Evolutionary hypothesis of telomere length in primary breast cancer- and brain tumor- patients: A tracer for Genomic-tumor heterogeneity and instability.

Abstract

It was previously reported that tumor samples had shorter telomeres than the surrounding normal tissue. Hereby, the initial sign of correlation between malignant tissue and telomere behavior could be noticed. Bridging knowledge between germ- and somatic- cells could facilitate understanding cellular evolution. The aim of our investigation was to provide evidence for the evolutionary hypothesis of telomere length in primary breast cancer and brain tumors which might be applied as a prognostic and/or predictive marker. DNA extraction from the frozen tissues was performed using high pure PCR template preparation kit. Standard protocol of Telo TTAGGG Telomere Length Assay kit, a non-radioactive chemiluminescent assay, was used. The protein expression in extracted cells was analyzed by immuno-Fluorescence. We also detected telomerase activity. The genomic/ tumor ratio (G/T) for telomere length in two group of patients affected with primary breast cancer (BC) and primary brain tumor (BT) revealed significant differences in both BC patients (G/T ratio: <2 kb <, p=0.025) and in BTs(G/T ratio: <2.64 kb <, p=0.001). The pattern of telomere signals by Q-FISH show that in all samples, except one, signal intensity has been significantly decreased in tissue related to blood, either in breast cancer patients or in patients with brain tumors (0.041 ≥ p ≥0.001). However, the data achieved by Q-FISH support the results of Southern blot. These data reflect a significant diversity either in BC- or in BT-patients, providing evidence for the evolutionary hypothesis of telomere length in cancer development and progression.