Radiation exerts direct as well as indirect effects on DNA through the generation of reactive oxygen species (ROS). Irradiated hematopoietic progenitor cells (HPCs) experience DNA strand breaks, favoring genetic instability, due to ROS generation. Our aim was to study the effect of a range of radiation doses in HPCs and the possible protective mechanisms activated by insulin-like growth factor-...

Pancreatic cancer is an aggressive malignancy with a characteristic metastatic course of disease and resistance to conventional radiotherapy. As a result, the continual development of novel therapeutic agents is required to improve the current situation. In the present study, the effect of the hedgehog pathway inhibitor, cyclopamine, on cellular radiosensitivity was determined in K‑RASwt Colo‑3...

Inhibition of heat shock protein 90 (HSP90) leads to inappropriate processing of proteins involved in cell survival pathways. We found that HSP90 inhibitor, 17-(dimethylaminoethylamino)-17-demethoxygeldanamycin (DMAG), is synergistic with radiation for non-small cell lung cancer cell lines, NCI-H460 and A549. To establish the optimal schedule for this combination, cells were radiated before, af...

Background Lipopolysaccharide (LPS) promotes tumor metastases. The aim of this study was to determine the ability of a hypertonic environment to attenuate the pro metastatic properties of LPS both in vitro, and in vivo. Methods LPS stimulated, and unstimulated, 4T1 tumor cells were cultured in either an isotonic or hypertonic environment. The effect on invasion, migration, pro-matellomatrixpr...

In order to elucidate the influence of the location of a cell within a tumor on cell survival, 12 to 16 samples from an individual 9L s.c. tumor were assayed for colony formation. These samples (4 to 6 mg) were taken from untreated, heated, or irradiated tumors, and the variances of the mean relative colony-forming efficiency (RCFE) for individual tumors or groups of similarly treated tumors we...

The following factors must be considered when dye exclu sion assays are interpreted, (a) It may require several days for lethally damaged cells to lose their membrane integrity follow ing a cytotoxic insult, (b) During this time, the "surviving" cells may continue to proliferate, (c) Also during this time, some lethally damaged cells may undergo an early disintegration, so that they are not pre...

The capillary human tumor clonogenic cell assay (HTCA) has been shown to have important advantages over conventional HTCAs. In the present report, this promising novel HTCA was further optimized and characterized using 46 primary human tumor specimens, 6 human tumor cell lines (1 astrocytoma, 2 colon carcinomas, 1 melanoma), and 2 murine leukemias. Hydrocortisone, epidermal growth factor, heat-...

BACKGROUND Glioblastoma is the most common tumor of the central nervous system and one of the hardest tumors to treat. Consequently, the search for novel therapeutic options is imperative. 7-epiclusianone, a tetraprenylated benzophenone isolated from the epicarp of the native plant Garcinia brasiliensis, exhibits a range of biological activities but its prospect anticancer activity is underexpl...

OBJECTIVES The aim of this study was to evaluate the efficiency of cetuximab-based anti-EGFR treatment and Aurora kinase A / B knockdown as a function of Aurora kinase polymorphism in HNSCC cell lines. MATERIALS AND METHODS First, protein expression of Aurora kinase A / B and EGFR and Aurora kinase A polymorphism were studied in tumour samples. The survival and proliferation of Aurora kinase ...

BACKGROUND AND PURPOSE Previously, we have reported that 2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide (DCQ) is a radiosensitizer. Here, we investigate the mechanism of radiosensitization. MATERIALS AND METHODS EMT6 cells were treated with DCQ for 4h prior to ionizing radiation (IR). Flow cytometry, clonogenic assay, TUNEL, and Western blotting were performed to assess the effect of ...