Tenascin induction in tenascin nonproducing carcinoma cell lines in vivo and by TGF‐β1 in vitro

Abstract

Tenascin, a novel six-armed extracellular-matrix glycoprotein, is expressed in a temporally and spatially restricted pattern during carcinogenesis in association with stromal-epithelial interactions. In this study, we have tested the hypothesis that tenascin expression depends upon the change of the cellular environment from in vitro to in vivo. The distribution and alterations in the expression of tenascin were compared between in vitro and in vivo studies in a variety of human epithelial- and nonepithelial-derived cell lines. When cell lines were transplanted into nude mice, all xenografts induced host-mouse-stroma-derived tenascin. Four carcinoma-derived cell lines and all sarcoma-derived lines, which secreted tenascin in vitro, were found to produce human tenascin after transplantation. Furthermore, three carcinoma-derived cell lines, A431, HEp-2, and MCF7, which did not synthesize tenascin in vitro, did synthesize human tenascin after transplantation. These tenascin nonproducing carcinoma cell lines did not express tenascin mRNA in vitro. The addition of TGF-beta 1 to the culture medium induced the synthesis and secretion of tenascin, but TGF-beta 2 and bFGF were less effective. TGF-beta 1 also induced other extracellular-matrix components, fibronectin and laminin. TGF-beta 1 did not induce tenascin in tenascin nonproducing carcinoma cell lines, such as WiDr and A549, in which human tenascin was not induced after transplantation. We have established an in vitro system in which tenascin is induced by the diffusible factor TGF-beta 1. This system could shed light on the mechanism of induction of human tenascin observed in vivo in tenascin nonproducing carcinoma cell lines.

Localization of precursor proteins and mRNA of type I and III collagens in usual interstitial pneumonia and sarcoidosis

“…Some collagens, tenascin-C and fibronectin also have common receptors, such as integrins a2b1 and avb3 (Ramos et al 1997). Furthermore, TGF-b not only stimulates collagen synthesis (Fine et al 1990), but also regulates the content of procollagen, fibronectin and tenascin-C (Ignotz et al 1987, McAnulty et al 1991, Sakai et al 1994. These extracellular matrix proteins are obviously closely associated within the process of fibrogenesis.…”

Tenascin pattern of expression and established prognostic factors in invasive breast carcinoma

“…Recent studies demonstrated that cancer cells also produce TN in culture or in growing tumor when injected in vivo [23][24][25]. Immunohistochemistry of cancer tissues, including comedo carcinoma of the breast [7] and squamous cell carcinoma and adenocarcinoma of the lung [26], have demonstrated cytoplasmic TN staining, suggesting that cancer cells also produce TN.…”

Role of endogenous TGF-β in glucocorticoid-induced lung type II cell differentiation

“…A number of these genes are related to the immune response and extracellular matrix and presumably represent targets of glucocorticoid anti-inflammatory action. Many of these proteins are known to be TGF-␤ responsive (e.g., PAI-1, collagens, lysyl oxidase, tenascin, cystatin), but others represent new candidate targets (2,19,23,28). As cellular localization of expression has not been determined, it is possible that some of these genes are primarily expressed and regulated in fibroblasts that contaminate the epithelial cell preparation.…”