BACKGROUND This study was designed to clarify differences in apoptotic signal transduction between gastric cancer cells and leukemia cells. MATERIALS AND METHODS In order to study apoptotic signal transduction of gastric cancer cells, MKN45 gastric cancer cells expressing the wild-type p53 gene and U937 myeloid leukemia cells expressing a mutated p53 gene were prepared. Cisplatin (CDDP) was u...

The human monocyte-like cell line U937, which is a cholesterol auxotroph, does not grow on mevalonate, squalene, or 4,4-dimethyl cholest-7-en-3 beta-ol. It grows on cholest-7-en-3 beta-ol and converts it to cholesterol. When deprived of an exogenous source of cholesterol, the cells accumulate 4 alpha-methyl-cholest-8-en-3-one. The cell-free extracts of U937 are also devoid of 3-ketoreductase ac...

Resveratrol has been shown to induce anti-proliferation and apoptosis of human cancer cell lines. In the present study, we determined the effect of high intracellular levels of the anti-apoptosis protein Bcl-2 on caspase-3 activation, PLC-gamma1 degradation and cytochrome c release during resveratrol-induced apoptosis. For this, we used U937/vector and U937/Bcl-2 cells, which were generated by ...

The Hedgehog (Hh) signaling pathway is involved in a variety of tumor-related diseases, including leukemia. The aim of this study was to determine whether there is an interaction between the Hh signaling pathway and transforming growth factor-β (TGF-β) in the HL60 and U937 cell lines. HL60 and U937 cells were treated with TGF-β, tumor necrosis factor-α (TNF-α) and specific inhibitor of Smad3 (S...

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) exerts profound effects on the proliferation, differentiation, and effector function of myeloid lineage cells. In contrast to its growth-promoting effects on normal myeloid progenitor cells, we found that GM-CSF unexpectedly inhibited the colony growth of U937 cells in agar culture. Furthermore, medium conditioned by recombinant GM...

beta-glucan receptors, with ligand specificity for yeast and fungal carbohydrate polymers, have been studied as phagocytic receptors of human monocytes. To characterize their structure, binding studies were carried out with human U937 cells and a rabbit IgG anti-Id that recognizes epitopes on monocyte beta-glucan receptors. Unstimulated U937 cells specifically bound large amounts of the anti-Id...

Undifferentiated U937 cells were not susceptible to herpes simplex virus type 1 (HSV-1) infection, but after differentiation with phorbol 12-myristate 13-acetate an increase in the permissivity to the virus was observed accompanied by the production of significant levels of viral particles. High levels of nitric oxide (NO) were produced in differentiated U937 cells infected with HSV-1. This pro...

Abstract Photodynamic therapy (PDT) is a promising cancer treatment with fewer side effects, and it eliminates tumors in target tissues reactive oxygen species produced by photosensitizers (PS) light. In this study, we isolated methyl pheophorbide A, which induces photodynamic cell death the U937 SK-HEP-1 cells, from perilla leaves. Its potential as material for development of new PS was also e...

Acute myelogenous leukemia (AML) cells express CD23 surface antigen after in vitro treatment with various cytokines, including interleukin-4 (IL-4) and interferon gamma. Subsequent ligation of CD23 by specific monoclonal antibody (MoAb) induces substantial morphologic and functional modifications in these cells. In the present study, we investigated the role of CD23 in the proliferation and the...

Rosmarinus officinalis L., a medicinal herb from the labiates family, has been reported to be of potential benefit in the treatment and prevention of several diseases. In particular its phenolics have demonstrated protective effects on various types of cancer through several mechanisms. The present study aimed to determine the effects of rosemary phenolic extracts on human cell functions, with ...