PROTON CHANNEL INHIBITION ALTERS CELL PROLIFERATION AND CELL CYCLE IN BREAST CANCER CELLS

VENTURA, C; ASUAJE, A; ENRIQUE, N; MARTÍN, P; NÚÑEZ, M; COCCA, C; MILESI, V

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

Sociedad Argentina de Investigación Clínica (SAIC)

Metabolic reprogramming of cancer cells conduces to a high production of acidic substances which must be extruded to maintain cell viability. Here, we studied the effect of 2-(6-chloro-1H-benzimidazol- 2-yl)guanidine (ClGBI), an inhibitor of the proton channel Hv1, on proliferation and cell cycle of tumorigenic (MDA-MB-231 and MCF-7) and non-tumorigenic (MCF-10A) human breast cell lines. Concentration-response curve (0-20μM) and time-course (10-48h) were assayed to study cell proliferation (clonogenic assay), cell viability (MTT), cell cycle (flow cytometry) and mitotic cells (immunofluorescence using DAPI and anti-α-tubulin antibody). Results: ClGBI reduced the clonogenicity of MDA-MB-231, MCF-7 and MCF-10A cells in a concentration dependent way (IC50: 3.4±0.2, 2.6±0.7 and 6.0±0.4 μM, respectively), getting the maximal inhibition at 10μM (p<0.001 vs. C). This effect was partially reversed after removing the inhibitor only in MCF-10A cells. ClGBI 10μM reduced the viability of MDA-MB-231 (70±10% vs. C, p<0.001) and MCF-7 (60±15% vs. C, p<0.001) cells after 48h of treatment, and this effect was not reverted by removing the inhibitor. However, MCF-10A viability was not altered. Additionally, ClGBI 10μM increased the percentage of mitotic cells in MDA-MB-231 (3.7±0.7% vs. 0.8±0.2% present in control cells, p<0.05) and MCF-7 (4.9±1.2% vs. 0.7±0.1% present in the control cells, p<0.05) after 10h of treatment. This parameter was not affected in MCF-10A cells, even with a greater concentration (20μM) or time (48h) analyzed. Finally, 10h of exposure to ClGBI 10μM increased the percentage of cells in G2/M, in MDA-MB-231 (27.8±2.5% vs. 21.0±0.7% observed in the control cells, p<0.05) and MCF-7 (35.4±1.6% vs. 31.2±0.7%, p:ns) cells. Cell cycle distribution was not affected in MCF-10A cells. In summary, 10μM ClGBI alters viability, cell proliferation and cell cycle in tumorigenic human breast cells, without affecting these parameters in the non-tumorigenic cell line, MCF-10A.