Inhibition of CD73 stimulates the migration and invasion of B16F10 melanoma cells in vitro, but results in impaired angiogenesis and reduced melanoma growth in vivo.

The role of ecto-5'-nucleotidase (CD73), an enzyme providing interstitial adenosine, was investigated in B16F10 melanoma progression. Chemical inhibition of CD73 decreased adherence of cells to extracellular matrix proteins in vitro and led to enhanced migration and invasion. Both processes were reversed by adenosine receptor agonists. In CD73­deficient mice, tumor growth was decreased in comparison with that of wild-type animals. Additionally, the vasculature of CD73-inhibited tumors was impaired and neoangiogenesis in Matrigel plugs was reduced. It is, therefore, proposed that although CD73 shows anti-invasive and antimigratory function in B16F10 melanoma cells, its proangiogenic action is prevalent in vivo and may contribute to increased tumor growth.

Waclaw Szybalski's contribution to immunotherapy: HGPRT mutation & HAT selection as first steps to gene therapy and hybrid techniques in mammalian cells.

In this report we describe Waclaw Szybalski's fundamental contribution to gene therapy and immunotherapy. His 1962 PNAS paper (Szybalska and Szybalski, 1962) documented the first successful gene repair in mammalian cells. Furthermore, this was also the first report on the HAT selection method used later in many applications. Most importantly, somatic cell fusion and HAT selection were subsequently used to develop monoclonal antibody technology, which contributed significantly to the progress of today's medicine.

Cytocidal effect of interleukin 1 (IL-1) on HeLa cells is mediated by both soluble and transmembrane tumor necrosis factor (TNF).

Interleukin 1 (IL-1) is a pleiotropic cytokine able to induce cytocidal effect. The aim of the presented work was to analyze the mechanism of IL-1-induced cytocidal effect in HeLa cells in the presence of cycloheximide (CHX). We found that the pattern of IL-1-induced cell death shares significant similarities with the effect of tumor necrosis factor (TNF) in these cells. Subsequently, we identified IL-1 cytotoxicity as an indirect effect. The supernatant collected from the cells treated with IL-1 and CHX showed toxic activity towards IL-1-resistant while TNF-sensitive A9 cells. Furthermore, antibodies neutralizing TNF blocked HeLa cell death induced by IL-1/CHX. TNF was then detected in HeLa cells by means of flow cytometry, fluorescence microscopy and ELISA of detergent-soluble cell extracts. In the presence of an inhibitor of TNF sheddase (TACE), the cytotoxic effect of IL-1/CHX and the amount of TNF protein in detergent-soluble cell extracts were enhanced. These results suggest that in response to interleukin 1/CHX, the amount of transmembrane TNF is increased. Taken together, we demonstrated that the mechanism of IL-1 cytotoxic activity in HeLa cells in the presence of CHX depends on the function of soluble and transmembrane TNF.