Application of Radiopharmaceuticals in Targeted Tumor Therapies / 中国生物化学与分子生物学报

Radiopharmaceuticals are radionuclide preparations or radiolabelled compounds used for clinical diagnosis or treatment. The targeted radionuclide therapy uses molecular carriers with high affinity for tumor cells to target radionuclides into specific tumor tissues to treat tumors. Compared with traditional radiotherapy and chemotherapy, it is more selective. With the development of nuclear medicine, the popularization of SPECT/CT, PET/CT, the discovery of new targets and the development of new radiopharmaceuticals, the targeted therapy with radiopharmaceuticals is playing an increasingly important role in the clinical treatment of tumors. This review briefly describes the classification, composition and characteristics of radiopharmaceuticals; the application of radioimmunodrugs targeting tumor-associated antigen in non-Hodgkin's lymphoma, colorectal cancer and prostate cancer; the clinical application of receptor-mediated radionuclide drugs in the treatment of neuroendocrine tumors, prostate cancer and breast cancer, and the research progress of radiopharmaceuticals based on gene modification in targeted tumor therapies. Finally, the application prospects and challenges of radiopharmaceuticals in cancer treatment are summarized in order to provide some references for the development and clinical application of radiopharmaceuticals for targeted tumor therapy.

The Regulatory Mechanism and Role of CircRNA in Tumors / 中国生物化学与分子生物学报

Circular RNAs (circRNAs) are a class of non-coding RNAs that form closed rings in structure. They contain a high content in eukaryotic transcripts, and are characterized by richness, stability, high conservatism and tissue specificity. In recent years, it has been gradually revealed that circRNA can bind to some miRNAs or proteins and participate in the regulatory mechanisms of biogenesis and molecular functions, including the regulation of miRNAs molecular sponge, protein translation, gene transcription and RNA splicing. With the application of high-throughput sequencing and bioinformatics, circRNA has gradually become a new research hotspot in the field of non-coding RNA due to its special properties. The latest research evidence shows that circRNA plays a key role in the occurrence and development of tumors, and is inextricably linked with cell proliferation, apoptosis, angiogenesis, and metastasis, indicating that targeting circRNA will be attractive treatment strategies and potential biomarkers. In this paper, the characteristics and mechanism of circRNA were briefly described, the mechanism of action and regulation of circRNAs in human tumors were summarized, and the strategies and development prospects of circRNA in tumor research were further discussed. In sum, circRNA plays an important role in early diagnosis, precise treatment and prognosis prediction of tumors.

Simulated microgravity conditions and carbon ion irradiation induce spermatogenic cell apoptosis and sperm DNA damage / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the effect of simulated microgravity and carbon ion irradiation (CIR) on spermatogenic cell apoptosis and sperm DNA damage to the testis of male Swiss Webster mice, and assess the risk associated with space environment.</p><p><b>METHODS</b>Sperm DNA damage indicated by DNA fragmentation index (DFI) and high DNA stainability (HDS) was measured by sperm chromatin structure assay (SCSA). Apoptosis of spermatogenic cells was detected by annexin V-propidium iodide assay. Bax (the expression levels of p53) and proliferating cell nuclear antigen (PCNA) were measured by immunoblotting; p53 and PCNA were located by immunohistology.</p><p><b>RESULTS</b>HDS, DFI, apoptosis index, and the expression levels of p53 and Bax were detected to be significantly higher in the experimental groups (P<0.05) compared with those in the control group; however, the PCNA expression varied to a certain degree. p53- and PCNA- positive expression were detected in each group, mainly in relation to the spermatogonic cells and spermatocytes.</p><p><b>CONCLUSION</b>The findings of the present study demonstrated that simulated microgravity and CIR can induce spermatogenic cell apoptosis and sperm DNA damage. Sperm DNA damage may be one of the underlying mechanisms behind male fertility decline under space environment. These findings may provide a scientific basis for protecting astronauts and space traveler's health and safety.</p>