as a radiosensitizer, especially active towards cells in hypoxia (Douple & Richmond, 1978). Subsequent laboratory tests using tumor cell lines and clinical studies demonstrated enhanced cytotoxicity of irradiation-modified cisplatin (Dewit, 1987; Coughlin & Richmond, 1989). In this context, the possibility of CDDP reactions with water radiolysis products (eaq, OH•) and emergence of a highly rea...

Our studies showed that various nitrofuran derivatives have excellent radiosensitizing properties in hypoxic Chinese hamster cells at concentrations at which there is no effect on plating efficiency. The radiosensitizing effect is primarily a dose-modifying effect, with nitrofurantoin, nitrofurazone, and nifuroxime (each at 500 ¿M) in complete medium giving enhancement ratios of 1.65, 2.0, and...

The effectiveness of the radiosensitizer gemcitabine (GEM) was evaluated in a mouse glioma along with the imaging biomarker diffusion-weighted magnetic resonance imaging (DW-MRI) for early detection of treatment effects. A genetically engineered murine GBM model [Ink4a-Arf(-/-) Pten(loxP/loxP)/Ntv-a RCAS/PDGF(+)/Cre(+)] was treated with gemcitabine (GEM), temozolomide (TMZ) +/- ionizing radiati...

Cancer stem-like cells (CSCs) are the principal causes of tumor radio-resistance, dormancy and recurrence after radiotherapy. Clinical trials show hyperthermia (HT) might be a potent radiation sensitizer. In this study, CSCs were found to be more susceptible to radiation when combined with HT treatment. Treated cells showed significantly reduced self-renewal, cell survival and proliferation in ...

BACKGROUND Treatment of nasopharyngeal carcinoma requires the application of high dosages of radiation, leading to severe long-term complications in the majority of patients. Sensitizing tumor cells to radiation could be a means to increase the therapeutic window of radiation. Nasopharyngeal carcinoma cells display alterations in autophagy and blockade of autophagy has been shown to sensitize t...

Recent measurements of the spin-down rates of soft gamma ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs) have been interpreted as evidence that these objects are “magnetars”: neutron stars spinning down by magnetic dipole radiation, but with a magnetic field two orders of magnitude larger than that of ordinary neutron stars. We discuss the evidence disfavouring this interpretation. We a...

Autophagy is a natural self-degradative process by which cells eliminate misfolded proteins and damaged organelles. Autophagy has been shown to have multiple functions in tumor cells that may be dependent on the tumor type and the treatment conditions. Autophagy can have a cytoprotective role and be thought of as a survival mechanism or be cytotoxic in nature and mediate cell death. Radiation, ...

5-Iododeoxyuridine (IUdR) and caffeine are recognized as potential radiosensitizers with different mechanisms of interaction with ionizing radiation (IR). To assess the interaction of these two types of radiosensitizers, we compared treatment responses to these drugs alone and in combination with IR in two p53-proficient and p53-deficient pairs of human colon cancer cell lines (HCT116 versus HC...

BACKGROUND DCQ (2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide), a synthetic quinoxaline 1,4-dioxide, enhances the cytotoxic effect of ionizing radiation (IR) in vivo and in vitro. We sought to clarify whether increased radiation-induced DNA damage, decreased rate of damage repair, and the generation of reactive oxygen species (ROS) contribute to DCQ enhancement of IR. METHODS Murine ...