Radiation-responsive transcriptome analysis in human lymphoid cells

Aptamer selection of radiation-sensitive protein p21 and electrical impedance detection-based applications in radiation dose assessment

Radiation dose assessment is the main basis for the diagnosis of acute radiation sickness. At present, there is a lack of rapid and portable dose assessment methods, which has an important impact on the rapid diagnosis and precise treatment of radiation accident patients and nuclear practitioners. We selected and obtained specific aptamers for radiation-sensitive protein p21 protein by the magnetic cross-linking precipitation (MCP)-SELEX procedure. The aptamer has a high affinity for binding to the p21 protein and its Kd value is 2.21 × 10-7 mol/L. We subsequently established a new method for radiation dose assessment of an electrochemical impedance (EIS) aptasensor with screen-printed electrode chips. There was a good dose-effect relationship between the p21 protein expression level in PBMCs in human peripheral blood detected by this method within the dose range of 0-10 Gy, and detection limit of radiation dose is 0.38 Gy (LOD, S/N = 3). This dose range covers the diagnostic range of acute radiation sickness in the bone marrow. This method is not only portable but also fast, saving hours to days compared with the previous dose assessment method based on radiation sensitive protein. It can be applied to the rapid and portable diagnosis of acute radiation sickness.

Changes in miRNA expressions in the injured small intestine of mice following high‑dose radiation exposure

The small intestine is one of the most highly regenerative and radiosensitive tissues in mammals, including humans. Exposure to high doses of ionizing radiation causes serious intestinal damage. Recently, several investigations have been conducted using radioprotective agents to determine ways for reducing intestinal damage caused by radiation exposure. However, a thorough understanding of functional changes occurring in the small intestine of mice exposed to high-dose radiation is necessary for developing novel and more potent radioprotective agents. In this study, we examined changes in microRNA (miRNA/miR) expressions in the small intestine of mice at 72 h after X-ray exposure (10 Gy). We identified seven upregulated miRNAs and six downregulated miRNAs in the small intestine of mice following radiation exposure using miRNA microarray analysis. Particularly, miR-34a-5p was highly expressed, which was confirmed by reverse transcription-quantitative PCR. Forkhead box P1 (Foxp1) was predicted to be a target of the mRNA of miR-34a-5p using OmicsNet. Decreased Foxp1 expression in the small intestine following radiation exposure was confirmed, suggesting that Foxp1 expression recovery may induce the suppression of radiation-induced enteritis. Therefore, miR-34a-5p is a potential target molecule for developing novel radioprotective agents.

Network-based approaches for anticancer therapy (Review)

Cancer is a complex disease resulting from alterations of multiple signaling networks. Cancer networks have been identified as scale-free networks and may contain a functionally important key player called a hub that is linked to a large number of interactors. Since a hub can serve as a biological marker in a given network, targeting the hub could be an effective strategy for enhancing the efficacy of cancer treatment. Chemotherapies and radiotherapies are generally used to treat tumors not amenable to resection, and target single or multiple molecules associated with hubs. However, these therapies may unexpectedly induce the resistance of cancer cells to drugs and radiation. Cancer cells can overcome therapy-induced damage via the activation of back-up signaling pathways and flexible modulation of affected networks. These activities are considered to be the main reasons for chemoresistance and radioresistance, and subsequent failure of cancer therapies. Much effort is required to identify the key molecules that control the modulation of signaling networks in response to drugs and radiation. Network-based therapy that affects network flexibility, including rewired network structures and hub molecules in these networks, could minimize the occurrence of side-effects and be a promising strategy for enhancing the therapeutic efficacy of cancer treatments. This review is intended to offer an overview of current research efforts including ones focused on cancer-associated complex networks, their modulation in response to cancer therapy, and further strategies targeting networks that may improve cancer treatment efficacy.