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INTRODUCTION: Tumor cells, just as other living cells, possess the potential for proliferation, differentiation, cell cycle arrest, and apoptosis. There is a specific metabolic phenotype associated with each of these conditions, characterized by the production of both energy and special substrates necessary for the cells to function in that particular state. Unlike that of normal living cells, the metabolic phenotype of tumor cells supports the proliferative state. AIM: To present the metabolic hypothesis that (1) cell transformation and tumor growth are associated with the activation of metabolic enzymes that increase glucose carbon utilization for nucleic acid synthesis, while enzymes of the lipid and amino acid synthesis pathways are activated in tumor growth inhibition, and (2) phosphorylation and allosteric and transcriptional regulation of intermediary metabolic enzymes and their substrate availability together mediate and sustain cell transformation from one condition to another. CONCLUSION: Evidence is presented that demonstrates opposite changes in metabolic phenotypes induced by TGF-beta, a cell-transforming agent, and tumor growth-inhibiting phytochemicals such as genistein and Avemar, or novel synthetic anti-leukemic drugs such as STI571 (Gleevec). Intermediary metabolic enzymes that mediate the growth signaling pathways and promote malignant cell transformation may serve as high-efficacy nongenetic novel targets for cancer therapies.

Macrophages activated by lipopolysaccharide and/or phorbol esters exhibited high sensitivity to Avemar, a fermented wheat germ extract. Avemar synergized with lipopolysaccharide and PMA in the induction of the transcription of cytokine genes and release of inflammatory cytokines. At higher concentrations the preparation had a significant negative effect on the proliferation and survival of activated myeloid cell types. Avemar treatment induced the synthesis of ICAM-1 and synergized with the ICAM-inducing effect of TNF, but had no effect on VCAM-1 expression on microvascular endothelial cells. The effect of Avemar on signaling pathways, which are involved in cell activation was studied on HeLa cells as a model system. Avemar treatment increased the activity of stress kinases in a concentration-dependent way, resulting in the activation of AP-1 transcription factor. NF-kappa B-sensitive reporters were also activated by Avemar; in contrast, no effect of the preparation was observed on PKA-sensitive signaling pathways.