RESUMO
Objective:To investigate the effect of ubiquitin binding enzyme 2T (UBE2T) on the radiosensitivity of lung adenocarcinoma and unravel its possible mechanism.Methods:A total of 45 patients pathologically diagnosed with different stages of lung adenocarcinoma and treated with radiotherapy in the Second Affiliated Hospital of Zunyi Medical University from March, 2019 to December, 2021 were enrolled, and the efficacy was evaluated according to response evaluation criteria in solid tumors (RECIST1.1). All patients were divided into radiosensitive group ( n=25) and radioresistant group ( n=20). Radiosensitive group was complete remission (CR)+partial remission (PR), and radioresistant group was stable disease (SD) + progression disease (PD). Immunohistochemistry (IHC) was used to calculate the score based on the staining intensity and the number of positive cells. Chi-square test was combined to analyze the correlation between the expression level of UBE2T in paraffin specimens of lung adenocarcinoma patients and the radiosensitivity of patients. Lentivirus UBE2T-interfered (UBE2Tsh) A549 and UBE2T-overexpressed SPC-A-1 lung adenocarcinoma cells and their respective controls were constructed for irradiation and colony formation assay. The survivor fraction curve was fitted by single-hit multi-target model. The DNA double-strand break (DSB) marker γH2AX foci were detected by immunofluorescence (IF). The expression levels of UBE2T, γH 2AX and Rad51 proteins were detected by Western blot. Cell cycle and apoptosis rate of A549 were determined by flow cytometry. Binary variables were statistically analyzed by Fisher's exact probability method and measurement data were assessed by t-test. Results:High-expression level of UBE2T was correlated with the radiosensitivity of lung adenocarcinoma patients ( P<0.05). UBE2Tsh improved the radiosensitivity of A549 lung adenocarcinoma cells, and the sensitizing enhancement ratio (SER) was 1.795. UBE2T overexpression decreased the radiosensitivity of SPC-A-1 lung adenocarcinoma cells with an SER of 0.293. γH2AX foci number per cell were significantly increased in UBE2Tsh A549 cells after irradiation ( P<0.01) . Compared with the control group, the expression level of γH2AX protein was up-regulated ( P<0.01)and that of Rad51 protein was down-regulated in UBE2Tsh A549 cells after radiation ( P<0.001). Compared with the control group, the expression level of γH2AX protein was down-regulated ( P<0.05) and that of Rad51 protein was up-regulated in UBE2T overexpressed SPC-A-1 cells ( P<0.001). The proportion of UBE2Tsh A549 cells in G 2 phase was decreased ( P<0.01) and cell apoptosis was increased ( P<0.001). Conclusions:UBE2T might promote the radioresistance of lung adenocarcinoma cells by enhancing DNA DSB repair induced by radiotherapy, inducing cell cycle G 2 phase arrest, and reducing cell apoptosis.
RESUMO
Objective:To detect the common pathogenic bacteria in rat wounds using electronic nose so as to explore the feasibility of electronic nose for rapid screening of pathogenic bacteria in clinic.Methods:The wound was cutted from the left and right side of the psoas muscle of 45 SD rats. The type of standard bacterial fluids applied to the wound was divided into Staphylococcus aureus group, Escherichia coli group, Pseudomonas aeruginosa group, Acinetobacter baumannii group and Klebsiella pneumoniae group according to the random number table, with 9 mice per group. Three days later, the wound pus was sent to culture. Five standard bacterial fluids were detected by electronic nose, and the overall recognition rate and individual recognition rate of standard bacterial fluids were calculated by neural network (BP). The wound pus in each group was detected by electronic nose to visually compare the overlap degree of the radar map of the wound pus with the standard bacterial fluid characteristic radar map. The detection rate of wound pus in each group by electronic nose was compared. The wound pus in each group was submitted for examination, and the clinical detection rate of wound pus in each group was compared. The consistency was compared between electronic nose test and clinical test.Results:The overall BP identification rate of five standard bacteria liquid was 93.2%. The BP single identification rate of the Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae reached over 99.0%, and was more than 88.0% for Pseudomonas aeruginosa and Acinetobacter baumannii. The radar pattern of wound pus was highly overlapped with the characteristics of radar pattern of standard bacterial fluid. The detection rate of wound pus by electronic nose was the highest (100.0%) in Pseudomonas aeruginosa group and Escherichia coli group, followed by 88.9% in Klebsiella pneumoniae group and 72.2% in Pseudomonas aeruginosa group and Acinetobacter baumannii group. Using electronic nose, the detection rate in Pseudomonas aeruginosa group and Acinetobacter baumannii group was significantly different from that in Staphylococcus aureus group and Escherichia coli group ( P<0.05). The clinical detection rate of wound pus was 100.0% in Staphylococcus aureus group, Escherichia coli group and Klebsiella pneumoniae group, 94.4% in Pseudomonas aeruginosa group and 66.7% in Acinetobacter baumannii group. The clinical detection rate in Acinetobacter baumannii group differed significantly compared to that in Staphylococcus aureus group, Escherichia coli group and Klebsiella pneumoniae group ( P<0.05), while there was no significant difference between Acinetobacter baumannii group and Pseudomonas aeruginosa group ( P>0.05). Comparison of detection rate of wound pus between electronic nose and clinic examination showed a Kappa coefficient of 0.475. Conclusions:The animal wound pus detected by electronic nose can obtain a feature map with high repeatability compared to the standard bacterial fluid. The electronic nose detection has a medium degree of consistency with clinical detection, providing an experimental basis for the feasibility of using electronic nose to rapidly screen types of pathogenic bacteria.
