Acquired tamoxifen resistance (TamR) remains a major challenge in breast cancer endocrine therapy. The mechanism of acquiring tamoxifen resistance remains elusive, and no effective drugs are available. In this investigation, we determined that the expression of the DNA damage marker γH2AX is upregulated under minichromosome maintenance protein 7 (MCM7) knockdown in phospho Ser807/811-retinoblastoma protein (p-Rb) defect cells. In addition, the expression of p-Rb was lower in TamR cells than in parental cells, and the expression of γH2AX was significantly upregulated when MCM7 was knocked down in TamR cells. Simvastatin, an agent for hypercholesterolemia treatment, activated the MCM7/p-RB/γH2AX axis and induced DNA damage in TamR cells, especially when combined with tamoxifen. Finally, in vitro and in vivo experiments demonstrated that simvastatin combined with tamoxifen increased TamR cell apoptosis and inhibited xenograft growth. In conclusion, simvastatin may suppress TamR cell growth by inhibiting MCM7 and Rb and subsequently inducing DNA damage.
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http://dx.doi.org/10.1038/srep41776 | DOI Listing |
Breast Cancer Res
January 2025
Servicio de Oncología, Centro Universitario Contra el Cáncer (CUCC), Hospital Universitario "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León, 66451, Monterrey, Nuevo León, México.
Background: Hereditary predisposition to breast and ovarian cancer syndrome (HBOC) is a pathological condition with increased cancer risk, including breast (BC), ovarian cancer (OC), and others. HBOC pathogenesis is caused mainly by germline pathogenic variants (GPV) in BRCA1 and BRCA2 genes. However, other relevant genes are related to this syndrome diagnosis, prognosis, and treatment, including TP53, PALB2, CHEK2, ATM, etc.
View Article and Find Full Text PDFBiol Direct
January 2025
Department of Clinical Laboratory, Affiliated Hangzhou First People's Hospital, School of Medicine, Westlake University, Hangzhou, Zhejiang, China.
Thioredoxin1 (TRX1) and telomerase are both attractive oncology targets that are tightly implicated in tumor initiation and development. Here, we reported that the 6-dithio-2-deoxyguanosine analog thiotert exhibits an effective cytotoxic effect on myelodysplastic syndromes (MDS) cell SKM-1 and lymphoma cell U-937. Further studies confirmed that thiotert effectively disrupts cellular redox homeostasis, as evidenced by elevated intracellular reactive oxygen species (ROS) levels, increased MnSOD, accelerated DNA impairment, and activated apoptosis signal.
View Article and Find Full Text PDFGeroscience
January 2025
Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.
Aging is influenced by a complex interplay of multifarious factors, including an individual's genetics, environment, and lifestyle. Notably, high altitude may impact aging and age-related diseases through exposures such as hypoxia and ultraviolet (UV) radiation. To investigate this, we mined risk exposure data (summary exposure value), disease burden data (disability-adjusted life years (DALYs)), and death rates and life expectancy from the Global Health Data Exchange (GHDx) and National Data Management Center for Health of Ethiopia for each subnational region of Ethiopia, a country with considerable differences in the living altitude.
View Article and Find Full Text PDFOncogene
January 2025
State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, China.
Mismatch repair deficiency (dMMR) cancers are highly sensitive to immunotherapy, but only account for a small fraction of cancer patients. How to increase immunotherapy efficacy on MMR-proficient (pMMR) cancer is still a major challenge. This study demonstrates that pyrithione zinc (PYZ), an FDA-approved drug, can enhance tumor immunogenicity via altering MMR and activating STING signaling.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, N-7491, Trondheim, Norway.
The cytotoxic mechanisms of thymidylate synthase inhibitors, such as the multitarget antifolate pemetrexed, are not yet fully understood. Emerging evidence indicates that combining pemetrexed with histone deacetylase inhibitors (HDACi) may enhance therapeutic efficacy in non-small cell lung cancer (NSCLC). To explore this further, A549 NSCLC cells were treated with various combinations of pemetrexed and the HDACi MS275 (Entinostat), and subsequently assessed for cell viability, cell cycle changes, and genotoxic markers.
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