scholarly journals Interactome analysis of Bag-1 isoforms reveals novel interaction partners in endoplasmic reticulum-associated degradation

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256640
Author(s):  
Nisan Denizce Can ◽  
Ezgi Basturk ◽  
Tugba Kizilboga ◽  
Izzet Mehmet Akcay ◽  
Baran Dingiloglu ◽  
...  
Keyword(s):  
Protein Quality ◽  
Interaction Network ◽  
Breast Cancer Patients ◽  
Glycosylation Pattern ◽  
Multifunctional Protein ◽  
Ubiquitinated Proteins ◽  
Interaction Partners ◽  
Hsp70 Chaperone ◽  
Interaction Map ◽  
Mcf 7

Bag-1 is a multifunctional protein that regulates Hsp70 chaperone activity, apoptosis, and proliferation. The three major Bag-1 isoforms have different subcellular localizations and partly non-overlapping functions. To identify the detailed interaction network of each isoform, we utilized mass spectrometry-based proteomics and found that interactomes of Bag-1 isoforms contained many common proteins, with variations in their abundances. Bag-1 interactomes were enriched with proteins involved in protein processing and degradation pathways. Novel interaction partners included VCP/p97; a transitional ER ATPase, Rad23B; a shuttling factor for ubiquitinated proteins, proteasome components, and ER-resident proteins, suggesting a role for Bag-1 also in ER-associated protein degradation (ERAD). Bag-1 pull-down from cells and tissues from breast cancer patients validated these interactions and showed cancer-related prominence. Using in silico predictions we detected hotspot residues of Bag-1. Mutations of these residues caused loss of binding to protein quality control elements and impaired proteasomal activity in MCF-7 cells. Following CD147 glycosylation pattern, we showed that Bag-1 downregulated VCP/p97-dependent ERAD. Overall, our data extends the interaction map of Bag-1, and broadens its role in protein homeostasis. Targeting the interaction surfaces revealed in this study might be an effective strategy in the treatment of cancer.

scholarly journals Deregulation of protein phosphatase 2A inhibitor SET is associated with malignant progression in breast cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Katsunori Tozuka ◽  
Pattama Wongsirisin ◽  
Shigenori E. Nagai ◽  
Yasuhito Kobayashi ◽  
Miki Kanno ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Progression ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Recurrent Breast Cancer ◽  
Stage I ◽  
Breast Cancer Patients ◽  
Potential Biomarker ◽  
Phosphatase 2A ◽  
Mcf 7

AbstractTo understand the mechanism underlying metastasis, identification of a mechanism-based and common biomarker for circulating tumour cells (CTCs) in heterogenous breast cancer is needed. SET, an endogenous inhibitor of protein phosphatase 2A, was overexpressed in all subtypes of invasive breast carcinoma tissues. Treatment with SET-targeted siRNAs reduced the motility of MCF-7 and MDA-MB-231 cells in transwell assay. SET knockdown reduced the number of mammospheres by 60–70% in MCF-7 and MDA-MB-231 cells, which was associated with the downregulation of OCT4 and SLUG. Hence, we analysed the presence of SET-expressing CTCs (SET-CTCs) in 24 breast cancer patients. CTCs were enriched using a size-based method and then immunocytochemically analysed using an anti-SET antibody. SET-CTCs were detected in 6/6 (100%) patients with recurrent breast cancer with a median value of 12 (12 cells/3 mL blood), and in 13/18 (72.2%) patients with stage I–III breast cancer with a median value of 2.5, while the median value of healthy controls was 0. Importantly, high numbers of SET-CTCs were correlated with lymph node metastasis in patients with stage I–III disease. Our results indicate that SET contributes to breast cancer progression and can act as a potential biomarker of CTCs for the detection of metastasis.

scholarly journals Role of the Ndc1 interaction network in yeast nuclear pore complex assembly and maintenance

2009 ◽  
Vol 185 (3) ◽  
pp. 475-491 ◽  
Author(s):  
Evgeny Onischenko ◽  
Leslie H. Stanton ◽  
Alexis S. Madrid ◽  
Thomas Kieselbach ◽  
Karsten Weis
Keyword(s):  
Nuclear Pore Complex ◽  
Structural Integrity ◽  
Fluorescent Protein ◽  
Interaction Network ◽  
Nucleocytoplasmic Transport ◽  
Nuclear Pore ◽  
Binding Partners ◽  
Interaction Partners ◽  
Redundant Functions

The nuclear pore complex (NPC) mediates all nucleocytoplasmic transport, yet its structure and biogenesis remain poorly understood. In this study, we have functionally characterized interaction partners of the yeast transmembrane nucleoporin Ndc1. Ndc1 forms a distinct complex with the transmembrane proteins Pom152 and Pom34 and two alternative complexes with the soluble nucleoporins Nup53 and Nup59, which in turn bind to Nup170 and Nup157. The transmembrane and soluble Ndc1-binding partners have redundant functions at the NPC, and disruption of both groups of interactions causes defects in Ndc1 targeting and in NPC structure accompanied by significant pore dilation. Using photoconvertible fluorescent protein fusions, we further show that the depletion of Pom34 in cells that lack NUP53 and NUP59 blocks new NPC assembly and leads to the reversible accumulation of newly made nucleoporins in cytoplasmic foci. Therefore, Ndc1 together with its interaction partners are collectively essential for the biosynthesis and structural integrity of yeast NPCs.

scholarly journals Antiestrogen-resistant human breast cancer cells require activated Protein Kinase B/Akt for growth

2005 ◽  
Vol 12 (3) ◽  
pp. 599-614 ◽  
Author(s):  
T Frogne ◽  
J S Jepsen ◽  
S S Larsen ◽  
C K Fog ◽  
B L Brockdorff ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Cell Lines ◽  
Human Breast Cancer ◽  
Neutralizing Antibodies ◽  
Breast Cancer Cells ◽  
Resistant Cell ◽  
Breast Cancer Patients ◽  
Human Breast ◽  
Mcf 7

Development of acquired resistance to antiestrogens is a major clinical problem in endocrine treatment of breast cancer patients. The IGF system plays a profound role in many cancer types, including breast cancer. Thus, overexpression and/or constitutive activation of the IGF-I receptor (IGF-IR) or different components of the IGF-IR signaling pathway have been reported to render breast cancer cells less estrogen dependent and capable of sustaining cell proliferation in the presence of antiestrogens. In this study, growth of the antiestrogen-sensitive human breast cancer cell line MCF-7 was inhibited by treatment with IGF-IR-neutralizing antibodies. In contrast, IGF-IR-neutralizing antibodies had no effect on growth of two different antiestrogen-resistant MCF-7 sublines. A panel of antiestrogen-resistant cell lines was investigated for expression of IGF-IR and either undetectable or severely reduced IGF-IR levels were observed. No increase in insulin receptor substrate 1 (IRS-1) or total PKB/Akt (Akt) was detected in the resistant cell lines. However, a significant increase in phosphorylated Akt (pAkt) was found in four of six antiestrogen-resistant cell lines. Overexpression of pAkt was associated with increased Akt kinase activity in both a tamoxifen- and an ICI 182,780-resistant cell line. Inhibition of Akt phosphorylation by the phosphatidylinositol 3-kinase (PI3-K) inhibitor wortmannin or the Akt inhibitor SH-6 (structurally modified phosphatidyl inositol ether liquid analog PIA 6) resulted in a more pronounced growth inhibitory effect on the antiestrogen-resistant cells compared with the parental cells, suggesting that signaling via Akt is required for antiestrogen-resistant cell growth in at least a subset of our antiestrogen-resistant cell lines. PTEN expression and activity was not decreased in cell lines overexpressing pAkt. Our data demonstrate that Akt is a target for treatment of antiestrogen-resistant breast cancer cell lines and we suggest that antiestrogen-resistant breast cancer patients may benefit from treatment targeted to inhibit Akt signaling.

Chemotherapy of breast cancer patients induces a shift in the glycosylation pattern of plasma complement components C3 and C4

Immunobiology ◽  
2012 ◽  
Vol 217 (11) ◽  
pp. 1150
Author(s):  
Rudolf Oehler ◽  
Christine Schalko ◽  
Anna Michlmayr ◽  
Rupert Bartsch ◽  
Michael Bergmann ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Breast Cancer Patients ◽  
Glycosylation Pattern ◽  
Complement Components

scholarly journals Effect of Wnt5a on drug resistance in estrogen receptor-positive breast cancer

2020 ◽  
Author(s):  
Ai Amioka ◽  
Takayuki Kadoya ◽  
Satoshi Sueoka ◽  
Yoshie Kobayashi ◽  
Shinsuke Sasada ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Poor Prognosis ◽  
Breast Cancer Tissue ◽  
Cancer Tissue ◽  
Breast Cancer Patients ◽  
Mtor Signaling Pathway ◽  
The Poor ◽  
Er Positive ◽  
Mcf 7 ◽  
Positive Breast Cancer

Abstract BackgroundIt was previously reported by us that Wnt5a-positive breast cancer can be classified as estrogen receptor (ER)-positive breast cancer and its prognosis is worse than that of Wnt5a-negative breast cancer. Herein, the molecular mechanisms underlying the poor prognosis of Wnt5a-positive breast cancer patients were examined. MethodsA total of 151 consecutive ER-positive breast cancer patients who underwent resection between January 2011 and February 2014 were enrolled. DNA microarray and pathway analyses were performed conducted using MCF-7 cells stably expressing Wnt5a (MCF-7/Wnt5a(+)). Based on the results, cell viability and drug sensitivity assays as well as mutation analysis , were performed using culture cells and breast cancer tissue. The relationship between Wnt5a and the PI3K–AKT–mTOR signaling pathway was examined.ResultsThe relapse-free survival rate in patients with Wnt5a-positive breast cancer was significantly lower than that in patients with Wnt5a-negative breast cancer ( P = 0.047). DNA microarray data indicated that only the cytochrome P450 (CYP) pathway was significantly upregulated in MCF-7/Wnt5a(+) cells ( P = 0.0440). MCF-7/Wnt5a(+) cells showed reduced sensitivity to the metabolic substrates of CYP, tamoxifen ( P < 0.001), and paclitaxel ( P < 0.001). PIK3CA mutations were unrelated to Wnt5a expression in breast cancer tissue and culture cells.ConclusionsIn ER-positive breast cancer, Wnt5a upregulated the CYP metabolic pathway; additionally, it inhibited the sensitivity to tamoxifen and paclitaxel, which constitute the standard treatment options for ER-positive breast cancer. Wnt5a could be involved in the poor prognosis of ER-positive breast cancer independently of the PI3K–AKT–mTOR signaling pathway.

scholarly journals ERβ-induced MFN2 inhibits the migration and invasiveness of breast cancer cells by inhibiting the P-AKT signaling pathway

2020 ◽  
Author(s):  
Mengyu Wei ◽  
Jun Hao ◽  
Xiaomei Liao ◽  
Yinfeng Liu ◽  
Ruihuan Fu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Breast Cancer Cells ◽  
Akt Pathway ◽  
Cancer Cell Migration ◽  
Breast Cancer Patients ◽  
Human Breast ◽  
Mcf 7

Abstract Background Mitofusin 2 (MFN2) is localized on the outer membrane of mitochondria and is closely related to the migration of malignant tumor cells. Estrogen receptor β (ERβ) plays an anticancer role in breast cancer. Our previous experiments showed that ERβ can induce MFN2 expression, which then inhibits breast cancer cell migration. However, the exact mechanism by which ERβ-induced MFN2 inhibits breast cancer cell migration is unknown. Methods In this study, immunohistochemistry was first used to detect the expression of MFN2 in breast cancer tissues, and its relationship with the clinicopathological characteristics and prognosis of breast cancer patients was analyzed. MCF-7 and MDA-MB-231 cells were transfected with ERβ and MFN2 knockdown or expression plasmids. Western blot was used to detect the effects of ERβ on MFN2 and MFN2 on P-AKT473 and MMP2; the P-AKT pathway inhibitor LY294002 was administered to cells transfected with MFN2 knockdown plasmids, Western blot, immunocytofluorescence, and a wound healing assay revealed the effect of MFN2 on its downstream signaling pathway and the migration of breast cancer cells. Results This study found that the expression of MFN2 is related to the molecular type and prognosis of breast cancer patients ( P <0.05). The positive expression rate of MFN2 in triple-negative breast cancer was significantly lower than that in the HER2 + and luminal types. However, MFN2 expression was unrelated to age, tumor size, lymph node metastasis, TNM stage, histological type and grade ( P >0.05); ERβ positively regulated MFN2 expression and reduced the migration of both MCF-7 and MDA-MB-231 cells, while MFN2 knockdown increased the expression of P-AKT473 and MMP2. In contrast, the overexpression of MFN2 inhibited the expression of P-AKT473 and MMP2. These results showed that in MFN2 knockdown cells treated with LY294002, P-AKT473 and MMP2 expression levels were reversed. The reversal of P-AKT473 and MMP2 expression levels inhibits the invasiveness of human breast cancer cells. Conclusion MFN2 is related to the molecular subtype and prognosis of breast cancer. In human breast cancer MCF-7 and MDA-MB-231 cells, ERβ-induced MFN2 can inhibit the P-AKT pathway, which inhibits the invasiveness and migration of both breast cancer cell lines.

scholarly journals Mycobacterium tuberculosis Rv0991c Is a Redox-Regulated Molecular Chaperone

mBio ◽  
2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Samuel H. Becker ◽  
Kathrin Ulrich ◽  
Avantika Dhabaria ◽  
Beatrix Ueberheide ◽  
William Beavers ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Quality Control ◽  
Mycobacterium Tuberculosis ◽  
Molecular Chaperone ◽  
Protein Quality ◽  
Protein Quality Control ◽  
Cellular Protein ◽  
Content Type ◽  
Hsp70 Chaperone

ABSTRACT The bacterial pathogen Mycobacterium tuberculosis is the leading cause of death by an infectious disease among humans. Here, we describe a previously uncharacterized M. tuberculosis protein, Rv0991c, as a molecular chaperone that is activated by oxidation. Rv0991c has homologs in most bacterial lineages and appears to function analogously to the well-characterized Escherichia coli redox-regulated chaperone Hsp33, despite a dissimilar protein sequence. Rv0991c is transcriptionally coregulated with hsp60 and hsp70 chaperone genes in M. tuberculosis, suggesting that Rv0991c functions with these chaperones in maintaining protein quality control. Supporting this hypothesis, we found that, like oxidized Hsp33, oxidized Rv0991c prevents the aggregation of a model unfolded protein in vitro and promotes its refolding by the M. tuberculosis Hsp70 chaperone system. Furthermore, Rv0991c interacts with DnaK and can associate with many other M. tuberculosis proteins. We therefore propose that Rv0991c, which we named “Ruc” (redox-regulated protein with unstructured C terminus), represents a founding member of a new chaperone family that protects M. tuberculosis and other species from proteotoxicity during oxidative stress. IMPORTANCE M. tuberculosis infections are responsible for more than 1 million deaths per year. Developing effective strategies to combat this disease requires a greater understanding of M. tuberculosis biology. As in all cells, protein quality control is essential for the viability of M. tuberculosis, which likely faces proteotoxic stress within a host. Here, we identify an M. tuberculosis protein, Ruc, that gains chaperone activity upon oxidation. Ruc represents a previously unrecognized family of redox-regulated chaperones found throughout the bacterial superkingdom. Additionally, we found that oxidized Ruc promotes the protein-folding activity of the essential M. tuberculosis Hsp70 chaperone system. This work contributes to a growing body of evidence that oxidative stress provides a particular strain on cellular protein stability.

P38-β/SAPK-inhibiting and apoptosis-inducing activities of (E)-4-chloro-2-((3-ethoxy-2-hydroxybenzylidene) amino)phenol

2020 ◽  
Vol 39 (10) ◽  
pp. 1374-1389
Author(s):  
O Karaosmanoğlu
Keyword(s):  
Protein Kinase ◽  
Mapk Pathway ◽  
Neutral Red ◽  
Mitogen Activated Protein Kinase ◽  
Breast Cancer Patients ◽  
Trastuzumab Resistance ◽  
Qrt Pcr ◽  
Amino Phenol ◽  
Induced Apoptosis ◽  
Mcf 7

The present study has three purposes; first evaluating cytotoxicity of (E)-4-chloro-2-((3-ethoxy-2-hydroxybenzylidene)amino)phenol (ACES), second deciphering ACES-mediated cellular death mechanism, and third estimating ACES-mediated alterations in the expressions of mitogen-activated protein kinase (MAPK) pathway-related genes. Neutral red uptake assay, cell cycle analysis, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) measurements, caspase 3/7 and 9 activations, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were implemented. IC50 values of ACES-treated five cells were around 4–6 µg/mL. However, Caco-2 and Huh-7 cells were found to be twofold resistant and fivefold sensitive with IC50 values of 11 µg/mL and 0.93 µg/mL, respectively. In this study, it was initially reported that ACES exhibits selective cytotoxicity to Huh-7 cells. In addition, ACES induced apoptosis by nuclear fragmentation, MMP disruption, and intracellular ROS elevation in MCF-7 cells. qRT-PCR experiment indicated the expressions of 30 genes including ATF2, CREB1, MYC, NFATC4 (NFAT3), CCNA1, CCNB1, CCND2, CDK2, CDKN1A (p21CIP1), CDKN1C (p57KIP2), CDKN2A (p16INK4a), CDKN2B (p15INK4b), DLK1, NRAS, CDC42, PAK1, MAP4K1 (HPK1), MAP3K3 (MEKK3), MAP2K3 (MEK3), MAP2K6 (MEK6), MOS, MAPK1 (ERK2), MAPK8 (JNK1), MAPK10 (JNK3), MAPK11 (p38-β), LAMTOR3 (MP1), MAPK8IP2 (JIP-1), PRDX6 (AOP2), COL1A1, and HSPA5 (Grp78) were downregulated at least 1.5-fold. Moreover, ACES effectively inhibited expressions of genes that code for elements of p38-β/stress-activated protein kinase (SAPK) pathway. ACES has the potential to be used for the reversal of trastuzumab resistance in breast cancer patients by inhibiting p38/SAPK pathway in MCF-7 cells. Therefore, with the selective cytotoxic, apoptosis-inducing, and p38-β/SAPK-inhibiting activities, ACES can be utilized for developing a novel anticancer drug.

scholarly journals Label-free quantitative identification of abnormally ubiquitinated proteins as useful biomarkers for human lung squamous cell carcinomas

2020 ◽  
Vol 11 (1) ◽  
pp. 73-94 ◽  
Author(s):  
Miaolong Lu ◽  
Wei Chen ◽  
Wei Zhuang ◽  
Xianquan Zhan
Keyword(s):  
Squamous Cell ◽  
Lung Squamous Cell Carcinoma ◽  
Interaction Network ◽  
Molecular Network ◽  
Label Free ◽  
Ubiquitinated Protein ◽  
Network Systems ◽  
Cell Lung Carcinoma ◽  
E3 Ligases ◽  
Ubiquitinated Proteins

Abstract Background Ubiquitination is an important molecular event in lung squamous cell carcinoma (LSCC), which currently is mainly studied in nonsmall cell lung carcinoma cell models but lacking of ubiquitination studies on LSCC tissues. Here, we presented the ubiquitinated protein profiles of LSCC tissues to explore ubiquitination-involved molecular network alterations and identify abnormally ubiquitinated proteins as useful biomarkers for predictive, preventive, and personalized medicine (PPPM) in LSCC. Methods Anti-ubiquitin antibody-based enrichment coupled with LC-MS/MS was used to identify differentially ubiquitinated proteins (DUPs) between LSCC and control tissues, followed by integrative omics analyses to identify abnormally ubiquitinated protein biomarkers for LSCC. Results Totally, 400 DUPs with 654 ubiquitination sites were identified,, and motifs A-X (1/2/3)-K* were prone to be ubiquitinated in LSCC tissues. Those DUPs were involved in multiple molecular network systems, including the ubiquitin–proteasome system (UPS), cell metabolism, cell adhesion, and signal transduction. Totally, 44 hub molecules were revealed by protein–protein interaction network analysis, followed by survival analysis in TCGA database (494 LSCC patients and 20,530 genes) to obtain 18 prognosis-related mRNAs, of which the highly expressed mRNAs VIM and IGF1R were correlated with poorer prognosis, while the highly expressed mRNA ABCC1 was correlated with better prognosis. VIM-encoded protein vimentin and ABCC1-encoded protein MRP1 were increased in LSCC, which were all associated with poor prognosis. Proteasome-inhibited experiments demonstrated that vimentin and MRP1 were degraded through UPS. Quantitative ubiquitinomics found ubiquitination level was decreased in vimentin and increased in MRP1 in LSCC. These findings showed that the increased vimentin in LSCC might be derived from its decreased ubiquitination level and that the increased MRP1 in LSCC might be derived from its protein synthesis > degradation. GSEA and co-expression gene analyses revealed that VIM and MRP1 were involved in multiple crucial biological processes and pathways. Further, TRIM2 and NEDD4L were predicted as E3 ligases to regulate ubiquitination of vimentin and MRP1, respectively. Conclusion These findings revealed ubiquitinomic variations and molecular network alterations in LSCC, which is in combination with multiomics analysis to identify ubiquitination-related biomarkers for in-depth insight into the molecular mechanism and therapeutic targets and for prediction, diagnosis, and prognostic assessment of LSCC.

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