Year: 2017
Type: article
Abstract: BACKGROUND: Human triple-negative breast cancer has limited therapeutic choices. Breast tumor cells have depolarized plasma membrane potential. Using this unique electrical property, we aim to develop an effective selective killing of triple-negative breast cancer. METHODS: We used an engineered L-type voltage-gated calcium channel (Cec), activated by membrane depolarization without inactivation, to induce excessive calcium influx in breast tumor cells. Patch clamp and flow cytometry were used in testing the killing selectivity and efficiency of human breast tumor cells in vitro. Bioluminescence and ultrasound imaging were used in studies of human triple-negative breast cancer cell MDA-MB-231 xenograft in mice. Histological staining, immunoblotting and immunohistochemistry were used to investigate mechanism that mediates Cec-induced cell death. RESULTS: Activating Cec channels expressed in human breast cancer MCF7 cells produced enormous calcium influx at depolarized membrane. Activating the wild-type Cav1.2 channels expressed in MCF7 cells also produced a large calcium influx at depolarized membrane, but this calcium influx was diminished at the sustained membrane depolarization due to channel inactivation. MCF7 cells expressing Cec died when the membrane potential was held at -10 mV for 1 hr, while non-Cec-expressing MCF7 cells were alive. MCF7 cell death was 8-fold higher in Cec-expressing cells than in non-Cec-expressing cells. Direct injection of lentivirus containing Cec into MDA-MB-231 xenograft in mice inhibited tumor growth. Activated caspase-3 protein was detected only in MDA-MB-231 cells expressing Cec, along with a significantly increased expression of activated caspase-3 in xenograft tumor treated with Cec. CONCLUSIONS: We demonstrated a novel strategy to induce constant calcium influx that selectively kills human triple-negative breast tumor cells.
Source: BMC Cancer
Institution: West Virginia University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,390
Awards: G1274820946, G1739031488, G2202983096, CoBRE for Signal Transduction and Cancer Phase III, G3639368626, G4196128219, G4741720324, G474381023, G486607418, G5696691222, G6428352718, Special Becton Dickinson Fortessa Flow Cytometer, CoBRE for Signal Transduction and Cancer Phase III, G7251701605, G8377306051, West Virginia Clinical and Translational Science Institute: Improving Health through Partnerships and Transformative Research, G9000038508, G9000061046, G9000133327, G9000161317, G9000227321, West Virginia IDeA Network of Biomedical Research Excellence (WV-INBRE)
OpenAlex ID: W2592850813