Significant role of macrophages in human cancers associated with Epstein-Barr virus (Review).

Epstein-Barr virus (EBV) is a ubiquitous pathogen that was first identified as a human cancer virus. Many human cancers are associated with EBV, and we demonstrated that EBV infects macrophages. Macrophages infected with EBV show a close correlation with many human cancers, and thus more attention must be given to the role of macrophages infiltrating into cancer tissues associated with EBV.

Involvement of NANOG upregulation in malignant progression of human cells.

Previously, we isolated cell lines that display various degrees of transformed phenotypes from a single-cell population of human diploid fibroblasts (RB) containing a large deletion (13q14-22) in one copy of chromosome 13. They included a cell line transfected with SV40 early genes (RBSV), an immortalized cell line (RBI), an anchorage-independent cell line (RBS), and a tumorigenic cell line (RBT). Here, we analyzed gene expression profiles in these cell lines and showed that expression of some fibroblast-specified or mesenchyme-specified genes were downregulated, and those of stem cell-specified genes, including NANOG, were upregulated during malignant progression.

Macrophage involvement in Epstein-Barr virus-related tumors.

Epstein-Barr virus (EBV) is known as a causative agent of Burkitt's lymphoma, nasopharyngeal carcinoma and approximately 10% of stomach carcinoma cases. In other human cancers, EBV gene expression including lytic infection protein detected using in situ hybridization and immunofluorescence staining has been reported. Moreover, the expression and replication of EBV genes in cultured normal macrophages and in histiocytes of Langerhans' cell histiocytosis have been identified.

Downregulation of drs tumor suppressor gene in highly malignant human pulmonary neuroendocrine tumors.

Neuroendocrine tumors in the lung fall into four categories: typical carcinoid tumor (TC), atypical carcinoid tumor (AC), large-cell neuroendocrine carcinoma (LCNEC) and small-cell lung carcinoma (SCLC), in ascending order of malignancy. The drs gene was originally isolated as a suppressor against v-src transformation and was shown to induce apoptosis in human cancer cells. The expression of drs was markedly downregulated in various human cancer tissues and cell lines.

Expression of Epstein-Barr virus in renal cell carcinoma.

There have been few studies regarding the etiology of renal cell carcinoma. To examine the possible involvement of Epstein-Barr virus (EBV) in this disease, 9 renal cell carcinoma (RCC), 2 nephroblastoma (Wilms' tumor) and 2 RCC cell lines were subjected to mRNA in situ hybridization and indirect immunofluorescence staining. Messenger RNA in situ hybridization using BamHIW, EBNA LP, EBNA 2 and EBER1 probes of EBV revealed signals in all the examined samples, although some samples showed weak signals using the EBNA LP probe.