scholarly journals GREB1 regulates PI3K/Akt signaling to control hormone-sensitive breast cancer proliferation

2020 ◽  
Author(s):  
Corinne N Haines ◽  
Hope D Klingensmith ◽  
Makanko Komara ◽  
Craig J Burd
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Growth Regulation ◽  
Mtor Pathway ◽  
Estrogen Signaling ◽  
Molecular Function ◽  
Breast Cancers ◽  
Cancer Proliferation ◽  
Gene Target

Abstract Over 70% of breast cancers express the estrogen receptor (ER) and depend on ER activity for survival and proliferation. While hormone therapies that target receptor activity are initially effective, patients invariably develop resistance which is often associated with activation of the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway. While the mechanism by which estrogen regulates proliferation is not fully understood, one gene target of ER, growth regulation by estrogen in breast cancer 1 (GREB1), is required for hormone-dependent proliferation. However, the molecular function by which GREB1 regulates proliferation is unknown. Herein, we validate that knockdown of GREB1 results in growth arrest and that exogenous GREB1 expression initiates senescence, suggesting that an optimal level of GREB1 expression is necessary for proliferation of breast cancer cells. Under both of these conditions, GREB1 is able to regulate signaling through the PI3K/Akt/mTOR pathway. GREB1 acts intrinsically through PI3K to regulate phosphatidylinositol (3,4,5)-triphosphate levels and Akt activity. Critically, growth suppression of estrogen-dependent breast cancer cells by GREB1 knockdown is rescued by expression of constitutively activated Akt. Together, these data identify a novel molecular function by which GREB1 regulates breast cancer proliferation through Akt activation and provides a mechanistic link between estrogen signaling and the PI3K pathway.

scholarly journals GREB1 regulates proliferation of estrogen receptor positive breast cancer through modulation of PI3K/Akt/mTOR signaling

2019 ◽  
Author(s):  
Corinne N. Haines ◽  
H.D. Klingensmith ◽  
Craig J. Burd
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Growth Regulation ◽  
Mtor Pathway ◽  
Estrogen Signaling ◽  
Molecular Function ◽  
Breast Cancers ◽  
Gene Target

AbstractOver 70% of breast cancers express the estrogen receptor (ER) and depend on ER activity for survival and proliferation. While hormone therapies that target receptor activity are initially effective, patients invariably develop resistance which is often associated with activation of the PI3K/Akt/mTOR pathway. While the mechanism by which estrogen regulates proliferation is not fully understood, one gene target of ER, growth regulation by estrogen in breast cancer 1 (GREB1), is required for hormone-dependent proliferation. However, the molecular function by which GREB1 regulates proliferation is unknown. Herein, we validate that knockdown of GREB1 results in growth arrest and that exogenous GREB1 expression initiates oncogene-induced senescence, suggesting that an optimal level of GREB1 expression is necessary for proliferation of breast cancer cells. Under both of these conditions, GREB1 is able to regulate signaling through the PI3K/Akt/mTOR pathway. GREB1 acts intrinsically through PI3K to regulate PIP3 levels and Akt activity. Critically, growth suppression of estrogen-dependent breast cancer cells by GREB1 knockdown is rescued by expression of constitutively activated Akt. Together, these data identify a novel molecular function by which GREB1 regulates breast cancer proliferation through Akt activation and provides a mechanistic link between estrogen signaling and the PI3K pathway.

scholarly journals Transcriptional coregualtor NUPR1 maintains tamoxifen resistance in breast cancer cells

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Lingling Wang ◽  
Jiashen Sun ◽  
Yueyuan Yin ◽  
Yanan Sun ◽  
Jinyi Ma ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Critical Role ◽  
Endocrine Resistance ◽  
Autophagic Flux ◽  
Physical Interaction ◽  
Premature Senescence ◽  
Breast Cancers ◽  
Transcriptional Coregulator

AbstractTo support cellular homeostasis and mitigate chemotherapeutic stress, cancer cells must gain a series of adaptive intracellular processes. Here we identify that NUPR1, a tamoxifen (Tam)-induced transcriptional coregulator, is necessary for the maintenance of Tam resistance through physical interaction with ESR1 in breast cancers. Mechanistically, NUPR1 binds to the promoter regions of several genes involved in autophagy process and drug resistance such as BECN1, GREB1, RAB31, PGR, CYP1B1, and regulates their transcription. In Tam-resistant ESR1 breast cancer cells, NUPR1 depletion results in premature senescence in vitro and tumor suppression in vivo. Moreover, enforced-autophagic flux augments cytoplasmic vacuolization in NUPR1-depleted Tam resistant cells, which facilitates the transition from autophagic survival to premature senescence. Collectively, these findings suggest a critical role for NUPR1 as a transcriptional coregulator in enabling endocrine persistence of breast cancers, thus providing a vulnerable diagnostic and/or therapeutic target for endocrine resistance.

scholarly journals Tioconazole and Chloroquine Act Synergistically to Combat Doxorubicin-Induced Toxicity via Inactivation of PI3K/AKT/mTOR Signaling Mediated ROS-Dependent Apoptosis and Autophagic Flux Inhibition in MCF-7 Breast Cancer Cells

2021 ◽  
Vol 14 (3) ◽  
pp. 254
Author(s):  
Afnan H. El-Gowily ◽  
Samah A. Loutfy ◽  
Ehab M. M. Ali ◽  
Tarek M. Mohamed ◽  
Mohammed A. Mansour
Keyword(s):  
Breast Cancer ◽  
Combination Therapy ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Mtor Pathway ◽  
Tumor Growth Inhibition ◽  
Autophagic Flux ◽  
Ki 67 ◽  
Mcf 7

Cancer is a complex devastating disease with enormous treatment challenges, including chemo- and radiotherapeutic resistance. Combination therapy demonstrated a promising strategy to target hard-to-treat cancers and sensitize cancer cells to conventional anti-cancer drugs such as doxorubicin. This study aimed to establish molecular profiling and therapeutic efficacy assessment of chloroquine and/or tioconazole (TIC) combination with doxorubicin (DOX) as anew combination model in MCF-7 breast cancer. The drugs are tested against apoptotic/autophagic pathways and related redox status. Molecular docking revealed that chloroquine (CQ) and TIC could be potential PI3K and ATG4B pathway inhibitors. Combination therapy significantly inhibited cancer cell viability, PI3K/AkT/mTOR pathway, and tumor-supporting autophagic flux, however, induced apoptotic pathways and altered nuclear genotoxic feature. Our data revealed that the combination cocktail therapy markedly inhibited tumor proliferation marker (KI-67) and cell growth, along with the accumulation of autophagosomes and elevation of LC3-II and p62 levels indicated autophagic flux blockage and increased apoptosis. Additionally, CQ and/or TIC combination therapy with DOX exerts its activity on the redox balance of cancer cells mediated ROS-dependent apoptosis induction achieved by GPX3 suppression. Besides, Autophagy inhibition causes moderately upregulation in ATGs 5,7 redundant proteins strengthened combinations induced apoptosis, whereas inhibition of PI3K/AKT/mTOR pathway with Beclin-1 upregulation leading to cytodestructive autophagy with overcome drug resistance effectively in curing cancer. Notably, the tumor growth inhibition and various antioxidant effects were observed in vivo. These results suggest CQ and/or TIC combination with DOX could act as effective cocktail therapy targeting autophagy and PI3K/AKT/mTOR pathways in MCF-7 breast cancer cells and hence, sensitizes cancer cells to doxorubicin treatment and combat its toxicity.

scholarly journals Transcriptome profiles of stem-like cells from primary breast cancers allow identification of ITGA7 as a predictive marker of chemotherapy response

2021 ◽  
Author(s):  
Noha Gwili ◽  
Stacey J. Jones ◽  
Waleed Al Amri ◽  
Ian M. Carr ◽  
Sarah Harris ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Predictive Marker ◽  
Therapy Resistance ◽  
Differentially Expressed ◽  
Molecular Profile ◽  
Chemotherapy Response ◽  
Breast Cancers

Abstract Background Breast cancer stem cells (BCSCs) are drivers of therapy-resistance, therefore are responsible for poor survival. Molecular signatures of BCSCs from primary cancers remain undefined. Here, we identify the consistent transcriptome of primary BCSCs shared across breast cancer subtypes, and we examine the clinical relevance of ITGA7, one of the genes differentially expressed in BCSCs. Methods Primary BCSCs were assessed using immunohistochemistry and fluorescently labelled using Aldefluor (n = 17). Transcriptomes of fluorescently sorted BCSCs and matched non-stem cancer cells were determined using RNA-seq (n = 6). ITGA7 expression was examined in breast cancers using immunohistochemistry (n = 305), and its functional role was tested using siRNA in breast cancer cells. Results Proportions of BCSCs varied from 0 to 9.4%. 38 genes were significantly differentially expressed in BCSCs; genes were enriched for functions in vessel morphogenesis, motility, and metabolism. ITGA7 was found to be significantly downregulated in BCSCs, and low expression significantly correlated with reduced survival in patients treated with chemotherapy, and with chemoresistance in breast cancer cells in vitro. Conclusions This study is the first to define the molecular profile of BCSCs from a range of primary breast cancers. ITGA7 acts as a predictive marker for chemotherapy response, in accordance with its downregulation in BCSCs.

scholarly journals Spot 14: A Marker of Aggressive Breast Cancer and a Potential Therapeutic Target

Endocrinology ◽  
2006 ◽  
Vol 147 (9) ◽  
pp. 4048-4055 ◽  
Author(s):  
William B. Kinlaw ◽  
Jennifer L. Quinn ◽  
Wendy A. Wells ◽  
Christopher Roser-Jones ◽  
Joel T. Moncur
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Therapeutic Target ◽  
Milk Fat ◽  
Breast Cancer Cells ◽  
De Novo ◽  
Lipid Synthesis ◽  
Breast Cancers ◽  
Spot 14 ◽  
Aggressive Breast Cancer

Spot 14 (S14) is a nuclear protein that communicates the status of dietary fuels and fuel-related hormones to genes required for long-chain fatty acid synthesis. In mammary gland, S14 is important for both epithelial proliferation and milk fat production. The S14 gene is amplified in some breast cancers and is strongly expressed in most. High expression of S14 in primary invasive breast cancer is conspicuously predictive of recurrence. S14 mediates the induction of lipogenesis by progestin in breast cancer cells and accelerates their growth. Conversely, S14 knockdown impairs de novo lipid synthesis and causes apoptosis. We found that breast cancer cells do not express lipoprotein lipase (LPL) and hypothesize that they do not have access to circulating lipids unless the local environment supplies it. This may explain why primary breast cancers with low S14 do not survive transit from the LPL-rich mammary fat pad to areas devoid of LPL, such as lymph nodes, and thus do not appear as distant metastases. Thus, S14 is a marker for aggressive breast cancer and a potential target as well. Future effort will center on validation of S14 as a therapeutic target and producing antagonists of its action.

scholarly journals Dysregulation of Transcription Factor EB Contributes to Cell Proliferation, Metastasis and Stemness in Breast Cancer

2021 ◽  
Author(s):  
Ningwei Fu ◽  
Ning Fan ◽  
Wenchao Luo ◽  
Lijia Lv ◽  
Jing Li ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Cancer Stem Cells ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Migration And Invasion ◽  
Breast Cancer Stem Cells ◽  
Cancer Proliferation ◽  
Mammosphere Formation

Abstract Purpose: TFEB is a key regulator of autophagy-lysosomal biogenesis pathways, while its dysregulation is highly prevalent in various human cancers, but the specific contribution to breast cancer remains poorly understood. The main purpose of this study is to explore the role of TFEB in breast cancer proliferation, metastasis and maintaining breast cancer stem cells (BCSCs) traits, thus uncovering its underlying mechanism.Methods: Bioinformatics, western blotting and immunohistochemical staining were applied to analyze the expression of TFEB in breast cancer. Stable down-regulation TFEB cells were established in MCF-7 and MDA-MB-231 breast cancer cell lines. MTT, clone formation, wound healing, transwell and 3D tumor invasion assays were used to evaluate the proliferation, migration and invasion ability of breast cancer cells. Mammosphere formation, immunocytochemical (ICC) staining were used to detect the effect of down-regulating TFEB on breast cancer stem cells. Results: we demonstrated that higher expression of TFEB was found in breast cancer. TFEB depletion had inhibitory effects on cellular proliferation, migration and invasion of breast cancer cells. Moreover, knockdown TFEB decreased mammosphere formation ability of BCSCs and expression of cancer stem cell markers. Autophagy-lysosomal related proteins were decreased by down regulation of TFEB. Conclusion: we uncovered a critical role of TFEB in breast cancer proliferation and metastasis, and BCSCs self-renewal and stemness. The underlying mechanisms involve in maintaining BCSCs traits, and dysregulating lysosome functions.

scholarly journals Estrogen Signaling Induces Mitochondrial Dysfunction-Associated Autophagy and Senescence in Breast Cancer Cells

Biology ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 68
Author(s):  
Khuloud Bajbouj ◽  
Jasmin Shafarin ◽  
Jalal Taneera ◽  
Mawieh Hamad
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Mitochondrial Damage ◽  
Estrogen Signaling ◽  
Ovarian Cancer Cells ◽  
Cellular Iron ◽  
Mitochondrial Membrane Depolarization ◽  
Apoptotic Effects ◽  
Mcf 7

Previous work has shown that although estrogen (E2) disrupts cellular iron metabolism and induces oxidative stress in breast and ovarian cancer cells, it fails to induce apoptosis. However, E2 treatment was reported to enhance the apoptotic effects of doxorubicin in cancer cells. This suggests that E2 can precipitate anti-growth effects that render cancer cells more susceptible to chemotherapy. To investigate such anti-growth non-apoptotic, effects of E2 in cancer cells, MDA-MB-231 and MCF-7 cells were evaluated for the expression of key autophagy and senescence markers and for mitochondrial damage following E2 treatment. Treated cells experienced mitochondrial membrane depolarization along with increased expression of LC3-I/II, Pink1 and LAMP2, increased LC3-II accumulation and increased lysosomal and mitochondrial accumulation and flattening. E2-treated MCF-7 cells also showed reduced P53 and pRb780 expression and increased Rb and P21 expression. Increased expression of the autophagy markers ATG3 and Beclin1 along with increased levels of β-galactosidase activity and IL-6 production were evident in E2-treated MCF-7 cells. These findings suggest that E2 precipitates a form of mitochondrial damage that leads to cell senescence and autophagy in breast cancer cells.

scholarly journals Selective Effects of Thioridazine on Self-Renewal of Basal-Like Breast Cancer Cells

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Matthew Tegowski ◽  
Cheng Fan ◽  
Albert S. Baldwin
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Cancer Cell ◽  
Breast Cancer Cells ◽  
Cell Types ◽  
Breast Cancer Cell Lines ◽  
Breast Cancers ◽  
Self Renewal ◽  
Basal Like Breast Cancer

AbstractSeveral recent publications demonstrated that DRD2-targeting antipsychotics such as thioridazine induce proliferation arrest and apoptosis in diverse cancer cell types including those derived from brain, lung, colon, and breast. While most studies show that 10–20 µM thioridazine leads to reduced proliferation or increased apoptosis, here we show that lower doses of thioridazine (1–2 µM) target the self-renewal of basal-like breast cancer cells, but not breast cancer cells of other subtypes. We also show that all breast cancer cell lines tested express DRD2 mRNA and protein, regardless of thioridazine sensitivity. Further, DRD2 stimulation with quinpirole, a DRD2 agonist, promotes self-renewal, even in cell lines in which thioridazine does not inhibit self-renewal. This suggests that DRD2 is capable of promoting self-renewal in these cell lines, but that it is not active. Further, we show that dopamine can be detected in human and mouse breast tumor samples. This observation suggests that dopamine receptors may be activated in breast cancers, and is the first time to our knowledge that dopamine has been directly detected in human breast tumors, which could inform future investigation into DRD2 as a therapeutic target for breast cancer.

scholarly journals Review of: Tamoxifen and TRAIL synergistically induce apoptosis in breast cancer cells

2008 ◽  
Vol 11 (2) ◽  
Author(s):  
Alison J. Butt
Keyword(s):  
Breast Cancer ◽  
Tumor Growth ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Single Agent ◽  
Xenograft Model ◽  
Estrogen Receptor Α ◽  
Tumor Xenograft ◽  
Breast Cancers ◽  
Induced Apoptosis

Citation of original article:C. Lagadec, E. Adriaenssens, R. A. Toillon, V. Chopin, R. Romon, F. Van Coppenolle, H. Hondermarck, X. Le Bourhis. Oncogene advance online publication, 3 September 2007; doi:10.1038/sj.onc.1210749.Abstract of the original article:Tamoxifen (TAM), is widely used as a single agent in adjuvant treatment of breast cancer. Here, we investigated the effects of TAM in combination with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in estrogen receptor-α (ER-α)-positive and -negative breast cancer cells. We showed that cotreatment with TAM and TRAIL synergistically induced apoptosis regardless of ER-α status. By contrast, cotreatment did not affect the viability of normal breast epithelial cells. Cotreatment with TAM and TRAIL in breast cancer cells decreased the levels of antiapoptotic proteins including FLIPs and Bcl-2, and enhanced the levels of proapoptotic proteins such as FADD, caspase 8, tBid, Bax and caspase 9. Furthermore, cotreatment-induced apoptosis was efficiently reduced by FADD- or Bid-siRNA, indicating the implication of both extrinsic and intrinsic pathways in synergistic apoptosis induction. Importantly, cotreatment totally arrested tumor growth in an ER-α-negative MDA-MB-231 tumor xenograft model. The abrogation of tumor growth correlated with enhanced apoptosis in tumor tissues. Our findings raise the possibility to use TAM in combination with TRAIL for breast cancers, regardless of ER-α status.

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