scholarly journals Bacteria modulate tamoxifen-induced death via host fatty acid metabolism

2021 ◽  
Author(s):  
Cedric Diot ◽  
Aurian P. Garcia-Gonzalez ◽  
Andre F. Vieira ◽  
Melissa Walker ◽  
Megan Honeywell ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Fatty Acid ◽  
Acid Metabolism ◽  
C Elegans ◽  
Er Positive ◽  
Order Of Magnitude ◽  
High Doses ◽  
Target Effect ◽  
Magnitude Difference ◽  
Positive Breast Cancer

Tamoxifen is a selective estrogen receptor (ER) modulator that is used to treat ER positive breast cancer, but that at high doses kills both ER-positive and ER negative breast cancer cells. We recapitulate this off-target effect in Caenorhabditis elegans, which does not have an ER ortholog. We find that different bacteria dramatically modulate tamoxifen toxicity in C. elegans, with a three-order of magnitude difference between animals fed Escherichia coli, Comamonas aquatica, and Bacillus subtilis. Remarkably, host fatty acid (FA) biosynthesis mitigates tamoxifen toxicity, and different bacteria provide the animal with different FAs, resulting in distinct FA profiles. Surprisingly these bacteria modulate tamoxifen toxicity by different death mechanisms, some of which are modulated by FA supplementation and others by antioxidants. Together, this work reveals a complex interplay between microbiota, FA metabolism and tamoxifen toxicity that may provide a blueprint for similar studies in more complex mammals.

Antitumor Activity and Underlying Mechanism of Phomoxanthone B in MCF7 Cells

2020 ◽  
Vol 20 ◽  
Author(s):  
Chuan Chen ◽  
Ziyue Zhao ◽  
Qian Dong ◽  
XueHui Gao ◽  
Huibin Xu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Antitumor Activity ◽  
Oxidative Phosphorylation ◽  
Tumor Cells ◽  
Transcriptome Analysis ◽  
Mcf7 Cells ◽  
Er Positive ◽  
Induced Apoptosis ◽  
Positive Breast Cancer

Background:: Xanthones are a class of heterocyclic natural products, which are promising sources of anticancer leads. Phomoxanthone B（PXB）and Phomoxanthone A（PXA）are xanthone dimers. PXA is well studied as an anti-cancer agent, but PXB is not. In our study, PXB was isolated from the endophytic fungus Phomopsis sp. By254. Objective:: The purpose of this study was to identify the underlying anti-tumor mechanisms of PXB in breast cancer MCF7 cell line. Methods:: Apoptosis, cell cycle, proliferation, invasion and migration assays were used to assess the antitumor activity of PXB. RNA sequencing was used to analyze the effect of PXB treatment on gene expression in MCF7 cells. Results:: PXB showed cytotoxicity toward a variety of tumor cells, especially MCF7 cells. PXB inhibited the migration and invasion, arrested cell cycle at G2/M phase and induced apoptosis associated with caspase-3 activation in MCF7 cells. The detailed transcriptome analysis revealed that PXB affected several pathways related to tumorigenesis, metabolisms-, and oxidative phosphorylation in MCF7 cells. KEGG transcriptome analysis revealed that PXB upregulated pro-survival signal pathways such as MAPK, PI3K-AKT and STAT3 pathways. We found that PXB also significantly upregulated the expression of IL24, DDIT3 and XAF1, which may contribute to PXB-induced apoptosis. We further found that PXB may downregulate oxidative phosphorylation by decreasing the expression of electron transport chain genes, especially MT-ND1, which is a potential unfavorable prognostic marker for ER-positive breast cancer. Conclusion:: PXB exerts strong cytotoxicity against human tumor cells and has a potential for ER-positive breast cancer treatment.

scholarly journals Clinical CYP2D6 Genotyping to Personalize Adjuvant Tamoxifen Treatment in ER-Positive Breast Cancer Patients: Current Status of a Controversy

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 771
Author(s):  
Tessa A. M. Mulder ◽  
Mirjam de With ◽  
Marzia del Re ◽  
Romano Danesi ◽  
Ron H. J. Mathijssen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Clinical Outcome ◽  
Cancer Patients ◽  
Plasma Concentrations ◽  
Tamoxifen Treatment ◽  
Current Status ◽  
Endocrine Treatment ◽  
Breast Cancer Patients ◽  
Er Positive ◽  
Positive Breast Cancer

Tamoxifen is a major option for adjuvant endocrine treatment in estrogen receptor (ER) positive breast cancer patients. The conversion of the prodrug tamoxifen into the most active metabolite endoxifen is mainly catalyzed by the enzyme cytochrome P450 2D6 (CYP2D6). Genetic variation in the CYP2D6 gene leads to altered enzyme activity, which influences endoxifen formation and thereby potentially therapy outcome. The association between genetically compromised CYP2D6 activity and low endoxifen plasma concentrations is generally accepted, and it was shown that tamoxifen dose increments in compromised patients resulted in higher endoxifen concentrations. However, the correlation between CYP2D6 genotype and clinical outcome is still under debate. This has led to genotype-based tamoxifen dosing recommendations by the Clinical Pharmacogenetic Implementation Consortium (CPIC) in 2018, whereas in 2019, the European Society of Medical Oncology (ESMO) discouraged the use of CYP2D6 genotyping in clinical practice for tamoxifen therapy. This paper describes the latest developments on CYP2D6 genotyping in relation to endoxifen plasma concentrations and tamoxifen-related clinical outcome. Therefore, we focused on Pharmacogenetic publications from 2018 (CPIC publication) to 2021 in order to shed a light on the current status of this debate.

scholarly journals Alternative dosing of exemestane in postmenopausal women with ER-positive breast cancer. Design and methods of a randomized presurgical trial

2021 ◽  
pp. 106498
Author(s):  
Aliana Guerrieri-Gonzaga ◽  
Davide Serrano ◽  
Parjhitham Thomas ◽  
Katherine D. Crew ◽  
Nagi B. Kumar ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Postmenopausal Women ◽  
Er Positive ◽  
Design And Methods ◽  
Positive Breast Cancer

Goserelin Versus Cyclophosphamide, Methotrexate, and Fluorouracil as Adjuvant Therapy in Premenopausal Patients With Node-Positive Breast Cancer: The Zoladex Early Breast Cancer Research Association Study

2002 ◽  
Vol 20 (24) ◽  
pp. 4628-4635 ◽  
Author(s):  
W. Jonat ◽  
M. Kaufmann ◽  
W. Sauerbrei ◽  
R. Blamey ◽  
J. Cuzick ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Research ◽  
Side Effects ◽  
Association Study ◽  
Early Breast Cancer ◽  
Research Association ◽  
Node Positive ◽  
Er Positive ◽  
Premenopausal Patients ◽  
Positive Breast Cancer

PURPOSE: Current adjuvant therapies have improved survival for premenopausal patients with breast cancer but may have short-term toxic effects and long-term effects associated with premature menopause. PATIENTS AND METHODS: The Zoladex Early Breast Cancer Research Association study assessed the efficacy and tolerability of goserelin (3.6 mg every 28 days for 2 years; n = 817) versus cyclophosphamide, methotrexate, and fluorouracil (CMF) chemotherapy (six 28-day cycles; n = 823) for adjuvant treatment in premenopausal patients with node-positive breast cancer. RESULTS: Analysis was performed when 684 events had been achieved, and the median follow-up was 6 years. A significant interaction between treatment and estrogen receptor (ER) status was found (P = .0016). In ER-positive patients (approximately 74%), goserelin was equivalent to CMF for disease-free survival (DFS) (hazard ratio [HR], 1.01; 95% confidence interval [CI], 0.84 to 1.20). In ER-negative patients, goserelin was inferior to CMF for DFS (HR, 1.76; 95% CI, 1.27 to 2.44). Amenorrhea occurred in more than 95% of goserelin patients by 6 months versus 58.6% of CMF patients. Menses returned in most goserelin patients after therapy stopped, whereas amenorrhea was generally permanent in CMF patients (22.6% v 76.9% amenorrheic at 3 years). Chemotherapy-related side effects such as nausea/vomiting, alopecia, and infection were higher with CMF than with goserelin during CMF treatment. Side effects related to estrogen suppression were initially higher with goserelin, but when goserelin treatment stopped, reduced to a level below that observed in the CMF group. CONCLUSION: Goserelin offers an effective, well-tolerated alternative to CMF in premenopausal patients with ER-positive and node-positive early breast cancer.

scholarly journals Relationship Between Plasma Estradiol Levels and Estrogen-Responsive Gene Expression in Estrogen Receptor–Positive Breast Cancer in Postmenopausal Women

2010 ◽  
Vol 28 (7) ◽  
pp. 1161-1167 ◽  
Author(s):  
Anita K. Dunbier ◽  
Helen Anderson ◽  
Zara Ghazoui ◽  
Elizabeth J. Folkerd ◽  
Roger A'Hern ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Estrogen Receptor ◽  
Postmenopausal Women ◽  
Multivariable Analysis ◽  
Independent Set ◽  
Breast Cancers ◽  
Plasma Estradiol ◽  
Er Positive ◽  
Positive Breast Cancer

Purpose To determine whether plasma estradiol (E2) levels are related to gene expression in estrogen receptor (ER)–positive breast cancers in postmenopausal women. Materials and Methods Genome-wide RNA profiles were obtained from pretreatment core-cut tumor biopsies from 104 postmenopausal patients with primary ER-positive breast cancer treated with neoadjuvant anastrozole. Pretreatment plasma E2 levels were determined by highly sensitive radioimmunoassay. Genes were identified for which expression was correlated with pretreatment plasma E2 levels. Validation was performed in an independent set of 73 ER-positive breast cancers. Results The expression of many known estrogen-responsive genes and gene sets was highly significantly associated with plasma E2 levels (eg, TFF1/pS2, GREB1, PDZK1 and PGR; P < .005). Plasma E2 explained 27% of the average expression of these four average estrogen-responsive genes (ie, AvERG; r = 0.51; P < .0001), and a standardized mean of plasma E2 levels and ER transcript levels explained 37% (r, 0.61). These observations were validated in an independent set of 73 ER-positive tumors. Exploratory analysis suggested that addition of the nuclear coregulators in a multivariable analysis with ER and E2 levels might additionally improve the relationship with the AvERG. Plasma E2 and the standardized mean of E2 and ER were both significantly correlated with 2-week Ki67, a surrogate marker of clinical outcome (r = −0.179; P = .05; and r = −0.389; P = .0005, respectively). Conclusion Plasma E2 levels are significantly associated with gene expression of ER-positive breast cancers and should be considered in future genomic studies of ER-positive breast cancer. The AvERG is a new experimental tool for the study of putative estrogenic stimuli of breast cancer.

Molecular identification of ER?-positive breast cancer cells by the expression profile of an intrinsic set of estrogen regulated genes

2004 ◽  
Vol 200 (3) ◽  
pp. 440-450 ◽  
Author(s):  
Alessandro Weisz ◽  
Walter Basile ◽  
Claudio Scafoglio ◽  
Lucia Altucci ◽  
Francesco Bresciani ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Expression Profile ◽  
Molecular Identification ◽  
Breast Cancer Cells ◽  
Er Positive ◽  
Positive Breast Cancer
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