scholarly journals Design and Characterization of a Cell-Penetrating Peptide Derived from the SOX2 Transcription Factor

2021 ◽  
Vol 22 (17) ◽  
pp. 9354
Author(s):  
Neha S. Gandhi ◽  
Edina Wang ◽  
Anabel Sorolla ◽  
Yu Jie Kan ◽  
Adil Malik ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Transcription Factor ◽  
Cancer Cells ◽  
Nuclear Localization ◽  
Cellular Proliferation ◽  
Dominant Negative ◽  
Random Coil ◽  
Nuclear Localization Sequence ◽  
Mrna Levels ◽  
Breast Cancers

SOX2 is an oncogenic transcription factor overexpressed in nearly half of the basal-like triple-negative breast cancers associated with very poor outcomes. Targeting and inhibiting SOX2 is clinically relevant as high SOX2 mRNA levels are positively correlated with decreased overall survival and progression-free survival in patients affected with breast cancer. Given its key role as a master regulator of cell proliferation, SOX2 represents an important scaffold for the engineering of dominant-negative synthetic DNA-binding domains (DBDs) that act by blocking or interfering with the oncogenic activity of the endogenous transcription factor in cancer cells. We have synthesized an interference peptide (iPep) encompassing a truncated 24 amino acid long C-terminus of SOX2 containing a potential SOX-specific nuclear localization sequence, and the determinants of the binding of SOX2 to the DNA and to its transcription factor binding partners. We found that the resulting peptide (SOX2-iPep) possessed intrinsic cell penetration and promising nuclear localization into breast cancer cells, and decreased cellular proliferation of SOX2 overexpressing cell lines. The novel SOX2-iPep was found to exhibit a random coil conformation predominantly in solution. Molecular dynamics simulations were used to characterize the interactions of both the SOX2 transcription factor and the SOX2-iPep with FGF4-enhancer DNA in the presence of the POU domain of the partner transcription factor OCT4. Predictions of the free energy of binding revealed that the iPep largely retained the binding affinity for DNA of parental SOX2. This work will enable the future engineering of novel dominant interference peptides to transport different therapeutic cargo molecules such as anti-cancer drugs into cells.

scholarly journals Loss of an Estrogen Receptor Isoform (ERαΔ3) in Breast Cancer and the Consequences of Its Reexpression: Interference with Estrogen-Stimulated Properties of Malignant Transformation

1997 ◽  
Vol 11 (13) ◽  
pp. 2004-2015 ◽  
Author(s):  
I. Erenburg ◽  
B. Schachter ◽  
R. Mira y Lopez ◽  
L. Ossowski
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Vector Control ◽  
Cancer Cells ◽  
Dominant Negative ◽  
Breast Cancer Cell Lines ◽  
Breast Cancers ◽  
Normal Breast Epithelium ◽  
Anchorage Independent Growth

Abstract Comparison of mRNA ratios of a non-DNA-binding estrogen receptor (ERα) isoform, missing exon 3 (ERαΔ3), to the full-length ERα, in normal breast epithelium to that in primary breast cancers and breast cancer cell lines revealed a 30-fold reduction of this ratio in cancer cells (P < 0.0001). To test what functions may have been affected by the loss of ERαΔ3, stable clones of MCF-7 cells expressing ectopic ERαΔ3 protein, at the range of physiological ERα, were generated. In vector-transfected controls the ERαΔ3-mRNA and protein were less than 10% while in the ERαΔ3-expressing clones, ERαΔ3-mRNA and protein ranged from 36–76% of the total ERα. Estrogen (E2) stimulated the expression of pS2-mRNA in pMV7 vector control cells, but the stimulation was reduced by up to 93% in ERαΔ3-expressing clones. In addition, several properties associated with the transformed phenotype were also strongly affected when ERαΔ3 protein was reexpressed. Compared with vector-transfected control cells, the saturation density of the ERαΔ3-expressing clones was reduced by 50–68%, while their exponential growth rate was only slightly (14.5 ± 5%) lower. The in vivo invasiveness of the ERαΔ3-expressing cells was significantly reduced (P = 0.007) by up to 79%. E2 stimulated anchorage-independent growth of the pMV7 vector control cells, but reduced it to below baseline levels in ERαΔ3 clones. The reduction of the pS2 response to E2 in the ERαΔ3-expressing clones and the E2 block of anchorage-independent growth to below baseline were more pronounced than expected from the dominant negative function of ERαΔ3. These observations suggest that E2 may activate an additional ERαΔ3-dependent inhibitory pathway. The drastic reduction of ERαΔ3 to ERα ratio in breast cancer, and the fact that when present in breast cancer cells this isoform leads to a suppression, rather than enhancement, of the transformed phenotype by E2 suggests that the regulation of ERα-mRNA splicing may need to be altered for the breast carcinogenesis to proceed.

Targeted Delivery in Breast Cancer Cells via Iodine: Nuclear Localization Sequence Conjugate

2011 ◽  
Vol 22 (8) ◽  
pp. 1567-1575 ◽  
Author(s):  
Hui-Yuan Wang ◽  
Cao Li ◽  
Wen-Jie Yi ◽  
Yun-Xia Sun ◽  
Si-Xue Cheng ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Nuclear Localization ◽  
Targeted Delivery ◽  
Breast Cancer Cells ◽  
Nuclear Localization Sequence ◽  
Localization Sequence

scholarly journals Inflammatory conversion of quiescent osteoblasts by metastatic breast cancer cells through pERK1/2 aggravates cancer-induced bone destruction

Bone Research ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jungho Back ◽  
Minh Nam Nguyen ◽  
Lu Li ◽  
Saelim Lee ◽  
Inkyu Lee ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Bone Destruction ◽  
Metastatic Breast ◽  
Mek Inhibitor ◽  
Dominant Negative ◽  
Cancer Growth ◽  
Breast Cancers ◽  
Bone Homeostasis

AbstractDisruption of bone homeostasis caused by metastatic osteolytic breast cancer cells increases inflammatory osteolysis and decreases bone formation, thereby predisposing patients to pathological fracture and cancer growth. Alteration of osteoblast function induces skeletal diseases due to the disruption of bone homeostasis. We observed increased activation of pERK1/2 in osteolytic breast cancer cells and osteoblasts in human pathological specimens with aggressive osteolytic breast cancer metastases. We confirmed that osteolytic breast cancers with high expression of pERK1/2 disrupt bone homeostasis via osteoblastic ERK1/2 activation at the bone-breast cancer interface. The process of inflammatory osteolysis modulates ERK1/2 activation in osteoblasts and breast cancer cells through dominant-negative MEK1 expression and constitutively active MEK1 expression to promote cancer growth within bone. Trametinib, an FDA-approved MEK inhibitor, not only reduced breast cancer-induced bone destruction but also dramatically reduced cancer growth in bone by inhibiting the inflammatory skeletal microenvironment. Taken together, these findings suggest that ERK1/2 activation in both breast cancer cells and osteoblasts is required for osteolytic breast cancer-induced inflammatory osteolysis and that ERK1/2 pathway inhibitors may represent a promising adjuvant therapy for patients with aggressive osteolytic breast cancers by altering the shared cancer and bone microenvironment.

scholarly journals Integrin α3β1 Promotes Invasive and Metastatic Properties of Breast Cancer Cells through Induction of the Brn-2 Transcription Factor

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 480
Author(s):  
Rakshitha Pandulal Miskin ◽  
Janine S. A. Warren ◽  
Abibatou Ndoye ◽  
Lei Wu ◽  
John M. Lamar ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Transcription Factor ◽  
Cancer Cells ◽  
Cell Invasion ◽  
Breast Cancer Cells ◽  
Gene Promoter ◽  
Akt Inhibitor ◽  
Integrin Α3β1

In the current study, we demonstrate that integrin α3β1 promotes invasive and metastatic traits of triple-negative breast cancer (TNBC) cells through induction of the transcription factor, Brain-2 (Brn-2). We show that RNAi-mediated suppression of α3β1 in MDA-MB-231 cells caused reduced expression of Brn-2 mRNA and protein and reduced activity of the BRN2 gene promoter. In addition, RNAi-targeting of Brn-2 in MDA-MB-231 cells decreased invasion in vitro and lung colonization in vivo, and exogenous Brn-2 expression partially restored invasion to cells in which α3β1 was suppressed. α3β1 promoted phosphorylation of Akt in MDA-MB-231 cells, and treatment of these cells with a pharmacological Akt inhibitor (MK-2206) reduced both Brn-2 expression and cell invasion, indicating that α3β1-Akt signaling contributes to Brn-2 induction. Analysis of RNAseq data from patients with invasive breast carcinoma revealed that high BRN2 expression correlates with poor survival. Moreover, high BRN2 expression positively correlates with high ITGA3 expression in basal-like breast cancer, which is consistent with our experimental findings that α3β1 induces Brn-2 in TNBC cells. Together, our study demonstrates a pro-invasive/pro-metastatic role for Brn-2 in breast cancer cells and identifies a role for integrin α3β1 in regulating Brn-2 expression, thereby revealing a novel mechanism of integrin-dependent breast cancer cell invasion.

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 The ETS Transcription Factor ESE-1 Transforms MCF-12A Human Mammary Epithelial Cells via a Novel Cytoplasmic Mechanism

2004 ◽  
Vol 24 (12) ◽  
pp. 5548-5564 ◽  
Author(s):  
Jason D. Prescott ◽  
Karen S. N. Koto ◽  
Meenakshi Singh ◽  
Arthur Gutierrez-Hartmann
Keyword(s):  
Breast Cancer ◽  
Transcription Factor ◽  
Epithelial Cells ◽  
Nuclear Localization ◽  
Human Breast Cancer ◽  
Mammary Epithelial Cells ◽  
Cell Transformation ◽  
Mammary Epithelial ◽  
Human Breast ◽  
Human Mammary Epithelial

ABSTRACT Several different transcription factors, including estrogen receptor, progesterone receptor, and ETS family members, have been implicated in human breast cancer, indicating that transcription factor-induced alterations in gene expression underlie mammary cell transformation. ESE-1 is an epithelium-specific ETS transcription factor that contains two distinguishing domains, a serine- and aspartic acid-rich (SAR) domain and an AT hook domain. ESE-1 is abundantly expressed in human breast cancer and trans-activates epithelium-specific gene promoters in transient transfection assays. While it has been presumed that ETS factors transform mammary epithelial cells via their nuclear transcriptional functions, here we show (i) that ESE-1 protein is cytoplasmic in human breast cancer cells; (ii) that stably expressed green fluorescent protein-ESE-1 transforms MCF-12A human mammary epithelial cells; and (iii) that the ESE-1 SAR domain, acting in the cytoplasm, is necessary and sufficient to mediate this transformation. Deletion of transcriptional regulatory or nuclear localization domains does not impair ESE-1-mediated transformation, whereas fusing the simian virus 40 T-antigen nuclear localization signal to various ESE-1 constructs, including the SAR domain alone, inhibits their transforming capacity. Finally, we show that the nuclear localization of ESE-1 protein induces apoptosis in nontransformed mammary epithelial cells via a transcription-dependent mechanism. Together, our studies reveal two distinct ESE-1 functions, apoptosis and transformation, where the ESE-1 transcription activation domain contributes to apoptosis and the SAR domain mediates transformation via a novel nonnuclear, nontranscriptional mechanism. These studies not only describe a unique ETS factor transformation mechanism but also establish a new paradigm for cell transformation in general.

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 Estradiol Abrogates Apoptosis in Breast Cancer Cells through Inactivation of BAD: Ras-dependent Nongenomic Pathways Requiring Signaling through ERK and Akt

2004 ◽  
Vol 15 (7) ◽  
pp. 3266-3284 ◽  
Author(s):  
Romaine Ingrid Fernando ◽  
Jay Wimalasena
Keyword(s):  
Breast Cancer ◽  
Tumor Necrosis Factor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Dominant Negative ◽  
Induced Apoptosis ◽  
Factor Α ◽  
Necrosis Factor

Estrogens such as 17-β estradiol (E2) play a critical role in sporadic breast cancer progression and decrease apoptosis in breast cancer cells. Our studies using estrogen receptor-positive MCF7 cells show that E2 abrogates apoptosis possibly through phosphorylation/inactivation of the proapoptotic protein BAD, which was rapidly phosphorylated at S112 and S136. Inhibition of BAD protein expression with specific antisense oligonucleotides reduced the effectiveness of tumor necrosis factor-α, H2O2, and serum starvation in causing apoptosis. Furthermore, the ability of E2 to prevent tumor necrosis factor-α-induced apoptosis was blocked by overexpression of the BAD S112A/S136A mutant but not the wild-type BAD. BAD S112A/S136A, which lacks phosphorylation sites for p90RSK1 and Akt, was not phosphorylated in response to E2 in vitro. E2 treatment rapidly activated phosphatidylinositol 3-kinase (PI-3K)/Akt and p90RSK1 to an extent similar to insulin-like growth factor-1 treatment. In agreement with p90RSK1 activation, E2 also rapidly activated extracellular signal-regulated kinase, and this activity was down-regulated by chemical and biological inhibition of PI-3K suggestive of cross talk between signaling pathways responding to E2. Dominant negative Ras blocked E2-induced BAD phosphorylation and the Raf-activator RasV12T35S induced BAD phosphorylation as well as enhanced E2-induced phosphorylation at S112. Chemical inhibition of PI-3K and mitogen-activated protein kinase kinase 1 inhibited E2-induced BAD phosphorylation at S112 and S136 and expression of dominant negative Ras-induced apoptosis in proliferating cells. Together, these data demonstrate a new nongenomic mechanism by which E2 prevents apoptosis.

scholarly journals Use of Proton Pump Inhibitors as Adjunct Treatment for Triple-Negative Breast Cancers. An Introductory Study

2014 ◽  
Vol 17 (3) ◽  
pp. 439 ◽  
Author(s):  
Wayne Goh ◽  
Inna Sleptsova-Freidrich ◽  
Nenad Petrovic
Keyword(s):  
Breast Cancer ◽  
Cancer Treatment ◽  
Cancer Cells ◽  
Proton Pump ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Dependent Manner ◽  
Breast Cancers ◽  
Gastric Type ◽  
Dose Dependent

PURPOSE: Triple negative breast cancers (estrogen, progesterone and human epidermal growth factor 2 (HER2) receptor-negative) are among the most aggressive forms of cancers with limited treatment options. Doxorubicin is one of the agents found in many of the current cancer treatment protocols, although its use is limited by dose-dependent cardiotoxicity. This work investigates one of the ways to suppress cancer growth by inhibiting tumor cell ability to remove acid accumulated during its metabolism by proton pump inhibitor esomeprazole (a drug with extensive clinical use) which could serve as an addition to doxorubicin therapy. METHODS: In this work, we have investigated growth suppression of triple-negative breast cancer cells MDA-MB-468 by esomeprazole and doxorubicin by trypan blue exclusion assay. Measurement of acidification of treated cancer cells was performed using intracellular pH-sensitive probe, BCECF-AM. Finally, expression of gastric type proton pump (H+/K+ ATPase, a target for esomeprazole) on MDA-MB-468 cells was detected by immunofluorescence and Western blotting. RESULTS: We have found that esomeprazole suppresses growth of triple-negative breast cancer cell in vitro in a dose-dependent manner through increase in their intracellular acidification. In contrast, esomeprazole did not have significant effect on non-cancerous breast epithelial MCF-10A cells. Esomeprazole increases doxorubicin effects suggesting that dual treatments might be possible. In addition, response of MDA-MB-468 cells to esomeprazole could be mediated by gastric type proton pump (H+/K+ ATPase) in cancer cells contrary to previous beliefs that this proton pump expression is restricted to parietal cells of the stomach epithelia. CONCLUSION: This study provides first evidence that adjunct use of esomeprazole in breast cancer treatment might be a possible to combat adverse effects of doxorubicin and increase its effectiveness. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

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