No abstract

No abstract

No abstract

Estrogens play important roles in the cell proliferation and invasion of estrogen-dependent human neoplasms. Aromatase overexpression has been also reported in hepatitis and hepatocellular carcinoma (HCC) compared with normal liver but its details in these hepatic disorders have remained unclear. Therefore, in this study, we first immunolocalized aromatase using immunohistochemistry in patients with liver cirrhosis, steatosis, hepatitis, HCC, and metastasis liver carcinoma (MLC) in order to study the detailed status of intrahepatic aromatase. Aromatase immunoreactivity was predominantly detected in nonneoplastic hepatocytes around tumor cells. We then evaluated the effects of an interaction between hepatocytes and carcinoma cells upon aromatase mRNA expression, using HepG2 as a substitute model of hepatocytes by coculture systems. Aromatase mRNA levels in HepG2 were significantly increased by coculture with all carcinoma cell lines examined. We also evaluated alternative splicing of aromatase exon 1 but the same splicing variant was used in HepG2 cells regardless of carcinoma cell lines employed in the coculture system. These findings obtained in HepG2 indicated that carcinoma cells, whether metastatic or primary, induced aromatase expression in adjacent normal hepatocytes possibly through the soluble aromatase inducible factors in human hepatic microenvironments.

We describe here a case involving a patient presenting initially with subcutaneous panniculitis, which developed after 12 years into aggressive subcutaneous natural killer (NK) cell lymphoma with peripheral blood involvement and hemophagocytosis. The surface marker of lymphoid cells in peripheral blood was CD2+3-7+8-16+56+. Skin biopsies were taken in May 1986 and June 1998. The initial biopsy revealed a diffuse proliferation of atypical lymphoid cells in the subcutaneous tissue with panniculitis, while the second biopsy revealed the presence of large lymphoid cells in the subcutaneous tissue with necrotic changes, consistent with a diagnosis of malignant lymphoma (diffuse pleomorphic type). The lymphoid cells from these two specimens were positive for CD56 and such cytotoxic molecules as T-cell intracellular antigen-1 (TIA-1), granzyme B, and, interestingly, also positive for Epstein-Barr (EB) virus by in situ hybridization. This suggests that chronic EB virus infections play an important role in the early stages of tumorigenesis and in the progression of NK cell lymphoproliferative disorders.