TY - JOUR
T1 - Synergistic promoting effects of pentoxifylline and simvastatin on the apoptosis of triple-negative MDA-MB-231 breast cancer cells
AU - Za, Yessica Cristina Castellanos Espar
AU - Wu, Shuang
AU - Huang, Limin
AU - Buquet, Catherine
AU - Shen, Rong
AU - Nzalez, Berenice Sanchez Go
AU - Latorre, Ethel Awilda García
AU - Boyer, Olivier
AU - Varin, Remi
AU - Jiménez-Zamudio, Luis Antonio
AU - Janin, Anne
AU - Vannier, Jean Pierre
AU - Li, Hong
AU - Lu, He
N1 - Publisher Copyright:
© 2018 Spandidos Publications. All rights reserved.
PY - 2018/4
Y1 - 2018/4
N2 - Pentoxifylline (PTX), a xanthine family molecule and simvastatin (SIM), an anti-hypercholesterolemic agent, have recently been considered as sensitizers to chemotherapy and radiotherapy. The present in vitro study evaluated their antitumor synergistic effects on MDA-MB-231 breast cancer cells characterized by the triple-negative phenotype (TNP). The anti-proliferative effects of these two agents were evaluated by MTT and clonogenic assays. Cell cycle progression was examined using propidium iodide staining. Apoptosis was investigated by Annexin V labeling, and by examining caspase 3 activity and DNA fragmentation. Autophagic vesicles and reactive oxygen species (ROS) levels were monitored by flow cytometry. Western blot analysis was performed to evaluate molecular targets. Our results revealed that when used alone, PTX and SIM exerted antitumor effects. Nevertheless, used in combination, the inhibition of cell proliferation was synergistically superior (80% vs 42%) than that observed following treatment with each agent alone after 48 h. PTX alone (0.5 mM) induced both apoptosis (25%) and autophagy (25%); however, when used in combination with SIM (0.5 μM), the balance between these processes was disrupted and the cells underwent apoptosis (>65%) as opposed to autophagy (<13%). This imbalance was associated with an increase in ERK1/2 and AKT activation, but not with an increase in mTOR phosphorylation, and with the suppression of the NF-κB pathway. In addition, in the cells treated with both agents, almost 78% of the cells were arrested at the G0/G1 phase and lost their colony-forming ability (38±5%) compared to the cells treated with PTX alone (115±5%). On the whole, these results suggest that the induction of autophagy may be a protective mechanism preventing MDA-MB-231 cancer cell death. The combined use of PTX and SIM may drive dormant autophagic cancer cells to undergo apoptosis and thus this may be a novel treatment strategy for breast cancer characterized by the TNP.
AB - Pentoxifylline (PTX), a xanthine family molecule and simvastatin (SIM), an anti-hypercholesterolemic agent, have recently been considered as sensitizers to chemotherapy and radiotherapy. The present in vitro study evaluated their antitumor synergistic effects on MDA-MB-231 breast cancer cells characterized by the triple-negative phenotype (TNP). The anti-proliferative effects of these two agents were evaluated by MTT and clonogenic assays. Cell cycle progression was examined using propidium iodide staining. Apoptosis was investigated by Annexin V labeling, and by examining caspase 3 activity and DNA fragmentation. Autophagic vesicles and reactive oxygen species (ROS) levels were monitored by flow cytometry. Western blot analysis was performed to evaluate molecular targets. Our results revealed that when used alone, PTX and SIM exerted antitumor effects. Nevertheless, used in combination, the inhibition of cell proliferation was synergistically superior (80% vs 42%) than that observed following treatment with each agent alone after 48 h. PTX alone (0.5 mM) induced both apoptosis (25%) and autophagy (25%); however, when used in combination with SIM (0.5 μM), the balance between these processes was disrupted and the cells underwent apoptosis (>65%) as opposed to autophagy (<13%). This imbalance was associated with an increase in ERK1/2 and AKT activation, but not with an increase in mTOR phosphorylation, and with the suppression of the NF-κB pathway. In addition, in the cells treated with both agents, almost 78% of the cells were arrested at the G0/G1 phase and lost their colony-forming ability (38±5%) compared to the cells treated with PTX alone (115±5%). On the whole, these results suggest that the induction of autophagy may be a protective mechanism preventing MDA-MB-231 cancer cell death. The combined use of PTX and SIM may drive dormant autophagic cancer cells to undergo apoptosis and thus this may be a novel treatment strategy for breast cancer characterized by the TNP.
KW - Apoptosis
KW - Autophagy
KW - Breast cancer
KW - Pentoxifylline
KW - Simvastatin
UR - http://www.scopus.com/inward/record.url?scp=85042766817&partnerID=8YFLogxK
U2 - 10.3892/ijo.2018.4272
DO - 10.3892/ijo.2018.4272
M3 - Artículo
C2 - 29436616
SN - 1019-6439
VL - 52
SP - 1246
EP - 1254
JO - International Journal of Oncology
JF - International Journal of Oncology
IS - 4
ER -