Integrated bioinformatics analysis for conducting a prognostic model and identifying immunotherapeutic targets in gastric cancer.

BACKGROUND: Gastric cancer is the third leading cause of death from cancer worldwide and has a poor prognosis. Practical risk scores and prognostic models for gastric cancer are lacking. While immunotherapy has succeeded in some cancers, few gastric cancer patients benefit from immunotherapy. Immune genes and the tumor microenvironment (TME) are essential for cancer progression and immunotherapy response. However, the roles of immune genes and the tumor microenvironment in immunotherapy remain unclear. The study aimed to construct a prognostic prediction model and identify immunotherapeutic targets for gastric cancer (GC) patients by exploring immune genes and the tumor microenvironment. RESULTS: An immune-related risk score (IRRS) model, including APOH, RNASE2, F2R, DEFB126, CXCL6, and CXCL3 genes, was constructed for risk stratification. Patients in the low-risk group, which was characterized by elevated tumor mutation burden (TMB) have higher survival rate. The risk level was remarkably correlated with tumor-infiltrating immune cells (TIICs), the immune checkpoint molecule expression, and immunophenoscore (IPS). CXCL3 and CXCL6 were significantly upregulated in gastric cancer tissues compared with normal tissues using the UALCAN database and RT-qPCR. The nomogram showed good calibration and moderate discrimination in predicting overall survival (OS) at 1-, 3-, and 5- year for gastric cancer patients using risk-level and clinical characteristics. CONCLUSION: Our findings provided a risk stratification and prognosis prediction tool for gastric cancer patients and further the research into immunotherapy in gastric cancer.

Application of Paclitaxel-loaded EGFR Peptide-conjugated Magnetic Polymeric Liposomes for Liver Cancer Therapy.

Developing the methodologies that allow for safe and effective delivery of therapeutic drugs to target sites is a very important research area in cancer therapy. In this study, polyethylene glycol (PEG)-coated magnetic polymeric liposome (MPL) nanoparticles (NPs) assembled from octadecyl quaternized carboxymethyl chitosan (OQC), PEGylated OQC, cholesterol, and magnetic NPs, and functionalized with epithelial growth factor receptor (EGFR) peptide, were successfully prepared for in-vivo liver targeting. The two-step liver targeting strategy, based on both magnetic force and EGFR peptide conjugation, was evaluated in a subcutaneous hepatocellular carcinoma model of nude mouse. The results showed that EGFR-conjugated MPLs not only accumulated in the liver by magnetic force, but could also diffuse into tumor cells as a result of EGFR targeting. In addition, paclitaxel (PTX) was incorporated into small EGFR-conjugated MPLs (102.0±0.7 nm), resulting in spherical particles with high drug encapsulation efficiency (>90%). The use of the magnetic targeting for enhancing the transport of PTX-loaded EGFR-conjugated MPLs to the tumor site was further confirmed by detecting PTX levels. In conclusion, PTX-loaded EGFR-conjugated MPLs could potentially be used as an effective drug delivery system for targeted liver cancer therapy.

[Changes of colonic permeability and its correlation with TNF-α, NF-κB p65 in ulceration colitis mice].

OBJECTIVE: To study the changes of colonic permeability and its correlation with TNF-α, NF-κB p65 in indextran sulphate sodium (DSS) -induced ulcerative colitis(UC) of mice. METHODS: Forty-eight ICR mice were randomly divided into the control group and the model group. The acute UC model was induced by quantified intragastric administration of 2.5% DSS in mice. The disease activity index(DAI), histopathology scores, colonic permeability, expression of TNF-α, NF-κB p65 in colonic tissue were determined. The change of colonic permeability and its correlation with DAI, TNF-α, NF-κB p65 were analyzed. RESULTS: Compareded with the control group, DAI colonic permeability of colonic tissue,and the expression of TNF-α NF-κB p65 in the model group were increased significantly (P<0.01, P<0.01). The increased colonic permeability correlated with DAI (P<0.01), and the expression of TNF-α(P<0.01), NF-κB p65(P<0.01) changed significantly. CONCLUSIONS: The alteration of colonic permeability and increased expression of TNF-α, NF-κB p65 may play important roles in the occurrence and development of UC.

Expression and clinical significance of the long non-coding RNA PVT1 in human gastric cancer.

BACKGROUND: Highly sensitive markers are urgently needed for the diagnosis and grading of gastric cancer and for managing drug resistance. The recent identification of long-non-coding RNAs (lncRNAs) has provided new approaches for resolving this challenge. The aim of this study was to screen and identify new biomarkers for human gastric cancer from lncRNAs. METHODS: First, we used lncRNA microarrays to conduct a preliminary screening for candidate lncRNAs of gastric cancer biomarkers in both human gastric cancer tissues and in two gastric cancer cell lines, SGC7901 cells and paclitaxel-resistant SGC7901 cells. The lncRNA plasma-cytoma variant translocation 1 (PVT1) was found to exhibit higher expression in both gastric cancer tissues and the SGC7901 paclitaxel-resistant cell line. Quantitative polymerase chain reaction was used for large-scale analysis in a large number of human gastric cancer tissues to verify the involvement of PVT1 in development of gastric cancer. The relationships between PVT1 expression and clinical features were also analyzed. RESULTS: PVT1 showed higher expression in human gastric cancer tissues than in adjacent non-cancerous tissues and in SGC7901 paclitaxel-resistant cells compared with SGC7901 cells. PVT1 expression was correlated with lymph node invasion of gastric cancer. CONCLUSION: PVT1 is a new biomarker for human gastric cancer and may indicate lymph node invasion. Therefore, PVT1 shows potential as a novel therapeutic target for the treatment of gastric cancer and enhancement of paclitaxel sensitivity.