title: [Utility of chromosome banding with ALU I enzyme for identifying methylated areas in breast cancer].
abstract: Cancer is a group of disorders characterized by uncontrolled cell growth which is produced by two successive events: increased cell proliferation (tumor or neoplasia) and the invasive capacity of these cells (metastasis). DNA methylation is an epigenetic process which has been involved as an important pathogenic factor of cancer. DNA methylation participates in the regulation of gene expression, directly, by preventing the union of transcription factors, and indirectly, by promoting the "closed" structure of the chromatine. The objectives of this study were to identify hypermethyled chromosomal regions through the use of restriction Alu I endonuclease, and to relate cytogenetically these regions with tumor suppressive gene loci. Sixty peripheral blood samples of females with breast cancer were analyzed. Cell cultures were performed and cytogenetic spreads, previously digested with Alu I enzyme, were stained with Giemsa. Chromosomal centromeric and not centromeric regions were stained in 37% of cases. About 96% of stained hypermethyled chromosomal regions (1q, 2q, 6q) were linked with methylated genes associated with breast cancer. In addition, centromeric regions in chromosomes 3, 4, 8, 13, 14, 15 and 17, usually unstained, were found positive to digestion with Alu I enzime and Giemsa staining. We suggest the importance of this technique for the global visualization of the genome which can find methylated genes related to breast cancer, and thus lead to a specific therapy, and therefore a better therapeutic response.
authors.affiliation: Instituto de Investigaciones Genéticas, Facultad de Medicina, Universidad del Zulia, Maracaibo, Venezuela. arojasa26@gmail.com
authors.forename: Alicia
authors.initials: A
authors.lastname: Rojas-Atencio
authors.forename: Leonard
authors.initials: L
authors.lastname: Yamarte
authors.forename: Karelis
authors.initials: K
authors.lastname: Urdaneta
authors.forename: Marisol
authors.initials: M
authors.lastname: Soto-Alvarez
authors.forename: Francisco
authors.initials: F
authors.lastname: Alvarez Nava
authors.forename: Jenny
authors.initials: J
authors.lastname: Cañizalez
authors.forename: Maribel
authors.initials: M
authors.lastname: Quintero
authors.forename: Raquel
authors.initials: R
authors.lastname: Atencio
authors.forename: Richard
authors.initials: R
authors.lastname: González
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000235:genetics*; D002871:Chromosome Banding / Q000379:methods*; D019175:DNA Methylation; D015252:Deoxyribonucleases, Type II Site-Specific; D005260:Female; D006801:Humans; D008875:Middle Aged
chemical_list: C024669:endodeoxyribonuclease AluI; D015252:Deoxyribonucleases, Type II Site-Specific