The Na+/H+ antiporter is a ubiquitous membrane-bound enzyme involved in pH regulation of vertebrate cells. It is specifically inhibited by the diuretic drug amiloride and activated by a variety of signals including growth factors, mitogens, neurotransmitters, tumor promoters, and others.

SLC9A1 and cancer metastasis

Recent research has highlighted the fundamental role of the tumour's extracellular metabolic microenvironment in malignant invasion. This microenvironment is acidified primarily by the tumour-cell Na(+)/H(+) exchanger NHE1 and the H(+)/lactate cotransporter, which are activated in cancer cells. NHE1 also regulates formation of invadopodia - cell structures that mediate tumour cell migration and invasion.

References

 Cardone RA, Casavola V, Reshkin SJ. The role of disturbed pH dynamics and the Na+/H+ exchanger in metastasis. Nat Rev Cancer. 2005 Oct;5(10):786-95. PMID: #16175178#