Potassium increases the antitumor effects of ascorbic acid in breast cancer cell linesin vitro.
Ascorbic acid (A) has been demonstrated to exhibit anti-cancer activity in association with chemotherapeutic agents. Potassium (K) is a regulator of cellular proliferation. In the present study, the biological effects of A and K bicarbonate, alone or in combination (A+K), on breast cancer cell lines were evaluated. The survival of cancer cells was determined by sulforhodamine B cell proliferation assay, while analysis of the cell cycle distribution was conducted via fluorescence-activated cell sorting. In addition, the expression of signaling proteins was analyzed upon treatment. The results indicated that there was a heterogeneous response of the different cell lines to A and K, and the best effects were achieved by A+K and A treatment. The interaction between A+K indicated an additive or synergistic effect. In addition, A+K increased the percentage of cells in the sub-G1 phase of the cell cycle, and was the most effective treatment in activating the degradation of poly(adenosine diphosphate-ribose) polymerase-1. In the breast cancer cell line MCF-7, A+K induced the appearance of the 18 kDa isoform of B-cell lymphoma-2-associated X protein (Bax), which is a more potent inducer of apoptosis than the full-length Bax-p21. The effects of A and K on the phosphorylation of extracellular signal-regulated kinase (ERK)1 and ERK2 were heterogeneous. In addition, treatment with K, A and A+K inhibited the expression of nuclear factor-κB. Overall, the results of the present study indicated that K potentiated the anti-tumoral effects of A in breast cancer cellsin vitro.
Department of Sports Science, Human and Health, University of Rome 'Foro Italico', Rome I-00135, Italy.
Giovanni Vanni
GV
Frajese
Department of Clinical Sciences and Translational Medicine, University of Rome 'Tor Vergata', Rome I-00133, Italy.
Monica
M
Benvenuto
Department of Clinical Sciences and Translational Medicine, University of Rome 'Tor Vergata', Rome I-00133, Italy.
Massimo
M
Fantini
Department of Sports Science, Human and Health, University of Rome 'Foro Italico', Rome I-00135, Italy.
Elena
E
Ambrosin
Department of Experimental Medicine, University of Rome 'Sapienza', Rome I-00185, Italy.
Pamela
P
Sacchetti
Department of Experimental Medicine, University of Rome 'Sapienza', Rome I-00185, Italy.
Laura
L
Masuelli
Department of Clinical Sciences and Translational Medicine, University of Rome 'Tor Vergata', Rome I-00133, Italy.
Maria Gabriella
MG
Giganti
Department of Clinical Sciences and Translational Medicine, University of Rome 'Tor Vergata', Rome I-00133, Italy.
Andrea
A
Modesti
Department of Clinical Sciences and Translational Medicine, University of Rome 'Tor Vergata', Rome I-00133, Italy.
Roberto
R
Bei
apoptosis; ascorbic acid; breast cancer; potassium