Statins have antiproliferative and anti-tumoral effects in MCF-7 cells. We determined the effect of statins upon MCF-7 cell cycle, toxicity, cell death, reactive oxygen species (ROS) production and mitochondrial membrane potential. Fluvastatin, simvastatin and atorvastatin inhibited cell proliferation. Antiproliferation was associated with a decrease in the DNA synthesis and a cell cycle arrest in the G1 and G2/M phases. A loss in the mitochondrial membrane potential was observed with fluvastatin. Statins induced increase in ROS production that was associated with cell death, which was abrogated by the antioxidant NAC. Our results suggest that the cytotoxic effect observed is mediated by an oxidative stress.

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Altered claudin expression is related to metastatic potential, poor prognosis, or tumor recurrence. We analyzed if the overexpression of claudin-6, claudin-7, or claudin-9 in AGS cells altered cell motility, invasiveness, or proliferation rate. Claudin-7, claudin-9, and claudin-6 enhanced their invasive potential by 3.4-fold, 1.6-fold, and 2.0-fold, respectively. Claudin-6 and claudin-9 enhanced cell migration, while the proliferation rate of claudin-6-, claudin-7-, and claudin-9-transfected cells increased by 12.7%, 9.0%, and 13.3%, respectively. Claudin-7 and claudin-9 overexpression increased claudin-1 and zonula occludens-1 levels. In summary, individual increased expression of claudin-6, claudin-7, or claudin-9 is sufficient to enhance tumorigenic properties of a gastric adenocarcinoma cell line.

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SUMMARY The relationship between the histological diagnosis and serological and tissue markers of HBV replication in 41 Greek and 29 British patients with chronic HBV infection were studied. All the nine Greek and 13 British patients who were HBeAg positive had HBV-DNA in serum and HBcAg expression in the hepatocytes. The majority (73%) of these patients had active liver disease. Forty seven per cent of the Greek and 19% of the British patients who were anti-HBe positive continued to display HBcAg in the liver with or without HBV-DNA detected in serum. All but three of these patients had persistently active liver disease. Continuing inflammatory activity in the liver, however, was also found in 31% of anti-HBe positive patients who had no evidence of HBV replication. In these patients, other factors such as delta agent, NANB viruses, alcohol abuse or an autoimmune reaction initiated by HBV may be contributory.