Induction of invasion in vivo of alpha-catenin-positive HCT-8 human colon-cancer cells

Variants from the HCT-8 colon-cancer cell line were implanted s.c. and orth otopically into nude mice. Well differentiated HCT-8/E11 and HCT-8/E41 cell s have a functional E-cadherin-catenin complex and are non-invasive into pr ecultured chick heart fragments in vitro whereas poorly differentiated HCT- 8/E11R1 cells are deficient in alpha -catenin protein and invasive in heart fragments. We investigated whether these differences were maintained in vi vo. In contrast with in vitro observations, in vivo the 3 HCT-8 variants be haved very similarly and ail formed undifferentiated tumors. The in vivo in vasive behavior of HCT-8 cells was site-dependently modulated: HCT-8 cells invaded when injected into the cecum but not when injected s.c. Metastases to the liver or lungs were not observed. The composition and expression of the E-cadherin-catenin complex in nude mouse HCT-8 tumors was the same as i n HCT-8 cells in culture on solid substrate. We conclude that the in vivo i nvasive behavior of HCT-8 cells is not determined by whether alpha -catenin is expressed or not but by as yet unidentified host factors. (C) 2000 Wile y-Liss, Inc.