Galectin-7 Expression Potentiates HER-2-Positive Phenotype in Breast Cancer

Andrée-Anne Grosset (1, 2) , Françoise Poirier (3) , Louis Gaboury (2) , Yves St-Pierre (1)

1 INRS-IAF - Institut Armand Frappier
2 IRIC - Institut de Recherche en Immunologie et en Cancérologie [UdeM-Montréal]
3 IJM (UMR_7592) - Institut Jacques Monod

HER-2 positive tumors are among the most aggressive subtypes of breast cancer and are frequently associated with metastasis and poor outcome. As with other aggressive subtypes of breast cancer, these tumors are associated with abnormally high expression of galectin-7 (gal-7), which confers metastatic breast tumor cells with increased invasive behavior. Although previous studies in the rat model of breast tumorigenesis have shown that gal-7 is also increased in primary breast tumor, its contribution to the development of the primary breast tumors remains unclear. In the present work, we have used genetically-engineered gal-7-deficient mice to examine the role of gal-7 in the development of the mammary gland and of breast cancer. Using histological and immunohistological analysis of whole mammary glands at different stages of development, we detected no significant changes between normal and gal-7-deficient mice. To test the involvement of gal-7 in breast cancer, we next examined the effects of loss of gal-7 on mammary tumor development by crossing gal-7-deficient mice with the mammary tumor transgenic mouse strain FVB-Tg(MMTV-Erbb2)NK1Mul/J. Finally, assessment of mice survival and tumor volume showed a delay of mammary tumor growth in the absence of systemic gal-7. These data suggest that gal-7 could potentiate the phenotype of HER-2 positive primary breast cancer.

Domaines: Sciences du Vivant [q-bio]; Cancer; Biologie cellulaire

Andrée-Anne Grosset, Françoise Poirier, Louis Gaboury, Yves St-Pierre. Galectin-7 Expression Potentiates HER-2-Positive Phenotype in Breast Cancer. PLoS ONE, 2016, 11 (11), pp.e0166731. ⟨10.1371/journal.pone.0166731⟩. ⟨pasteur-01421098⟩