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Integrin expression on colorectal tumor cells growing as monolayers, as multicellular tumor spheroids, or in nude mice
Author(s) -
Hauptmann Steffen,
Denkert Carsten,
Löhrke Heinz,
Tietze Lothar,
Ott Stephan,
Klosterhalfen Bernd,
Mittermayer Christian
Publication year - 1995
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910610613
Subject(s) - spheroid , cell culture , flow cytometry , integrin , microbiology and biotechnology , alpha (finance) , biology , beta (programming language) , nude mouse , immunofluorescence , focal adhesion , cell , pathology , chemistry , immunology , medicine , antibody , biochemistry , construct validity , genetics , nursing , computer science , patient satisfaction , programming language
In this study we compared the expression of integrin alpha chains 2, 3, 4, 5, 6, v and the beta chains 1, 3, 4 in 2 colorectal carcinoma cell lines (HRT‐18 and CX‐2), growing in confluent and subconfluent monolayer cultures, as multicellular tumor spheroids and in nude mice, using the immunofluorescence technique (confocal microscopy) and flow cytometry. The fast‐growing cell line HRT‐18 expressed, in confluent and subconfluent monolayer cultures, alpha 2, 3 and beta 1 with a continuous membranous staining pattern, whereas alpha v, alpha 6, and beta 4 were expressed continuously membranous in the intermediate and apical part of the cell layer, and clustered at focal contacts at the base of the cells. In spheroids and tumors of nude mice the focal pattern of alpha v, 6 and beta 4 was changed into a diffuse one. Using flow cytometry, the expression of alpha 3 was found to be reduced in spheroids of HRT‐18. The slowly‐growing cell line CX‐2 expressed, under the same conditions in monolayer culture, alpha 6, beta 1 and beta 4, and very weakly alpha 2, 3, 5 and v. Alpha 3 was expressed in spheroids of CX‐2 only at the outer rim where the cells proliferate. In contrast, alpha 2 and 5 were expressed mainly in the quiescent, non‐proliferating area. Alpha 6 was reduced in spheroids of CX‐2. In the nude mouse tumor of CX‐2, alpha 5 was expressed only focally and very weakly, alpha 2 was no longer detectable, but alpha v appeared to be enhanced in a focal pattern. These data indicate that integrin expression of tumor cells depends upon the culture system and that integrin expression in multicellular tumor spheroids is more similar to the in vivo situation in nude mouse tumors. © 1995 Wiley‐Liss, Inc .