Ekkehard Dikomey

Learn More
BACKGROUND AND PURPOSE When treated by radiotherapy, patients with squamous cell carcinomas of the head and neck (HNSCC) positive for HPV and p16(INK4a) possess a clearly favorable prognosis as compared to those with HPV-negative HNSCC. The aim of this work was to study whether the better outcomes might be caused by an enhanced cellular radiosensitivity. (More)
PURPOSE To test the relationship between cell killing and non-repaired DNA strand breaks both in repair proficient and deficient cell lines. MATERIALS AND METHODS Five of the cell lines used are repair competent (CHO, CHO K1, rat rhabdomyosarcoma R1H, mouse balb and normal human fibroblasts), while four display a reduced repair capacity (scid, xrs1, xrs5,(More)
PURPOSE To examine the association of polymorphisms in ATM (codon 158), GSTP1 (codon 105), SOD2 (codon 16), TGFB1 (position -509), XPD (codon 751), and XRCC1 (codon 399) with fibrosis and also individual radiosensitivity. METHODS AND MATERIALS Retrospective analysis with 69 breast cancer patients treated with breast-conserving radiotherapy; total dose(More)
PURPOSE To examine the association of polymorphisms in ATM (codon 158), GSTP1 (codon 105), SOD2 (codon 16), TGFB1 (position -509), XPD (codon 751), and XRCC1 (codon 399) with the risk of severe erythema after breast conserving radiotherapy. METHODS AND MATERIALS Retrospective analysis of 83 breast cancer patients treated with breast conserving(More)
PURPOSE The aim of this study was to test under which conditions non-repaired DNA double-strand breaks (dsb) could be used as an indicator of cellular radiosensitivity of normal human fibroblasts. MATERIALS AND METHODS The experiments were performed with a primary normal skin fibroblast line (NFHH) derived from a healthy donor. Cells were X-irradiated(More)
PURPOSE It is known that blockage of epidermal growth factor receptor (EGFR)/phosphatidylinositol 3-kinase (PI3K) activity enhances radiation sensitivity of human tumor cells presenting a K-RAS mutation. In the present study, we investigated whether impaired repair of DNA double-strand breaks (DSB) is responsible for the radiosensitizing effect of EGFR and(More)
Preclinical and clinical results indicate that the EGFR can mediate radioresistance in different solid human tumours. Combination of radiotherapy and EGFR inhibitors can improve local tumour control compared to irradiation alone and has been introduced into clinical radiotherapy practice. So far several mechanisms have been identified in preclinical studies(More)
BACKGROUND Cellular and clinical sensitivity to ionizing radiation (IR) is determined by DNA double-strand breaks (DSB) repair. Here, we investigate the molecular mechanism underlying the extreme response of a head and neck tumor case (SKX) to standard radiotherapy. METHODS Immunofluorescence (IF) was used for the assessment of DSB repair, Western blot(More)
In mammalian cells repair of radiation-induced DNA damage appears to be also controlled by the epidermal growth factor receptor (EGFR) with a special impact on DNA double-strand break (DSB) repair. Aim of this study was to demonstrate this interaction between EGFR signalling and DNA DSB repair and to identify the underlying downstream pathways. We(More)
Induction and repair of double-strand breaks (dsb) were measured in exponentially growing CHO-10A cells using the constant- and graded-field gel electrophoresis. Dsb repair was studied after an X-ray dose of 60 Gy. The repair curve obtained was biphasic with the respective half-times of tau 1 = 3.8 +/- 0.9 and tau 2 = 118 +/- 30 min. The number of(More)