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MCF‐7 breast cancer cell internal pH regulation
Author(s) -
Papineau Alyssa,
Runge Steven,
Washington Tyrone,
Naylor Kari,
Horton Leah
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.730.6
Subject(s) - intracellular ph , extracellular , chemistry , ph indicator , biophysics , ph meter , biochemistry , biology
Tumors create an extracellular pH (pH e ) barrier and form an isolated microenvironment roughly 0.5 pH units lower than physiological pH, while the intracellular pH (pH i ) is maintained within 0.2 pH units of physiological levels. Reduced tumor pH i is associated with apoptosis, and lowered arterial and tissue pH are seen with heavy exercise. PURPOSE To determine the pH i response of MCF‐7 cells subjected to acidic environments. MCF‐7 cells loaded with BCECF, a pH indicator, were used to create a standard curve of fluorescent ratios at six pH levels. MCF‐7 cells were then subjected to pH e levels of 6.75 and 6.25 at 0, 15, 30, 45, 60, 120, 180, and 1,440 minutes of pH e exposure. Data were referenced to MCF‐7 cells at a physiological pH e of 7.25. A treatment effect was seen at pH e 6.25 (p = 0.0002). Compared to the control, cells subjected to pH e 6.25 for 15, 30, 45, and 1,440 minutes had lower pH i levels (p = 0.0464, p = 0.0002, p = 0.0257, and p = 0.0054, respectively). An interaction of pH e and time (p = 0.0483) on pH i was observed. The pH i values were lower at pH e 6.25 than at pH e 6.75 after 30, 180, and 1,440 minutes of exposure (p = 0.0193, p = 0.0200, and p < 0.0001, respectively). In conclusion, MCF‐7 cells subjected to a pH e of 6.75 maintained their pH i , but a different recovery response was seen at pH e 6.25. A decreased tolerance of lower pH levels may provide a mechanism by which heavy exercise would prove beneficial for breast cancer patients.