MOLECULAR-BASIS OF TUMOR PROGRESSION - MECHANISMS OF ORGAN-SPECIFIC TUMOR-METASTASIS

Tumor cell metastasis is an extremely complex process governed by many different classes of molecules with each class having a separate func tion. Metastasis is the result of multiple sequential steps and is a h ighly organized, nonrandom, and organ-selective process. Recent advanc es in tumor and molecular biology have permitted the identification of a variety of heterogeneous molecules governing invasion (degradative enzymes, motility factors), adhesion (integrins, selectins, cadherins, immunoglobulin-like superfamily, annexins), and growth (paracrine and autocrine growth factors) of tumor cells. This diverse group of biolo gical molecules is collectively responsible for determining whether tu mor cells can progress from a single malignant cell to a lethal, multi organ, metastatic disease.