title: Effect of Melatonin in Epithelial Mesenchymal Transition Markers and Invasive Properties of Breast Cancer Stem Cells of Canine and Human Cell Lines.
abstract: Cancer stem cells (CSCs) have been associated with metastasis and therapeutic resistance and can be generated via epithelial mesenchymal transition (EMT). Some studies suggest that the hormone melatonin acts in CSCs and may participate in the inhibition of the EMT. The objectives of this study were to evaluate the formation of mammospheres from the canine and human breast cancer cell lines, CMT-U229 and MCF-7, and the effects of melatonin treatment on the modulation of stem cell and EMT molecular markers: OCT4, E-cadherin, N-cadherin and vimentin, as well as on cell viability and invasiveness of the cells from mammospheres. The CMT-U229 and MCF-7 cell lines were subjected to three-dimensional culture in special medium for stem cells. The phenotype of mammospheres was first evaluated by flow cytometry (CD44(+)/CD24(low/-) marking). Cell viability was measured by MTT colorimetric assay and the expression of the proteins OCT4, E-cadherin, N-cadherin and vimentin was evaluated by immunofluorescence and quantified by optical densitometry. The analysis of cell migration and invasion was performed in Boyden Chamber. Flow cytometry proved the stem cell phenotype with CD44(+)/CD24(low/-) positive marking for both cell lines. Cell viability of CMT-U229 and MCF-7 cells was reduced after treatment with 1mM melatonin for 24 h (P<0.05). Immunofluorescence staining showed increased E-cadherin expression (P<0.05) and decreased expression of OCT4, N-cadherin and vimentin (P<0.05) in both cell lines after treatment with 1 mM melatonin for 24 hours. Moreover, treatment with melatonin was able to reduce cell migration and invasion in both cell lines when compared to control group (P<0.05). Our results demonstrate that melatonin shows an inhibitory role in the viability and invasiveness of breast cancer mammospheres as well as in modulating the expression of proteins related to EMT in breast CSCs, suggesting its potential anti-metastatic role in canine and human breast cancer cell lines.
authors.affiliation: Department of Molecular Biology, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP, Brazil.
authors.forename: Naiane do Nascimento
authors.initials: Ndo N
authors.lastname: Gonçalves
authors.affiliation: Department of Molecular Biology, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP, Brazil.
authors.forename: Jucimara
authors.initials: J
authors.lastname: Colombo
authors.affiliation: Department of Biology, Universidade Estadual Paulista "Júlio de Mesquita Filho", São José do Rio Preto, SP, Brazil.
authors.forename: Juliana Ramos
authors.initials: JR
authors.lastname: Lopes
authors.affiliation: Department of Biology, Universidade Estadual Paulista "Júlio de Mesquita Filho", São José do Rio Preto, SP, Brazil.
authors.forename: Gabriela Bottaro
authors.initials: GB
authors.lastname: Gelaleti
authors.affiliation: Department of Molecular Biology, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP, Brazil.
authors.forename: Marina Gobbe
authors.initials: MG
authors.lastname: Moschetta
authors.affiliation: Department of Molecular Biology, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP, Brazil.
authors.forename: Nathália Martins
authors.initials: NM
authors.lastname: Sonehara
authors.affiliation: Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: Eva
authors.initials: E
authors.lastname: Hellmén
authors.affiliation: Department of Biology, Universidade Estadual Paulista "Júlio de Mesquita Filho", São José do Rio Preto, SP, Brazil.
authors.forename: Caroline de Freitas
authors.initials: Cde F
authors.lastname: Zanon
authors.affiliation: Department of Biology, Universidade Estadual Paulista "Júlio de Mesquita Filho", São José do Rio Preto, SP, Brazil.
authors.forename: Sônia Maria
authors.initials: SM
authors.lastname: Oliani
authors.affiliation: Department of Molecular Biology, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP, Brazil.|Department of Biology, Universidade Estadual Paulista "Júlio de Mesquita Filho", São José do Rio Preto, SP, Brazil.
authors.forename: Debora Aparecida Pires de Campos
authors.initials: DA
authors.lastname: Zuccari
mesh_terms: D000818:Animals; D001940:Breast / Q000187:drug effects / Q000473:pathology; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004285:Dogs; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D005260:Female; D006801:Humans; D061986:MCF-7 Cells; D008550:Melatonin / Q000494:pharmacology*; D009361:Neoplasm Invasiveness / Q000473:pathology / Q000517:prevention & control*; D014411:Neoplastic Stem Cells / Q000187:drug effects* / Q000473:pathology
chemical_list: D008550:Melatonin