Volume 10 Supplement 2

Breast Cancer Research 2008

Open Access

TSC22 in mammary gland development and breast cancer

  • C Huser1,
  • V Heath1,
  • M-A Pringle1,
  • AK Bell1,
  • D Crighton2,
  • K Ryan2,
  • G Inman2,
  • T Stein1 and
  • B Gusterson1
Breast Cancer Research200810(Suppl 2):P17

https://doi.org/10.1186/bcr1901

Published: 13 May 2008

Mammary gland involution is characterised by a high degree of apoptosis. By identifying genes that are upregulated at this developmental stage, we aimed to discover key factors that are involved in the induction of mammary epithelial cell death and therefore present potential tumour suppressors for breast cancer. Among 96 genes recently identified as specifically upregulated early during involution were the transforming growth factor beta (TGFβ)-stimulated clone 22 homologue (TSC-22/TGFβ1-induced transcript 4) and TGFβ3 [1]. TGFβ3 has recently been shown to be necessary for induction of apoptosis during mammary gland involution, while TSC-22 overexpression can lead to cell death. We have therefore tested whether TSC-22 mRNA expression can be induced by TGFβ3 and whether it is involved in or necessary for TGFβ-induced apoptosis. We further show that TSC-22 can enhance TGFβ3-induced Smad response and epithelial cell death. In addition, overexpression of TSC-22 alone can induce a Smad response and apoptosis in mammary epithelial cell cultures, which is independent of p53. Further, we have performed tests to study the necessity for Smad proteins during TSC-22-induced apoptosis, and to establish the intracellular localisation of TSC-22. A pilot study on a small cohort of archival breast cancer cases, representing all stages of malignant progression, shows that TSC-22 protein was reduced or undetectable in 60% of breast carcinomas when compared with adjacent normal breast tissue, suggesting that TSC-22 could indeed be a potential novel tumour suppressor gene. We shall present data showing that methylation of the TSC-22 promoter is not involved in the reduction of TSC-22 protein in breast cancer.

Declarations

Acknowledgements

Funded by a project grant from Breast Cancer Campaign to TS.

Authors’ Affiliations

(1)
Division of Cancer Sciences and Molecular Pathology, University of Glasgow
(2)
Division of Cancer Sciences and Molecular Pathology, CRUK Beatson Laboratories

References

  1. Stein T, Morris JS, Davies CR, Weber-Hall SJ, Duffy MA, Heath VJ, Bell AK, Ferrier RK, Sandilands GP, Gusterson BA: Involution of the mouse mammary gland is associated with an immune cascade and an acute-phase response, involving LBP, CD14 and STAT3. Breast Cancer Res. 2004, 6: R75-R91. 10.1186/bcr753.View ArticlePubMedGoogle Scholar

Copyright

© BioMed Central Ltd 2008

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