Role of pHi, and proton transporters in oncogene-driven neoplastic transformation.
The change of a normal, healthy cell to a transformed cell is the first step in the evolutionary arc of a cancer. While the role of oncogenes in this 'passage' is well known, the role of ion transporters in this critical step is less known and is fundamental to our understanding the early physiological processes of carcinogenesis. Cancer cells and tissues have an aberrant regulation of hydrogen ion dynamics leading to a reversal of the normal tissue intracellular to extracellular pH gradient (ΔpHi to ΔpHe). When this perturbation in pH dynamics occurs during carcinogenesis is less clear. Very early studies using the introduction of different oncogene proteins into cells observed a concordance between neoplastic transformation and a cytoplasmic alkalinization occurring concomitantly with a shift towards glycolysis in the presence of oxygen, i.e. 'Warburg metabolism'. These processes may instigate a vicious cycle that drives later progression towards fully developed cancer where the reversed pH gradient becomes ever more pronounced. This review presents our understanding of the role of pH and the NHE1 in driving transformation, in determining the first appearance of the cancer 'hallmark' characteristics and how the use of pharmacological approaches targeting pH/NHE1 may open up new avenues for efficient treatments even during the first steps of cancer development.
Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari, , Bari 70126, Italy.
Stephan Joel
SJ
Reshkin
Maria Raffaella
MR
Greco
Rosa Angela
RA
Cardone
D027682:Cation Transport Proteins / Q000378:metabolism*; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism*; D003593:Cytoplasm / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D009857:Oncogenes / Q000235:genetics / Q000502:physiology*; D017494:Proton Pumps / Q000378:metabolism*; D000074082:Sodium-Hydrogen Exchanger 1; D017923:Sodium-Hydrogen Exchangers / Q000378:metabolism*
D027682:Cation Transport Proteins; D017494:Proton Pumps; C490998:SLC9A1 protein, human; D000074082:Sodium-Hydrogen Exchanger 1; D017923:Sodium-Hydrogen Exchangers
NHE1; angiogenesis; growth factors; invasion; pH and cancer; tumour microenvironment