the level of MMTV transcription is 
      rigorously influenced by dietary energy level, and that 40% dietary restriction 
      of C3H/Ou mice not only suppresses mammary MMTV transcription and prevents 
      mammary tumor development in uniparous mice, but also permits normal conception, 
      gestation, lactation, and the production of healthy litters as long as the 
      nutritional demands of gestation and lactation are met.
FAU - Engelman, R W
AU  - Engelman RW
AD  - All Children's Hospital, University of South Florida College of Medicine, St. 
      Petersburg 33701.
FAU - Fukaura, Y
AU  - Fukaura Y
FAU - Hamada, N
AU  - Hamada N
FAU - Good, R A
AU  - Good RA
FAU - Day, N K
AU  - Day NK
LA  - eng
GR  - AG05633/AG/NIA NIH HHS/United States
GR  - CA41061/CA/NCI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Cancer Res
JT  - Cancer research
JID - 2984705R
RN  - 0 (Caseins)
RN  - 0 (RNA, Messenger)
RN  - 9002-62-4 (Prolactin)
SB  - IM
MH  - Adenocarcinoma/microbiology/*prevention & control
MH  - Animals
MH  - Blotting, Northern
MH  - Body Weight
MH  - Caseins/biosynthesis
MH  - *Diet, Reducing
MH  - Enzyme-Linked Immunosorbent Assay
MH  - Female
MH  - *Labor, Obstetric
MH  - *Lactation/metabolism
MH  - Mammary Neoplasms, Animal/microbiology/*prevention & control
MH  - Mammary Tumor Virus, Mouse/*drug effects
MH  - Mice
MH  - Mice, Inbred C3H
MH  - Pregnancy
MH  - Prolactin/blood
MH  - RNA, Messenger/biosynthesis
MH  - *Transcription, Genetic
EDAT- 1991/10/01 00:00
MHDA- 1991/10/01 00:01
CRDT- 1991/10/01 00:00
PHST- 1991/10/01 00:00 [pubmed]
PHST- 1991/10/01 00:01 [medline]
PHST- 1991/10/01 00:00 [entrez]
PST - ppublish
SO  - Cancer Res. 1991 Oct 1;51(19):5123-8.