Laminin expression by two clones isolated from the colon carcinoma cell line lovo that differ in metastatic potential and basement‐membrane organization

Abstract

In the present report we describe the characteristics of 2 clones, E2 and C5, isolated from the human colon adenocarcinoma cell line LoVo. When grafted to immunosuppressed newborn rats, these clones formed tumors that varied with regard to differentiation rate, basement-membrane organization and lung metastatic potential. Production and distribution of laminin by E2, C5 and related tumors was studied by immunohistochemistry with an anti-laminin monoclonal antibody 4C12 (MAb 4C12). In lowly metastatic E2-derived tumors, strong regular stainings were observed which were strictly peri-tumoral and corresponded to the basal lamina. Since the antibody interacted with human laminin (the graft) but not with rat laminin (the host), this result indicated that basement-membrane laminin was supplied mainly by tumor-cell synthesis. In highly metastatic C5-derived tumors, the staining obtained with MAb 4C12 was peri-cellular and unorganized. Laminin synthesis by E2 and C5 cells in sub-cultures or soon after dissociation from explanted tumors was studied by metabolic labelling with 35S-methionine under steady-state conditions followed by immunoprecipitation and SDS-PAGE. High-molecular-weight laminin comprised by disulfide-linked A and B chains, i.e., heterotrimeric laminin, was found in cell lysates and in the secretion medium of cell lines and tumor cells. In addition, B1B2 dimers and free B chains were observed in cell lysates. Quantitatively, laminin expression by E2 and C5 clones or tumor cells was not significantly different. These findings suggest that basement-membrane defects in invasive clone LoVo C5 were not due to laminin under-expression.

Complementary DNA Arrays Identify CD63 Tetraspanin and α3 Integrin Chain as Differentially Expressed in Low and High Metastatic Human Colon Carcinoma Cells

“…E2 and C5 clones were originally reported to induce colon carcinoma xenografts that differed in basement membrane organization, cellular differentiation grade, and metastatic ability, C5 cells being significantly more prone than E2 cells to induce spontaneous lung metastases in immune-deficient hosts (Remy et al, 1992). We here identified the CD63 tetraspanin, not previously known to be implicated in colon cancer progression, and the ␣3 integrin chain as two components whose expression could modulate metastatic ability.…”

“…When grafted to immunosuppressed newborn rats, E2 and C5 cells induce tumors that differ in basement membrane organization, grade of tumor cell differentiation, and potential to spontaneously metastasize to the lungs of recipient hosts (Remy et al, 1992). The cDNA clones were from a normalized infant brain library and the arrays used in the present study consisted of PCR products from 2208 cDNA clone inserts subjected to clone and sequence-clustering analyses .…”

Anti-?4 integrin antibodies enhance migratory and invasive abilities of human colon adenocarcinoma cells and their MMP-2 expression

“…In this study, we found that the ␤4 integrin subunit can enhance the migratory and invasive properties of the LoVo C5 clone that we isolated and characterized (Rémy et al, 1992). We propose that a mechanism contributing to this enhancement is the induction of MMP-2 expression.…”

“…The role of the ␤4 integrin subunit in migration and invasion was tested by measuring the ability of LoVo C5 cells to metastasize in an experimental metastasis model (Rémy et al, 1992). Lung metastases developed in 43% of rats co-injected with LoVo C5 cells and the anti-␤4 antibody compared with only 8% in those injected with LoVo C5 cells only.…”

“…PBS (100 l) containing 8 ϫ 10 4 cells was injected s.c. with or without 20 g anti-␤4 3E1 into the ventral area of each newborn rat. Immediately after that, as previously described (Rémy et al, 1992), the rat was immunosuppressed by a dorsal s.c. injection of rat anti-thymocyte serum; this was repeated on days 2, 7 and 14, to maintain the animal in immunosuppression. Rats were kept in a specific pathogen-free environment throughout the experiment.…”