Association of ERα-36 expression with the de novo resistance of tamoxifen in ER-positive breast cancer

2021 ◽  
pp. 1-5
Author(s):  
Amir Juliansyah ◽  
Septiman Rahman ◽  
Indra Indra ◽  
Berti Nelwan ◽  
Prihantono Prihantono

BACKGROUND: Approximately 70–80% of breast cancer express ER-alpha and hormonal therapies, given significant improvements in patient survival. About 50% of ER-positive breast cancer patients with advanced disease insensitive to tamoxifen treatment when diagnosed. Recent studies have shown that ERα-36 is a crucial factor in the resistance of tamoxifen. OBJECTIVE: This study aims to determine the association between ERα-36 expression and de novo resistance of tamoxifen in patients with ER-positive breast cancer. METHODS: This study was an observational study using a cross-sectional method and was conducted at Wahidin Sudirohusodo Hospital and Unhas Hospital. ERα-36 protein expression was assessed using an immunohistochemistry assay. The association of ERα-36 expression and resistance of tamoxifen was tested with the Chi-square test. RESULTS: A total of 50 locally advanced breast cancer cases were included in this study, 22 cases (44%) had overexpression of ERα-36, and 28 cases (56%) had not, 24 cases (48%) had experience resistance to tamoxifen and 26 cases (52%) had not. There was a significant association between ERα-36 expressions and resistance of tamoxifen (p = 0.000). CONCLUSIONS: There was an association between the expression of ER-α36 with de novo resistance of tamoxifen in ER-positive breast cancer. ER-α36 could act as a worth considering biomarker for de novo resistance of tamoxifen in therapeutic strategies.

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 ◽  
...  

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.


2008 ◽  
Vol 42 (2) ◽  
pp. 87-103 ◽  
Author(s):  
Sandra E Ghayad ◽  
Julie A Vendrell ◽  
Ivan Bieche ◽  
Frédérique Spyratos ◽  
Charles Dumontet ◽  
...  

Cross-resistance to molecules used in endocrine therapy is among the main challenges in the treatment of estrogen receptor-α (ERα) positive breast cancer. In this study, we used two different cell models of resistance to anti-estrogens: MVLN/CL6.7 cells and VP229/VP267 cells selected after exposure to tamoxifen respectively in vitro and in vivo to characterize a phenotype rarely observed, i.e. acquisition of cross-resistance to the pure ER antagonist fulvestrant. As MVLN/CL6.7 cells and VP229/VP267 cell lines are original and valuable models of cross-resistance to tamoxifen and fulvestrant, we examined candidate genes using a RTQ-PCR strategy to identify new biomarkers of endocrine resistance. Out of the 26 candidate genes tested, 19 displayed deregulation of expression at the basal level in at least one of the two resistant cell lines. Eight genes (TACC1, NOV, PTTG1, MAD2L1, BAK1, TGFB2, BIRC5, and CCNE2) were significantly overexpressed in samples from ER-positive breast cancer patients who relapsed after tamoxifen treatment (n=24) compared with samples from patients who did not (n=24). Five genes (TACC1, NOV, PTTG1, BAK1, and TGFB2) were correlated with significantly shorter relapse-free survival (univariate analysis). Finally, we identified TACC1 and a three-gene expression signature (TACC1, NOV, and PTTG1) as independent prognostic markers (multivariate analysis). Aberrant mRNA and protein levels of TACC1, NOV, and PTTG1 were also observed under tamoxifen and/or fulvestrant exposure in resistant CL6.7 cells compared with their respective control MVLN cells. In conclusion, our data identify TACC1, NOV, and PTTG1 as promising new markers that could be used in the clinical management of ER-positive breast cancer patients.


1990 ◽  
Vol 8 (8) ◽  
pp. 1310-1320 ◽  
Author(s):  
F Boccardo ◽  
A Rubagotti ◽  
P Bruzzi ◽  
M Cappellini ◽  
G Isola ◽  
...  

Between November 1, 1983 and June 30, 1987, 510 node-positive, estrogen receptor (ER)-positive breast cancer patients have been randomly allocated to receive either chemotherapy (six intravenous [IV] cyclophosphamide, methotrexate, and fluorouracil [CMF] courses followed by four IV epirubicin courses) or 5 years of tamoxifen treatment or a combination of both therapies. After a median follow-up of 40 months, patients receiving the combined treatment achieved the best results, and those treated with chemotherapy alone achieved the worst, the difference being particularly evident in postmenopausal women. However, while the concurrent use of chemotherapy and tamoxifen did improve the results achieved by chemotherapy alone, particularly in postmenopausal women and in those with four or more involved nodes, it did not significantly improve the results achieved by tamoxifen alone, particularly in patients with higher ER tumor concentrations. Side effects were more numerous and more severe in patients receiving chemotherapy (with or without tamoxifen). Our findings, although still preliminary, confirm that tamoxifen should be the treatment of choice for postmenopausal breast cancer patients with node-positive, ER-positive tumors. In addition, the findings suggest that tamoxifen may represent a safe alternative to chemotherapy (at least to the cytotoxic regimen we used) for younger women, provided they have ER-positive tumors. In patients with ER-positive tumors, the addition of chemotherapy to tamoxifen does not seem to improve significantly the effectiveness of tamoxifen alone.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yomna Zamzam ◽  
Yosra Abdelmonem Zamzam ◽  
Marwa Aboalsoud ◽  
Heba Harras

Background. Despite the undeniable benefit of tamoxifen therapy for ER-positive breast cancer patients, approximately one-third of those patients either do not respond to tamoxifen or develop resistance. Thus, it is a crucial step to identify novel, reliable, and easily detectable biomarkers indicating resistance to this drug. Objective. The aim of this work is to explore SOX2 and AGR2 biomarker expression in the tumor tissue of ER-positive breast cancer patients in combination with the evaluation of serum AGR2 level of these patients in order to validate these biomarkers as early predictors of tamoxifen resistance. Methods. This study was conducted on 224 ER-positive breast cancer patients. All patients were primarily subjected to serum AGR2 levelling by ELISA and their breast cancer tissue immunostained for SOX2 and AGR2. After 5 years of follow-up, the patients were divided into 3 groups: group 1 was tamoxifen sensitive and groups 2 and 3 were tamoxifen resistant. Time to failure of tamoxifen treatment was considered the time from the beginning of tamoxifen therapy to the time of discovery of breast cancer recurrence or metastases (in months). Results. SOX2 and AGR2 biomarkers expression and serum AGR2 level were significantly higher in groups 2 and 3 in comparison to group 1, while the relationship between Her2 neu expression and Ki67 index in the 3 different groups was statistically nonsignificant. Lower SOX2 and AGR2 expression and low AGR2 serum levels in the studied patients of groups 2 and 3 were significantly associated with longer time-to-failure of tamoxifen treatment. According to the ROC curve, the combined use of studied markers validity was with a sensitivity of 100%, specificity of 96%, PPV 96%, and NPV 100% ( p < 0.001 ; AUC: 0.984). Conclusions. Integrated use of SOX2 and AGR2 biomarkers with serum AGR2 assay holds a promising hope for their future use as predictive markers for early detection of tamoxifen resistance in ER-positive breast cancer patients.


2021 ◽  
Author(s):  
Yanyan Wang ◽  
Xiaonan Gong ◽  
Yujie Zhang

Tamoxifen is an estrogen receptor (ER) antagonist that is most commonly used for the treatment of ER-positive breast cancer. However, tamoxifen resistance remains a major cause of cancer recurrence and progression. Here, we aimed to identify hub genes implicated in the progression and prognosis of ER-positive breast cancer following tamoxifen treatment. Microarray data (GSE9893) for 155 tamoxifen-treated primary ER-positive breast cancer samples were obtained from the Gene Expression Omnibus database. In total, 1,706 differentially expressed genes, including 859 upregulated genes and 847 downregulated genes, were identified between relapse samples and relapse-free samples. Weighted correlation network analysis clustered genes into 13 modules, among which the tan and blue modules were the most significantly related to prognosis. From these two modules, we further identified and validated two prognosis-related hub genes (GRSF1 and MAPT) via survival analysis based on several publicly available datasets. High expression of GRSF1 predicted poor prognosis, whereas MAPT indicated favorable outcomes in ER-positive breast cancer. Using breast cancer cell lines and tissue samples, we confirmed that GRSF1 was significantly upregulated and MAPT was downregulated in the tamoxifen-resistant group compared with the tamoxifen-sensitive group. The prognostic value of GRSF1 and MAPT was also verified in 48 tamoxifen-treated ER-positive breast cancer patients in our hospital. Gene set enrichment analysis suggested that GRSF1 was potentially involved in RNA degradation and cell cycle pathways, while MAPT was strongly linked to immune-related signaling pathways. Taken together, our findings established novel prognostic biomarkers to predict tamoxifen sensitivity, which may facilitate individualized management of breast cancer.


Oncotarget ◽  
2017 ◽  
Vol 8 (32) ◽  
pp. 52142-52155 ◽  
Author(s):  
Takashi Takeshita ◽  
Yutaka Yamamoto ◽  
Mutsuko Yamamoto-Ibusuki ◽  
Mai Tomiguchi ◽  
Aiko Sueta ◽  
...  

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