PXE Research Update Patrick F. Terry President PXE International, Inc. January 14, 2009 1
PXE Research Update Patrick F. Terry
President PXE International, Inc.
January 14, 2009 1
Webinar Instructions Slides are Numbered. 1, 2, 3…
Talk: ~ 45 Minutes Questions: Ask questions by typing your
question “Questions Box” during the presentation and it will be answered as I go.
Concerns: Use the “Questions Box”
Questions & Answers: We will have time at the end for a discussion.
No Medical Advice. I’m Not a Doctor!!! More Info at the End. Stay on the line.
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Presentation Background & Overview Basic Genetics Genetics of PXE PXE Animal Models Next Steps Toward an Intervention:
Diagnostic Test Current Treatments Therapy Approach Drug Development
Human Clinical Trials 3
1995 4
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TM
Genomic Health, Inc. Redwood City California
www.GenomicHealth.com NASDAQ: GHDX
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Patient Managed Research Foundation Not for Profit Patient Support Organization
501(c)3 Foundation
Fir
ew
all
PXE International
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PXE International BioBank
Founded, Supported, & Managed Since 1995 9
PXE Gene
Therapeutic Intervention
Genomic SNP/rSNPs
Proteomics
Regulomics
Cellular Modeling
Model Organisms Protein
Production Rational
Intervention Design Experimental
Assays
In vivo Studies
Delivery Vectors
Protein Structure/Function
Molecular Pathway Genotype / Phenotype
Associations
Accurate Correlative
Linkage
Phenotype Severity
Prediction
Epidemiological Research
Sequence Analysis
Code Sequence Cause Mutations Diagnostics
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PXE Around the World = PXE Patients
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PXE ASSOCIATED RESEARCH
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Benefit Sharing - Academics
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Bio-informatics
Technical Equipment
Training / Staffing & Consumables
Funds & Publicatio
ns
Genetics
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Male Genome 17
Haploid Genome 18
PXE International
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PXE International
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Recessive Disease
ATTAGATCTATGCTATAGGCGT
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PXE Gene Found
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About 10 years ago, several groups had used a candidate gene approach in an attempt to identify gene mutations responsible for the PXE phenotype. The failure of this approach prompted several investigators to consider a systematic genome search for the PXE gene (Struk et al., 1997, van Soest et al.,1997). These studies both reported a single locus at 16p13.1. 5cM region. The locus was refined to an 820-kb region containing 6 candidate genes. (1998) The exclusion of five of these genes and the identification of the first mutations responsible for the development of PXE in a gene encoding a protein associated with multi-drug resistance-associated Protein (ABCC6). (2000)
Pseudoxanthoma Elasticum
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PXE International 24
Complex Inheritance Patterns Even though the first description of the disease was performed over a century ago (Darier, 1896), most cases of PXE have been reported in just the last two decades. In the majority of cases, PXE appears to be inherited as an autosomal recessive (AR) or sporadic means. Mild manifestations of PXE have also been found in known carriers in recessive families (Bachelli et al, 1990) suggesting that heterozygote (haplo-insufficiency) individuals might be at risk particularly for the development of certain signs. The overall incidence of PXE in North America and Europe has been reported to be between 1:25,000 to 1:100,000 live births.
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ABC Transporters
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ATP-binding cassette transporters (ABC-transporter)
Atp Binding Cassette = ABC
DNA super-family that is the largest and most ancient family with examples from prokaryotes (simple bacteria), plants, to humans.
These are transmembrane proteins that function in the transport of a wide variety of substances across extra- and intracellular membranes, including metabolic products, lipids, sterols, and drugs.
ABC transporters are involved in tumor drug resistance, cystic fibrosis, bacterial multidrug resistance, pseudoxanthoma elasticum, and a wide range of other inherited human diseases.
ABCC6 / MRP6
ATP ATP
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The WAVE® System
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NH2
COOH
ABCC6 Mutations Hundreds of Alterations in the Gene/Protein
Extracellular
Intracellular
R1114C T1130M G1133A R1138Q, R1138W A1139T
V1298F G1302R A1303P R1314W R1314Q L1335Q R1339H R1339C
I1342T Q1347H
A78T
E125K
A950T L946I T944I
G663C E669D Q698P L726P M751K G755R R760W R765Q D777N V787I
F568S
G992R
R391G K392N
R1221C, R1221H
L1226I
L463H
L495H
G1501S
G1481S
R600C
R881S
S535P
T364R
T811M
R382W
S317R
Membrane
R1164Q
R518Q
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FUNCTION
P. Terry PXE Int.
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Two
Piston
Pump
PXE International
ABCC10
ABCC11
ABCC12
ABCC13
ABCC6
Sub Family C
3 Billion Years of Evolution
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ABC - Human Diseases
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Disease Transporter Cancer ABCB1 (MDR1), ABCC1 (MRP1),
ABCG2 (MXR) Stargardt disease & AMD ABCA4 (ABCR)
Cystic fibrosis ABCC7 (CFTR) Tangier Disease and Familial HDL deficiency ABCA1 (ABC1) Progressive familial intrahepatic cholestasis ABCB11 (SPGP), ABCB4 (MDR2) Dubin-Johnson syndrome ABCC2 (MRP2) Pseudoxanthoma elasticum ABCC6 (MRP6) Persistent hypoglycemia of infancy ABCC8 (SUR1), ABCC9 (SUR2) Sideroblastic anemia and ataxia ABCB7 (ABC7) Adrenoleukodystrophy ABCD1 (ALD) Sitosterolemia ABCG5, ABCG8 Immune deficiency ABCB2 (Tap1), ABCB3 (Tap2) Lamellar Icthyosis ABCA12
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Genotype Phenotype
Project
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Results Thus Far… 1. Gene Discovery 2. Mutational Database 3. Biorepository 4. Patient Registry 5. Genotype-Phenotype Program 6. Rigorous Participant Protections 7. IPR - Patent and Licensing 8. Clinical Diagnostics 9. Animal Models 10. Functional Screening Assay 11. Clinical Biomarker Program 12. Drug Discovery Program 13. Human Clinical Trials 14. Drug/Treatment Development 34
Research
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Human & Animal Disease 36
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Blood
Bile / Liver
ECM
To Blood ??? Peptides Enzymes Elastase Proteinase inhibitors
ABCC6
LIVER
FUNCTION
Elastin & Collagen Fibrils
Mineralization
ABCC6
Stieger, et al. ‘House Keeping Function’ Basal layer expression of ABCC6 is incorrect. Personal Communication
Peptide ?
PXE International
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Metabolism &
Liver Function
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Diagnostic Testing
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Human & Animal Intervention Approaches
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Drug Research
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Eye Intervention Treatments
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NIH Clinical Center
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Questions… • Natural function & transported substrate? • Liver function & metabolism • ABCC6 tissue-based function characterization? • Variable expressivity and penetrance (Animal & Human) • Extreme & intermediate phenotypes • Pathogenesis & secondary consequences? • Correlations - genotype/phenotype, protein structure
modifications, gene modifiers / environmental factors • Possible early disease interventions • Human clinical intervention trials • Clinical evidence for Avastin & Lucentis treatment
effectiveness 45
Current Projects • Validated functional assay for natural compounds,
drugs & small molecule screening • Non-coding & functional element analysis • Additional gene(s) involvement • Full mutational spectrum database • Mouse model & clinical workup • Fish model & clinical workup • Liver transplant in mouse • Liver transplant patient workup • Systematic clinical phenotype workups • Human intervention trial at NIH (2009)
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Exploratory Research
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• PXE Specific Mineralization – Phosphate – Magnesium – Vitamin K
• ??? Bio-activity & Prohibition of Mineralization • ??? Absorption and Transport (Liver & Kidney) • ??? Tissue Stores and Distribution • ??? Proximal & Distal w/Circulatory Exposure • ??? Liver Metabolism Cycle
Dynamic Interplay
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Questions?