scholarly journals Nelfinavir induces the unfolded protein response in ovarian cancer cells, resulting in ER vacuolization, cell cycle retardation and apoptosis

2009 ◽  
Vol 8 (3) ◽  
pp. 226-232 ◽  
Author(s):  
Ansgar Brüning ◽  
Petra Burger ◽  
Marianne Vogel ◽  
Martina Rahmeh ◽  
Andrea Gingelmaier ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Unfolded Protein Response ◽  
Cancer Cells ◽  
Ovarian Cancer Cells ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
Protein Response

scholarly journals Metformin Dysregulates the Unfolded Protein Response and the WNT/β-Catenin Pathway in Endometrial Cancer Cells through an AMPK-Independent Mechanism

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1067
Author(s):  
Domenico Conza ◽  
Paola Mirra ◽  
Gaetano Calì ◽  
Luigi Insabato ◽  
Francesca Fiory ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Unfolded Protein Response ◽  
Cancer Cells ◽  
Independent Manner ◽  
Growth And Survival ◽  
Unfolded Protein ◽  
Compound C ◽  
Survival Pathways ◽  
The Unfolded Protein Response ◽  
Protein Response

Multiple lines of evidence suggest that metformin, an antidiabetic drug, exerts anti-tumorigenic effects in different types of cancer. Metformin has been reported to affect cancer cells’ metabolism and proliferation mainly through the activation of AMP-activated protein kinase (AMPK). Here, we show that metformin inhibits, indeed, endometrial cancer cells’ growth and induces apoptosis. More importantly, we report that metformin affects two important pro-survival pathways, such as the Unfolded Protein Response (UPR), following endoplasmic reticulum stress, and the WNT/β-catenin pathway. GRP78, a key protein in the pro-survival arm of the UPR, was indeed downregulated, while GADD153/CHOP, a transcription factor that mediates the pro-apoptotic response of the UPR, was upregulated at both the mRNA and protein level. Furthermore, metformin dramatically inhibited β-catenin mRNA and protein expression. This was paralleled by a reduction in β-catenin transcriptional activity, since metformin inhibited the activity of a TCF/LEF-luciferase promoter. Intriguingly, compound C, a well-known inhibitor of AMPK, was unable to prevent all these effects, suggesting that metformin might inhibit endometrial cancer cells’ growth and survival through the modulation of specific branches of the UPR and the inhibition of the Wnt/β-catenin pathway in an AMPK-independent manner. Our findings may provide new insights on the mechanisms of action of metformin and refine the use of this drug in the treatment of endometrial cancer.

Sequencing of Argonaute-bound miRNA/mRNA hybrids reveals regulation of the unfolded protein response by microRNA-320a

2021 ◽  
Author(s):  
Christopher J Fields ◽  
Lu Li ◽  
Nicholas M Hiers ◽  
Tianqi Li ◽  
Peike Sheng ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Er Stress ◽  
Unfolded Protein Response ◽  
Cancer Cells ◽  
Rna Polymerase Ii ◽  
Mirna Biogenesis ◽  
Unfolded Protein ◽  
Colorectal Cancer Cells ◽  
The Unfolded Protein Response ◽  
Protein Response

MicroRNAs (miRNA) are short non-coding RNAs widely implicated in gene regulation. Most metazoan miRNAs utilize the RNase III enzymes Drosha and Dicer for biogenesis. One notable exception is the RNA polymerase II transcription start sites (TSS) miRNAs whose biogenesis does not require Drosha. The functional importance of the TSS-miRNA biogenesis is uncertain. To better understand the function of TSS-miRNAs, we applied a modified Crosslinking, Ligation, and Sequencing of Hybrids on Argonaute (AGO-qCLASH) to identify the targets for TSS-miRNAs in HCT116 colorectal cancer cells with or without DROSHA knockout. We observed that miR-320a hybrids dominate in TSS-miRNA hybrids identified by AGO-qCLASH. Targets for miR-320a are enriched in the eIF2 signaling pathway, a downstream component of the unfolded protein response. Consistently, in miR-320a mimic- and antagomir- transfected cells, differentially expressed genes are enriched in eIF2 signaling. Within the AGO-qCLASH data, we identified the endoplasmic reticulum (ER) chaperone Calnexin as a direct miR-320a target, thus connecting miR-320a to the unfolded protein response. During ER stress, but not amino acid deprivation, miR-320a up-regulates ATF4, a critical transcription factor for resolving ER stress. Our study investigates the targetome of the TSS-miRNAs in colorectal cancer cells and establishes miR-320a as a regulator of unfolded protein response.

scholarly journals A novel role in cytokinesis reveals a housekeeping function for the unfolded protein response

2007 ◽  
Vol 177 (6) ◽  
pp. 1017-1027 ◽  
Author(s):  
Alicia A. Bicknell ◽  
Anna Babour ◽  
Christine M. Federovitch ◽  
Maho Niwa
Keyword(s):  
Cell Cycle ◽  
Unfolded Protein Response ◽  
Normal Cell ◽  
Growth Conditions ◽  
Unfolded Protein ◽  
Functional Capabilities ◽  
Cellular Events ◽  
The Unfolded Protein Response ◽  
Protein Response ◽  
Upr Pathway

The unfolded protein response (UPR) pathway helps cells cope with endoplasmic reticulum (ER) stress by activating genes that increase the ER's functional capabilities. We have identified a novel role for the UPR pathway in facilitating budding yeast cytokinesis. Although other cell cycle events are unaffected by conditions that disrupt ER function, cytokinesis is sensitive to these conditions. Moreover, efficient cytokinesis requires the UPR pathway even during unstressed growth conditions. UPR-deficient cells are defective in cytokinesis, and cytokinesis mutants activate the UPR. The UPR likely achieves its role in cytokinesis by sensing small changes in ER load and making according changes in ER capacity. We propose that cytokinesis is one of many cellular events that require a subtle increase in ER function and that the UPR pathway has a previously uncharacterized housekeeping role in maintaining ER plasticity during normal cell growth.

scholarly journals Borrelidin Induces the Unfolded Protein Response in Oral Cancer Cells and Chop-Dependent Apoptosis

2015 ◽  
Vol 6 (11) ◽  
pp. 1122-1127 ◽  
Author(s):  
Alpa Sidhu ◽  
Justin R. Miller ◽  
Ashootosh Tripathi ◽  
Danielle M. Garshott ◽  
Amy L. Brownell ◽  
...  
Keyword(s):  
Oral Cancer ◽  
Unfolded Protein Response ◽  
Cancer Cells ◽  
Unfolded Protein ◽  
Oral Cancer Cells ◽  
The Unfolded Protein Response ◽  
Protein Response
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