ZIP6 is associated with breast tumor grade, size, and stage, suggesting that it is a potent driving force toward malignancy; ZIP7 plays an important role in tamoxifen-resistant breast cancer cells, and ZIP10 is involved in invasion and metastasis of breast cancer cells.
Knockdown of LIV-1 expression resulted in (i) decreased expression of cancer stem cell-related molecules such as LIN28 and ATP-binding cassette sub-family G member 2, (ii) decreased spheroid-forming ability, (iii) decreased migration, (iv) decreased incidence of tumor formation in nude mice, and (v) upregulation of miR-7 expression.
Our results indicate a causative role for ZIP6 in cell motility and migration, providing ZIP6 as a new target for prediction of clinical cancer spread and also suggesting a ZIP6-dependent mechanism of tumour metastasis.
Herein, the physiological effects of zinc are reviewed in light of this mineral's role in cancer growth with specific attention being given to LIV-1 and the potential importance of this transporter to breast cancer etiology.