Volume 8 Supplement 2

Breast cancer research: the past and the future

Open Access

Functional analysis of altered Tenascin isoform expression in breast cancer

  • RA Alcock1,
  • JH Pringle1,
  • JA Shaw1,
  • DL Holliday2,
  • M Allen2,
  • RA Walker1 and
  • JL Jones2
Breast Cancer Research20068(Suppl 2):P20

https://doi.org/10.1186/bcr1575

Published: 01 November 2006

Background

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.

Methods

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.

Results

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.

Conclusion

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.

Authors’ Affiliations

(1)
Breast Cancer Research Unit, University of Leicester
(2)
Tumour Biology Laboratory, Institute of Cancer, Queen Mary's School of Medicine and Dentistry

References

  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.PubMedGoogle Scholar

Copyright

© BioMed Central Ltd 2006

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