ABSTRACT
BACKGROUND: High expression of constitutive histone γ-H2AX, a sensitive marker of DNA damage, might be indicative of defective DNA repair pathway or genomic instability. 53BP1 (p53-binding protein 1) is a conserved checkpoint protein with properties of a DNA double-strand breaks sensor. This study explores the relationship between the clinical radiosensitivity of tumor patients and the expression/induction of γ-H2AX and 53BP1 in vitro. METHODS: Using immunostaining, we assessed spontaneous and radiation-induced foci of γ-H2AX and 53 BP1 in peripheral blood mononuclear cells derived from unselected breast cancer (BC) patients (n=57) undergoing radiotherapy (RT). Cells from apparently healthy donors (n=12) served as references. RESULTS: Non-irradiated cells from controls and unselected BC patients exhibited similar baseline levels of DNA damage assessed by γ-H2AX and 53BP1 foci. At the same time, the γ-H2AX assay of in vitro irradiated cells revealed significant differences between the control group and the group of unselected BC patients with respect to the initial (0.5 Gy, 30 min) and residual (2 Gy, 24 h post-radiation) DNA damage. The numbers of 53BP1 foci analyzed in 35 BC patients were significantly higher than in controls only in case of residual DNA damage. A weak correlation was found between residual foci of both proteins tested. In addition, cells from cancer patients with an adverse acute skin reaction (grade 3) to RT showed significantly increased radiation-induced γ-H2AX foci and their protracted disappearance compared to the group of BC patients with normal skin reaction (grade 0-1). The mean number of γ-H2AX foci after 5 clinical fractions was significantly higher than that before RT, especially in clinically radiosensitive patients. CONCLUSIONS: The γ-H2AX assay may have potential for screening individual radiosensitivity of breast cancer patients. TRIAL REGISTRATION: http://www.krebshilfe.de/wir-foerdern.html.
Subject(s)
Breast Neoplasms/genetics , Breast Neoplasms/radiotherapy , Histones/genetics , Intracellular Signaling Peptides and Proteins/genetics , Radiation Tolerance/genetics , Adult , Aged , DNA Damage/radiation effects , Female , Fluorescent Antibody Technique , Humans , Immunohistochemistry , Leukocytes, Mononuclear/radiation effects , Middle Aged , Tumor Suppressor p53-Binding Protein 1ABSTRACT
This study explores the impact of Hsp90 inhibitors NVP-AUY922 and NVP-BEP800 in combination with ionizing radiation (IR) on the migration and invasion of lung carcinoma A549 and glioblastoma SNB19 cells, under normoxia or hypoxia. Independent of oxygen concentration, both drugs decreased the migration and invasion rates of non-irradiated tumor cells. Combined drug-IR treatment under hypoxia inhibited cell invasion to a greater extent than did each treatment alone. Decreased migration of cells correlated with altered expression of several matrix-associated proteins (FAK/p-FAK, Erk2, RhoA) and impaired F-actin modulation. The anti-metastatic efficacy of the Hsp90 inhibitors could be useful in combinational therapies of cancer.
Subject(s)
Cell Hypoxia , Cell Movement/drug effects , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Isoxazoles/pharmacology , Neoplasm Invasiveness/prevention & control , Pyrimidines/pharmacology , Resorcinols/pharmacology , Blotting, Western , Brain Neoplasms/pathology , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Flow Cytometry , Glioblastoma/pathology , Humans , Lung Neoplasms/pathology , Microscopy, Electron, Scanning , Wound Healing/drug effectsABSTRACT
T cell-mediated heterologous immunity to different pathogens is promising for the development of immunotherapeutic strategies. Aspergillus fumigatus and Candida albicans, the 2 most common fungal pathogens causing severe infections in immunocompromised patients, are controlled by CD4+ type 1 helper T (T(H)1) cells in humans and mice, making induction of fungus-specific CD4+ T(H)1 immunity an appealing strategy for antifungal therapy. We identified an immunogenic epitope of the A fumigatus cell wall glucanase Crf1 that can be presented by 3 common major histocompatibility complex class II alleles and that induces memory CD4+ T(H)1 cells with a diverse T-cell receptor repertoire that is cross-reactive to C albicans. In BALB/c mice, the Crf1 protein also elicits cross-protection against lethal infection with C albicans that is mediated by the same epitope as in humans. These data illustrate the existence of T cell-based cross-protection for the 2 distantly related clinically relevant fungal pathogens that may foster the development of immunotherapeutic strategies.
