DNA double strand breaks repair and apoptosis induction in peripheral blood lymphocytes of head and neck cancer patients.

Aim: To evaluate the generation and repair of DNA double strand breaks (DSBs) as a critical factors that define the efficiency of radiation therapy of cancer patients.
Methods: Peripheral blood lymphocytes obtained from 18 patients with head and neck squamous cell carcinoma (HNSCC) and 18 healthy donors were studied. The efficiency of DSBs repair after genotoxic treatment with hydrogen peroxide and gamma-radiation were examined by neutral comet assay. MTT assay was used for cell viability analysis and Annexin V-FITC kit specific for kinase-3 was employed to determine apoptosis.
Results: Lymphocytes from HNSCC patients were sensitive to genotoxic treatment and displayed impaired DSBs repair. Finally, as a consequence of this finding we have evidenced higher rate of apoptosis induction after gamma-radiation treatment of lymphocytes from HNSCC patients than those from healthy controls.
Conclusions: DSBs repair and increased apoptosis in cells of patients with head and neck cancer is relevant for efficient therapy of HNSCC.