L. Daniel et al., A nude mice model of human rhabdomyosarcoma lung metastases for evaluatingthe role of polysialic acids in the metastatic process, ONCOGENE, 20(8), 2001, pp. 997-1004
PSA is an oncodevelopmental antigen usually expressed in human tumors with
high metastatic potential. Here we set up a metastatic model in nude mice b
y using TE671 cells, which strongly express PSA-NCAM. We observed the forma
tion of lung metastases when TE671 cells were injected intravenously, intra
muscularly, and intraperitoneously, hut not subcutaneously. Intraperitoneou
s injections also induced peritoneal carcinosis, ascites, and liver metasta
ses. To evaluate the putative role of PSA in the metastatic process we used
a specific cleavage of PSA on NCAM by endoneuraminidase-N on intraperitone
ous primary tumors. Mice with primary intramuscular tumors were taken as co
ntrol. Repeated injections of endoneuraminidase-N led to a decrease in PSA
expression in primary intraperitoneous nodules and ascites but not in intra
muscular primary tumors. Endoneuraminidase-N also increased the delay in as
citic formation and decreased the number of lung or liver metastases in the
case of intraperitoneous tumors but not in the case of intramuscular tumor
s. When metastases occurred in endoneuraminidase-N injected animals, they s
trongly expressed PSA-NCAM. Therefore, we established a relationship betwee
n PSA expression on the surface of primary tumor cells and the metastatic p
rocess.