The purpose of this work was to investigate the effect of fasting on the induction and growth of chemically-induced mammary carcinogenesis. Female Sprague-Dawley rats were given methylnitrosourea (MNU) i.p. (50 mg/kg) at 50 days of age; a group of rats were exposed to 4 day fasting followed by 1 day of refeeding before the administration of the carcinogen, while another group was exposed to three cycles of 3 days fasting in 10 days, beginning 1 week after MNU injection. Fasting enhanced the development of mammary tumours only in rats fasted after carcinogen damage, while it did not affect the induction of tumours in rats fasted before MNU, if compared with full-fed controls. The enhanced growth of mammary tumours sustained by fasting during promotion was observed in the cervical-thoracic region. In addition, exposure to fasting made rats susceptible to the development of MNU-induced extra-mammary cancers. Different from the preventive effect of caloric restriction on tumor development, these data demonstrate that fasting affects the promotion phase of carcinogenesis by enhancing the growth of MNU-induced mammary tumours.
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http://dx.doi.org/10.1093/carcin/18.8.1679 | DOI Listing |
Oncoimmunology
December 2025
Cancer Signaling and Microenvironment Program, Fox Chase Cancer Center, Philadelphia, PA, USA.
In an immunocompetent mouse model of multifocal, metachronous HR mammary carcinogenesis, we have recently demonstrated that a superior control of primary neoplastic lesions by focal radiotherapy does not necessarily translate into improved oncosuppression at non-irradiated (pre)malignant tissues. These data point to a link between local tumor control by radiotherapy and systemic oncogenesis that remains to be fully understood.
View Article and Find Full Text PDFMethods Cell Biol
January 2025
Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Arnie Charbonneau Cancer Research Institute, Calgary, AB, Canada. Electronic address:
Breast cancer is the most common cancer in women and continues to have a significant impact in cancer-associated deaths worldwide. Investigating the complex roles of infiltrating immune subsets within the tumor microenvironment (TME) will enable a better understanding of disease progression and reveal novel therapeutic strategies for patients with breast cancer. The mammary-specific expression of polyomavirus middle T oncoprotein (MMTV-PyMT) was first established in 1992 by William Muller and is the most commonly used genetically engineered mouse model (GEMM) for breast cancer research.
View Article and Find Full Text PDFVet Comp Oncol
January 2025
Laboratory of Comparative and Translational Oncology, Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering, University of São Paulo, Pirassununga, São Paulo, Brazil.
Inflammatory mammary carcinoma (IMC) is the most aggressive variant of invasive mammary tumours in dogs and in women. Decorin is an extracellular matrix molecule whose expression can be reduced or absent in various human cancers, which is associated with a poor prognosis. E-cadherin is a cell adhesion protein whose expression is reduced in several neoplasms.
View Article and Find Full Text PDFSci Rep
January 2025
Division of Hematology and Oncology, University of California, 1450 3rd Street, San Francisco, CA, 94143, USA.
For individuals at high risk of developing breast cancer, interventions to mitigate this risk include surgical removal of their breasts and ovaries or five years treatment with the anti-estrogen tamoxifen or aromatase inhibitors. We hypothesized that a silicone based anti-estrogen-eluting implant placed within the breast would provide the risk reduction benefit of hormonal therapy, but without the adverse effects that limit compliance. To this end, we demonstrate that when placed adjacent to mammary tissue in the 7,12-dimethylbenz[a]anthracene-induced rat breast cancer model a fulvestrant-eluting implant delays breast cancer with minimal systemic exposure.
View Article and Find Full Text PDFMol Biol Rep
January 2025
Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Background: Lately, significant attention has been drawn towards the potential efficacy of cholera toxin (CT)-an exotoxin produced by the small intestine pathogenic bacterium Vibrio cholera-in modulating cancer-promoting events. In a recent study, we demonstrated that early-life oral administration of non-pathogenic doses of CT in mice suppressed chemically-induced carcinogenesis in tissues distantly located from the gut. In the mammary gland, CT pretreatment was shown to reduce tumor multiplicity, increase apoptosis and alter the expression of several cancer-related molecules.
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