Invasion of malignant cells into 51Cr-labeled host tissues in organotypical culture.

We have attempted to quantitate malignant invasion in vitro. Therefore we adapted the 51Cr-release cytotoxicity test to organotypical culture systems, that proved useful for morphological analysis of invasion. We counted 51Cr-release from labeled fragments of embryonic chick heart and mesonephros, cultured either on semi-solid or in fluid medium, during their invasion by HeLa cells. Although demonstrated morphologically, malignant invasion did not bring about significant changes of 51Cr-release as compared to control cultures without HeLa cells. The failure of the 51Cr-release test in our experimental device might shed some light on the mechanisms of malignant invasion.