title: Telomerase activity and genetic alterations in primary breast carcinomas.
abstract: It has been proposed that the structural and numerical chromosome abnormalities recorded in breast cancer could be the result of telomere dysfunction and that telomerase is activated de novo to provide a survival mechanism curtailing further chromosomal aberrations. However, recent in vivo and in vitro data show that the ectopic expression of telomerase promotes tumorigenesis via a telomere length-independent mechanism. In this study, the relation between telomerase expression and the extent of chromosomal aberrations was investigated in 62 primary breast carcinomas. Telomerase activity was measured using a polymerase chain reaction-based telomeric repeat amplification protocol assay and 92% of the tumors were found to express telomerase with a relative activity ranging from 0 to 3839.6. Genetic alterations were determined by G-banding and comparative genomic hybridization analysis and 97% of the tumors exhibited chromosomal aberrations ranging from 0 to 44 (average: 10.98). In the overall series, the relationship between telomerase activity levels and genetic changes could be best described by a quadratic model, whereas in tumors with below-average genetic alteration numbers, a significant positive association was recorded between the two variables (coefficient=0.374, P=.017). The relationship between telomerase activity levels and the extent of genetic alteration may reflect the complex effect of telomerase activation upon tumor progression in breast carcinomas.
authors.affiliation: Department of Genetics, Saint Savas Hospital, Athens, Greece.
authors.forename: Anna
authors.initials: A
authors.lastname: Papadopoulou
authors.forename: Theoni
authors.initials: T
authors.lastname: Trangas
authors.forename: Manuel R
authors.initials: MR
authors.lastname: Teixeira
authors.forename: Sverre
authors.initials: S
authors.lastname: Heim
authors.forename: Euthimios
authors.initials: E
authors.lastname: Dimitriadis
authors.forename: Haroula
authors.initials: H
authors.lastname: Tsarouha
authors.forename: Johan A
authors.initials: JA
authors.lastname: Andersen
authors.forename: Evangelos
authors.initials: E
authors.lastname: Evangelou
authors.forename: Panayiotis
authors.initials: P
authors.lastname: Ioannidis
authors.forename: Niki J
authors.initials: NJ
authors.lastname: Agnantis
authors.forename: Nikos
authors.initials: N
authors.lastname: Pandis
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000201:enzymology* / Q000235:genetics*; D002277:Carcinoma / Q000201:enzymology* / Q000235:genetics*; D045744:Cell Line, Tumor; D002869:Chromosome Aberrations; D002871:Chromosome Banding; D003582:Cytogenetics; D018450:Disease Progression; D005260:Female; D006801:Humans; D008875:Middle Aged; D019098:Telomerase / Q000378:metabolism*; D013997:Time Factors
chemical_list: D019098:Telomerase