Background: Hepatocellular carcinoma (HCC) is the most common type of liver tumour, and is closely related to liver cirrhosis. Previous studies have focussed on the pathogenesis of liver cirrhosis developing into HCC, but the molecular mechanism remains unclear. The aims of the present study were to identify key genes related to the transformation of cirrhosis into HCC, and explore the associated molecular mechanisms.Methods: GSE89377, GSE17548, GSE63898 and GSE54236 mRNA microarray datasets from Gene Expression Omnibus (GEO) were analysed to obtain differentially expressed genes (DEGs) between HCC and liver cirrhosis tissues, and network analysis of protein-protein interactions (PPIs) was carried out. String and Cytoscape were used to analyse modules and identify hub genes, Kaplan-Meier Plotter and Oncomine databases were used to explore relationships between hub genes and disease occurrence, development and prognosis of HCC, and the molecular mechanism of the main hub gene was probed using Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway analysis. Results:In total, 58 DEGs were obtained, of which 12 and 46 were up-and down-regulated, respectively. Three hub genes (CDKN3, CYP2C9 and LCAT) were identified and associated prognostic information was obtained. CDKN3 may be correlated with the occurrence, invasion, and recurrence of HCC. Genes closely related to changes in the CDKN3 hub gene were screened, and Kyoto Encyclopedia of Genes and Genomes (KEGGs) pathway analysis identified numerous cell cycle-related genes.Conclusion: CDKN3 may affect the transformation of liver cirrhosis into HCC, and represents a new candidate molecular marker of the occurrence and progression of HCC.

The immune response facilitated by tumor-associated macrophages is a vital determinant of tumor progression. We identified differentially expressed genes between various macrophage phenotypes in the Gene Expression Omnibus, and used Kaplan-Meier Plotter to determine which of them altered the prognosis of esophageal carcinoma patients. Fibrinogen-like protein 2 ( FGL2 ), an immunosuppressive factor in the tumor microenvironment of various cancers, was upregulated in M2 macrophages, and higher FGL2 expression was associated with poorer survival in esophageal carcinoma patients. Using the TIMER database, we found that FGL2 expression correlated positively with the levels of immune markers of infiltrating B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils and dendritic cells in esophageal carcinoma samples. Correlation analyses in cBioPortal revealed that the mRNA levels of FGL2 correlated strongly with those of interleukin 10, matrix metalloproteinase 9, C-C motif chemokine ligand 5, T-cell immunoglobulin mucin 3, interleukin 13, vascular cell adhesion molecule 1, macrophage colony-stimulating factor and fibroblast growth factor 7 in esophageal carcinoma tissues. The same cytokines were upregulated when esophageal squamous cell carcinoma cells were co-cultured with M2-like tumor-associated macrophages. Thus, by secreting FGL2, M2-like tumor-associated macrophages may create an immunosuppressive tumor microenvironment that induces the occurrence and progression of esophageal carcinoma.

Macrophages are a double-edged sword with potential cancer-promoting and anti-cancer effects. Controversy remains regarding the effect of macrophages, especially M1 macrophages, on tumor promotion and suppression. We aimed to investigate the role of M1 macrophages in the occurrence and progression of esophageal squamous cell carcinoma (ESCC). Analyzing the data in Gene Expression Omnibus (GEO) database by The CIBERSORT algorithm found that M1 macrophages were one of the important components of many immune cells in ESCCs, and the increased in their number was obviously negatively correlated with tumor T staging. This result was verified by our experimental data: the density of CD68/HLA-DR double-stained M1 macrophages in ESCC tumor nest and tumor stroma were significantly higher than that in cancer-adjacent normal (CAN) tissues. The density of M1 macrophages in ESCC tumor nest was negatively correlated with the patient's lymph node metastasis and clinical stage (P < 0.05), and the negative tendency was more obvious for M1 macrophages in ESCC tumor stroma (P < 0.001). Exposure to M1 macrophage CM inhibited ESCC cell migration and invasion ability significantly (P < 0.05). Moreover, the increased M1 macrophage density in ESCC tumor stroma correlated positively with good prognosis of ESCC. M1 macrophages were involved in inhibiting ESCC cell migration and invasion, which could serve as a good prognostic factor in patients with ESCC.

Immunotherapy has developed rapidly and has gradually become one of the important methods for treatment of gastric cancer (GC). The research on tumor infiltrating immune cells (TIICs) and immune-related genes in the tumor microenvironment (TME) greatly encourages the development of immunotherapy. The devolution algorithm (CIBERSORT) was applied to infer the proportion of 22 TIICs based on gene expression profiles of GC tissues, which were downloaded from TCGA and GEO. TCGA was utilized to analyze the differential expression of immune-related genes, and explore the potential molecular functions of these genes. We have observed the enrichment of multiple TIICs in microenvironment of GC. Some of these cells were closely related to tumor mutational burden (TMB), microsatellite instability (MSI), Fuhrman grade, and TNM staging. Survival analysis showed that the infiltration level of CD8+ T cells, activated CD4+ memory T cells and M2 macrophages were significantly related to the prognosis of GC patients. The functional enrichment analysis of immune-related genes revealed that these genes were mainly associated with cytokine activation and response. Four significant modules were screened by PPI network and 20 key genes were screened from the modules. The expression levels of CALCR and PTH1R are strikingly related to the expression of immune checkpoint and the prognosis of GC patients. The type and number of TIICs in microenvironment of GC, as well as immune-related genes are closely related to tumor progression, and can be used as important indicators for patient prognosis assessment.