A novel bystander effect in tamoxifen treatment: PPIB derived from ER+ cells attenuates ER- cells via endoplasmic reticulum stress-induced apoptosis
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo Sapiens
SUBMITTER: 
Tao Huang
PROVIDER: PXD047000 | iProX | Thu Nov 16 00:00:00 GMT 2023
REPOSITORIES: iProX
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Project description:Tamoxifen (TAM) is the frontline therapy for estrogen receptor-positive (ER+) breast cancer in premenopausal women that interrupts ER signaling. As tumors with elevated heterogeneity, amounts of ER-negative (ER-) cells are present in ER+ breast cancer that cannot be directly killed by TAM. Despite complete remissions have been achieved in clinical practice, the mechanism underlying the elimination of ER- cells during TAM treatment remains an open issue. Herein, we deciphered the elimination of ER- cells in TAM treatment from the perspective of the bystander effect. Markable reductions were observed in tumorigenesis of ER- breast cancer cells by applying both supernatants from TAM-treated ER+ cells and a transwell co-culture system, validating the presence of a TAM-induced bystander effect. The major antitumor protein derived from ER+ cells, peptidyl-prolyl cis-trans isomerase B (PPIB), is the mediator of the TAM-induced bystander effect identified by quantitative proteomics. The attenuation of ER- cells was attributed to activated BiP/eIF2α/CHOP axis and promoted endoplasmic reticulum stress (ERS)-induced apoptosis, which can also be triggered by PPIB independently. Altogether, our study revealed a novel TAM-induced bystander effect in TAM treatment of ER+ breast cancer, raising the possibility of developing PPIB as a synergistic antitumor agent or even substitute endocrine therapy.
| S-EPMC10869711 | biostudies-literature
Project description:Tamoxifen (TAM) is the frontline therapy for estrogen receptor-positive (ER+) breast cancer in premenopausal women that interrupts ER signaling. As tumors with elevated heterogeneity, amounts of ER-negative (ER-) cells are present in ER+ breast cancer that cannot be directly killed by TAM. Despite complete remissions have been achieved in clinical practice, the mechanism underlying the elimination of ER- cells during TAM treatment remains an open issue. Herein, we deciphered the elimination of ER- cells in TAM treatment from the perspective of the bystander effect. Markable reductions were observed in tumorigenesis of ER- breast cancer cells by applying both supernatants from TAM-treated ER+ cells and a transwell co-culture system, validating the presence of a TAM-induced bystander effect. The major antitumor protein derived from ER- cells, peptidyl-prolyl cis-trans isomerase B (PPIB), is the mediator of the TAM-induced bystander effect identified by quantitative proteomics. The attenuation of ER- cells was attributed to activated BiP/eIF2α/CHOP axis and promoted endoplasmic reticulum stress (ERS)-induced apoptosis, which can also be triggered by PPIB independently. Altogether, our study revealed a novel TAM-induced bystander effect in TAM treatment of ER+ breast cancer, raising the possibility to develop PPIB as a synergistic antitumor agent or even substitute endocrine therapy.
2024-02-12 | GSE247920 | GEO
Project description:Although cancer stem cells (CSC) have been implicated in the development of resistance to anti-cancer therapy including chemotherapy, the mechanisms underlying chemo-resistance by CSC have not yet been elucidated. We herein isolated sphere-forming (cancer stem-like) cells from the cervical cancer cell line, SiHa, and examined the unfolded protein reaction (UPR) to chemotherapeutic-induced endoplasmic reticulum (ER) stress. We revealed that tunicamycin-induced ER stress-mediated apoptosis occurred in monolayer, but not sphere-forming cells. Biochemical assays demonstrated that sphere-forming cells were shifted to pro-survival signaling through the inactivation of IRE1 (XBP-1 splicing) and activation of PERK (elF2α phosphorylation) branches under tunicamycin-induced ER stress conditions. The proportion of apoptotic cells among sphere-forming cells was markedly increased by the tunicamycin+PERK inhibitor (PERKi) treatment, indicating that PERKi sensitized sphere-forming cells to tunicamycin-induced apoptosis. Cisplatin is also known to induce ER stress-mediated apoptosis. A low concentration of cisplatin failed to shift sphere-forming cells to apoptosis, although IRE1 branch, but not PERK, was activated. ER stress-mediated apoptosis occurred in sphere-forming cells by the cisplatin+IRE1α inhibitor (IRE1i) treatment. IRE1i, synergistic with cisplatin, up-regulated elF2α phosphorylation, and this was followed by the induction of CHOP in sphere-forming cells. The results of the present study demonstrated that the inhibition of ER stress sensors, combined with ER stress-inducible chemotherapy, shifted cancer stem-like cells to ER stress-mediated apoptosis.
| S-EPMC5239519 | biostudies-literature
Project description:BackgroundPalmitic acid (PA), the main component of dietary saturated fat, causes apoptosis in many cell types, including mouse granulosa cell. Melatonin, an important endogenous hormone, has beneficial effects on female reproductive processes. Since elevated PA levels are present in follicular fluid (FF) of patients with infertility and are shown to be toxic for granulosa cells, we investigated the molecular mechanisms of PA toxicity in mouse granulosa cells and explored the effects of melatonin on PA-induced apoptosis.MethodsGranulosa cells from immature female mice were cultured for 24 h in medium containing PA and/or melatonin. Then, the effects of PA alone or combined with melatonin on viability, apoptosis and endoplasmic reticulum (ER) stress in granulosa cells were detected by methyl thiazolyl tetrazolium (MTT) assay, flow cytometry assay and western blot. After 48 h of PA and/or melatonin treatment, the concentrations of estradiol (E2) and progesterone (P4) in the culture supernatants were measured with ELISA kits.ResultsIn this study, we explored the effects of melatonin on cell viability and apoptosis in PA-treated mouse granulosa cells and uncovered the signaling pathways involved in these processes. Our results showed that 200-800 μM PA treatment reduces cell viability, induces cell apoptosis, enhances the expression of apoptosis-related genes (Caspase 3 and B-cell lymphoma-2 (BCL-2) associated X protein (BAX)), and activates the expression of ER stress marker genes (glucose-regulated protein 78 (GRP78) and CCAAT/enhancer binding protein homologous protein (CHOP)). Melatonin treatment (1-10 μM) suppresses 400 μM PA-induced cell viability decrease, cell apoptosis, Caspase 3 activation, and BAX, CHOP, and GRP78 expression. In addition, we found that 10 μM melatonin successfully attenuated the 400 μM PA-induced estrogen (E2) and progesterone (P4) decreases.ConclusionsThis study suggests that PA triggers cell apoptosis via ER stress and that melatonin protects cells against apoptosis by inhibiting ER stress in mouse granulosa cells.
| S-EPMC6511168 | biostudies-literature
Project description:The endoplasmic reticulum (ER) is a vital subcellular organelle that orchestrates numerous essential biological processes, including protein synthesis and processing. Disruption of ER function can lead to ER stress, a condition closely associated with the progression and development of cancer. Consequently, inducing ER stress in cancer cells has emerged as an unconventional yet promising therapeutic approach. However, selectively targeting the ER within cancer cells remains a significant challenge. To address this, we have designed and synthesized a novel small-molecule library composed of non-steroidal anti-inflammatory drugs (NSAIDs), fluorescent probes, and ER-targeting moieties. Through screening the library in cancer cells, we identified a promising compound: an ibuprofen derivative conjugated with a dansyl group as a dual fluorescence tag and ER-targeting moiety. This ibuprofen derivative successfully localized into the ER of HCT-116 colon cancer cells within 3 h, induced ER stress by upregulating key stress markers such as CHOP, GRP94, IRE-1α, PERK, and Cas-12, while simultaneously inhibiting Cox-2. The resulting ER stress triggered autophagy by upregulating Beclin and LC3-II/LC3-I as autophagy markers, followed by apoptosis, culminating in significant cancer cell death, particularly when combined with bafilomycin A, 10-hydroxycamptothecin and obatoclax. This NSAID-based ER stress inducer provides a powerful tool for exploring the chemical biology of NSAIDs in the ER and holds great potential for advancing ER-targeted cancer therapies in combination with other anti-cancer drugs.
| S-EPMC11791515 | biostudies-literature
Project description:Colorectal cancer (CRC) is the third leading malignant tumor in the world, which has high morbidity and mortality. In this study we found that trichodermic acid (TDA), a secondary metabolite isolated from the plant endophytic fungus Penicillium ochrochloronthe with a variety of biological and pharmacological activities, exhibited the antitumor effects on colorectal cancer cells in vitro and in vivo. Our results showed that TDA inhibited the proliferation of colon cancer cells in a dose-dependent manner. TDA induces sustained endoplasmic reticulum stress, which triggers apoptosis through IRE1α/XBP1 and PERK/ATF4/CHOP pathways. In addition, we found that TDA mediated endoplasmic reticulum stress also induces autophagy as a protective mechanism. Moreover, combined treatment of TDA with autophagy inhibitors significantly enhanced its anticancer effect. In conclusion, our results indicated that TDA can induce ER stress and autophagy mediated apoptosis, suggesting that targeting ER stress and autophagy may be an effective strategy for the treatment of CRC.
| S-EPMC8197497 | biostudies-literature
Project description:MCF7 were treated with a CREBBP/EP300 acetyltransferase inhibitor CPI-1612 or DMSO and ChIP-seq was performed for H3K27ac and H3K9ac.
2022-03-04 | GSE190161 | GEO
Project description:Endoplasmic reticulum (ER) stress and apoptotic cell death play an important role in the pathogenesis and perpetuation of inflammatory bowel disease (IBD). We aimed to explore the potential of glutamine to reduce ER stress and apoptosis in a rat model of experimental IBD. Colitis was induced in male Wistar rats by intracolonic administration of 30 mg of 2,4,6-trinitrobenzene sulfonic acid (TNBS). Glutamine (25 mg/dL) was given by rectal route daily for 2 d or 7 d. Both oxidative stress (TBARS concentration and oxidised/reduced glutathione ratio) and ER stress markers (CHOP, BiP, calpain-1 and caspase-12 expression) increased significantly within 48 h of TNBS instillation, and glutamine attenuated the extent of the changes. Glutamine also inhibited the significant increases of ATF6, ATF4 and spliced XBP-1 mRNA levels induced by TNBS instillation. TNBS-colitis resulted in a significant increase in p53 and cytochrome c expression, and a reduced Bcl-xL expression and Bax/Bcl-2 ratio. These effects were significantly inhibited by glutamine. Treatment with the amino acid also resulted in significant decreases of caspase-9, caspase-8 and caspase-3 activities. Double immunofluorescence staining showed co-localization of CHOP and cleaved caspase-3 in colon sections. Phospho-JNK and PARP-1 expression was also significantly higher in TNBS-treated rats, and treatment with glutamine significantly decreased JNK phosphorylation and PARP-1 proteolysis. To directly address the effect of glutamine on ER stress and apoptosis in epithelial cells, the ER stress inducers brefeldin A and tunicamycin were added to Caco-2 cells that were treated with glutamine (5 mM and 10 mM). The significant enhancement in PERK, ATF6 phosphorylated IRE1, BiP and cleaved caspase-3 expression induced by brefeldin A and tunicamycin was partly prevented by glutamine. Data obtained indicated that modulation of ER stress signalling and anti-apoptotic effects contribute to protection by glutamine against damage in TNBS-induced colitis.
| S-EPMC3508929 | biostudies-literature
Project description:Farnesol (FOH) and other isoprenoid alcohols induce apoptosis in various carcinoma cells and inhibit tumorigenesis in several in vivo models. However, the mechanisms by which these isoprenoids mediate their effects are not yet fully understood. In this study, we show that FOH is effective inducer of apoptosis in several lung carcinoma cells, including H460 cells. This induction is associated with activation of caspase-3, -9, and -12, and cleavage of PARP. To obtain insight into the mechanism involved in FOH-induced apoptosis, we compared the gene expression profiles of FOH-treated and control H460 cells using microarray analysis. This analysis revealed that many of the genes implicated in endoplasmic reticulum (ER) stress, including ATF3, CHOP/GADD153, HERPUD1, BIP (GRP78), XBP1, PDIA4, and TDAG51, were highly up-regulated within 4 hr of FOH treatment suggesting that FOH-induced apoptosis involves an ER-stress response. This was supported by observations showing that treatment with FOH induces phosphorylation of eIF2alpha. FOH induces activation of several MAPK pathways, including p38, MEK-ERK, and JNK. Inhibition of MEK1/2 by U0126 inhibited the induction of ER stress-response genes. In addition, knockdown of the MEK1/2 and JNK1/2 expression by short interfering RNA (siRNA) effectively inhibited the induction of apoptosis and activation of caspase-3 and cleavage of PARP by FOH. However, only MEK1/2 siRNAs reduced the expression of ER stress-related genes and inhibited phosphorylation of eIF2alpha. Our results demonstrate that FOH-induced apoptosis is coupled to ER stress and that activation of MEK1/2 is an upstream event in the FOH-induced ER stress signaling cascade. Vehicle vs. 4h FOH Signature Gene lists (Replicates 1 & 2) are linked as supplementary files to the Series record. Keywords: gene expression
2008-02-26 | GSE7215 | GEO
Project description:Farnesol (FOH) and other isoprenoid alcohols induce apoptosis in various carcinoma cells and inhibit tumorigenesis in several in vivo models. However, the mechanisms by which these isoprenoids mediate their effects are not yet fully understood. In this study, we show that FOH is effective inducer of apoptosis in several lung carcinoma cells, including H460 cells. This induction is associated with activation of caspase-3, -9, and -12, and cleavage of PARP. To obtain insight into the mechanism involved in FOH-induced apoptosis, we compared the gene expression profiles of FOH-treated and control H460 cells using microarray analysis. This analysis revealed that many of the genes implicated in endoplasmic reticulum (ER) stress, including ATF3, CHOP/GADD153, HERPUD1, BIP (GRP78), XBP1, PDIA4, and TDAG51, were highly up-regulated within 4 hr of FOH treatment suggesting that FOH-induced apoptosis involves an ER-stress response. This was supported by observations showing that treatment with FOH induces phosphorylation of eIF2ï¡. FOH induces activation of several MAPK pathways, including p38, MEK-ERK, and JNK. Inhibition of MEK1/2 by U0126 inhibited the induction of ER stress-response genes. In addition, knockdown of the MEK1/2 and JNK1/2 expression by short interfering RNA (siRNA) effectively inhibited the induction of apoptosis and activation of caspase-3 and cleavage of PARP by FOH. However, only MEK1/2 siRNAs reduced the expression of ER stress-related genes and inhibited phosphorylation of eIF2ï¡. Our results demonstrate that FOH-induced apoptosis is coupled to ER stress and that activation of MEK1/2 is an upstream event in the FOH-induced ER stress signaling cascade. Vehicle vs. 4h FOH Signature Gene lists (Replicates 1 & 2) are linked as supplementary files to the Series record. Experiment Overall Design: H460 cells were treated for 4 hours with 250 micromolar FOH or vehicle (DMSO) in duplicate experiments. Each FOH treated sample was compared to its matched Vehicle and dye-flips were performed, resulting in 4 arrays (2 replicate sets x 2 technical replicates).
2008-04-07 | E-GEOD-7215 | biostudies-arrayexpress