scholarly journals PERK signaling through C/EBPδ contributes to ER stress-induced expression of immunomodulatory and tumor promoting chemokines by cancer cells

2021 ◽  
Vol 12 (11) ◽  
Author(s):  
Namratha Sheshadri ◽  
Dipak K. Poria ◽  
Shikha Sharan ◽  
Ying Hu ◽  
Chunhua Yan ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Er Stress ◽  
Cancer Cells ◽  
Transcriptional Profiling ◽  
Tumor Biology ◽  
Breast Cancer Cell Lines ◽  
Cancer Therapies ◽  
Global Protein Synthesis ◽  
Short Term Exposure ◽  
Factor C

AbstractCancer cells experience endoplasmic reticulum (ER) stress due to activated oncogenes and conditions of nutrient deprivation and hypoxia. The ensuing unfolded protein response (UPR) is executed by ATF6, IRE1 and PERK pathways. Adaptation to mild ER stress promotes tumor cell survival and aggressiveness. Unmitigated ER stress, however, will result in cell death and is a potential avenue for cancer therapies. Because of this yin-yang nature of ER stress, it is imperative that we fully understand the mechanisms and dynamics of the UPR and its contribution to the complexity of tumor biology. The PERK pathway inhibits global protein synthesis while allowing translation of specific mRNAs, such as the ATF4 transcription factor. Using thapsigargin and tunicamycin to induce acute ER stress, we identified the transcription factor C/EBPδ (CEBPD) as a mediator of PERK signaling to secretion of tumor promoting chemokines. In melanoma and breast cancer cell lines, PERK mediated early induction of C/EBPδ through ATF4-independent pathways that involved at least in part Janus kinases and the STAT3 transcription factor. Transcriptional profiling revealed that C/EBPδ contributed to 20% of thapsigargin response genes including chaperones, components of ER-associated degradation, and apoptosis inhibitors. In addition, C/EBPδ supported the expression of the chemokines CXCL8 (IL-8) and CCL20, which are known for their tumor promoting and immunosuppressive properties. With a paradigm of short-term exposure to thapsigargin, which was sufficient to trigger prolonged activation of the UPR in cancer cells, we found that conditioned media from such cells induced cytokine expression in myeloid cells. In addition, activation of the CXCL8 receptor CXCR1 during thapsigargin exposure supported subsequent sphere formation by cancer cells. Taken together, these investigations elucidated a novel mechanism of ER stress-induced transmissible signals in tumor cells that may be particularly relevant in the context of pharmacological interventions.

scholarly journals High concentration calcitriol induces endoplasmic reticulum stress related gene profile in breast cancer cells

2017 ◽  
Vol 95 (2) ◽  
pp. 289-294 ◽  
Author(s):  
Ali Burak Ozkaya ◽  
Handan Ak ◽  
Hikmet Hakan Aydin
Keyword(s):  
Breast Cancer ◽  
Vitamin D ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Survival Function ◽  
Active Form ◽  
Breast Cancer Cell Lines ◽  
Transcriptomic Profile

Calcitriol, the active form of vitamin D, is known for its anticancer properties including induction of apoptosis as well as the inhibition of angiogenesis and metastasis. Understanding the mechanisms of action for calcitriol will help with the development of novel treatment strategies. Since vitamin D exerts its cellular actions via binding to its receptor and by altering expressions of a set of genes, we aimed to evaluate the effect of calcitriol on transcriptomic profile of breast cancer cells. We previously demonstrated that calcitriol alters endoplasmic reticulum (ER) stress markers, therefore in this study we have focused on ER-stress-related genes to reveal calcitriols action on these genes in particular. We have treated breast cancer cell lines MCF-7 and MDA-MB-231 with previously determined IC50 concentrations of calcitriol and evaluated the transcriptomic alterations via microarray. During analysis, only genes altered by at least 2-fold with a P value < 0.05 were taken into consideration. Our findings revealed an ER-stress-associated transcriptomic profile induced by calcitriol. Induced genes include genes with a pro-survival function (NUPR1, DNAJB9, HMOX1, LCN2, and LAMP3) and with a pro-death function (CHOP (DDIT3), DDIT4, NDGR1, NOXA, and CLGN). These results suggest that calcitriol induces an ER-stress-like response inducing both pro-survival and pro-death transcripts in the process.

scholarly journals HDAC5-mediated deacetylation and nuclear localisation of SOX9 is critical for tamoxifen resistance in breast cancer

2019 ◽  
Vol 121 (12) ◽  
pp. 1039-1049 ◽  
Author(s):  
Yue Xue ◽  
Wenwen Lian ◽  
Jiaqi Zhi ◽  
Wenjuan Yang ◽  
Qianjin Li ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Transcription Factor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Nuclear Translocation ◽  
Tamoxifen Resistance ◽  
Nuclear Localisation ◽  
Tamoxifen Resistant ◽  
Factor C ◽  
Positive Breast Cancer

Abstract Background Tamoxifen resistance remains a significant clinical challenge for the therapy of ER-positive breast cancer. It has been reported that the upregulation of transcription factor SOX9 in ER+ recurrent cancer is sufficient for tamoxifen resistance. However, the mechanisms underlying the regulation of SOX9 remain largely unknown. Methods The acetylation level of SOX9 was detected by immunoprecipitation and western blotting. The expressions of HDACs and SIRTs were evaluated by qRT-PCR. Cell growth was measured by performing MTT assay. ALDH-positive breast cancer stem cells were evaluated by flow cytometry. Interaction between HDAC5 and SOX9 was determined by immunoprecipitation assay. Results Deacetylation is required for SOX9 nuclear translocation in tamoxifen-resistant breast cancer cells. Furthermore, HDAC5 is the key deacetylase responsible for SOX9 deacetylation and subsequent nuclear translocation. In addition, the transcription factor C-MYC directly promotes the expression of HDAC5 in tamoxifen resistant breast cancer cells. For clinical relevance, high SOX9 and HDAC5 expression are associated with lower survival rates in breast cancer patients treated with tamoxifen. Conclusions This study reveals that HDAC5 regulated by C-MYC is essential for SOX9 deacetylation and nuclear localisation, which is critical for tamoxifen resistance. These results indicate a potential therapy strategy for ER+ breast cancer by targeting C-MYC/HDAC5/SOX9 axis.

scholarly journals Pygenic Acid A (PA) Sensitizes Metastatic Breast Cancer Cells to Anoikis and Inhibits Metastasis In Vivo

2020 ◽  
Vol 21 (22) ◽  
pp. 8444
Author(s):  
Ga-Eun Lim ◽  
Jee Young Sung ◽  
Suyeun Yu ◽  
Younmi Kim ◽  
Jaegal Shim ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Er Stress ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Metastatic Breast ◽  
Breast Cancer Cell Lines ◽  
Syngeneic Mouse Model ◽  
Apoptosis Protein ◽  
4T1 Cells

Metastasis is the main cause of cancer-related deaths. Anoikis is a type of apoptosis caused by cell detachment, and cancer cells become anoikis resistant such that they survive during circulation and can successfully metastasize. Therefore, sensitization of cancer cells to anoikis could prevent metastasis. Here, by screening for anoikis sensitizer using natural compounds, we found that pygenic acid A (PA), a natural compound from Prunella vulgaris, not only induced apoptosis but also sensitized the metastatic triple-negative breast cancer cell lines, MDA-MB-231 cells (human) and 4T1 cells (mouse), to anoikis. Apoptosis protein array and immunoblotting analysis revealed that PA downregulated the pro-survival proteins, including cIAP1, cIAP2, and survivin, leading to cell death of both attached and suspended cells. Interestingly, PA decreased the levels of proteins associated with anoikis resistance, including p21, cyclin D1, p-STAT3, and HO-1. Ectopic expression of active STAT3 attenuated PA-induced anoikis sensitivity. Although PA activated ER stress and autophagy, as determined by increases in the levels of characteristic markers, such as IRE1α, p-elF2α, LC3B I, and LC3B II, PA treatment resulted in p62 accumulation, which could be due to PA-induced defects in autophagy flux. PA also decreased metastatic characteristics, such as cell invasion, migration, wound closure, and 3D growth. Finally, lung metastasis of luciferase-labeled 4T1 cells decreased following PA treatment in a syngeneic mouse model when compared with the control. These data suggest that PA sensitizes metastatic breast cancer cells to anoikis via multiple pathways, such as inhibition of pro-survival pathways and activation of ER stress and autophagy, leading to the inhibition of metastasis. These findings suggest that sensitization to anoikis by PA could be used as a new therapeutic strategy to control the metastasis of breast cancer.

scholarly journals Mutation in FBXO32 causes dilated cardiomyopathy through up-regulation of ER-stress mediated apoptosis

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Nadya Al-Yacoub ◽  
Dilek Colak ◽  
Salma Awad Mahmoud ◽  
Maya Hammonds ◽  
Kunhi Muhammed ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Er Stress ◽  
Target Genes ◽  
Transcriptional Profiling ◽  
Underlying Mechanism ◽  
Effector Proteins ◽  
Homozygous Mutation ◽  
Unfolded Protein ◽  
Canonical Pathways ◽  
The Unfolded Protein Response

AbstractEndoplasmic reticulum (ER) stress induction of cell death is implicated in cardiovascular diseases. Sustained activation of ER-stress induces the unfolded protein response (UPR) pathways, which in turn activate three major effector proteins. We previously reported a missense homozygous mutation in FBXO32 (MAFbx, Atrogin-1) causing advanced heart failure by impairing autophagy. In the present study, we performed transcriptional profiling and biochemical assays, which unexpectedly revealed a reduced activation of UPR effectors in patient mutant hearts, while a strong up-regulation of the CHOP transcription factor and of its target genes are observed. Expression of mutant FBXO32 in cells is sufficient to induce CHOP-associated apoptosis, to increase the ATF2 transcription factor and to impair ATF2 ubiquitination. ATF2 protein interacts with FBXO32 in the human heart and its expression is especially high in FBXO32 mutant hearts. These findings provide a new underlying mechanism for FBXO32-mediated cardiomyopathy, implicating abnormal activation of CHOP. These results suggest alternative non-canonical pathways of CHOP activation that could be considered to develop new therapeutic targets for the treatment of FBXO32-associated DCM.

scholarly journals POU1F1 transcription factor induces metabolic reprogramming and breast cancer progression via LDHA regulation

Oncogene ◽  
2021 ◽  
Author(s):  
Anxo Martínez-Ordoñez ◽  
Samuel Seoane ◽  
Leandro Avila ◽  
Noemi Eiro ◽  
Manuel Macía ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Transcription Factor ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Cancer Progression ◽  
Breast Cancer Cells ◽  
Metabolic Reprogramming ◽  
Migration And Invasion ◽  
Breast Cancer Cell Lines

AbstractMetabolic reprogramming is considered hallmarks of cancer. Aerobic glycolysis in tumors cells has been well-known for almost a century, but specific factors that regulate lactate generation and the effects of lactate in both cancer cells and stroma are not yet well understood. In the present study using breast cancer cell lines, human primary cultures of breast tumors, and immune deficient murine models, we demonstrate that the POU1F1 transcription factor is functionally and clinically related to both metabolic reprogramming in breast cancer cells and fibroblasts activation. Mechanistically, we demonstrate that POU1F1 transcriptionally regulates the lactate dehydrogenase A (LDHA) gene. LDHA catalyzes pyruvate into lactate instead of leading into the tricarboxylic acid cycle. Lactate increases breast cancer cell proliferation, migration, and invasion. In addition, it activates normal-associated fibroblasts (NAFs) into cancer-associated fibroblasts (CAFs). Conversely, LDHA knockdown in breast cancer cells that overexpress POU1F1 decreases tumor volume and [18F]FDG uptake in tumor xenografts of mice. Clinically, POU1F1 and LDHA expression correlate with relapse- and metastasis-free survival. Our data indicate that POU1F1 induces a metabolic reprogramming through LDHA regulation in human breast tumor cells, modifying the phenotype of both cancer cells and fibroblasts to promote cancer progression.

scholarly journals The Herbal Formula JI017 Induces ER Stress via Nox4 in Breast Cancer Cells

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1881
Author(s):  
Tae Woo Kim ◽  
Seong-Gyu Ko
Keyword(s):  
Breast Cancer ◽  
Combination Therapy ◽  
Er Stress ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Epithelial Mesenchymal Transition ◽  
Herbal Extract ◽  
Breast Cancer Cell Lines ◽  
Mesenchymal Transition ◽  
Stress Markers

Chemotherapy is a powerful anti-tumor therapeutic strategy; however, resistance to treatment remains a serious concern. To overcome chemoresistance, combination therapy with anticancer drugs is a potential strategy. We developed a novel herbal extract, JI017, with lower toxicity and lesser side effects. JI017 induced programmed cell death and excessive unfolded protein response through the release of intracellular reactive oxygen species (ROS) and calcium in breast cancer cells. JI017 treatment increased the expression of endoplasmic reticulum (ER) stress markers, including p-PERK, p-eIF2α, ATF4, and CHOP, via the activation of both exosomal GRP78 and cell lysate GRP78. The ROS inhibitors diphenyleneiodonium and N-acetyl cysteine suppressed apoptosis and excessive ER stress by inhibiting Nox4 in JI017-treated breast cancer cells. Furthermore, in paclitaxel-resistant breast cancer cell lines, MCF-7R and MDA-MB-231R, a combination of JI017 and paclitaxel overcame paclitaxel resistance by blocking epithelial-mesenchymal transition (EMT) processes, such as the downregulation of E-cadherin expression and the upregulation of HIF-1α, vimentin, Snail, and Slug expression. These findings suggested that JI017 exerts a powerful anti-cancer effect in breast cancer and a combination therapy of JI017 and paclitaxel may be a potential cancer therapy for paclitaxel resistant breast cancer.

scholarly journals Getting to grips with c-Myc

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Dirk Eick
Keyword(s):  
Transcription Factor ◽  
Cancer Cells ◽  
Factor C

The transcription factor c-Myc amplifies the transcription of many growth-related genes in cancer cells, but its role as an oncogene is not fully understood.

scholarly journals Intestinal epithelial cell endoplasmic reticulum stress promotes MULT1 up-regulation and NKG2D-mediated inflammation

2017 ◽  
Vol 214 (10) ◽  
pp. 2985-2997 ◽  
Author(s):  
Shuhei Hosomi ◽  
Joep Grootjans ◽  
Markus Tschurtschenthaler ◽  
Niklas Krupka ◽  
Juan D. Matute ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Transcription Factor ◽  
Epithelial Cells ◽  
Er Stress ◽  
Intestinal Inflammation ◽  
Binding Protein ◽  
Lymphoid Cells ◽  
Intestinal Epithelial ◽  
Related Transcription Factor ◽  
Factor C

Endoplasmic reticulum (ER) stress is commonly observed in intestinal epithelial cells (IECs) and can, if excessive, cause spontaneous intestinal inflammation as shown by mice with IEC-specific deletion of X-box–binding protein 1 (Xbp1), an unfolded protein response–related transcription factor. In this study, Xbp1 deletion in the epithelium (Xbp1ΔIEC) is shown to cause increased expression of natural killer group 2 member D (NKG2D) ligand (NKG2DL) mouse UL16-binding protein (ULBP)–like transcript 1 and its human orthologue cytomegalovirus ULBP via ER stress–related transcription factor C/EBP homology protein. Increased NKG2DL expression on mouse IECs is associated with increased numbers of intraepithelial NKG2D-expressing group 1 innate lymphoid cells (ILCs; NK cells or ILC1). Blockade of NKG2D suppresses cytolysis against ER-stressed epithelial cells in vitro and spontaneous enteritis in vivo. Pharmacological depletion of NK1.1+ cells also significantly improved enteritis, whereas enteritis was not ameliorated in Recombinase activating gene 1−/−;Xbp1ΔIEC mice. These experiments reveal innate immune sensing of ER stress in IECs as an important mechanism of intestinal inflammation.

scholarly journals SOX2OT Long Noncoding RNA Is Regulated by the UPR in Oestrogen Receptor-Positive Breast Cancer

Sci ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 24
Author(s):  
Carole Ferraro-Peyret ◽  
Marjan E. Askarian-Amiri ◽  
Debina Sarkar ◽  
Wayne R. Joseph ◽  
Herah Hansji ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Er Stress ◽  
Cancer Cells ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Oestrogen Receptor ◽  
Breast Cancer Cells ◽  
Glucose Deprivation ◽  
Breast Cancer Cell Lines ◽  
Oestrogen Deprivation

Endoplasmic reticulum (ER) stress perturbs cell homeostasis and induces the unfolded protein response (UPR). In breast cancer, this process is activated by oestrogen deprivation and is associated with tamoxifen resistance. We present evidence that the transcription factor SOX2 and the long noncoding RNA SOX2 overlapping transcript (SOX2OT) are up-regulated in oestrogen receptor-positive (ER+) breast cancer and in response to oestrogen deprivation. We examined the effect of the UPR on SOX2 and SOX2OT expression, and the effect of SOX2OT on UPR pathways in breast cancer cell lines. The induction of the UPR by thapsigargin or glucose deprivation up-regulates SOX2OT expression. This up-regulation is also shown with the anti-oestrogen 4OH-tamoxifen and mTOR inhibitor everolimus in ER + breast cancer cells that are sensitive to oestrogen deprivation or everolimus treatment. SOX2OT overexpression decreased BiP and PERK expression. This effect of SOX2OT overexpression was confirmed on BiP and PERK pathway by q-PCR. Our results show that a long noncoding RNA regulates the UPR and evince a new function of SOX2OT as a participant of ER stress reprogramming of breast cancer cells.

Sign in / Sign up

Export Citation Format

Share Document