Objective:To systematically evaluate the efficacy of low dose whole-lung irradiation in COVID-19 pneumonia based on the present evidence.Methods:All literature related to the application of low dose whole-lung irradiation in COVID-19 pneumonia were retrieved from Pubmed, Embase, the Cochrane Library, Web of Science, Google scholar, Scoupus, CNKI, Wanfang database, VIP database until May 2022. Two researchers independently screened the literature. For the literature that met the inclusion criteria, both data extraction and literature quality evaluation were blinded. Revman 5.3 software was used for statistical analysis.Results:A total of 5 controlled clinical trials involving 194 patients met the inclusion criteria. No statistically significant differences were detected in the low dose whole-lung irradiation group compared with the best supportive care group for clinical recovery rates, intubation rates, radiographic improvement rates and 28 d-overall survival.Conclusions:In patients of COVID-19 pneumonia, low dose whole-lung irradiation conferred no significant benefit to clinical outcomes. Currently, the routine use of low dose whole-lung irradiation for the treatment of moderate to severe COVID-19 pneumonia is not recommended.

OBJECTIVE: This study aimed to explore the influence of Rce1 on invasion and migration of tongue squamous cell carcinoma cells by silencing the Rce1 gene with RNA interference. METHODS: The tongue squamous cell carcinoma Cal-27 and SCC-4 cells were cultured in vitro. The small interfering RNA (siRNA) of the Rce1 gene was designed, and the Rcel gene expression was silenced vialiposome transfection. According to the siRNA transfected by liposome, the experimental group was divided into three groups, namely, Rce1-siRNA-1, Rce1-siRNA-2, and Rce1-siRNA-3 groups. Negative control group was transfected by siCON, and the blank control group was untransfected by siRNA. The Rce1, RhoA, and K-Ras gene expression levels in each group were analyzed by real-time quantitative polymerase chain reaction. The Rce1, RhoA, K-Ras, MMP-2, and MMP-9 protein expression levels were analyzed by Western blot. The invasiveness of tongue cancer cell Cal-27 and SCC-4 were determined by Transwell invasion assay, and cell migration assay was performed by cell scratch assay. RESULTS: Real-time quantitative polymerase chain reaction and Western blot results showed that compared with the negative and blank control groups, the Rce1 gene and protein expression levels in three experimental groups decreased (P<0.05). The RhoA, K-Ras gene and protein expression levels were insignificantly different among groups (P>0.05). Meanwhile, the MMP-2 and MMP-9 expression levels decreased (P<0.05). Transwell invasion assay results showed that the total number of cells in the PET film of the experimental groups was significantly decreased compared with the control group (P<0.05). The cell scratch test showed that the cell closure time of the scratch in the interference group was significantly longer than those in the control and blank groups (P<0.05). CONCLUSIONS Silencing Rce1 in vitro can effectively downregulate its expression in tongue squamous cell carcinoma cells Cal-27 and SCC-4 and reduce the migration and invasion abilities of these cells.
Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Endopeptidases ; metabolism ; Humans ; Neoplasm Invasiveness ; RNA Interference ; RNA, Small Interfering ; Tongue Neoplasms ; metabolism ; therapy ; Transfection