Pharmacogenomic Applications to the Practice of Medicine “ If it were not for the great variability among individuals medicine might as well be a science not an art.” Sir William Osler, 1892 Min Goo Lee Yonsei University
질병유전체학약물유전체학 유전자 연구 단일 유전자 유전병 ; 선천성 면역결핍증 복합 유전자 유전병 ; 당뇨병 심장질환 약동학 관련 유전자 : 흡수, 대사, 배설 약력학 관련 유전자 : 약물 작용 수용체 질병 진단 및 예후 판정각 개인에 알맞은 최적의 치료
Pharmacogenomic Applications Tailored Medicine Maximum Efficacy Optimal Dosage Reduced ADR New Drug Development Efficient Clinical Trials New Target Chemogenomics
Discovery Genomics Target Selection Primary Science (Patients, Laboratory) Knowledge Based Gene variant-specific metabolic differences SNP Map Array of Genes Drug Response Profiles Surrogate Marker New Target Focused use of functional genomic technologies Screening use of functional genomic technologies Secondary Science (In Sillico)
Knowledge Based Approaches Pharmacokinetic Targets Drug Metabolism Drug Transport Etc … Pharmacodynamic Targets Beta-Receptor Potassium Channel Etc …
CYP2D6 Genetic Variants: CYP 2D6*4 (no activity) - Asians < Caucasians - PMs : Asians (~1%) < Caucasians (7%) CYP 2D6*10 (low activity) - Asians > Caucasians - Asians : ~20% low activity Bertilsson et al. CPT 1992;51:388 Propranolol, clozapine, haloperidol, imipramine etc
CYP 2C19 CYP 2C19*2 and *3 (no activity) : Asians > Caucasians – PMs : Asians (~20%) > Caucasians (3%) – Single mutant allele (heterozygote) : intermediate enzyme activity : >50% ( Asians ) vs. 20% (Caucasians) Diazepam, omeprazole, lansoprazole, and other CYP2C19 substrate drugs For most Asians, half of Caucasian dose is enough ?
CYP 3A4/5 Metabolizes nearly 50% of clinically useful drugs – Nifedipine, midazolam, erythromycin, cyclosporine, etc. Accumulating evidence of ethnic differences in PK – Asians vs. Caucasian – African vs. Caucasian
No Activity (No Enzyme Expressed) Decreased ActivityIncreased Activity CYP2A6*2, 2A6*4A, 2A6*4B, 2A6*4D, 2A6*5, CYP2A6*3 CYP2A6*6, 2A6*7, 2A6*9 CYP2C19*2A, 2C19*2B, 2C19*3, 2C19*4, 2C19*5A, 2C19*5B, 2C19*6, 2C19*7, 2C19*8 CYP2D6*3A, 2D6*4A, 2D6*4B 2D6*4C, 2D6*4D, 2D6*4K, 2D6*4X2, 2D6*5, 2D6*6A, 2D6*6B, 2D6*6C, 2D6*7, 2D6*8, 2D6*11, 2D6*12, 2D6*13, 2D6*14, 2D6*15, 2D6*16, 2D6*19, 2D6*20, 2D6*38 CYP2D6*2A, 2D6*9, 2D6*10A, 2D6*10B, 2D6*17, 2D6*18, 2D6*36, 2D6*41 CYP2D6*2XN CYP2D6*1XN CYP1A2*1CCYP1A2*1F CYP2E1*2CYP2E1*1D CYP2C9*2, 2C9*3 CYP3A5*3, CYP3A5*5, CYP3A5*6 CYP3A5*1 CYP2B6*6
MRP1MRP6MRP3 Bile salts NTCP K+K+ Na + OATPs OCTs OATs Hydrophobic organic compounds Hydrophilic organic anions Type I cations Organic anions MRP2 Anionic conjugates MDR1 Cytotoxic cations MDR3 Phospholipids AE2 Cl - /HCO 3 - BSEP Bile salts HEPATOCYTE BILE CANALICULUS Na +
TMD Arm II Arm I NBD ATP TMD NBD Molecule ABC 수송단백 1. CFTR – 음이온 수송 2. MDR & MRP – 유기물 수송 3. SUR – 인슐린분비 4. TAP – 항원발현
MDR MRP CFTR 음이온 수송 유기물 수송
약물 배출 단백의 주요 작용부위 흡수분포배설 소장 및 대장 : 약물과 독성물질의 흡수 억제 혈액 - 뇌 장벽 : 약물과 독성물질의 뇌 진입억제 혈액 - 태반 장벽 : 약물과 독성물질의 태아 진입억제 간장 : 대사된 약물과 독성물질을 담즙 및 혈액으로 분비 신장 : 약물과 독성물질을 혈액 으로부터 소변으로 분비
MRP2 BSEP MDRI MDR3 MRP6 MRP1 Digoxin Fexofenadine Anti-cancer Drugs
MDR-1 # C3435T #
ATG TAC Wild-type allele ACG TGC Mutant allele Hetero- dupelxing ATG TAC ACG TGC ACG TAC ATG TGC Homoduplex mutant Homoduplex wild-type Heteroduplexes TDGS (Two-Dimensional Gene Scanning)
Normal Bronchiectasis Ex2 2 Exon22-S C,G Exon22-AS G,C 21
MDR1 MRP2MRP3 22
Discovery Genomics Genome Sequence SNP Map Gene Array Differential Expression
SNP 란 ? SNP 지도란 ? SNP 지도가 어떻게 약효 예측에 이용될 수 있나 ? 각 개인의 유전자 염기 서열에서 차이를 보이는 부분 G G T A A C T G G G C A A C T G 인간 유전자에 SNP 가 위치한 곳을 나열한 표 Human DNA 임상시험에서 약효를 보이는 군 효과 있을 것으로 예측되는 지표 임상시험에서 약효가 없는 군 효과 없을 것으로 예측되는 지표
Abbreviated SNP linkage disequilibrium profile for efficacy and common adverse events Abbreviated SNP linkage disequilibrium profile for serious, rare adverse events Comprehensive medicine response profile to predict efficacy and adverse events Research Phase II clinical trials Smaller, faster and more efficient phase III studies Market approval with medicine response profile; ‘ pharmacogenetic ’ surveillance Enhancement with comprehensive medicine response profile; ‘ traditional ’ surveillance ‘ Non-responsive ’ profiles define unmet need Used to select patients for phase III clinical trials
Comparison of differential expression technologies TechnologySensitivityTemplate requiredCoverage(%) DNA microarray1: ㎍ total RNAVariable RTQ-PCR1: ng mRNA100% Differential Display 1: ㎍ mRNA96% (240 random primer reactions) SAGE<1: ㎍ total RNA92% ( sequencing reactions) RDA<1: ㎍ mRNAN/A GeneCalling1: ㎍ mRNA95% (96 restriction enzyme pairs) TOGA<1: % (4 enzymes 256 reactions each) 2DE/MS Proteomics ~1: Variable 50-66%
유전자 염기서열 유전자 변이 발견 유전체형 결정 (Haplotype) 유전자 대량 검색법 개발 임상 약리학 및 임상 의학 연구 맞춤약 치료 (Tailored Medicine) 분자세포 연구 실험동물 연구 SNP MAP 새로운 약효 유전자 검색 ATGCCCA ATG CCA A C or
Discovery Genomics Knowledge Based Tailored Medicine Maximum Efficacy Optimal Dosage Reduced ADR New Drug Development Efficient Clinical Trials New Target Chemogenomics High Cost Industry Oriented