RESUMO
Background: Gap junctions, as one of the major ways to maintain social connections between cells, are now considered as one of the potential regulators of tumor metastasis. However, to date, studies on the relationship between gap junctions and colorectal cancer (CRC) are limited. Methods: We synthesized connexins-coding gene expression data from public Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Bioinformatics analysis was performed using R software and several database resources such as MEXPRESS database, Gene Set Cancer Analysis (GSCA) database, Human Protein Atlas (HPA) database, Tumor Immune Single Cell Hub (TISCH) database, Search Tool for Retrieval of Gene Interaction Relationships (STRING), and Cytoscape software, etc., to investigate the biological mechanisms that may be involved in connexins. Immunofluorescence and immunohistochemical staining were used to validate the expression and localization of GJA4. Results: We found that CRC patients can be divided into two connexin clusters and that patients in cluster C1 had shorter survival than in cluster C2. The infiltration of M1 macrophages and NK cells was lower in cluster C1, while the levels of M2 macrophages and immune checkpoints were higher, indicating an immunosuppressed state in cluster C1. In addition, the epithelial-mesenchymal transition (EMT) phenotype was significantly activated in cluster C1. We observed that GJA4 was up-regulated in colorectal cancer tissues, which was related to poor prognosis. It was mainly expressed in fibroblasts, but the expression levels in normal intestinal epithelial cells were low. Finally, we found that GJA4 was associated with M2 macrophages and may be a potential immunosuppressive factor. Conclusion: We found that there is a significant correlation between abnormal connexins expression and patients' prognosis, and connexins play an important role in stromal-tumor interactions. Connexins, especially GJA4, can help enhance our understanding of tumor microenvironment (TME) and may guide more effective immunotherapeutic strategies.
RESUMO
OBJECTIVE: The objective of this research is to construct a clinic-usable genechip method for detection of hepatitis B virus lamivudine-resistant mutants and basal core promotor/Pre-C mutants, compare this method with DNA sequencing to investigate this genechip's character (sensity, specificity, stability and practicability in clinic) and apply it in clinic. METHODS: This genechip detection method can detect the DNA and 8 mutative site of HBV, include 3 lamivudine-resistant mutation site(No. 180, 204, 207 site in DNA polymerase gene), 5 HBeAg escape-related mutation site (nt 1896, 1899, 1862, 1764,1762 site in BCP/Pre-C region).The results of genechip method was verified by DNA sequencing. RESULTS: In detecting HBV DNA, the results of genechip were agree with 100% of the results of DNA sequencing. In detecting HBV mutants, 251 sites (in 32 samples, 256 sites) showed the same results using both methods, and only 5 sites were not completely match (P > 0.05). In these 5 sites, genechip methods got multi-infection results, but sequencing got single-infection results. CONCLUSION: These results suggest that genechip method has the same positive rate and almost these same specificity with DNA sequencing method, and is better than DNA sequencing method in detecting multi-infected HBV strains. [Key words]
