Combined haploinsufficiency and genetic control of the G2/M checkpoint in irradiated cells

Whole-blood immunoassay for γH2AX as a radiation biodosimetry assay with minimal sample preparation

The current state of the art in high-throughput minimally invasive radiation biodosimetry involves the collection of samples in the field and analysis at a centralized facility. We have developed a simple biological immunoassay for radiation exposure that could extend this analysis out of the laboratory into the field. Such a forward placed assay would facilitate triage of a potentially exposed population. The phosphorylation and localization of the histone H2AX at double-stranded DNA breaks has already been proven to be an adequate surrogate assay for reporting DNA damage proportional to radiation dose. Here, we develop an assay for phosphorylated H2AX directed against minimally processed sample lysates. We conduct preliminary verification of H2AX phosphorylation using irradiated mouse embryo fibroblast cultures. Additional dosimetry is performed using human blood samples irradiated ex vivo. The assay reports H2AX phosphorylation in human blood samples in response to ionizing radiation over a range of 0-5 Gy in a linear fashion, without requiring filtering, enrichment, or purification of the blood sample.

Roles of glucose transporter-1 and the phosphatidylinositol 3‑kinase/protein kinase B pathway in cancer radioresistance (review)

The mechanisms underlying cancer radioresistance remain unclear. Several studies have found that increased glucose transporter‑1 (GLUT‑1) expression is associated with radioresistance. Recently, the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway was reported to be involved in the control of GLUT‑1 trafficking and activity. Activation of the PI3K/Akt pathway may itself be associated with cancer radioresistance. Thus, increasing attention has been devoted to the effects of modifying the expression of GLUT‑1 and the PI3K/Akt pathway on the increase in the radiosensitivity of cancer cells. This review discusses the importance of the association between elevated expression of GLUT‑1 and activation of the PI3K/Akt pathway in the development of radioresistance in cancer.