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.

Hepatocellular carcinoma(HCC)is the most common type of primary liver cancer and the third leading cause of cancer-related deaths,and it is a serious threat to human health and has become a clinical problem that needs to be solved urgently.Extracellular vesicles(EV)are membrane vesicles containing multiple components and play an important role in the development and progression of HCC.This article summarizes the effect of EVs of different origins on HCC and analyzes the mechanism of action of EV on HCC,so as to provide new perspectives for the diagnosis and treatment of HCC.

Gastric cancer is one of the most common cancers in the world,and with the rise of immune-targeted therapy,it has provided new treatment options for many patients with advanced gastric cancer.However,not all cancer patients can benefit from monoclonal antibody therapy against programmed death-1 and its ligand and against cytotoxic T lymphocyte associated antigen-4.Therefore,the discovery of new immune checkpoints has become a future therapeutic trend.In this review,we summarized and analyzed the biological characteristics of V-domain Ig suppressor of T cell activation,B7 homolog 3 and lymphocyte-activation gene 3 of novel immune checkpoint T cell activation,as well as their effects on the occurrence and development of gastric cancer.At the same time,the effectiveness of corresponding immunosuppressants in preclinical and clinical trials was also evaluated,in order to provide a theoretical reference for the targeted therapy of gastric cancer.

Treatment resistance of hepatocellular carcinoma(HCC)is an important factor restricting its treatment outcome.Autophagy is a process involving multiple steps and targets and is closely associated with the proliferation and apoptosis of tumor cells.At the same time,there is significant crosstalk between autophagy and tumor treatment resistance.Therefore,autophagy may be one of the key factors hindering tumor cell death after medical intervention.Transforming growth factor-β(TGF-β),epithelial-mesenchymal transition(EMT),and long non-coding RNA(lncRNA)are important factors leading to drug resistance of HCC.This article discusses the possible mechanism of TGF-β,EMT,and lncRNA mediating complex molecular networks and inducing drug resistance of HCC,in order to provide new ideas for improving the sensitivity of HCC treatment.

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.