Common genomic signaling among initial DNA damage and radiation-induced apoptosis in peripheral blood lymphocytes from locally advanced breast cancer patients

Abstract

Purpose: To investigate the genomic signaling that defines sensitive lymphocytes to radiation and if such molecular profiles are consistent with clinical toxicity; trying to disclose the radiobiology mechanisms behind these cellular processes.

Patients and methods: Twelve consecutive patients suffering from locally advanced breast cancer and treated with high-dose hyperfractionated radiotherapy were recruited. Initial DNA damage was measured by pulsed-field gel electrophoresis and radiation-induced apoptosis was measured by flow cytometry. Gene expression was assessed by DNA microarray.

Results: Thirty-four constitutive genes segregated patients with lower DNA-double strand break from those patients with higher DNA-double strand break (p < 0.01). Forty-two genes segregated patients according to radiation-induced apoptosis (p < 0.01). We found common canonical pathways and common biological processes significantly regulated between both set of genes.

Conclusion: We introduced new data in the field of molecular genomics regarding to the relation established between radiation toxicity and these predictive factors to radiation injury.