Lithium-mediated downregulation of PKB/Akt and cyclin E with growth inhibition in hepatocellular carcinoma cells

We studied in vitro effects of glycogen synthase kinase 3β (GSK3β)-inhibitor lithium on the growth of hepatocellular carcinoma (HCC) cells. Lithium induced strong growth inhibition (>70%) in 75% (n = 9 of 12) of cell lines, apparently independent from the status of major genes that are mutated in HCC including p53, p16INK4a, β-catenin and Axin1. Comparative studies with a growth-sensitive Huh7 and growth-resistant Hep40 cell lines showed that lithium induces growth arrest in Huh7 cells but not in Hep40 cells. Lithium induced the accumulation of N-terminally phosphorylated inactive form of GSK3β with concomitant increase in β-catenin and β-catenin/TCF transcriptional activity in both cell lines. This suggests that lithium-mediated HCC growth inhibition is independent of its well-known stimulatory effect on Wnt-β-catenin signaling. The main differences between Huh7 and Hep40 responses to lithium treatment were observed at the levels PKB/Akt and cyclin E proteins. Lithium induced depletion of both proteins in growth-sensitive Huh7, but not in growth-resistant Hep40 cells. PKB/Akt and Cyclin E are 2 major proteins that are known to be constitutively active in HCC. The targeting of both proteins with lithium may be the main reason why most HCC cells are responsive to lithium-mediated growth inhibition, independent of their p53, retinoblastoma and Wnt-β-catenin pathways. The exploration of molecular mechanisms involved in lithium-mediated growth inhibition in relation with PKB/Akt and cyclin E downregulation may provide new insights for therapy of liver tumors. © 2005 Wiley-Liss, Inc

Impaired phagocytosis and reactive oxygen species production in phagocytes is associated with systemic vasculitis

BACKGROUND: Anti-neutrophil cytoplasmic antibodies associated vasculitides (AAV) is a group of autoimmune diseases, characterized by small vessel inflammation. Phagocytes such as neutrophils and monocytes are the main effector cells found around the inflamed vessel wall. Therefore, we wanted to investigate aspects of function and activation of these cells in patients with AAV.METHODS: Flow cytometry was used to evaluate: the expression of activation markers (CD11c, CD62L, CD177 and C5aR); the number of recently released neutrophils from bone marrow, defined as CD10(-)D16(low) cells in peripheral blood; and the capacity of peripheral blood monocytes and polymorphonuclear leukocytes (PMN) to produce reactive oxygen species and to phagocytose opsonized bacteria.RESULTS: AAV patients (n = 104) showed an increase of CD10(-)CD16(low) neutrophils and total PMN in peripheral blood, suggesting a combination of increased bone marrow release and prolonged survival. An increased percentage of AAV PMN expressed CD177 but no other signs of activation were seen. A decreased production of reactive oxygen species was observed in AAV phagocytes, which was associated with disease activity. Moreover, granulocytes from patients with microscopic polyangiitis showed lower oxidative burst capacity compared to patients with granulomatosis with polyangiitis or eosinophilic granulomatosis with polyangiitis. In addition, decreased phagocytosis capacity was seen in PMN and monocytes.CONCLUSION: Our results indicate that phagocytes from AAV patients have impaired function, are easily mobilized from bone marrow but are not particularly activated. The association between low reactive oxygen species formation in PMN and disease severity is consistent with findings in other autoimmune diseases and might be considered as a risk factor

Human HSP 60 peptide responsive T cell lines are similarly present in both Behçet's disease patients and healthy controls

Heat shock protein (HSP, 60/65 kDa) is investigated as a candidate autoantigen in Behcet's disease (BD), a systemic vasculitis of unknown origin, and a prominent response to 'disease-specific epitopes' of mycobacterial and human HSP60/65 is described in BD patients. In this study, long-term T cell lines from peripheral blood of BD patients (n = 6) and controls (n = 7) were stimulated with mycobacterial recombinant HSP and purified protein derivate (PPD) and expanded with IL-2. In the BD group, 15 out 27 and in the controls, 25 out of 35 PPD specific T cell lines have responded to the synthetic peptides of the human HSP60. Out of the primarily HSP-specific T cell lines, 17/23 in patients and 8/8 in controls did recognize a peptide of human origin. T cell lines specifically reactive to 136-150, 179-197, 244-258 and 336-351 could be raised with similar frequency in both groups. In contrast to a previous report, T cells also reacted to peptide 425-441 frequently in both groups. The results demonstrate that the human proliferative response to mycobacterial HSP may also target the self-protein in both BID patients and controls. However, the responsive T cells may have different effects depending on their functional features such as cytokine secretions. (C) 2001 Elsevier Science B.V. All rights reserved