Resistance of estrogen receptor-positive breast cancer cells to tamoxifen represents a major barrier to the successful treatment of breast cancer. In the present study, we found that vacuolar H+ ATPase (vATPase) inhibitors, bafilomycin A1 and concanamycin A, sensitize tamoxifen-induced cell death. siRNA targeting ATP6V0C, a 16-kDa hydrophobic proteolipid subunit of vATPase that plays a central role in H+ transport, markedly increased cell death induced by tamoxifen. Interestingly, bafilomycin A1 induced up-regulation of DR4/DR5 and CHOP. Knock-down of CHOP by siRNA suppressed the cell death induced by bafilomycin A1 and tamoxifen, suggesting that bafilomycin A1-mediated CHOP activation sensitizes to tamoxifen. In addition, we found that bafilomycin A1 enhances TRAIL-induced cell death in breast cancer cells. Furthermore, we showed that combination of vATPase inhibitors with tamoxifen also effectively induced cell death in HER2- and ERα-overexpressing breast cancer cells. Overall, our results demonstrate that inhibition of vATPase can potentiate the apoptotic effects of tamoxifen through up-regulation of CHOP.
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http://dx.doi.org/10.1016/j.bbrc.2013.06.106 | DOI Listing |
Neoplasia
December 2024
Felsenstein Medical Research Center, Beilinson Campus, Petah Tikva, Israel; Tel Aviv University, Faculty of Medicine and Health Sciences, Tel Aviv, Israel; Rabin Medical Center, Beilinson Campus, Petah Tikva, Israel; Davidoff Cancer Center, Beilinson Campus, Petah Tikva, Israel. Electronic address:
Triple-negative breast cancer (TNBC) is an aggressive subtype that accounts for 10-15 % of breast cancer. Current treatment of high-risk early-stage TNBC includes neoadjuvant chemo-immune therapy. However, the substantial variation in immune response prompts an urgent need for new immune-targeting agents.
View Article and Find Full Text PDFMed Phys
December 2024
Department of Physics, Lakehead University, Thunder Bay, Ontario, Canada.
Background: This study investigates a multi-angle acquisition method aimed at improving image quality in organ-targeted PET detectors with planar detector heads. Organ-targeted PET technologies have emerged to address limitations of conventional whole-body PET/CT systems, such as restricted axial field-of-view (AFOV), limited spatial resolution, and high radiation exposure associated with PET procedures. The AFOV in organ-targeted PET can be adjusted to the organ of interest, minimizing unwanted signals from other parts of the body, thus improving signal collection efficiency and reducing the dose of administered radiotracer.
View Article and Find Full Text PDFPLoS One
December 2024
Hangzhou Institute of Medicine (HIM), Zhejiang Cancer Hospital, Zhejiang, Hangzhou, China.
Purpose: Approximately 20% of all breast cancer cases are classified as triple-negative breast cancer (TNBC), which represents the most challenging subtype due to its poor prognosis and high metastatic rate. Caffeic acid phenethyl ester (CAPE), the main component extracted from propolis, has been reported to exhibit anticancer activity across various tumor cell types. This study aimed to investigate the effects and mechanisms of CAPE on TNBC.
View Article and Find Full Text PDFPLoS One
December 2024
Department of Ophthalmology, School of Medicine and Health Science, Debre Tabor University, Debre Tabor, Ethiopia.
Background: Breast cancer is a significant global health issue, responsible for a large number of female cancer deaths. Early detection through breast cancer screening is crucial in reducing mortality rates. However, regions such as Sub-Saharan Africa (SSA) face challenges in identifying breast cancer early, resulting in higher mortality rates and a lower quality of life.
View Article and Find Full Text PDFPLoS One
December 2024
Department of Oral Oncology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Metastasis in patients with oral squamous cell carcinoma has been associated with a poor prognosis. However, sensitive and reliable tests for monitoring their occurrence are unavailable, with the exception of PET-CT. Circulating tumor cells and cell-free DNA have emerged as promising biomarkers for determining treatment efficacy and as prognostic predictors in solid tumors such as breast cancer and colorectal cancer.
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