PH Regulation by Breast Cancer Cells In Vitro and In Vivo

摘要

Prior to 1994, measurement of tumor pH was limited to microelectrodes, which measure the interstitial/extracellular pH (pHe), and (31) P MRS of inorganic phosphate, which measured the intracellular pH (pHe). In 1994, we developed a method to simultaneously measure the intra and extracellular pH of tumors, using exogenous 3-amino propyl phosphonate (3-APP) and inorganic phosphate (Pi) (Gillies et al., 1994, Am J Physiol 267, C195-C203) . However, this method is limited to measuring average tumor pHe, and was not capable of reporting the pH range or localized values. MR-based pH measurement techniques have been improved in two ways. First, the data obtained from (31)P MRS of 3-APP have been more thoroughly analyzed to yield trans-tumoral pH ranges. Second, an alternative pH-sensitive marker has been developed to allow pH in mapping using multivoxel (1)H-MRS.