Development and characterization of a novel endoxifen-resistant breast cancer cell line highlights numerous differences from tamoxifen-resistant models.
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ABSTRACT:
PROVIDER: PRJNA691063 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
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| SRR13398517_1.fastq.gz | Fastqsanger.gz | |||
| SRR13398517_2.fastq.gz | Fastqsanger.gz | |||
| SRR13398518_1.fastq.gz | Fastqsanger.gz | |||
| SRR13398518_2.fastq.gz | Fastqsanger.gz | |||
| SRR13398519_1.fastq.gz | Fastqsanger.gz |
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Project description:Despite the availability of effective drugs that target ERα-positive breast cancer, resistance commonly occurs, resulting in relapse, metastasis, and death. Tamoxifen remains the most commonly-prescribed endocrine therapy worldwide, and “tamoxifen resistance” has been extensively studied. However, little consideration has been given to the role of tamoxifen’s primary active metabolite, endoxifen, in driving resistance mechanisms. Endoxifen is the most abundant active tamoxifen metabolite detected in patients and functions differently from the parent drug and other primary metabolites, including 4-hydroxy-tamoxifen (4HT). Many studies have shown that patients who extensively metabolize tamoxifen into endoxifen have superior outcomes relative to patients who do not, further supporting a primary role for endoxifen in driving tamoxifen responses. Therefore, “tamoxifen resistance” may be actually better modeled by “endoxifen resistance” for such patients. Here, we report the development of a novel endoxifen-resistant breast cancer cell line and have extensively compared this model to tamoxifen (4HT) and fulvestrant (ICI) resistant models. Endoxifen-resistant cells were found to be phenotypically and molecularly distinct from 4HT-resistant cells and more closely resembled ICI-resistant cells overall. Specifically, endoxifen resistance was associated with ERα and PR loss, estrogen insensitivity, EMT-like features, a unique gene signature, and striking resistance to most FDA-approved second- and third-line therapies. Given these findings, and the importance of endoxifen in the efficacy of tamoxifen therapy, our data indicate that endoxifen-resistant models may be more clinically relevant than existing models and suggest that a better understanding of endoxifen resistance could substantially improve patient care.
2021-01-11 | GSE164529 | GEO
Project description:Tamoxifen, an antagonist to estrogen receptor (ER), is a first line drug used in breast cancer treatment. However, this therapy is complicated by the fact that a substantial number of patients exhibit either de novo or acquired resistance. To characterize the signaling mechanisms underlying the resistance to tamoxifen, we established a tamoxifen-resistant cell line by treating the MCF7 breast cancer cell line with tamoxifen for over 6 months. We showed that this cell line exhibited resistance to tamoxifen both in vitro and in vivo. In order to quantify the phosphorylation alterations associated with tamoxifen resistance, we performed SILAC-based quantitative phosphoproteomic profiling on the resistant and vehicle-treated sensitive cell lines where we identified >5,600 unique phosphopeptides. We found phosphorylation levels of 1,529 peptides were increased (>2 fold) and 409 peptides were decreased (<0.5-fold) in tamoxifen resistant cells compared to tamoxifen sensitive cells. Gene set enrichment analysis revealed that focal adhesion pathway was the top enriched signaling pathway activated in tamoxifen resistant cells. We observed hyperphosphorylation of the focal adhesion kinases FAK1 and FAK2 in the tamoxifen resistant cells. Of note, FAK2 was not only hyperphosphorylated but also transcriptionally upregulated in tamoxifen resistant cells. Suppression of FAK2 by specific siRNA knockdown could sensitize the resistant cells to the treatment of tamoxifen. We further showed that inhibiting FAK activity using the small molecule inhibitor PF562271 repressed cellular proliferation in vitro and tumor formation in vivo. More importantly, our survival analysis revealed that high expression of FAK2 significantly associated with short metastasis-free survival of ER-positive breast cancer patients treated with tamoxifen-based hormone therapy. Our studies suggest that FAK2 is a great potential target for the development of therapy for the treatment of hormone refractory breast cancers.
2016-05-25 | PXD001812 | Pride
Project description:Despite the availability of drugs that target ERα-positive breast cancer, resistance commonly occurs, resulting in relapse, metastasis, and death. Tamoxifen remains the most commonly-prescribed endocrine therapy worldwide, and "tamoxifen resistance" has been extensively studied. However, little consideration has been given to the role of endoxifen, the most abundant active tamoxifen metabolite detected in patients, in driving resistance mechanisms. Endoxifen functions differently from the parent drug and other primary metabolites, including 4-hydroxy-tamoxifen (4HT). Many studies have shown that patients who extensively metabolize tamoxifen into endoxifen have superior outcomes relative to patients who do not, supporting a primary role for endoxifen in driving tamoxifen responses. Therefore, "tamoxifen resistance" may be better modeled by "endoxifen resistance" for some patients. Here, we report the development of novel endoxifen-resistant breast cancer cell lines and have extensively compared these models to 4HT and fulvestrant (ICI)-resistant models. Endoxifen-resistant cells were phenotypically and molecularly distinct from 4HT-resistant cells and more closely resembled ICI-resistant cells overall. Specifically, endoxifen resistance was associated with ERα and PR loss, estrogen insensitivity, unique gene signatures, and striking resistance to most FDA-approved second- and third-line therapies. Given these findings, and the importance of endoxifen in the efficacy of tamoxifen therapy, our data indicate that endoxifen-resistant models may be more clinically relevant than existing models and suggest that a better understanding of endoxifen resistance could substantially improve patient care. IMPLICATIONS: Here we report on the development and characterization of the first endoxifen-resistant models and demonstrate that endoxifen resistance may better model tamoxifen resistance in a subset of patients.
| S-EPMC8178211 | biostudies-literature
Project description:Purpose: Tamoxifen is the most commonly used antiestrogen drug for breast cancer treatment, however, acquired resistance is a considerable challenge in clinic. Complexity and redundancy in biological system implies tamoxifen resistance is associated with complex biological processes. The aim of this study is to attempt to reveal the mechanism of tamoxifen resistance using high-throughput sequencing technique. Methods: We applied digital gene expression (DGE), RNA-seq, Small RNA-seq, bisulifte-seq (reduced representation bisuflite sequencing (RRBS)) with Illumina sequencing platforms, and Array CGH to analyze two well-established tamoxifen resistant cell line models: one is the LCC cell line model that was derived from MCF-7 breast cancer cell line and developed tamoxifen resistance following a step-wise strategy. This cell line model includes LCC0 (estrogen-dependent and tamoxifen sensitive), LCC1 (estrogen-independent and tamoxifen sensitive), LCC2 (derived from LCC1 with increased small-dosage tamoxifen treatment, estrogen-independent, and tamoxifen-resistant), and LCC9 (derived from LCC1 with increased small-dosage fluvestrant treatment, estrogen-independent, and cross-resistance to both fluvestrant and tamoxifen). The other is the TAMR cell line model that was derived from MCF-7 breast cancer cell line and developed four tamoxifen-resistant sublines following the strategy of high-dosage of tamoxifen treatment. Each subline was developed from the survived single cell after the tamoxifen treatment. Results: The DGE and RNA-seq results showed characteristic expression features for the both cell line models, for instance, high expression of SOX2 and alterations of other SOX gene family members, decreased expression of PGR, PTEN, TP53, EZH2, SMAD3, TGF-β1, DNMT1, APOBEC3B, FOXO3 and FOXO4, and increased expression of CDH1, APOBEC3H, FOXA1, TET2, TET3, TDG, MBD4, DNMT3a and DNMT3b between the tamoxifen-resistant cell lines with their matched parental cell lines. Small RNA seq showed the decreased expressions of miR-1, miR-196-3p, miR-18a-5p, miR-125b-5p, and the increased expression of miR-23a-3p, miR-26b-5p, miR-320d, miR-141-3p, miR-23a-3p, miR-30a-5p, miR-9-5p, miR-200c, miR-129-5p, miR-125b-5p, miR-1285-3p and miR-30b-5p between the tamoxifen-resistant cell lines and their matched parental cell lines. Additionally, let-7a and let-7c have been found to present high expression levels in the tamoxifen resistant cells in the both cell line models, even it showed significantly decreased in some TAMR cells compared with their parental cell line. The RRBS showed similar DNA methylation levels between the LCC cell lines. Array CGH showed a small number of copy number variants between the LCC cell lines. Conclusion: Our present study suggests the development of tamoxifen resistance is associated with a dynamic process of cell fate changing. Therefore, new therapeutic method that targets whole cell system and cell fate dynamics, will be a promising strategy.
2018-06-01 | GSE55380 | GEO
Project description:Purpose: Tamoxifen is the most commonly used antiestrogen drug for breast cancer treatment, however, acquired resistance is a considerable challenge in clinic. Complexity and redundancy in biological system implies tamoxifen resistance is associated with complex biological processes. The aim of this study is to attempt to reveal the mechanism of tamoxifen resistance using high-throughput sequencing technique. Methods: We applied digital gene expression (DGE), RNA-seq, Small RNA-seq, bisulifte-seq (reduced representation bisuflite sequencing (RRBS)) with Illumina sequencing platforms, and Array CGH to analyze two well-established tamoxifen resistant cell line models: one is the LCC cell line model that was derived from MCF-7 breast cancer cell line and developed tamoxifen resistance following a step-wise strategy. This cell line model includes LCC0 (estrogen-dependent and tamoxifen sensitive), LCC1 (estrogen-independent and tamoxifen sensitive), LCC2 (derived from LCC1 with increased small-dosage tamoxifen treatment, estrogen-independent, and tamoxifen-resistant), and LCC9 (derived from LCC1 with increased small-dosage fluvestrant treatment, estrogen-independent, and cross-resistance to both fluvestrant and tamoxifen). The other is the TAMR cell line model that was derived from MCF-7 breast cancer cell line and developed four tamoxifen-resistant sublines following the strategy of high-dosage of tamoxifen treatment. Each subline was developed from the survived single cell after the tamoxifen treatment. Results: The DGE and RNA-seq results showed characteristic expression features for the both cell line models, for instance, high expression of SOX2 and alterations of other SOX gene family members, decreased expression of PGR, PTEN, TP53, EZH2, SMAD3, TGF-β1, DNMT1, APOBEC3B, FOXO3 and FOXO4, and increased expression of CDH1, APOBEC3H, FOXA1, TET2, TET3, TDG, MBD4, DNMT3a and DNMT3b between the tamoxifen-resistant cell lines with their matched parental cell lines. Small RNA seq showed the decreased expressions of miR-1, miR-196-3p, miR-18a-5p, miR-125b-5p, and the increased expression of miR-23a-3p, miR-26b-5p, miR-320d, miR-141-3p, miR-23a-3p, miR-30a-5p, miR-9-5p, miR-200c, miR-129-5p, miR-125b-5p, miR-1285-3p and miR-30b-5p between the tamoxifen-resistant cell lines and their matched parental cell lines. Additionally, let-7a and let-7c have been found to present high expression levels in the tamoxifen resistant cells in the both cell line models, even it showed significantly decreased in some TAMR cells compared with their parental cell line. The RRBS showed similar DNA methylation levels between the LCC cell lines. Array CGH showed a small number of copy number variants between the LCC cell lines. Conclusion: Our present study suggests the development of tamoxifen resistance is associated with a dynamic process of cell fate changing. Therefore, new therapeutic method that targets whole cell system and cell fate dynamics, will be a promising strategy.
2018-06-01 | GSE55343 | GEO
Project description:Resistance to tamoxifen is a major challenge in the treatment of estrogen receptor positive breast cancer. Acquired resistance to drug involves multilayered genetic and epigenetic regulation . The oncogene EZH2 plays significant role in the development of resistance against tamoxifen, widely used in the treatment of breast cancer. Inhibition of EZH2 has proven to reverse the tamoxifen resistance breast cancer cells back to the sensitive state. The molecular mechanism through which EZH2 inhibition triggers its effects are not known.This study was conducted to understand the global change in proteome profile of tamoxifen resistant MCF-7 breast cancer cells as a result of effect of EZH2 knockdown. Label Free Quantitative proteomics revealed a large number of proteins altered in acquired tamoxifen resistant cells compared to the sensitive cells. A total of 286 proteins were identified with normalized RT for each m/z out of which 86 proteins were upregulated by more than 1.3 fold and 98 proteins were down regulated by more than 1.3 fold in MCF-7 tamoxifen resistant breast cancer cells in comparison to the sensitive breast cancer cells. Upon EZH2 knockdown in tamoxifen resistant cells, a total of 115 proteins were found to be altered with 20 proteins upregulated by more than 1.3 fold and 49 proteins down regulated by more than 1.3 fold. Among the top upregulated proteins were L-lactate dehydrogenase A chain, Alpha and Gamma-enolase, Calreticulin, heat shock protein HSP-90-beta, Alpha-actinin-4, Elongation factor 1-alpha, Vimentin, Protein S100A6, Putative protein FAM10A5, Heterogeneous nuclear ribonucleoprotein A1 and Keratin 1. In addition, 15 proteins were found to be down regulated in EZH2si transfected tamoxifen sensitive cells which otherwise were highlyup regulated in resistant cells in the presence of normal level of EZH2. This indicates a possible regulation of these molecules by EZH2 leading to loss of resistance. Our data unveils important molecular players downstream to EZH2 knockdown leading to regain of sensitivity to tamoxifen in acquired tamoxifen resistance.Thus, EZH2 seems to exert its effects through regulation of metabolism, epithelial to mesenchymal transition and protein synthesis & folding. Hence, targeting EZH2 or the molecules down the cascade might be helpful in reacquiring sensitivity to tamoxifen intamoxifen-resistant cells.
2019-09-30 | PXD012609 | Pride
Project description:Tamoxifen Resistant (TR) gene profile from Breast cancer cell lines T47D and ZR75-1 with their oestrogen-deprieved conterparts were analysed for gene associated with TR. We used Microarray Affymetrix HU133plus 2.0 chips for gene expression of TR cell lines, normalised them against GEO data available for normal T47D (GSM70667) and ZR75-1 (GSM70668). We grew parental breast cancer cell lines in tamoxifen containing media (0.1 microM) for 6 months and labelled them tamoxifen resistant (TR). Oestrogen-Deprieved cells were grown in charcoal-stripped media for 6 months then tamoxifen (0.1 microM) was added to the media and cells maintained a further 6 months and termed Oestrogen deprieved-tamoxifen resistant (ODTR) .
2010-12-31 | E-GEOD-22664 | biostudies-arrayexpress
Project description:Tamoxifen resistance has been a major clinical problem and is accountable for relapse in about one third of ER positive breast cancer patients. Most of the recurrent patients will eventually receive chemotherapy. However, the chemosensitivity of these tamoxifen-resistant breast cancer patients has never been explored. In this study, we demonstrate that tamoxifen-resistant breast cancer cells express significantly more BARD1 and BRCA1, which results in the resistance to DNA-damaging chemotherapy including cisplatin and adriamycin , but not to paclitaxel. Silencing BARD1 or BRCA1 expression or inhibition of BRCA1 phosphorylation by Dinaciclib restored the sensitivity to cisplatin in tamoxifen-resistant cells. In addition, we identified that activated PI3K/AKT pathway in tamoxifen-resistant cells was responsible for the upregulation of BARD1 and BRCA1. PI3K inhibitors, BKM120 and BYL719, decreased the expression of BARD1 and BRCA1 in tamoxifen-resistant cells and re-sensitized them to cisplatin both in vitro and in xenografted mice. Higher BARD1 and BRCA1 expression was associated with poor prognosis of early breast cancer patients, especially the ones received radiotherapy, indicating the potential use of PI3K inhibitors to reverse chemoresistance and radioresistance in ER positive breast cancer patients.
2021-03-15 | GSE111926 | GEO
Project description:Tamoxifen is the most widely used antiestrogen in patients with estrogen receptor (ER) positive breast cancer . However, less than half of patients benefit from tamoxifen treatment and 30-50% acquire resistance and the disease progresses. Resistance to tamoxifen is a serious problem in breast cancer therapy and major efforts are underway to find out underlying mechanisms. To find out the differential expression levels of mRNAs in tamoxifen-sensitive T47D versus tamoxifen-resistant T47D (T47DR) human breast cancer cells, T47DR (tamoxifen-resistant) cell line was established from T47D cells after the following continuous exposure to 1 μmol/L 4-Hydroxytamoxifen (H7904, Sigma, USA) for more than 6 months.Thousands of significantly different mRNA expression levels were found and analysed. Our study provides a reference data for the study of tamoxifen resistance .
2020-06-01 | GSE129544 | GEO
Project description:MCF-7aro cells were used to generate a cell culture model system that is resistant to 3 aromatase inhibitors (AIs), letrozole, anastrozole and exemestane. For comparison, the MCF-7aro cells were also used to generate the tamoxifen-resistant cells as well as long-term estrogen deprived, LTEDaro. Affymetrix microarray analysis was performed to determine changes in gene expression that are unique to AI-resistance. Keywords: cell lines, aromatase inhibitor resistance, tamoxifen resistance
2008-03-22 | GSE10911 | GEO