Levels of plasmatic fibronectin in mice bearing adenocarcinomas of different metastasizing ability.

The levels of fibronectin (FN) were assayed in plasma of BALB/c mice subcutaneously inoculated with a mammary adenocarcinoma of moderate metastatic ability (M3) and a related variant tumor with higher metastasizing potential (MM3). The mean plasmatic FN concentration increased in parallel with increased M3 and MM3 size and weight. Highest and earliest FN increases were observed in mice inoculated with the rapidly growing M3 tumor. A strong correlation between the level of plasma fibronectin and the number of lung metastases was only found in MM3 inoculated mice. Plasma fibronectin level is a good biological marker of tumoral growth rate in these adenocarcinoma tumors, but its role in the metastatic process warrants investigation.