The use of ionizing radiation (IR) is essential for treating many human cancers. However, radioresistance markedly impairs the efficacy of tumor radiotherapy. IR enhances the production of reactive oxygen species (ROS) in a variety of cells which are determinant components in the induction of apoptosis. Much interest has developed to augment the effect of radiation in tumors by combining it wit...

The retinoblastoma (pRb), p107, and p130 pocket proteins bind to the E2F transcription factors to control gene expression. E2F4 protein levels increased and accumulated in the nuclei of prostate carcinoma cells subjected to ionizing radiation (IR). The IR-induced increase of E2F4 levels led to an increase in E2F4 binding to p130 but had no effect on E2F4/p107 or E2F5/p130 complexes. The increas...

Radiation therapy is a first-line treatment for prostate cancer patients with localized tumors. Although some patients respond well to the treatment, approximately 10% of low-risk and up to 60% of high-risk prostate cancer patients experience recurrent tumors. However, the molecular mechanisms underlying tumor recurrence remain largely unknown. Here we show that fractionated ionizing radiation ...

Radioadaptive response (RAR) describes phenomena where small conditioning doses of ionizing radiation (IR) reduce detrimental effects of subsequent higher IR doses. Current radiation protection regulations do not include RAR because of the large variability in expression among individuals and uncertainties of the mechanism. However, RAR should be regarded as an indispensable factor for estimati...

Head and neck squamous cell carcinoma (HNSCC) is the sixth leading cause of cancer worldwide. Although there are numerous treatment options for HNSCC, such as surgery, cytotoxic chemotherapy, molecularly targeted systemic therapeutics, and radiotherapy, overall survival has not significantly improved in the last 50 years. This suggests a need for a better understanding of how these cancer cells...

Radiation treatment is a pivotal therapy for several cancer types, including colorectal cancer. It has been shown that sublethal doses of radiation modulate gene expression, making tumor cells more susceptible to T-cell-mediated immune attack. We have recently shown that low dose radiation enhances expression of multiple death receptors (Fas, DR4 and DR5) and co-stimulatory molecules (4-1BBL an...

The infrared synchrotron radiation (IR-SR) beamline of SPring-8 as an IR light source was applied to characterize boron (B) atoms in silicon nanowires (SiNWs). The use of an IR-SR beam with much higher brilliance than conventional IR light sources and a wide range of wavenumbers from visible to far IR regions made it possible to detect a local vibrational mode of B in SiNWs. The use of this tec...

Background and Objective: Non-ionized radiation from arc welding may cause retinal lesions such as photo retinitis. In this report, a patient with bilateral macular bleeding which had been caused by inappropriate use of protective safety glasses is introduced. Case Report: On 26 July 2008 a 23-year-old male with blurred vision was referred to Shahid Beheshti's faculty of Rehabilitation Clinic....

Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have demonstrated that genes with upregulated expression induced by IR may play important roles in DNA damage sensing, cell cycle checkpoint and chromosomal repair, the relationship between the regulation of gene expression by IR and...