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Masterseminar „A statistical framework for the diagnostic of meningioma cancer“. Andreas Keller Supervised by: Professor Doktor H. P. Lenhof. Chair for Bioinformatics, Saarland University. Outline. Outline. Introduction Materials and Methods SEREX Microarray Conclusion
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Masterseminar „A statistical framework for the diagnostic of meningioma cancer“ Andreas Keller Supervised by: Professor Doktor H. P. Lenhof Chair for Bioinformatics, Saarland University
Outline Outline • Introduction • Materials and Methods • SEREX • Microarray • Conclusion • Discussion
Introduction • What are meningiomas • Benign brain tumors • Arising from coverings of brain and spinal cord • Slow growing • Most common neoplasm (brain) • Genetic alterations
Introduction meningioma in proportions • Two times more often in women as in men • More often in people older than 50 years
Outline Outline • Introduction • Materials and Methods • SEREX • Microarray • Conclusion • Discussion
SEREX serological identification of antigens by recombinant expression cloning se ex r
SEREX – Identification expression of a human fetal brain library proteins bind on membrane pooled sera detection 2nd antibody
SEREX – Screening agar plate specific genes patients serum 2nd antibody detection
Microarrays • System: • cDNA microarrays • 55.000 spots • Whole Genome Array • Data: • 8 samples per WHO grade • 2 dura as negative controle • 2 refPools as negative controle
Statistical Learning • Supervised Learning • Bayesian Statistics • Support Vector Machines • Discriminant Analysis • Unsupervised Learning (Clustering) • Feature Subset Selection • Component Analysis (PCA, ICA)
Statistical Learning • Crossvalidation • Error Rates • Training Error • CV Error • Test Error • Specificity vs. Sensitivity tradeoff • Receiver Operating Caracteristic Curve
Outline Outline • Introduction • Materials and Methods • SEREX • Microarray • Conclusion • Discussion
SEREX • Data situation: • p = 57 • n = 104 • Goal: • Predict meningioma vs. non meningioma • Predict WHO grade
Bayesian Approach class gene A gene B serum 1 serum 2 serum 3 serum 4 serum 5 serum 6 serum 7 serum 8 serum 9 serum 10 serum 11 serum 12 1 0 1 1 1 1 2 1 1 2 1 0 3 0 1 3 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0
Bayesian Approach class gene A gene B serum 1 serum 2 serum 3 serum 4 serum 5 serum 6 serum 7 serum 8 serum 9 serum 10 serum 11 serum 12 1 0 1 1 1 1 2 1 1 2 1 0 3 0 1 3 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 4 4 6 6 1 1 6 7 4 4 6 6 1 0 6 6
Bayesian Approach class gene A gene B serum 1 serum 2 serum 3 serum 4 serum 5 serum 6 serum 7 serum 8 serum 9 serum 10 serum 11 serum 12 1 0 1 1 1 1 2 1 1 2 1 0 3 0 1 3 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 2 2 6 6 5 6 6 6
SEREX Conclusion • Separation meningioma vs. non meningioma seems very well possible • Separation into different WHO grades seems to be possible with a certain error
SEREX Conclusion • Extend to other • Brain tumors (glioma) • Human cancer • Disease • Simplify experimental methods • Develop a prediction system
Outline Outline • Introduction • Materials and Methods • SEREX • Microarray • Conclusion • Discussion
Microarray • Data situation: • p = 53423 • n = 26 • 2 goals: • Find significant genes • Classify into WHO grades
Dimension reduction 6 approaches • Component analysis • Take genes which differ from DURA • Take genes which differ from refPool • Take genes which differ between grades • Take „publicated“ genes • Split into chromosomes
Component analysis • Principal component analysis • Independant component analysis
Analysis of grades tissues genes
Dura and refPool • Justification for Dura • Wherefrom to take? • How to take? • Genes different from normal tissue • Good to classify into meningioma vs. healthy • Justification for refPool • Genes different between WHO grades • Good to classify into grades
Published genes • Several 100 genes are connected with meningioma in several publications • Find these genes and investigate them • example: Lichter 2004 – 61 genes with different expression WHOI in contrast to WHOII and III
Split into chromosomes • losses: • 22 • 1p • 6q • 10q • 14q • 18q • gains: • 1p • 9q • 12q • 15q • 17q • 20q • As mentioned: often karyotypic alterations => Split genes into different chromosomes => Compare to karyotype
Classification • Classification: • Clustering • SVM • Discriminant Analysis • Least Squares
BN++ • BN++ as a statistical tool • Build a C++/R interface?? • Use MatLab?? • Use C++ librarys??
Outline Outline • Introduction • Materials and Methods • SEREX • Microarray • Conclusion • Discussion
Workflow • Large scale investigation of suspicious people by antigen analysis. • If a positive prediction is made do further analysis (CT or similar). • If necessary surgory. • Further examinations with the gained tissue.
Outline Outline • Introduction • Materials and Methods • SEREX • Microarray • Conclusion • Discussion
Outline Outline • Introduction • Materials and Methods • SEREX • Microarray • Conclusion • Discussion