1
|
Ibrahim S, Lan C, Chabot C, Mitsa G, Buchanan M, Aguilar-Mahecha A, Elchebly M, Poetz O, Spatz A, Basik M, Batist G, Zahedi RP, Borchers CH. Precise Quantitation of PTEN by Immuno-MRM: A Tool To Resolve the Breast Cancer Biomarker Controversy. Anal Chem 2021; 93:10816-10824. [PMID: 34324311 DOI: 10.1021/acs.analchem.1c00975] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The tumor suppressor PTEN is the main negative regulator of PI3K/AKT/mTOR signaling and is commonly found downregulated in breast cancer (BC). Conflicting data from conventional immunoassays such as immunohistochemistry (IHC) has sparked controversy about PTEN's role as a prognostic and predictive biomarker in BC, which can be largely attributed to the lack of specificity, sensitivity, and interlaboratory standardization. Here, we present a fully standardized, highly sensitive, robust microflow immuno-MRM (iMRM) assay that enables precise quantitation of PTEN concentrations in cells and fresh frozen (FF) and formalin-fixed paraffin-embedded (FFPE) tissues, down to 0.1 fmol/10 μg of extracted protein, with high interday and intraday precision (CV 6.3%). PTEN protein levels in BC PDX samples that were determined by iMRM correlate well with semiquantitative IHC and WB data. iMRM, however, allowed the precise quantitation of PTEN-even in samples that were deemed to be PTEN negative by IHC or western blot (WB)-while requiring substantially less tumor tissue than WB. This is particularly relevant because the extent of PTEN downregulation in tumors has been shown to correlate with severity. Our standardized and robust workflow includes an 11 min microflow LC-MRM analysis on a triple-quadrupole MS and thus provides a much needed tool for the study of PTEN as a potential biomarker for BC.
Collapse
Affiliation(s)
- Sahar Ibrahim
- Division of Experimental Medicine, McGill University, Montréal, Quebec H4A 3J1 Canada.,Clinical Pathology Department, Menoufia University, Shebeen, El Kom 32511, Egypt.,Segal Cancer Proteomics Centre, McGill University, Montréal, Quebec H3T 1E2, Canada
| | - Cathy Lan
- Segal Cancer Centre, McGill University, Montréal, Quebec H3T 1E2, Canada
| | - Catherine Chabot
- Segal Cancer Centre, McGill University, Montréal, Quebec H3T 1E2, Canada
| | - Georgia Mitsa
- Division of Experimental Medicine, McGill University, Montréal, Quebec H4A 3J1 Canada.,Segal Cancer Proteomics Centre, McGill University, Montréal, Quebec H3T 1E2, Canada
| | | | | | - Mounib Elchebly
- Segal Cancer Centre, McGill University, Montréal, Quebec H3T 1E2, Canada
| | - Oliver Poetz
- University of Tuebingen, Reutlingen 72770, Germany.,SIGNATOPE GmbH, Reutlingen 72770, Germany
| | - Alan Spatz
- Division of Experimental Medicine, McGill University, Montréal, Quebec H4A 3J1 Canada.,Segal Cancer Centre, McGill University, Montréal, Quebec H3T 1E2, Canada.,Department of Pathology, McGill University, Montréal, Quebec H3A 2B4, Canada.,OPTILAB-McGill University Health Centre, Montréal, Quebec H4A 3J1, Canada
| | - Mark Basik
- Division of Experimental Medicine, McGill University, Montréal, Quebec H4A 3J1 Canada.,Segal Cancer Centre, McGill University, Montréal, Quebec H3T 1E2, Canada.,Gerald Bronfman Department of Oncology, McGill University, Montréal, Quebec H3T 1E2, Canada
| | - Gerald Batist
- Segal Cancer Centre, McGill University, Montréal, Quebec H3T 1E2, Canada.,Gerald Bronfman Department of Oncology, McGill University, Montréal, Quebec H3T 1E2, Canada
| | - René P Zahedi
- Segal Cancer Proteomics Centre, McGill University, Montréal, Quebec H3T 1E2, Canada.,Center for Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Christoph H Borchers
- Segal Cancer Proteomics Centre, McGill University, Montréal, Quebec H3T 1E2, Canada.,Gerald Bronfman Department of Oncology, McGill University, Montréal, Quebec H3T 1E2, Canada.,Center for Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| |
Collapse
|
2
|
Pittalà MGG, Reina S, Cubisino SAM, Cucina A, Formicola B, Cunsolo V, Foti S, Saletti R, Messina A. Post-Translational Modification Analysis of VDAC1 in ALS-SOD1 Model Cells Reveals Specific Asparagine and Glutamine Deamidation. Antioxidants (Basel) 2020; 9:E1218. [PMID: 33276691 PMCID: PMC7761621 DOI: 10.3390/antiox9121218] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/19/2020] [Accepted: 11/28/2020] [Indexed: 12/12/2022] Open
Abstract
Mitochondria from affected tissues of amyotrophic lateral sclerosis (ALS) patients show morphological and biochemical abnormalities. Mitochondrial dysfunction causes oxidative damage and the accumulation of ROS, and represents one of the major triggers of selective death of motor neurons in ALS. We aimed to assess whether oxidative stress in ALS induces post-translational modifications (PTMs) in VDAC1, the main protein of the outer mitochondrial membrane and known to interact with SOD1 mutants related to ALS. In this work, specific PTMs of the VDAC1 protein purified by hydroxyapatite from mitochondria of a NSC34 cell line expressing human SOD1G93A, a suitable ALS motor neuron model, were analyzed by tryptic and chymotryptic proteolysis and UHPLC/High-Resolution ESI-MS/MS. We found selective deamidations of asparagine and glutamine of VDAC1 in ALS-related NSC34-SOD1G93A cells but not in NSC34-SOD1WT or NSC34 cells. In addition, we identified differences in the over-oxidation of methionine and cysteines between VDAC1 purified from ALS model or non-ALS NSC34 cells. The specific range of PTMs identified exclusively in VDAC1 from NSC34-SOD1G93A cells but not from NSC34 control lines, suggests the appearance of important changes to the structure of the VDAC1 channel and therefore to the bioenergetics metabolism of ALS motor neurons. Data are available via ProteomeXchange with identifier .
Collapse
Affiliation(s)
- Maria Gaetana Giovanna Pittalà
- Department of Biological, Geological and Environmental Sciences, Molecular Biology Laboratory, University of Catania, Via S. Sofia 64, 95123 Catania, Italy; (M.G.G.P.); (S.R.); (S.A.M.C.)
| | - Simona Reina
- Department of Biological, Geological and Environmental Sciences, Molecular Biology Laboratory, University of Catania, Via S. Sofia 64, 95123 Catania, Italy; (M.G.G.P.); (S.R.); (S.A.M.C.)
- we.MitoBiotech.srl, c.so Italia 172, 95129 Catania, Italy
| | - Salvatore Antonio Maria Cubisino
- Department of Biological, Geological and Environmental Sciences, Molecular Biology Laboratory, University of Catania, Via S. Sofia 64, 95123 Catania, Italy; (M.G.G.P.); (S.R.); (S.A.M.C.)
| | - Annamaria Cucina
- Department of Chemical Sciences, Organic Mass Spectrometry Laboratory, University of Catania, Via S. Sofia 64, 95123 Catania, Italy; (A.C.); (V.C.); (S.F.)
| | - Beatrice Formicola
- School of Medicine & Surgery, Nanomedicine Center NANOMIB, University of Milano-Bicocca, 20900 Monza, Italy;
| | - Vincenzo Cunsolo
- Department of Chemical Sciences, Organic Mass Spectrometry Laboratory, University of Catania, Via S. Sofia 64, 95123 Catania, Italy; (A.C.); (V.C.); (S.F.)
| | - Salvatore Foti
- Department of Chemical Sciences, Organic Mass Spectrometry Laboratory, University of Catania, Via S. Sofia 64, 95123 Catania, Italy; (A.C.); (V.C.); (S.F.)
| | - Rosaria Saletti
- Department of Chemical Sciences, Organic Mass Spectrometry Laboratory, University of Catania, Via S. Sofia 64, 95123 Catania, Italy; (A.C.); (V.C.); (S.F.)
| | - Angela Messina
- Department of Biological, Geological and Environmental Sciences, Molecular Biology Laboratory, University of Catania, Via S. Sofia 64, 95123 Catania, Italy; (M.G.G.P.); (S.R.); (S.A.M.C.)
- we.MitoBiotech.srl, c.so Italia 172, 95129 Catania, Italy
| |
Collapse
|
3
|
Postu PA, Ion L, Drochioiu G, Petre BA, Glocker MO. Mass spectrometric characterization of the zein protein composition in maize flour extracts upon protein separation by SDS-PAGE and 2D gel electrophoresis. Electrophoresis 2019; 40:2747-2758. [PMID: 31169923 DOI: 10.1002/elps.201900108] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 05/23/2019] [Accepted: 05/27/2019] [Indexed: 12/24/2022]
Abstract
Highly homogenous α zein protein was isolated from maize kernels in an environment-friendly process using 95% ethanol as solvent. Due to the polyploidy and genetic polymorphism of the plant source, the application of high resolution separation methods in conjunction with precise analytical methods, such as MALDI-TOF-MS, is required to accurately estimate homogeneity of products that contain natural zein protein. The α zein protein product revealed two main bands in SDS-PAGE analysis, one at 25 kDa and other at 20 kDa apparent molecular mass. Yet, high resolution 2DE revealed approximately five protein spot groups in each row, the first at ca. 25 kDa and the second at ca. 20 kDa. Peptide mass fingerprinting data of the proteins in the two dominant SDS-PAGE bands matched to 30 amino acid sequence entries out of 102 non-redundant data base entries. MALDI-TOF-MS peptide mapping of the proteins from all spots indicated the presence of only α zein proteins. The most prominent ion signals in the MALDI mass spectra of the protein mixture of the 25 kDa SDS gel band after in-gel digestion were found at m/z 1272.6 and m/z 2009.1, and the most prominent ion signals of the protein mixture of the 20 kDa band after in-gel digestion were recorded at m/z 1083.5 and m/z 1691.8. These ion signals have been found typical for α zein proteins and may serve as marker ion signals which upon chymotryptic digestion reliably indicate the presence of α zein protein in two hybrid corn products.
Collapse
Affiliation(s)
- Paula A Postu
- Department of Biology, Alexandru Ioan Cuza University, Iasi, Romania.,Transcend Research Center - Regional Institute of Oncology, Iasi, Romania
| | - Laura Ion
- Department of Chemistry, Alexandru Ioan Cuza University, Iasi, Romania
| | - Gabi Drochioiu
- Department of Chemistry, Alexandru Ioan Cuza University, Iasi, Romania
| | - Brindusa A Petre
- Transcend Research Center - Regional Institute of Oncology, Iasi, Romania.,Department of Chemistry, Alexandru Ioan Cuza University, Iasi, Romania
| | - Michael O Glocker
- Proteome Center Rostock, Medical Faculty and Natural Science Faculty, University of Rostock, Rostock, Germany
| |
Collapse
|
6
|
Hao P, Adav SS, Gallart-Palau X, Sze SK. Recent advances in mass spectrometric analysis of protein deamidation. MASS SPECTROMETRY REVIEWS 2017; 36:677-692. [PMID: 26763661 DOI: 10.1002/mas.21491] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Revised: 12/28/2015] [Accepted: 12/28/2015] [Indexed: 06/05/2023]
Abstract
Protein deamidation has been proposed to represent a "molecular clock" that progressively disrupts protein structure and function in human degenerative diseases and natural aging. Importantly, this spontaneous process can also modify therapeutic proteins by altering their purity, stability, bioactivity, and antigenicity during drug synthesis and storage. Deamidation occurs non-enzymatically in vivo, but can also take place spontaneously in vitro, hence artificial deamidation during proteomic sample preparation can hamper efforts to identify and quantify endogenous deamidation of complex proteomes. To overcome this, mass spectrometry (MS) can be used to conduct rigorous site-specific characterization of protein deamidation due to the high sensitivity, speed, and specificity offered by this technique. This article reviews recent progress in MS analysis of protein deamidation and discusses the strengths and limitations of common "top-down" and "bottom-up" approaches. Recent advances in sample preparation methods, chromatographic separation, MS technology, and data processing have for the first time enabled the accurate and reliable characterization of protein modifications in complex biological samples, yielding important new data on how deamidation occurs across the entire proteome of human cells and tissues. These technological advances will lead to a better understanding of how deamidation contributes to the pathology of biological aging and major degenerative diseases. © 2016 Wiley Periodicals, Inc. Mass Spec Rev 36:677-692, 2017.
Collapse
Affiliation(s)
- Piliang Hao
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Sunil S Adav
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Xavier Gallart-Palau
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Siu Kwan Sze
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| |
Collapse
|
10
|
Vilhauer L, Jervis J, Ray WK, Helm RF. The exo-proteome and exo-metabolome of Nostoc punctiforme (Cyanobacteria) in the presence and absence of nitrate. Arch Microbiol 2014; 196:357-67. [PMID: 24643449 DOI: 10.1007/s00203-014-0974-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 02/27/2014] [Indexed: 01/04/2023]
Abstract
The ability of nitrogen-fixing filamentous Cyanobacteria to adapt to multiple environments comes in part from assessing and responding to external stimuli, an event that is initiated in the extracellular milieu. While it is known that these organisms produce numerous extracellular substances, little work has been done to characterize both the metabolites and proteins present under standard laboratory growth conditions. We have assessed the extracellular milieu of Nostoc punctiforme when grown in liquid culture in the presence and absence of a nitrogen source (nitrate). The extracellular proteins identified were enriched in integrin β-propellor domains and calcium-binding sites with sequences unique to N. punctiforme, supporting a role for extracellular proteins in modulating species-specific recognition and behavior processes. Extracellular proteases are present and active under both conditions, with the cells grown with nitrate having a higher activity when normalized to chlorophyll levels. The released metabolites are enriched in peptidoglycan-derived tetrasaccharides, with higher levels in nitrate-free media.
Collapse
Affiliation(s)
- Laura Vilhauer
- Department of Biochemistry, Virginia Tech, 143 Life Sciences 1, Blacksburg, VA, 24061-0910, USA
| | | | | | | |
Collapse
|