Abstract
Expression of the zinc receptor, ZnR/GPR39, is increased in higher grade breast cancer tumors and cells. Zinc, its ligand, is accumulated at larger concentrations in the tumor tissue and can therefore activate ZnR/GPR39-dependent Ca2+ signaling leading to tumor progression. The K+/Cl− co-transporters (KCC), activated by intracellular signaling, enhance breast cancer cell migration and invasion. We asked if ZnR/GPR39 enhances breast cancer cell malignancy by activating KCC. Activation of ZnR/GPR39 by Zn2+ upregulated K+/Cl− co-transport activity, measured using NH4 + as a surrogate to K+ while monitoring intracellular pH. Upregulation of NH4 + transport was monitored in tamoxifen resistant cells with functional ZnR/GPR39-dependent Ca2+ signaling but not in MCF-7 cells lacking this response. The NH4 + transport was Na+-independent, and we therefore focused on KCC family members. Silencing of KCC3, but not KCC4, expression abolished Zn2+-dependent K+/Cl− co-transport, suggesting that KCC3 is mediating upregulated NH4 + transport. The ZnR/GPR39-dependent KCC3 activation accelerated scratch closure rate, which was abolished by inhibiting KCC transport with [(DihydroIndenyl) Oxy] Alkanoic acid (DIOA). Importantly, silencing of either ZnR/GPR39 or KCC3 attenuated Zn2+-dependent scratch closure. Thus, a novel link between KCC3 and Zn2+, via ZnR/GPR39, promotes breast cancer cell migration and proliferation.
Original language | American English |
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Pages (from-to) | 12-20 |
Number of pages | 9 |
Journal | Cell Calcium |
Volume | 81 |
DOIs | |
State | Published - 1 Jul 2019 |
Keywords
- Breast cancer
- K/Cl co-transport
- KCC3
- MAPK
- PI3K
- Zinc signaling
- ZnR/GPR39
All Science Journal Classification (ASJC) codes
- Physiology
- Molecular Biology
- Cell Biology