[Identification of differentially expressed genes in peripheral blood mononuclear cells of patients with hepatocellular carcinoma and its regulatory network analysis]

OBJECTIVE

To identify the differentially expressed genes (DEGs) in peripheral blood mononuclear cells (PBMC) of patients with hepatocellular carcinoma (HCC) and to analyze their regulatory network.

METHODS

The DEGs in PBMCs of HCC patients were screened based on GEO database. The functional enrichment analysis and interaction analysis were carried out for DEGs. MCODE algorithm was used to screen core genes of DEGs, and the mirDIP and starBase online tools were used to predict upstream miRNAs and lncRNAs of the core genes.

RESULTS

A total of 265 DEGs with a high credibility were identified, which were mainly enriched in the biological activity, such as regulation of cell proliferation, metabolic regulation, cell communication and signaling, and inflammatory diseases according to Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and the two analyses were correlated. Four diagnostic candidate genes were identified, including FUS RNA binding protein, C-X-C motif chemokine ligand 8, cullin 1 and RNA polymerase Ⅱ subunit H. Subsequently, 10 miRNAs, 1 lncRNAs and 38 circRNAs were predicted, and finally a lncRNA/circRNA-miRNA-mRNA-pathway regulatory networks was constructed.

CONCLUSIONS

The diagnostic candidate genes and its regulatory network in HCC PBMC have been identified based on data mining, which could provide potential tumor biomarkers for early diagnosis and treatment of HCC.

IL-8 expression and its possible relationship with estrogen-receptor-negative status of breast cancer cells

Estrogen-receptor (ER) status is an important parameter in breast cancer management as ER-positive breast cancers have a better prognosis than ER-negative tumors. This difference comes essentially from the lower aggressiveness and invasiveness of ER-positive tumors. Here, we demonstrate, that interleukin-8 (IL-8) was clearly overexpressed in most ER-negative breast, ovary cell lines and breast tumor samples tested, whereas no significant IL-8 level could be detected in ER-positive breast or ovarian cell lines. We have also cloned human IL-8 from ER-negative MDA-MB-231 cells, and we show that IL-8 produced by breast cancer cells is identical to monocyte-derived IL-8. Interestingly, the invasion potential of ER-negative breast cancer cells is associated at least in part with expression of IL-8, but not with IL-8 receptor levels. Moreover, IL-8 increases the invasiveness of ER-positive breast cancer cells by two fold, thus confirming the invasion-promoting role of IL-8. On the other hand, exogenous expression of estrogen receptors in ER-negative cells led to a decrease of IL-8 levels. In summary, our data show that IL-8 expression is negatively linked to ER status of breast and ovarian cancer cells. We also support the idea that IL-8 expression is associated with a higher invasiveness potential of cancer cells in vitro, which suggests that IL-8 could be a novel marker of tumor aggressiveness.