title: The Effect of Melatonin Adsorbed to Polyethylene Glycol Microspheres on the Survival of MCF-7 Cells.
abstract: Although melatonin exhibits oncostatic properties such as antiproliferative effects, the oral bioavailability of this hormone is less than 20%. Modified drug release systems have been used to improve the pharmacological efficiency of drugs. These systems can change the pharmacokinetics and biodistribution of the associated drugs. Thus, this study investigated the effect of melatonin adsorbed to polyethylene glycol (PEG) microspheres on MCF-7 human breast cancer cells. The MCF-7 cells were obtained from the American Type Culture Collection. MCF-7 cells were preincubated for 24 h with or without melatonin (100 ng/ml), PEG microspheres or melatonin adsorbed to PEG microspheres (100 ng/ml). Viability, intracellular calcium release and apoptosis in MCF-7 cells were determined by flow cytometry. MCF-7 cells incubated with melatonin adsorbed to PEG microspheres showed a lower viability rate (40.0 ± 8.3 with melatonin adsorbed to PEG microspheres compared to 54.1 ± 7.3 with melatonin; 81.8 ± 12.5 with PEG microsphere and 92.7 ± 4.1 with medium), increased spontaneous intracellular Ca2+ release (27.0 ± 8.6 with melatonin adsorbed to PEG microspheres compared to 21.5 ± 13.4 with melatonin; 10.1 ± 5.4 with PEG microsphere and 9.1 ± 5.6 with medium) and increased apoptosis index (51.2 ± 2.7 with melatonin adsorbed to PEG microspheres compared to 36.0 ± 2.1 with melatonin; 4.9 ± 0.5 with PEG microsphere and 3.1 ± 0.6 with medium). The results indicate that melatonin adsorbed to PEG microspheres exerts antitumor effects on human MCF-7 breast cancer cells. However, clinical tests must be performed to confirm the use of melatonin adsorbed to PEG microspheres as an alternative therapy against cancer.
authors.affiliation: Institute of Biological and Health Science, Federal University of Mato Grosso, Barra do Garx00E7;as, Brazil.
authors.forename: Eduardo Luzía
authors.initials: EL
authors.lastname: França
authors.forename: Adenilda Cristina
authors.initials: AC
authors.lastname: Honorio-França
authors.forename: Rubian Trindade da Silva
authors.initials: RT
authors.lastname: Fernandes
authors.forename: Camila Moreira Ferreira
authors.initials: CM
authors.lastname: Marins
authors.forename: Claudia Cristina de Souza
authors.initials: CC
authors.lastname: Pereira
authors.forename: Fernando de Pilla
authors.initials: Fde P
authors.lastname: Varotti
mesh_terms: D000704:Analysis of Variance; D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000473:pathology; D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D061986:MCF-7 Cells / Q000187:drug effects; D008550:Melatonin / Q000494:pharmacology*; D008863:Microspheres; D011092:Polyethylene Glycols / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D017304:Annexin A5; D011092:Polyethylene Glycols; D008550:Melatonin; D002118:Calcium