Hypoxia Induces Apoptosis of Microglia BV2 by Upregulating Kir2.1 to Activate Mitochondrial-Related Apoptotic Pathways.

Aim: To explore the role of Kir2.1 in hypoxia-induced microglial apoptosis. Methods: BV2 microglial cell lines were cultured and treated with ML133 hydrochloride, a Kir2.1 channel blocker, for 23 h and with 500 µmol/L of CoCl2 for 8 h. Cells were divided into the control, CoCl2 (hypoxia-induced model), and CoCl2+ML133 (hypoxia-induced model established after ML133 pretreatment) groups. Cell activity was assessed using the CCK-8 technique. The membrane potential and Kir2.1 current of BV2 were evaluated with the whole-cell patch-clamp technique. The protein levels and mRNA levels of Kir2.1, apoptotic proteins Bax and caspase-3, and antiapoptotic protein Bcl-2 in BV2 cells were evaluated via immunofluorescence, Western blot analysis, and real-time quantitative reverse transcription. The apoptosis rate of BV2 cells was detected via flow cytometry. Results: CCK-8 analysis showed that the cell activity of each group increased initially and then decreased. The 2 h intervention group had the highest cell activity, and that of the 8 h group was >90%. Hence, there was a significant difference in the results (P < 0.05). Western blot analysis revealed that the expression of cleaved caspase-3 significantly increased in the 8 h group compared with the 0 h group. Compared with the control group, the expression of Kir2.1 and mRNA in the CoCl2 group increased. Thus, hypoxia could upregulate the expression of Kir2.1. The whole-cell patch-clamp results showed that the Kir2.1 channel current amplitude of the CoCl2 group increased compared with that of the control group. Therefore, hypoxia could enhance Kir2.1 function. The apoptosis rate of the CoCl2 group was significantly higher than that of the control group. Further, the ML133 group had a significantly lower apoptosis rate than the CoCl2 group. The expression of apoptotic proteins Bax and cleaved caspase-3 increased in the CoCl2 group, and that of the antiapoptotic protein Bcl-2 decreased. The expression of apoptotic proteins Bax and cleaved caspase-3 reduced in the CoCl2+ML133 group, whereas that of the antiapoptotic protein Bcl-2 increased. Conclusion: Hypoxia can induce microglia BV2 apoptosis accompanied by the upregulation of Kir2.1 and mRNA expression levels and an increase in the Kir2.1 current. Moreover, ML133 can inhibit hypoxia-induced BV2 cell apoptosis. Hence, Kir2.1 may be involved in the process of hypoxia-induced BV2 cell apoptosis.

Immune Infiltration in Gastric Cancer Microenvironment and Its Clinical Significance.

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.

Distribution and prognostic impact of M1 macrophage on esophageal squamous cell carcinoma.

Macrophages are a double-edged sword with potential cancer-promoting and anticancer 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 database by the CIBERSORT algorithm found that M1 macrophages were one of the important components of many immune cells in ESCCs, and the increase 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 was 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-conditioned medium 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.

Tumor-associated macrophage polarization promotes the progression of esophageal carcinoma.

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.

Bioinformatics-based screening of key genes for transformation of liver cirrhosis to hepatocellular carcinoma.

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.

HLA-DQB1*03 and DRB1*07 alleles increase the risk of cervical cancer among Uighur and Han women in Xinjiang, China.

AIM: To explore the association between the determinant factors including HLA-DQB1*03, DRB1-*07, -*13 and high-risk HPV infection, the cervical squamous cell carcinoma (CSCC) pathogenesis among Chinese Uighur and Han population. MATERIALS & METHODS: HLA alleles were genotyped by PCR sequence-specific primers. RESULTS: HPV16 infection rate was significantly higher among the Uighurs and Hans with CSCC as compared with healthy controls, respectively. HLA-DQB1*03 significantly increased among Uighurs with CSCC, while HLA-DRB1*07 significantly increased among Hans with CSCC. Similar tendencies were observed for DQB1*03 with HPV16-positive Uighurs CSCC and DRB1*07 with HPV16-positive Hans CSCC. CONCLUSION: This study suggests that HLA-DQB1*03 and DRB1*07 alleles may influence the immune response to HPV16 infection and increase the risk of CSCC among the Uighurs and Hans in China.

High infiltration of CD68-tumor associated macrophages, predict poor prognosis in Kazakh esophageal cancer patients.

Tumor-associated macrophages (TAMs), the most important immune cells in tumor microenvironment, were reported to play a key role in cancer progression, but the correlation of TAMs and Kazakh esophageal squamous cell carcinoma (ESCC) was still not clear, so we sought to identify the function of TAMs in Kazakh ESCC clinicopathological and prognostic evaluation. CD68 as the TAMs marker, and immunohistochemistry (IHC) was used to quantify the TAMs infiltrated in tumor nest and stroma, the IHC staining was also used to evaluate the expression of MMP-9 in Kazakh ESCCs. The density of CD68-TAMs in ESCCs tumor nest and stromal, were significantly higher than those of CANs (P<0.05). The increasing number of CD68-positive TAMs in tumor nest and stromal were positively associated with tumors lymph node metastasis and clinical stage (P<0.05). The expression of MMP-9 in Kazakh ESCCs was higher than that of CAN tissues (P<0.05). Increased MMP-9 expression in ESCCs was significantly associated with lymph node metastasis and tumor clinical stage (P<0.05). Importantly, the number of CD68-positive TAMs in ESCCs was significantly correlated with the expression of MMP-9 (P<0.05). Furthermore, the survival analyses demonstrated that high-density of CD68-TAMs in tumor nest was positively related to the shorter overall survival time of patients (P<0.05). Increasing numbers of CD68-TAMs promote higher expression of MMP-9 and may play an important role in the occurrence and progression of Kazakh ESCCs, and which could be used as important prognostic markers for Kazakh ESCCs.