Skip to main content

Functional analysis of altered Tenascin isoform expression in breast cancer


Cellular interactions with the extracellular matrix (ECM) control many aspects of cell function. The complex ECM protein Tenascin-C (TN), which exists as multiple isoforms, is upregulated in breast cancer. We previously have identified a change in the TN isoform profile in breast cancer, with detection of two additional isoforms — TN16 and TN14/16 — not seen in normal breast [1]. The purpose of this study was to investigate directly the effects of these tumour-associated TNC isoforms on breast cancer cell behaviour.


A PCR-ligation approach was used to generate specific TNC isoform sequences which were Flag tagged and inserted into a pCMV vector. Transient transfection into breast cancer cell lines or primary normal fibroblasts was confirmed by RT-PCR, western blotting and immunohistochemistry. The effect of different TNC isoforms on breast cancer cell invasion, proliferation and gene expression was analysed.


Expression of TN16 and TN14/16 in breast cancer cells (MCF-7, T47D, MDAMB231) resulted in significantly enhanced tumour invasion compared with adult-type truncated TN, large TN and vector-only controls. A similar increase in tumour cell proliferation was detected. Coculture of tumour cells with primary breast fibroblasts overexpressing TN16 or TN14/16 or conditioned medium from these fibroblasts also led to enhanced tumour cell invasion. Expression of TN resulted in upregulation of MMP-1; however, this was equivalent for all TN isoforms. The invasion-promoting effect of TN16 and TN14/16 was dependent on direct interaction between tumour cells and was blocked by incorporation of anti-TN blocking antibodies. Furthermore, TN appears to be essential for tumour cell invasion, since with all isoforms invasion was minimal in the presence of anti-TN antibodies.


This study has demonstrated that the tumour-associated TN isoforms TN16 and TN14/16 significantly enhance breast cancer cell invasion and that blocking TN inhibits invasion. We aim to further investigate the invasion-promoting activity of these isoforms and to explore their therapeutic potential in more sophisticated tumour models.


  1. Adams M, Jones JL, Walker RA, Pringle JH, Bell SC: Altered Tenascin-C isoform expression in invasive and pre-invasive breast cancer. Cancer Res. 2002, 62: 3289-3297.

    CAS  PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and Permissions

About this article

Cite this article

Alcock, R., Pringle, J., Shaw, J. et al. Functional analysis of altered Tenascin isoform expression in breast cancer. Breast Cancer Res 8 (Suppl 2), P20 (2006).

Download citation

  • Published:

  • DOI: