title: Estrogen regulates luminal progenitor cell differentiation through H19 gene expression.
abstract: Although the role of estrogen signaling in breast cancer development has been extensively studied, the mechanisms that regulate the indispensable role of estrogen in normal mammary gland development have not been well studied. Because of the unavailability of culture system to maintain estrogen-receptor-positive (ERα(+)) cells in vitro, the molecular mechanisms that regulate estrogen/ERα signaling in the normal human breast are unknown. In the present study, we examined the effects of estrogen signaling on ERα(+) human luminal progenitors using a modified matrigel assay and found that estrogen signaling increased the expansion potential of these progenitors. Furthermore, we found that blocking ERα attenuated luminal progenitor expansion and decreased the luminal colony-forming potential of these progenitors. Additionally, blocking ERα decreased H19 expression in the luminal progenitors and led to the development of smaller luminal colonies. We further showed that knocking down the H19 gene in the luminal progenitors significantly decreased the colony-forming potential of the luminal progenitors, and this phenotype could not be rescued by the addition of estrogen. Lastly, we explored the clinical relevance of the estrogen-H19 signaling axis in breast tumors and found that ERα(+) tumors exhibited a higher expression of H19 as compared with ERα(-) tumors and that H19 expression showed a positive correlation with ERα expression in those tumors. Taken together, the present results indicate that the estrogen-ERα-H19 signaling axis plays a role in regulating the proliferation and differentiation potentials of the normal luminal progenitors and that this signaling network may also be important in the development of ER(+) breast cancer tumors.
authors.affiliation: Department of ImmunologyUniversity of Manitoba, 471 Apotex Centre 750 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0T5Manitoba Institute of Cell Biology675 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0V9Department of Biochemistry and Medical GeneticsUniversity of Manitoba, Winnipeg, Manitoba, Canada R3E 0W2 Department of ImmunologyUniversity of Manitoba, 471 Apotex Centre 750 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0T5Manitoba Institute of Cell Biology675 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0V9Department of Biochemistry and Medical GeneticsUniversity of Manitoba, Winnipeg, Manitoba, Canada R3E 0W2.
authors.forename: Pratima
authors.initials: P
authors.lastname: Basak
authors.affiliation: Department of ImmunologyUniversity of Manitoba, 471 Apotex Centre 750 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0T5Manitoba Institute of Cell Biology675 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0V9Department of Biochemistry and Medical GeneticsUniversity of Manitoba, Winnipeg, Manitoba, Canada R3E 0W2 Department of ImmunologyUniversity of Manitoba, 471 Apotex Centre 750 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0T5Manitoba Institute of Cell Biology675 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0V9Department of Biochemistry and Medical GeneticsUniversity of Manitoba, Winnipeg, Manitoba, Canada R3E 0W2.
authors.forename: Sumanta
authors.initials: S
authors.lastname: Chatterjee
authors.affiliation: Department of ImmunologyUniversity of Manitoba, 471 Apotex Centre 750 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0T5Manitoba Institute of Cell Biology675 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0V9Department of Biochemistry and Medical GeneticsUniversity of Manitoba, Winnipeg, Manitoba, Canada R3E 0W2.
authors.forename: Steven
authors.initials: S
authors.lastname: Weger
authors.affiliation: Department of ImmunologyUniversity of Manitoba, 471 Apotex Centre 750 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0T5Manitoba Institute of Cell Biology675 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0V9Department of Biochemistry and Medical GeneticsUniversity of Manitoba, Winnipeg, Manitoba, Canada R3E 0W2 Department of ImmunologyUniversity of Manitoba, 471 Apotex Centre 750 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0T5Manitoba Institute of Cell Biology675 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0V9Department of Biochemistry and Medical GeneticsUniversity of Manitoba, Winnipeg, Manitoba, Canada R3E 0W2.
authors.forename: M Christine
authors.initials: MC
authors.lastname: Bruce
authors.affiliation: Department of ImmunologyUniversity of Manitoba, 471 Apotex Centre 750 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0T5Manitoba Institute of Cell Biology675 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0V9Department of Biochemistry and Medical GeneticsUniversity of Manitoba, Winnipeg, Manitoba, Canada R3E 0W2 Department of ImmunologyUniversity of Manitoba, 471 Apotex Centre 750 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0T5Manitoba Institute of Cell Biology675 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0V9Department of Biochemistry and Medical GeneticsUniversity of Manitoba, Winnipeg, Manitoba, Canada R3E 0W2.
authors.forename: Leigh C
authors.initials: LC
authors.lastname: Murphy
authors.affiliation: Department of ImmunologyUniversity of Manitoba, 471 Apotex Centre 750 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0T5Manitoba Institute of Cell Biology675 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0V9Department of Biochemistry and Medical GeneticsUniversity of Manitoba, Winnipeg, Manitoba, Canada R3E 0W2 Department of ImmunologyUniversity of Manitoba, 471 Apotex Centre 750 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0T5Manitoba Institute of Cell Biology675 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 0V9Department of Biochemistry and Medical GeneticsUniversity of Manitoba, Winnipeg, Manitoba, Canada R3E 0W2 afshin.raouf@umanitoba.ca.
authors.forename: Afshin
authors.initials: A
authors.lastname: Raouf
mesh_terms: D001940:Breast / Q000166:cytology; D002454:Cell Differentiation / Q000502:physiology*; D045744:Cell Line, Tumor; D004847:Epithelial Cells / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000235:genetics; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D006801:Humans; D062085:RNA, Long Noncoding / Q000235:genetics* / Q000378:metabolism; D013234:Stem Cells / Q000502:physiology*
chemical_list: C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; C094335:H19 long non-coding RNA; D062085:RNA, Long Noncoding
keywords: ER+ breast cancer cells; ERα; H19; luminal progenitors