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Cancer Cell death Cell cycle Cytoskeleton Exo/endocytosis Differentiation Division Organelles Signalling Stem cells Trafficking
Cell Biology International (2002) 26, 593–598 (Printed in Great Britain)
Rami N. Suzukia,f1, Alan Entwistleb, Amanda J. Athertona, Catherine Clarkeac, Sunil R. Lakhanic and Michael J. O'Harea
aLudwig Institute for Cancer Research (LICR) Breast Cancer Laboratory/Royal Free and University College Medical School, Department of Surgery, 67–73 Riding House Street, London, W1W 7EJ, U.K.
bLICR Royal Free and University College Medical School Branch, Courtauld Building, 91 Riding House Street, London, W1W 7BS, U.K.
cThe Breakthrough Toby Robins Breast Cancer Research Centre, Chester Beatty Laboratories, Fulham Road, London, SW3 6JB, U.K.


Integrins have been shown to exert regulatory influences on mammary differentiation and morphogenesis in rodent experimental systems. We have, therefore, examined the expression patterns of integrin subunits on human breast tissues obtained at the 12th, 15th and 18th weeks of pregnancy. Myoepithelial cells were positive for all the integrin subunits examined. α2, α6 and β4 showed increased and more defined labelling during pregnancy, indicating that myoepithelial cells and extracellular matrix strengthen their support for the expanding alveoli during pregnancy. Sub-populations of stromal cells were positive for α1, α3, α6, β1 and β4. On luminal epithelial cells, α1, α2, α3, α6 and β1 were detectable. α2 showed a focal decrease, but the expression patterns of other integrins in luminal cells did not change during pregnancy. Therefore, the expression patterns of most integrins existing prior to pregnancy seem sufficient in this cell type to support the morphological and functional development during early pregnancy.

Key words: breast, pregnancy, integrin, differentiation.

f1To whom correspondence should be addressed: Rami Suzuki, ITX Corporation, Room 101, 1 Berkely Street, London W1J 8DJ, U.K. Tel: +44 207016 9377; Fax: +44 20 7016 9160; E-mail: College School of Medicine, Mint Wing, St Mary's Hospital, London, W2 1NY, U.K.. Tel: 07956-150-311; Fax: 0207-281-1082;

Received 15 May 2001; accepted 15 January 2002


ISSN Print: 1065-6995
ISSN Electronic: 1095-8355
Published by Portland Press Limited on behalf of the International Federation for Cell Biology (IFCB)