PMID- 8382558
OWN - NLM
STAT- MEDLINE
DCOM- 19930401
LR  - 20071114
IS  - 0008-5472 (Print)
IS  - 0008-5472 (Linking)
VI  - 53
IP  - 5
DP  - 1993 Mar 1
TI  - Calories, parity, and prolactin influence mammary epithelial kinetics and 
      differentiation and alter mouse mammary tumor risk.
PG  - 1188-94
AB  - Reduced calorie intake (RCI) suppresses mouse mammary tumor virus (MMTV) 
      transcription and reduces mammary tumor (MT) incidence in C3H/Ou mice. Since 
      efficient retroviral expression requires cell division, we investigated whether 
      the suppression of MMTV and MT by RCI reflects changes in mammary histogenesis 
      and lowered epithelial kinetics. Prolactin (PRL) augments MMTV transcription. 
      Since PRL levels may be lowered by RCI, we evaluated whether lowered PRL in ad 
      libitum-fed mice alters mammary histogenesis and MT incidence in a manner 
      comparable to RCI. Pregnancy augments MMTV transcription. Hence, we also 
      determined the effect of parity on mammary histogenesis, kinetics, and MT risk. 
      One hundred thirty-five C3H/Ou mice were fed ad libitum or a RCI level and 
      separated into six experimental groups. Twenty ad libitum-fed mice were injected 
      with a dopaminomimetic to lower PRL, and 20 RCI mice were engrafted with 
      adenohypophyses to elevate PRL. Twenty-seven ad libitum-fed mice and twenty-eight 
      RCI mice experienced a single parturition. RCI protected nulliparous (P = 0.0001) 
      and parous mice (P = 0.005) from MT development. Reduced calories or lowered PRL 
      with ad libitum feeding similarly influenced mammary histogenesis, kinetics and 
      MT risk (P > 0.5). Mammary glands of RCI mice or of ad libitum-fed mice with 
      lowered PRL were histologically comparable and principally ductular with a low 
      DNA-labeling index (DNA-LI) (P < 0.001). In contrast, the parenchyma of ad 
      libitum-fed mice or of RCI mice with elevated PRL had exuberant alveoli 
      formation, an elevated DNA-LI (P < 0.001), and preneoplastic lesions. Parity did 
      not change the elevated DNA-LI and MT risk of ad libitum-fed mice but increased 
      the mammary DNA-LI (P < 0.001) and MT incidence (P = 0.01) of RCI mice. 
      Prevention of mammary tumorigenesis in C3H/Ou mice by RCI may result from 
      modulated serum PRL activity and reduced mammary epithelial kinetics which 
      suppress MMTV transcription and minimize the risk of activating protooncogenes.
FAU - Engelman, R W
AU  - Engelman RW
AD  - All Children's Hospital, College of Medicine, University of South Florida, St. 
      Petersburg 33701.
FAU - Day, N K
AU  - Day NK
FAU - Good, R A
AU  - Good RA
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  - 9002-62-4 (Prolactin)
RN  - 9007-49-2 (DNA)
SB  - IM
MH  - Animals
MH  - Cell Differentiation
MH  - Cell Division
MH  - DNA/biosynthesis
MH  - *Energy Intake
MH  - Epithelial Cells
MH  - Female
MH  - Kinetics
MH  - Mammary Glands, Animal/*cytology
MH  - Mammary Neoplasms, Experimental/*etiology
MH  - Mammary Tumor Virus, Mouse/genetics
MH  - Mice
MH  - Mice, Inbred C3H
MH  - *Parity
MH  - Prolactin/*blood
MH  - Risk
MH  - Transcription, Genetic
EDAT- 1993/03/01 00:00
MHDA- 1993/03/01 00:01
CRDT- 1993/03/01 00:00
PHST- 1993/03/01 00:00 [pubmed]
PHST- 1993/03/01 00:01 [medline]
PHST- 1993/03/01 00:00 [entrez]
PST - ppublish
SO  - Cancer Res. 1993 Mar 1;53(5):1188-94.