Cellular Characteristics of Cancer Cells that Contribute to Metastasis

Metastasis: the spreading of cancer from one area of the body to another Cancer cells initially group together to form a primary tumor Cells may begin to break off from this tumor and travel to other parts of the body

These cancer cells are capable of establishing new tumors in locations remote from the site of the original disease Metastasis is a very complicated process that still has yet to be completely understood How do cancer cells metastasize?

1. Loss of contact inhibition: Most cells are “polite” and stop mitosing when they touch one other Cancer cells do not Cancer cells will be even more aggressive if they are near normal cells (faster when in a Petri dish)

2. Lack of cellular adhesion All normal cells stick together by one of two ways: Anchor to each other with a protein thread called fibronectin Cancer cells do not produce this

Normal cells stick together through the secretion of a starch called mucopolysaccharide Cellular glue Cancer cells do not express this

3. Membrane dissolving enzymes: Cancer produces enzymes that dissolve cell membranes and can get into tissue and vessels This is how it spreads—squeezes through vessels into the lumen

4. Tumor Angiogenesis Factor (TAF): Tumor needs support in order to grow (vascular system)

Metastatic Melanoma on the Heart