Substrate-adhering lymphoid cells show impaired tumorigenicity and increased immunogenicity

Cell adhesiveness is fundamental to a variety of biological phenomena, including tumour development and metastasis^1-4. Recently, Bubenik et al.⁵ have reported that in various malignant fibroblastoid cell lines those cells which demonstrated less adhesiveness were more tumorigenic. The relationship between cell adhesiveness, transformation and metastasis has been studied extensively in cells (fibroblastoid) grown as monolayers attached to their substratum and to each other^4,6-9, but, to our knowledge, there has been no report describing this relationship in suspension-borne (lymphoid) cells that grow free of each other and their substratum. We report here that substrate-adhering variant cells, selected from the tumorigenic, suspension-growing S49 mouse lymphoma, have impaired tumorigenicity. Furthermore, the substrate-adhering cells also have increased immunogenicity, as their inoculation into mice protects the mice from subsequent challenges with parental, non-adherent tumorigenic S49 cells. These findings suggest a new approach for the selection of immunogenic cells from suspension-borne tumorigenic cell populations.