Objective:To explore the effects of K-ras gene on the expressions of oncogenes and cancer suppressor genes in human bronchial epithelial (HBE) cells which were exposed to PM 2.5. Methods:According to the mRNA sequence of K-ras gene provided by GenBank in September 2019, interference sequences were designed and synthesized, and the recombinant lentiviral vector was transfected into HBE cell to construct the K-ras gene-silenced cells. HBE cells and K-ras gene-silenced cells were exposed to 10 μg/ml, 50 μg/ml PM 2.5 suspension and 10 μmol/L Cr 6+. Real-time fluorescent quantitative PCR was used to detect the mRNA expression levels of c-myc, c-fos, N-ras, cyclin-D1, p16 and p53 genes, the expression levels of p53 and c-myc proteins were detected by Western blot. Results:In K-ras silenced cell group, K-ras mRNA expression level decreased (80.5%±3.6%) and K-ras protein level decreased (58.9%±4.7%) when compared with the control group ( P<0.01) . Compared with the correspoding cell control group without exposure, the mRNA expression levels of c-myc, c-fos, N-ras and cyclin-D1 genes in HBE cell group exposed to different concentrations of PM 2.5, K-ras silenced cell group exposed to different concentrations of PM 2.5, HBE cell group exposed to 10 μmol/L Cr 6+ and K-ras silenced cell group exposed to 10 μmol/L Cr 6+ were increased, the mRNA expressions of p16 and p53 genes were decreased ( P<0.01) . Compared with HBE cell group exposed to 10 μg/ml PM 2.5, the mRNA expressions of c-myc, c-fos and p16 genes in K-ras silenced cells exposed to 10 μg/ml PM 2.5 were decreased, and the p53 mRNA level was increased ( P<0.01) . Compared with HBE cell group exposed to 50 μg/ml PM 2.5, the mRNA expression levels of c-fos, N-ras, cyclin-D1, p16 and p53 genes in K-ras silenced cell group exposed to 50 μg/ml PM 2.5 were decreased ( P<0.01) . Compared with the HBE cell group without exposure, c-myc protein increased and p53 protein decreased in HBE cells exposed to 50 μg/ml PM 2.5 ( P<0.05) . Compared with the K-ras silenced cell group without exposure, c-myc protein increased in K-ras silenced cells exposed to 50 μg/ml PM 2.5 ( P<0.05) . Conclusion:PM 2.5 can increase the expression levels of oncogenes in HBE cells, and K-ras gene silencing can inhibit the expression levels of oncogenes in HBE cells treated with PM 2.5.

Objective:To explore the effects of K-ras gene on the expressions of oncogenes and cancer suppressor genes in human bronchial epithelial (HBE) cells which were exposed to PM 2.5. Methods:According to the mRNA sequence of K-ras gene provided by GenBank in September 2019, interference sequences were designed and synthesized, and the recombinant lentiviral vector was transfected into HBE cell to construct the K-ras gene-silenced cells. HBE cells and K-ras gene-silenced cells were exposed to 10 μg/ml, 50 μg/ml PM 2.5 suspension and 10 μmol/L Cr 6+. Real-time fluorescent quantitative PCR was used to detect the mRNA expression levels of c-myc, c-fos, N-ras, cyclin-D1, p16 and p53 genes, the expression levels of p53 and c-myc proteins were detected by Western blot. Results:In K-ras silenced cell group, K-ras mRNA expression level decreased (80.5%±3.6%) and K-ras protein level decreased (58.9%±4.7%) when compared with the control group ( P<0.01) . Compared with the correspoding cell control group without exposure, the mRNA expression levels of c-myc, c-fos, N-ras and cyclin-D1 genes in HBE cell group exposed to different concentrations of PM 2.5, K-ras silenced cell group exposed to different concentrations of PM 2.5, HBE cell group exposed to 10 μmol/L Cr 6+ and K-ras silenced cell group exposed to 10 μmol/L Cr 6+ were increased, the mRNA expressions of p16 and p53 genes were decreased ( P<0.01) . Compared with HBE cell group exposed to 10 μg/ml PM 2.5, the mRNA expressions of c-myc, c-fos and p16 genes in K-ras silenced cells exposed to 10 μg/ml PM 2.5 were decreased, and the p53 mRNA level was increased ( P<0.01) . Compared with HBE cell group exposed to 50 μg/ml PM 2.5, the mRNA expression levels of c-fos, N-ras, cyclin-D1, p16 and p53 genes in K-ras silenced cell group exposed to 50 μg/ml PM 2.5 were decreased ( P<0.01) . Compared with the HBE cell group without exposure, c-myc protein increased and p53 protein decreased in HBE cells exposed to 50 μg/ml PM 2.5 ( P<0.05) . Compared with the K-ras silenced cell group without exposure, c-myc protein increased in K-ras silenced cells exposed to 50 μg/ml PM 2.5 ( P<0.05) . Conclusion:PM 2.5 can increase the expression levels of oncogenes in HBE cells, and K-ras gene silencing can inhibit the expression levels of oncogenes in HBE cells treated with PM 2.5.

Gastric cancer and esophagogastric junction cancer (EGJC) are one of the world 's most common types of malignant tumors. Traditional treatment methods mainly include radiotherapy, chemotherapy, and surgery, but the patients ' prognosis is limited. In recent years, with the development in treatment methods, immunotherapy and targeted therapy are gradually recognized as the first-line treatment methods. In immunotherapy, nivolumab and pabolizumab have shown clear efficacy in patients with programmed deathligand 1 positive, while other immunotherapies (such as tumor vaccine, engineered T cells, and non-specific immunomodulators) are still being tested or developed. In addition, targeted therapy has only shown comparatively large therapeutic potential in certain specific populations or in second-line treatment. For instance, tratuzumab has a clear curative effect on patients with positive human epidermal growth factor receptor 2, but has suboptimal efficacy in patients with amplification of other molecular targets. An in-depth discussion of the research progress of immunotherapy and targeted therapy in gastric cancer and EGJC will help to improve the prognosis of patients and provide a reference for accurate treatment of tumors.

Objective:To construct the c-myc gene silenced hepatocytes, study the effect of c-myc gene silence on expression of oncogenes and apoptosis genes in hepatocytes treated with PM2.5.Methods:According to the c-myc gene mRNA sequence provided by GenBank, three interfering sequences were designed and synthesized, the recombinant lentiviral vector was transfected into L02 hepatocytes. The real-time quantitative PCR and western blotting were used to identify the effect of c-myc gene silencing. L02 cells and c-myc gene silenced cells were used as experimental subjects. The normal L02 cells and c-myc silenced cells were treated with 50 μg/ml PM 2.5 water soluble solution, 10 μM positive control Cr 6+ and a blank control, the treatment period was 24 h. The mRNA levels of oncogenes (c-myc, c-fos, k-ras, p53) and apoptotic genes (Caspase-3, Caspase-8, Caspase-9) were detected by real-time PCR. The protein levels of oncogenes and apoptotic genes were detected by western blotting. Results:The mRNA level and protein level of c-myc decreased by 81% and 70% in c-myc silenced cells when compared with the normal L02 hepatocytes, the above results indicate that c-myc gene silenced cells were successfully constructed. After c-myc silenced cells were treated with PM2.5 water soluble solution, The mRNA levels of c-myc, c-fos, and k-ras decreased by 84.1%, 45.4%, and 54.6% ( P<0.05) , p53 increased by 192.9% ( P<0.05) , and the expression of Caspase-3, Caspase-8, and Caspase-9 decreased by 24.4%, 36.1%, 60.9% ( P<0.05) . In the Cr 6+ positive control group, the expression of c-myc, c-fos, and k-ras decreased by 72.1%, 82.2%, and 54.0% ( P<0.05) , p53 increased by 250.0% ( P<0.05) , the expression of Caspase-3, Caspase-8, and Caspase-9 decreased by 34.6%, 36.0%, 68.9% ( P<0.05) , respectively, when compared with the normal L02 hepatocytes ( P<0.05) . Western blotting results showed that the protein levels of c-myc and c-fos increased, p53 decreased after PM 2.5 exposure; the protein levels of Caspase-3, Caspase-8, Caspase-9 increased after PM 2.5 exposure ( P<0.05) . When in comparison with the c-myc silenced group, the protein levels of c-myc and c-fos decreased, p53 protein increased in PM 2.5 exposed group ( P<0.05) . Conclusion:c-myc gene silenced cells were successfully constructed in this paper. PM 2.5 could promote the expression of oncogenes and apoptotic genes in L02 cells, and c-myc gene silencing can inhibit the expression of oncogenes and apoptotic genes after PM 2.5 treatment in L02 cells.

Objective:To study the effect of p38 mitogen-activated protein kinase (MAPK) gene silencing on expression of apoptotic genes and oncogenes in hepatocytes treated with PM 2.5. Methods:From June to September 2019, according to the p38MAPK gene mRNA sequence provided by GenBank, three interfering sequences were designed and synthesized, ligated into PLVX-shRNA2-puro after annealing, and the recombinant lentiviral vector was transfected into L02 hepatocytes. The p38MAPK silencing cells were identified by real-time fluorescent quantitative PCR and western blotting. The normal L02 cells and p38MAPK silencing cells were treated with 50 μg/mL PM 2.5 water soluble solution, 10 μmol/L positive control Cr 6+, and a blank control group was set up, the treatment time was 24 h. The mRNA levels of oncogenes (c-fos, c-myc, k-ras) , tumor suppressor gene (p53) and apoptotic genes (Caspase-3, Caspase-8, Caspase-9) were detected by real-time PCR. The protein levels of oncogenes and apoptotic genes were detected by Western blotting. Results:The expression levels of p38MAPK mRNA and protein in p38MAPK gene silencing cells were significantly lower than those in L02 hepatocytes ( P<0.05) , and the p38MAPK gene silencing cell line was successfully constructed. Compared with the blank control group, the expression levels of the oncogenes c-fos, c-myc, k-ras and the apoptosis genes Caspase-3, Caspase-8 and Caspase-9 increased, the expression level of tumor suppressor gene p53 decreased in the L02 hepatocyte group treated with PM 2.5 water soluble matter, and the differences were statistically significant ( P<0.05) . Compared with the L02 hepatocytes group treated with PM 2.5 water soluble matter, the expression levels of the oncogenes c-fos, c-myc, k-ras and apoptosis genes Caspase-3, Caspase-8 and Caspase-9 decreased, the expression level of tumor suppressor gene p53 increased in the p38MAPK gene silencing cells group treated with PM 2.5 water soluble matter, and the differences were statistically significant ( P<0.05) . Conclusion:PM 2.5 has effects on the expression of oncogenes, tumor suppressor genes and apoptotic genes in L02 hepatocytes, while p38MAPK gene silencing can inhibit the effects of PM 2.5 on L02 hepatocytes.

Objective:To construct the c-myc gene silenced hepatocytes, study the effect of c-myc gene silence on expression of oncogenes and apoptosis genes in hepatocytes treated with PM2.5.Methods:According to the c-myc gene mRNA sequence provided by GenBank, three interfering sequences were designed and synthesized, the recombinant lentiviral vector was transfected into L02 hepatocytes. The real-time quantitative PCR and western blotting were used to identify the effect of c-myc gene silencing. L02 cells and c-myc gene silenced cells were used as experimental subjects. The normal L02 cells and c-myc silenced cells were treated with 50 μg/ml PM 2.5 water soluble solution, 10 μM positive control Cr 6+ and a blank control, the treatment period was 24 h. The mRNA levels of oncogenes (c-myc, c-fos, k-ras, p53) and apoptotic genes (Caspase-3, Caspase-8, Caspase-9) were detected by real-time PCR. The protein levels of oncogenes and apoptotic genes were detected by western blotting. Results:The mRNA level and protein level of c-myc decreased by 81% and 70% in c-myc silenced cells when compared with the normal L02 hepatocytes, the above results indicate that c-myc gene silenced cells were successfully constructed. After c-myc silenced cells were treated with PM2.5 water soluble solution, The mRNA levels of c-myc, c-fos, and k-ras decreased by 84.1%, 45.4%, and 54.6% ( P<0.05) , p53 increased by 192.9% ( P<0.05) , and the expression of Caspase-3, Caspase-8, and Caspase-9 decreased by 24.4%, 36.1%, 60.9% ( P<0.05) . In the Cr 6+ positive control group, the expression of c-myc, c-fos, and k-ras decreased by 72.1%, 82.2%, and 54.0% ( P<0.05) , p53 increased by 250.0% ( P<0.05) , the expression of Caspase-3, Caspase-8, and Caspase-9 decreased by 34.6%, 36.0%, 68.9% ( P<0.05) , respectively, when compared with the normal L02 hepatocytes ( P<0.05) . Western blotting results showed that the protein levels of c-myc and c-fos increased, p53 decreased after PM 2.5 exposure; the protein levels of Caspase-3, Caspase-8, Caspase-9 increased after PM 2.5 exposure ( P<0.05) . When in comparison with the c-myc silenced group, the protein levels of c-myc and c-fos decreased, p53 protein increased in PM 2.5 exposed group ( P<0.05) . Conclusion:c-myc gene silenced cells were successfully constructed in this paper. PM 2.5 could promote the expression of oncogenes and apoptotic genes in L02 cells, and c-myc gene silencing can inhibit the expression of oncogenes and apoptotic genes after PM 2.5 treatment in L02 cells.

Objective:To study the effect of p38 mitogen-activated protein kinase (MAPK) gene silencing on expression of apoptotic genes and oncogenes in hepatocytes treated with PM 2.5. Methods:From June to September 2019, according to the p38MAPK gene mRNA sequence provided by GenBank, three interfering sequences were designed and synthesized, ligated into PLVX-shRNA2-puro after annealing, and the recombinant lentiviral vector was transfected into L02 hepatocytes. The p38MAPK silencing cells were identified by real-time fluorescent quantitative PCR and western blotting. The normal L02 cells and p38MAPK silencing cells were treated with 50 μg/mL PM 2.5 water soluble solution, 10 μmol/L positive control Cr 6+, and a blank control group was set up, the treatment time was 24 h. The mRNA levels of oncogenes (c-fos, c-myc, k-ras) , tumor suppressor gene (p53) and apoptotic genes (Caspase-3, Caspase-8, Caspase-9) were detected by real-time PCR. The protein levels of oncogenes and apoptotic genes were detected by Western blotting. Results:The expression levels of p38MAPK mRNA and protein in p38MAPK gene silencing cells were significantly lower than those in L02 hepatocytes ( P<0.05) , and the p38MAPK gene silencing cell line was successfully constructed. Compared with the blank control group, the expression levels of the oncogenes c-fos, c-myc, k-ras and the apoptosis genes Caspase-3, Caspase-8 and Caspase-9 increased, the expression level of tumor suppressor gene p53 decreased in the L02 hepatocyte group treated with PM 2.5 water soluble matter, and the differences were statistically significant ( P<0.05) . Compared with the L02 hepatocytes group treated with PM 2.5 water soluble matter, the expression levels of the oncogenes c-fos, c-myc, k-ras and apoptosis genes Caspase-3, Caspase-8 and Caspase-9 decreased, the expression level of tumor suppressor gene p53 increased in the p38MAPK gene silencing cells group treated with PM 2.5 water soluble matter, and the differences were statistically significant ( P<0.05) . Conclusion:PM 2.5 has effects on the expression of oncogenes, tumor suppressor genes and apoptotic genes in L02 hepatocytes, while p38MAPK gene silencing can inhibit the effects of PM 2.5 on L02 hepatocytes.

Objective To explore the independent risk factors that affect the overall survival(OS)of elderly patients with hepatocellular carcinoma(HCC,≥60 years old)and build a nomogram prediction model.Methods Clinical data of all elderly patients with HCC from the SEER database from 2005 to 2020 were downloaded from SEER database.In accordance with the inclusion and exclusion criteria,the screened patients were randomly assigned to a training group(70%)and a validation group(30%).The independent risk factors of elderly patients with HCC were determined by univariate and multivariate Cox regression analyses and further validated by Kaplan-Meier survival analysis.On the basis of the determined variables,nomograms were developed and verified to predict the OS of elderly patients with HCC at 6,12,and 24 months.The consistency index(C index),calibration curve,receiver's operating characteristic(ROC)curve,and area under curve(AUC)were used to evaluate the prediction efficiency and discrimination ability of the prediction model,and decision curve analysis(DCA)was used to evaluate the potential clinical application value of the nomogram.Results A total of 1134 elderly patients with HCC were included,with 793 in the training group and 341 in the validation group.Seven variables,including age,clinical grade,clinical stage,M stage,tumor size classification,and radiotherapy,were identified as independent prognostic factors of this population.The constructed nomogram shows excellent prediction performance,with C indices of 0.745 in the training group and 0.704 in the validation group.The AUC values of the training group at 6,12,and 24 months were 0.785,0.788,and 0.798,respectively,and those of the validation group were 0.780,0.725,and 0.607,respectively.The calibration curve shows good consistency from the predicted survival probability to the actual probability.The ROC curve and DCA show that the nomogram proposed in this study has good prediction ability.Conclusion Age,clinical grade,clinical stage,M stage,tumor size classification,and radiotherapy are important influencing factors for the survival of elderly patients with HCC.The prediction model of prognosis nomogram constructed in this study has good predictive value,and it can be used to predict the OS of elderly patients with HCC,which could be helpful for individualized survival assessment and clinical management of these patients.