Development of a Novel in-situ Telomere Length Quantification System to Address Suitability of Telomerase Inhibitor Therapy to Breast Cancer Following Corrective Surgery

摘要

Normal breast epithelial cells undergo progressive telomeric shortening throughout their replicative lifespan culminating in critically short telomeres, which trigger replicative senescence. Breast cancer cells are able to bypass this growth-arrest mechanism through deregulated expression of telomerase, which maintains telomeres above the minimal critical length. Based on this observation the suitability of these tumors to telomerase inhibitors as direct or adjuvant therapy needs to be determined. To do this we have developed a novel quantitative fluorescence in-situ hybridization system to analyze total nuclear telomeric signal from normal and tumor-derived breast epithelial cells in tissue culture. This technique has been applied to normal human fibroblasts (W138) successfully and will be applied to two normal Human Mammary Epithelial Cell (HMEC) lines, HMEl3 and HME 17%. Through collection of regular cell and DNA samples we will determine the mean telomere lengths and rate of shortening for each HMEC line and use Q-FISH to determine a per nuclei telomere dynamic. These findings will then be applied to 3-D matrigel models before finally generating predictions of telomere lengths within resected breast tumor samples. This will allow us to determine the suitability of telomerase inhibitors in vivo.