Transformed melanoma cells form metastatic tumors in vivo

Primary Mel-STR melanomas give rise to widespread metastases in vivo. Immunocompromised NOD/SCID mice were injected subcutaneously with 5 105 GFPlabeled Mel-STR cells. Organs were collected at necropsy and immediately visualized for GFP epifluorescence or fixed for paraffin embedding. Images of whole organs (a,c,e,g) and hematoxylin and eosin–stained sections (b,d,f,h) of lungs, livers, spleens and small intestines taken from representative metastasisbearing mice. Dashed lines demarcate tumor cell regions. M, metastasis; OP, organ parenchyma; CE, colonic epithelium; BV, blood vessel; LN, lymph node; Intest, small bowel. Arrows in h indicate a front of melanoma cells invading from the outside surface of the small bowel, through the muscularis propria, into the colonic epithelium.

September 4, 2005.