Here, we present a two-dimensional gel electrophoresis (2DE) coupled with mass spectrometry (MS) to separate and identify human pituitary adenoma tissue proteome, which presents a good and reproducible 2DE pattern. Many proteins are observed in each 2DE spot when analyzing complex cancer proteome with the use of high-sensitivity MS.
A subscription to JoVE is required to view this content. Sign in or start your free trial.
Method Article
Two-dimensional Gel Electrophoresis Coupled with Mass Spectrometry Methods for an Analysis of Human Pituitary Adenoma Tissue Proteome
In This Article
Summary
Abstract
Human pituitary adenoma (PA) is a common tumor that occurs in the human pituitary gland in the hypothalamus-pituitary-targeted organ axis systems, and may be classified as either clinically functional or nonfunctional PA (FPA and NFPA). NFPA is difficult for early stage diagnosis and therapy due to barely elevating hormones in the blood compared to FPA. Our long-term goal is to use proteomics methods to discover reliable biomarkers for clarification of PA molecular mechanisms and recognition of effective diagnostic, prognostic markers and therapeutic targets. Effective two-dimensional gel electrophoresis (2DE) coupled with mass spectrometry (MS) methods were presented here to analyze human PA proteomes, including preparation of samples, 2D gel electrophoresis, protein visualization, image analysis, in-gel trypsin digestion, peptide mass fingerprint (PMF), and tandem mass spectrometry (MS/MS). 2-Dimensional gel electrophoresis matrix-assisted laser desorption/ionization mass spectrometry PMF (2DE-MALDI MS PMF), 2DE-MALDI MS/MS, and 2DE-liquid chromatography (LC) MS/MS procedures have been successfully applied in an analysis of NFPA proteome. With the use of a high-sensitivity mass spectrometer, many proteins were identified with the 2DE-LC-MS/MS method in each 2D gel spot in an analysis of complex PA tissue to maximize the coverage of human PA proteome.
Introduction
PA is a common tumor that occurs in the human pituitary gland in the hypothalamus-pituitary-targeted organ axis systems, which play important roles in the human endocrine system. PA includes clinically functional and nonfunctional PAs (FPA and NFPA)1,2. NFPA is difficult in early stage diagnosis and therapy because of only slightly elevated hormone levels (e.g., LH, and FSH) in blood compared to FPA, which has significantly increased levels of corresponding hormones in blood3,4,5. The clarification of molecul....
Access restricted. Please log in or start a trial to view this content.
Protocol
The present protocol follows the guidelines of the Xiangya Hospital Medical Ethics Committee of Central South University, China. A head cap and gloves should be worn for the entire experimental procedure to avoid keratin contamination from skin and hair8.
1. Preparation of Samples
- Collect PA tissues (0.2 - 0.5 mg) from the neurosurgical department. Immediately freeze in liquid nitrogen, and then transfer to -80 °C for storage.
- Add 2 mL of 0.9% NaCl in deionized distilled water (ddH2O). Use this solution to lightly wash the blood from the tissue surface (3x).
Note:<....
Access restricted. Please log in or start a trial to view this content.
Results
1. 2DE-MALDI MS PMF: With the experimental procedure described above, a total of 150 µg proteins were extracted from FSH-expressed NFPA tissues (female; 50 years old, ACTH (-), GH (-), PRL (-), LH (-), FSH (+), and TSH (-)) and arrayed with an 18 cm IPG strip (pH 3-10 NL) and a large-format SDS-PAGE gel, then visualized with silver staining. We obtained a reproducible and good 2DE gel pattern of NFPA tissue proteome (Figure 1.......
Access restricted. Please log in or start a trial to view this content.
Discussion
2DE, coupled with MS methods including 2DE-MS PMF and 2DE-MS/MS, has been successfully used in our long-term program - the use of proteomics to study human NFPA proteomic variations and molecular network variations for the elucidation of molecular mechanisms and discovery of effective biomarkers for NFPAs. 2DE-based comparative proteomics with good reproducibility plays an important role in the identification of NFPA proteomic variations9,10,
Access restricted. Please log in or start a trial to view this content.
Disclosures
The authors declare that there is no conflict of interests.
Acknowledgements
This work was supported by the National Natural Science Foundation of China (Grant No. 81572278 and 81272798 to XZ), the grants from China "863" Plan Project (Grant No. 2014AA020610-1 to XZ), the Xiangya Hospital Funds for Talent Introduction (to XZ), and the Hunan Provincial Natural Science Foundation of China (Grant No. 14JJ7008 to XZ). The authors also acknowledge the scientific contribution of Dr. Dominic M. Desiderio in the University of Tennessee Health Science Center. X.Z. continuously developed and used 2DE-MS methods to analyze pituitary adenoma proteome starting from 2001, conceived the concept for the present manuscript, wrote and revised the manusc....
Access restricted. Please log in or start a trial to view this content.
Materials
| Name | Company | Catalog Number | Comments |
|---|---|---|---|
| Ettan IPGphor 3 | GE Healthcare | isoelectric focusing system. | |
| Ettan DALTsix multigel caster | Amersham Pharmacia Biotech, Piscataway, NJ, USA | ||
| Ettan DALT II System | Amersham Pharmacia Biotech, Piscataway, NJ, USA | The vertical electrophoresis system | |
| Ettan IPGphor strip holder | Amersham Pharmacia Biotech, Piscataway, NJ, USA | ||
| Ettan DALTsix multigel caster | Amersham Pharmacia Biotech, Piscataway, NJ, USA | Multigel caster | |
| Voyager DE STR MALDI-TOF MS | ABI, Foster City,CA | MALDI-MS PMF | |
| MALDI-TOF-TOF | Autoflex III, Bruker | MALDI-MS/MS mass spectrometer | |
| LTQ-OrbiTrap Velos Pro ETD | Thermo Scientific, Waltham, MA, USA | ESI-MS/MS mass spectrometer | |
| EASY-nano LC system | Proxeon Biosystems, Odense, Denmark | High performance liquid chromatography system | |
| PepMap C18 trap column | 300 μm i.d. × 5 mm length; Dionex Corp., Sunnyvale, CA, USA | ||
| RP C18 column | 75 μm i.d., 15 cm length; Dionex Corp., Sunnyvale, CA, USA | ||
| KimWipe | Kimvipe | Insoluble paper towel | |
| Watter | Made by PURELAB flex instrument | ||
| Polytron Model P710/35 homogenizer | Brinkmann Instruments, Westbury, NY | ||
| PDQuest | Bio-Rad, Hercules, CA | 2D gel image analysis software | |
| SEQUEST | Thermo Proteome Discoverer 1.3 (version No. 1.3.0.339) | ||
| DataExplore (ver. 4.0.0.0) software | MS spectrum-processing software | ||
| Mascot software | PMF-based protein searching software | ||
| Mascot software | MS/MS-based protein searching software | ||
| Proteome Discoverer software v.1.3 beta | Thermo Scientific | ||
| Xcalibur software v.2.1 | MS/MS data-acquired management software | ||
| Uniprot version 201410.1_HUMAN.fasta | Human protein database | ||
| SEQUEST (version No. 1.3.0.339) | MS/MS-based protein searching software I | ||
| MASCOT (version 2.3.02) | MS/MS-based protein searching software II | ||
| C18 ZipTip microcolumn | Millipore | ||
| PeptideMass Standard kit | Perspective Biosystems | ||
| Pierce BCA Protein Assay Kit | Thermo Fisher Scientific | 23227 | |
| 2-D Quant Kit | GE Healthcare | 80-6483-56 | |
| BIS-ACRYLAMIDE | AMRESCO | 0172 | |
| ACRYLAMIDE | AMRESCO | 0341 | |
| DTT | Sigma-Aldrich | D0632 | |
| Thiourea | Sigma-Aldrich | T8656 | |
| Urea | VETEC | V900119 | |
| SDS | AMRESCO | 0227 | |
| CHAPS | AMRESCO | 0465 | |
| TEMED | AMRESCO | M146 | |
| Ammonium Persulfate | AMRESCO | M133 | |
| Trypsin | Promega, Madison, WI, USA | V5111 | |
| IPG buffer pH 3-10, NL | GE Healthcare | 17-6000-87 | |
| Immobiline Dry Strip pH 3-10NL,18cm | GE Healthcare | 17-1235-01 |
References
- Zhan, X., Wang, X., Cheng, T. Human pituitary adenoma proteomics: new progresses and perspectives. Front. Endocrinol. 7 (54), (2016).
- Zhan, X., Desiderio, D. M. Comparative proteomics analysis of human pituitary adenomas: Current status....
Access restricted. Please log in or start a trial to view this content.
Reprints and Permissions
