Fermented wheat germ extract induces apoptosis and downregulation of major histocompatibility complex class I proteins in tumor T and B cell lines

Abstract

The fermented wheat germ extract (code name: MSC, trade name: Avemar), with standardized benzoquinone content has been shown to inhibit tumor propagation and metastases formation in vivo. The aim of this study was to understand the molecular and cellular mechanisms of the anti-tumor effect of MSC. Therefore, we have designed in vitro model experiments using T and B tumor lymphocytic cell lines. Tyrosine phosphorylation of intracellular proteins and elevation of the intracellular Ca 2+ concentration were examined using immunoblotting with anti-phosphotyrosine antibody and cytofluorimetry by means of Ca 2+ sensitive fluorescence dyes, Fluo-3AM and FuraRed-AM, respectively. Apoptosis was measured with cytofluorimetry by staining the DNA with propidium iodide and detecting the 'sub-G 1 ' cell population. The level of the cell surface MHC class I molecules was analysed with indirect immunofluorescence on cytofluorimeter using a monoclonal antibody to the non-polymorphic region of the human MHC class I. MSC stimulated tyrosine phosphorylation of intracellular proteins and the influx of extracellular Ca 2+ resulted in elevation of intracellular Ca 2+ concentration. Prominent apoptosis of 20-40% was detected upon 24 h of MSC treatment of the cell lines. As a result of the MSC treatment, the amount of the cell surface MHC class I proteins was downregulated by 70-85% compared to the non-stimulated control. MSC did not induce a similar degree of apoptosis in healthy peripheral blood mononuclear cells. Inhibition of the cellular tyrosine phosphatase activity or Ca 2+ influx resulted in the opposite effect increasing or diminishing the Avemar induced apoptosis as well as the MHC class I downregulation, respectively. A benzoquinone component (2,6-dimethoxi-pbenzoquinone) in MSC induced similar apoptosis and downregulation of the MHC class I molecules in the tumor T and B cell lines to that of MSC. These results suggest that MSC acts on lymphoid tumor cells by reducing MHC class I expression and selectively promoting apoptosis of tumor cells on a tyrosine phosphorylation and Ca 2+ influx dependent way. One of the components in MSC, 2,6-dimethoxi-pbenzoquinone was shown to be an important factor in MSC mediated cell response.

A medical nutriment has supportive value in the treatment of colorectal cancer

“…It has also been demonstrated that MSC induces apoptosis of cancer cells (Fajka-Boja et al, 2002). A recent study of the underlying mechanism behind the programmed cell death induction effect of MSC has pointed to the involvement of poly(ADPribose) polymerase cleavage and thus to the role of caspase-3, which indicated that decreasing cell motility and therefore inhibition of metastasis could also be direct consequences of MSC treatment .…”

“…The downregulation of MHC class I molecules on the membrane surface of the tumour cells by MSC increases the natural killer cell activity against neoplastic cells (Fajka-Boja et al, 2002). The upregulation of tumour necrosis factor alpha (TNF-a) secretion by the MSC-treated macrophages increases the antitumour activity of these cells .…”

“…no. 503), has recently been shown to induce apoptosis, to inhibit carbon flow to nucleic acid synthesis (Boros et al, 2001;Comín-Anduix et al, 2002) and to induce major histocompatibility complex (MHC) class I proteins' downregulation (Fajka-Boja et al, 2002) in tumour cells. It has also been published that the extract strongly inhibited the development of azoxymethane-induced colon cancer in rats (Zalatnai et al, 2001).…”

Fermented Wheat Germ Extract Inhibits Glycolysis/Pentose Cycle Enzymes and Induces Apoptosis through Poly(ADP-ribose) Polymerase Activation in Jurkat T-cell Leukemia Tumor Cells

“…It is likely that multiple naturally produced compounds contained in the crude powder of fermented wheat germ induce the complex metabolic-and apoptosis-inducing effects inhibiting multiple tyrosine phosphorylase signaling cascades and the down-regulation of major histocompatibility complex I (MHC I) involved in immune protection, migration, tumor metastasis formation, and growth, as shown in other in vitro models of leukemia (30). Comparison of the anticancer metabolic effects of Avemar to that of the new effective anti-leukemia drug Gleevec reveals similarities in the metabolic enzyme and carbon substrate flow modifying effects toward nucleic acid synthesis.…”

Avemar, a nontoxic fermented wheat germ extract, attenuates the growth of sensitive and 5-FdUrd/Ara-C cross-resistant H9 human lymphoma cells through induction of apoptosis

“…MSC was demonstrated to induce apoptosis in pancreatic carcinoma cells, T and B lymphocytic tumor cell lines, leukemia and melanoma cells in vitro (5,(9)(10)(11). In lymphoid tumor cells, apoptosis was selectively induced via tyrosine phosphorylation and Ca 2+ influx (10).…”