Page 57 - Pharmaceutical- Guide to Biopharmaceutical
P. 57

Characterization  Quality Control  Pharmacokinetics


 Biomarker Discovery  MALDI-8020





 Profiling Cancer Cells Using a   benefits

 Benchtop MALDI-TOF MS System                                                                                      Cell Line Optimization
 click here            •   Enables rapid and highly sensitive benchtop profiling.
                       •   Easy maintenance and low running costs
 Operating Principle and Features  extracellular vesicles from regular lymph node cells metastasized from
 colon cancer versus from lymph node cells with elevated chemotherapy   •   Can search a wide range of molecular weights for nucleic acids, proteins, and molecules.
 Compared to quadrupole or magnetic sector mass spectrometers,   resistance.
 matrix-assisted laser desorption/ionization time-of-flight (MALDI-  Protein was collected from the extracellular vesicles obtained from
 TOF) mass spectrometers offer the advantage of both a broad mass   cultivated cells and then the MALDI-8020 system was used to obtain a   Culture
 measurement range and fast measurement speed. They are especially   mass spectrum. Alpha-cyano-4-hydroxycinnamic acid (CHCA) was used
 well-suited for measuring nucleic acids, proteins, and molecules.   as a matrix. eMSTAT Solution was used to analyze the resulting mass
 Though a benchtop system with a compact size, the MALDI-8020   spectrum by multivariate analysis (Fig. 1).
 offers world-class resolution and sensitivity levels. In addition, a shorter
 vacuum evacuation time is achieved by increasing the laser speed and   Results
 modifying the exhaust system, and a significantly shorter measurement
 time is achieved by increasing stage speed.  Components derived from the protein were detected in the m/z 2,000
 to 25,000 range of the extracellular vesicle mass spectrum. Multivariate
 Measurement Method  analysis score plot results discriminated between groups with resistance
    versus groups with sensitivity to fluorouracil. From the peak matrix,                                          Purification
 Cancer cells can metastasize throughout the body by means of   peaks that characterized chemotherapy resistance were detected in the
 extracellular vesicles. Therefore, a MALDI-TOF MS system was used   m/z 2,000 to 7,000 range (Fig. 2).
 to profile differences in the expression level of proteins derived from
               Specifications

               Instrument                   MALDI-8020
 Cell culture
               Mass range                   m/z 1 to 500,000
 Collect supernatant
               Mass resolution              >5,000 FWHM
 Spin at   Spin at   Spin at
 500 g  16,500 g  120,000 g                                                                                        Characterization
               Sensitivity                  >250 amol
 cells  cell debris  Extracellular
 vesicles
               Mass accuracy                <20 ppm with internal calibration, <150 ppm with external calibration
 Sequential Ultracentrifugation  Spot sample and matrix  Acceleration voltage  15 kV
 Sample preparation  MALDI-8020  eMSTAT Solution
               Laser                        Solid-state laser wavelength: 355 nm   Repetition frequency: 50, 100, or 200 Hz (variable)
 Fig. 1   Workflow for Extracellular Vesicle Analysis
               Flight distance              850 mm
               Detector                     Electron Multiplier
 Mass spectrum  Ion source cleaning         Includes automatic cleaning functionality (depending on built-in solid-state laser)
 Peak Matrix:  Sample plate                 Disposable FlexiMass-DS and stainless steel FlexiMass-SR               Quality Control
 This shows the group-speci c
 peaks detected.
 Red   : Peaks detected in   Operating noise  <55 dB
      all mass spectra
 Pink   : Peaks detected in   Main unit power supply  Single-phase 100 V AC, 50/60 Hz, 1 kVA
      only some mass spectra
 Green  : Peaks not detected in   Dimensions  W 600 mm × D 745 mm × H 1,055 mm (excluding protrusions)
      any mass spectra
 Score Plot    Weight                       86 kg
 ● Primary colon cancer
 ● Resistant to 5  mol/L  uorouracil  Operating environment  Temperature: 18 to 28 °C     Humidity: Max. 70 % (with no condensation)
 ● Resistant to 25  mol/L  uorouracil
 ● Resistant to 125  mol/L  uorouracil  Data analysis software  eMSTAT Solution
 Fig. 2   PLS-DA Analysis Results for Four Extracellular Vesicle Groups  Data analysis   Univariate analysis  t-Test, Mann-Whitney U-Test, ANOVA (analysis of variance)  Pharmacokinetics
               functionality
 Conclusion  Application Examples (Shimadzu Application News No.)   Multivariate analysis  PCA (principal component analysis), PLS-DA
                              Discriminant analysis Support Vector Machine (SVM), Random Forest
 Using the MALDI-8020 system in combination with statistical analysis   • Profiling protein expression in tissue
 software shows its potential for use in biomarker discovery research.   • Analyzing glycans and glycopeptides (B113)  Other  Dynamic grouping
 This type of protein profiling method can be expected to be useful for   • Analyzing the primary structures of protein (B105)  Display functionality  Multivariate analysis  Peak Matrix, Box Plot, ROC, AUC, Score/Loading Plot, Dendrogram
 less invasive cancer diagnosis or for monitoring chemotherapy.
                              Discriminant analysis Discriminant analysis results (Group, Score) superimpose points for unknown samples on a score plot  Others
               Input/output data  Input     Peak list (ASCII, JCAMP, or mzML format)
 The extracellular vesicles and cell extracts from primary colon cancer and metastasized lymph node subclones with resistance to 5, 25, and 125 μM concentrations of 5-fluorouracil (FU) were provided by    Output  Peak list (txt format), data analysis results (xlsm format), graph screenshot
 Dr. Gerald Stubiger of the Medical University of Vienna.


 56                                                                                                               57
 index                                                                                                   index
   52   53   54   55   56   57   58   59   60   61   62