Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Demonstration of a dual function of MMP-11 in a breast cancer model

In human carcinomas, stromelysin-3/matrix metalloproteinase 11 (ST3, MMP11) expression by nonmalignant fibroblastic cells located in the immediate vicinity of cancer cells is a bad prognostic factor. Using mouse models of primary tumors, it has been demonstrated that ST3 is a key player during local invasion, favouring cancer cell survival in connective tissue through an antiapoptotic function. To investigate the ST3 impact on additional phases of cancer cell invasion, we developed mammary gland cancer prone MMTV-ras transgenic mice in wild-type (ras+/+;ST3+/+) or ST3-deficient (ras+/+;ST3-/-) genotype and studied their whole natural cancer history. The tumour- free survival and delay between the first ras oncogenic hit and primary tumour appearance increased in ras+/+;ST3-/- mice (P < 0.000001 and <0.0000007, respectively). A systematic search for occult primary tumours and metastases revealed, in addition to a lower total number and size of primary tumours (P < 0.02), an unexpected higher number of metastases (P < 0.01) in ras+/+;ST3-/- mice. Moreover, for a similar number and size of primary invasive tumours, ras+/+;ST3-/- mice developed more metastases, indicating that the cancer cells evolving in ST3-deficient stroma have an increased potential to hematogenous dissemination. We conclude that the ST3 microenvironment is a consistently active partner of invading cancer cells but that its function differs throughout cancer progression, being tumour enhancer or repressor in processes leading to local or distal invasion.
Such a dual effect for an MMP might shed light, at least partially, for the absence of survival benefit for patients included in anti-MMP clinical trials.

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Rigshospitalet - Finsenlaboritoriet
Strandboulevarden 49
DK-2100 Copenhagen
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