Article

Transferrin receptor (CD71) is a marker of poor prognosis in breast cancer and can predict response to tamoxifen

Mansoura University Department of Histopathology Mansoura Egypt
Breast Cancer Research and Treatment (Impact Factor: 4.2). 01/2009; 119(2):283-293. DOI: 10.1007/s10549-009-0345-x
Source: PubMed

ABSTRACT Transferrin receptor (CD71) is involved in the cellular uptake of iron and is expressed on cells with high proliferation.
It may be implicated in promoting the growth of endocrine resistant phenotypes within ER+/luminal-like breast cancer. We used
a panel of in vitro cell models of acquired resistance to tamoxifen (TAMR), Faslodex (FASR) or severe oestrogen deprivation
(MCF-7X) and the ER+ luminal MCF-7 parental line to determine CD71 mRNA expression and to study transferrin (Tf) effects on
in vitro tumour growth and its inhibition. Furthermore, CD71 protein expression was assessed in a well-characterized series
of patients with invasive breast carcinoma using tissue microarrays. Our results demonstrated a striking elevation of CD71
in all cell models of acquired resistance. Exogenous Tf significantly promoted growth in MCF-7-X and MCF-7 cells but more
so in MCF-7-X; this growth was significantly reduced by Faslodex (FAS) or a phosphoinositide-3 kinase inhibitor (LY294002).
Increased CD71 expression was associated with poor NPI score, tumour proliferation, basal CKs, p53, EGFR, HER2, steroid receptor
negativity and shortened breast cancer specific survival (P<0.001). On multivariate analysis, CD71 was found to be an independent prognostic factor in the ER+ cohort of patients.
In conclusion, therapies of current interest in breast cancer (e.g. FAS, PI3K-inhibitors) appear able to partially impact
on transferrin/CD71-promoted growth, but further investigation of this important mitogenic mechanism may assist in designing
new therapeutic strategies to target highly proliferative, endocrine resistant breast cancers. CD71 appears to be a candidate
marker of a subgroup of ER+/luminal-like breast cancer characterised by poor outcome and resistance to tamoxifen.

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Available from: Mohammed A Aleskandarany, Aug 22, 2015
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