Neoplasia: An International Journal for Oncology Research (Mar 2003)

Telomerase Activity and Genetic Alterations in Primary Breast Carcinomas

  • Anna Papadopoulou,
  • Theoni Trangas,
  • Manuel R. Teixeira,
  • Sverre Heim,
  • Euthimios Dimitriadis,
  • Haroula Tsarouha,
  • Johan A. Andersen,
  • Evangelos Evangelo,
  • Panayiotis Ioannidis,
  • Niki J. Agnantis,
  • Nikos Pandis

DOI
https://doi.org/10.1016/S1476-5586(03)80009-X
Journal volume & issue
Vol. 5, no. 2
pp. 170 – 178

Abstract

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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.

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