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Synthesis and protein distribution of the unspliced large tenascin-C isoform in oral squamous cell carcinoma

✍ Scribed by Hindermann, Winfried; Berndt, Alexander; Borsi, Laura; Luo, Xinmei; Hyckel, Peter; Katenkamp, Detlef; Kosmehl, Hartwig


Publisher
John Wiley and Sons
Year
1999
Tongue
English
Weight
234 KB
Volume
189
Category
Article
ISSN
0022-3417

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✦ Synopsis


The inclusion or omission of the alternatively spliced region in the tenascin-C (Tn-C) mRNA gives rise to the large (Tn-C L ) or small (Tn-C S ) variant, respectively. Tn-C L is thought to be a typical component of provisional extracellular matrices (ECMs) and is expressed during tumour stroma remodelling. Tn-C L synthesis has been studied using RNA/RNA in situ hybridization, and Tn-C L protein distribution, using immunohistochemistry (clone BC-2), in 18 oral squamous cell carcinomas (OSCCs) of different grades of malignancy. While the Tn-C L protein was demonstrated within the whole stromal compartment regardless of grade of malignancy, the majority of the Tn-C L mRNA signal-bearing cells were carcinoma cells. Only a few stromal myofibroblasts were able to synthesize Tn-C L , as revealed by -smooth muscle actin double staining. In well-differentiated carcinomas (G1), the Tn-C L synthesizing carcinoma cells were localized as a single positive cell layer in the tumour stroma interface, particularly in invasive areas. A higher grade of malignancy (G2/G3) is associated with a significantly increased number of Tn-C L synthesizing carcinoma cells randomly distributed within the invading tumour areas. Double-staining experiments (Tn-C L mRNA ISH/BC-2 immunohistochemistry) indicate that these cells are capable of organizing and depositing a three-dimensional Tn-C L matrix. Even though an instructive and/or inductive role of the carcinoma cells in tumour stroma formation cannot be excluded, these results demonstrate that carcinoma cells can directly produce the ECM components of tumour stroma.