Delineating the Effects of Ionizing Radiation on Erythropoietic Lineage-Implications for Radiation Biodosimetry

Targeting erythroid progenitor cells for cancer immunotherapy

Immunotherapy, especially immune checkpoint blockade therapy, represents a major milestone in the history of cancer therapy. However, the current response rate to immunotherapy among cancer patients must be improved; thus, new strategies for sensitizing patients to immunotherapy are urgently needed. Erythroid progenitor cells (EPCs), a population of immature erythroid cells, exert potent immunosuppressive functions. As a newly recognized immunosuppressive population, EPCs have not yet been effectively targeted. In this review, we summarize the immunoregulatory mechanisms of EPCs, especially for CD45+ EPCs. Moreover, in view of the regulatory effects of EPCs on the tumor microenvironment, we propose the concept of EPC-immunity, present existing strategies for targeting EPCs, and discuss the challenges encountered in both basic research and clinical applications. In particular, the impact of existing cancer treatments on EPCs is discussed, laying the foundation for combination therapies. The aim of this review is to provide new avenues for improving the efficacy of cancer immunotherapy by targeting EPCs.

Impact of Radiation Therapy on Biological Parameters in Cancer Patients: Sub-analysis from the RIT Prospective Epidemiological Study

Scarce data investigate the impact of radiotherapy (RT) on biology markers. An analysis of ancillary study of RIT (Radiation Impact on Thromboembolic events) prospective trial was carried out. All patients with non-metastatic solid tumors and treated with radiotherapy and/or brachytherapy in curative and consenting to have blood samples were included. A significant decrease in white blood count, (i.e. lymphocytes, monocytes, neutrophils and basophils) and platelet counts was observed after RT and maintained at 6 months. Whereas, eosinophils, D-dimers and hemoglobin levels were affected respectively 3 months and 6 months after RT initiation. Conversely, red cells count and CRP level were not affected by RT. This study is an advocacy to develop an understanding of basic immune system in relation with RT.

The Effect of Low-Energy Laser-Driven Ultrashort Pulsed Electron Beam Irradiation on Erythropoiesis and Oxidative Stress in Rats

Anemia is a commonly observed consequence of whole-body exposure to a dose of X-ray or gamma irradiation of the order of the mean lethal dose in mammals, and it is an important factor for the determination of the survival of animals. The aim of this study was to unravel the effect of laser-driven ultrashort pulsed electron beam (UPEB) irradiation on the process of erythropoiesis and the redox state in the organism. Wistar rats were exposed to laser-driven UPEB irradiation, after which the level of oxidative stress and the activities of different antioxidant enzymes, as well as blood smears, bone marrow imprints and sections, erythroblastic islets, hemoglobin and hematocrit, hepatic iron, DNA, and erythropoietin levels, were assessed on the 1st, 3rd, 7th, 14th, and 28th days after irradiation. Despite the fact that laser-driven UPEB irradiation requires quite low doses and repetition rates to achieve the LD₅₀ in rats, our findings suggest that whole-body exposure with this new type of irradiation causes relatively mild anemia in rats, with subsequent fast recovery up to the 28th day. Moreover, this novel type of irradiation causes highly intense processes of oxidative stress, which, despite being relatively extinguished, did not reach the physiologically stable level even at the 28th day after irradiation due to the violations in the antioxidant system of the organism.

Dose-Response Effects of Low-Dose Ionizing Radiation on Blood Parameters in Industrial Irradiation Workers

While previous studies have focused on the health effects of occupational exposure of radiations on medical radiation workers, few have analyzed the dose-response relationship between low radiation doses and changes in blood parameters. Even fewer studies have been conducted on industrial worker populations. Using a prospective cohort study design, this study collected health examination reports and personal dose monitoring data from 705 industrial irradiation workers who underwent regular physical examinations at Dongguan Sixth People’s Hospital. The dose-response effects of low-dose ionizing radiation on blood parameters were assessed using a generalized linear model and restricted cubic spline model. Red blood cell counts decreased then increased, before decreasing again with increasing ionizing radiation. This was in contrast to the curve of the total platelet count after irradiation. Additionally, a radiation dose of 2.904 mSv was the turning point for the nonlinear curve of hemoglobin count changes. In conclusion, long-term, low-dose ionizing radiation affects blood cell levels in industrial irradiation workers. There is a nonlinear dose-response relationship between red blood cell, platelet, and hemoglobin counts and the cumulative radiation dose. These findings should alert radiation workers to seek preventive medical treatment before the occurrence of any serious hematopoietic disease.

Over-Expression of Centromere Protein U Participates in the Malignant Neoplastic Progression of Breast Cancer

The expression of Centromere Protein U (CENP-U) is closely related to tumor malignancy. Till now, the role of CENP-U in the malignant progression of breast cancer remains unclear. In this study, we found that CENP-U protein was highly expressed in the primary invasive breast cancer tissues compared to the paired adjacent histologically normal tissues and ductal carcinoma in situ (DCIS) tissues. After CENP-U was knocked down, the proliferation and colony-forming abilities of breast cancer cells were significantly suppressed, whereas the portion of apoptotic cells was increased. Meanwhile, the PI3K/AKT/NF-κB pathway was significantly inhibited. In vivo studies showed that, the inhibition of CENP-U repressed the tumor growth in orthotopic breast cancer models. Therefore, our study demonstrated that the CENP-U might act as an oncogene and promote breast cancer progression via activation of the PI3K/AKT/NF-κB pathway, which suggests a promising direction for targeting therapy in breast cancer.

Response of HPRT Gene Fragment Functionalized Gold Nanoparticles to Gamma Ray Irradiation

Radiation-sensitive biomolecules are highly significant for studying biological effects of radiation and developing ionizing radiation detectors based on biomolecules. In this work, we selected hypoxanthine phosphoribosyl transferase gene fragments sensitive to gamma-ray irradiation as a sensing element for radiation detection. The end was modified with thiol groups. The thiol-modified oligonucleotide sequences were coupled to the surface of gold nanoparticles by Au-S covalent bonds. The DNA attached to the surface of gold nanoparticles forms a DNA-AuNPs assembly through base pairing. The assembly was irradiated by gamma rays. And its response to radiation was studied with ultraviolet-visible spectroscopy and surface-enhanced Raman scattering (SERS) spectroscopy techniques. SERS spectroscopy and ultraviolet spectroscopy can detect the response of the DNA-AuNPs assembly to gamma-ray irradiation below 100 and 100 - 250 Gy, respectively. The results indicated that it was feasible to develop a new approach of gamma-ray detectors using biomolecular assemblies of gold nanoparticles.