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Human prolactin regulates transfected MMTV LTR-directed gene expression in a human breast-carcinoma cell line through synergistic interaction with steroid hormones
- Source :
- International Journal of Cancer. 52:928-933
- Publication Year :
- 1992
- Publisher :
- Wiley, 1992.
-
Abstract
- Prolactin plays a key role in the regulation and growth of mammary cells, and influences tumor promotion. We have shown that chronic energy restriction intake depresses prolactin levels, inhibits production of MMTV proviral DNA and proto-oncogene expression in mammary glands and prevents development of mammary tumors. Since the expression and proto-oncogene activation of MMTV are regulated by promoter/enhancer elements within its long terminal repeat (LTR), in the present study we used a chloramphenicol acetyl transferase (CAT) reporter gene system and gene transfection methods to study the effect of prolactin on MMTV LTR using a human ductal carcinoma cell line T47D stably or transiently transfected with a plasmid consisting of the LTR upstream of CAT gene. Human prolactin or dexamethasone induced, respectively, a 2-fold or 6-fold increase in CAT activity compared with background CAT activity in the absence of hormones. However, the combination of human prolactin and dexamethasone strongly enhanced (20-fold) induction of the LTR compared with the control. Human prolactin also showed a synergistic effect with progesterone on LTR induction. Both LTR and CAT genes needed to be linked for induction of CAT activity by prolactin and dexamethasone. Our results indicate that human prolactin can act synergistically with steroid hormones to regulate MMTV LTR-directed gene expression in transfected T47D cells. © 1992 Wiley-Liss, Inc.
- Subjects :
- Chloramphenicol O-Acetyltransferase
Cancer Research
medicine.medical_specialty
viruses
medicine.medical_treatment
Breast Neoplasms
Transfection
Proto-Oncogene Mas
Dexamethasone
Chloramphenicol acetyltransferase
Internal medicine
Gene expression
Tumor Cells, Cultured
medicine
Humans
Repetitive Sequences, Nucleic Acid
Reporter gene
biology
Mouse mammary tumor virus
biology.organism_classification
Molecular biology
Long terminal repeat
Prolactin
Steroid hormone
Endocrinology
Gene Expression Regulation
Mammary Tumor Virus, Mouse
Oncology
DNA, Viral
Female
hormones, hormone substitutes, and hormone antagonists
Subjects
Details
- ISSN :
- 10970215 and 00207136
- Volume :
- 52
- Database :
- OpenAIRE
- Journal :
- International Journal of Cancer
- Accession number :
- edsair.doi.dedup.....1e876df1cd01d7e0e0d8cf9db4d86bfb
- Full Text :
- https://doi.org/10.1002/ijc.2910520617