RNAi - technologies, markets and companies

0. Executive Summary .... 11

1. Technologies for suppressing gene function.... 13

Introduction...... 13

RNA13

Non-coding RNA13

RNA research and potential applications....14

Role of RNA in regulation of the dihydrofolate reductase gene......14

Gene regulation 15

Post-transcriptional regulation of gene expression ...........15

Alternative RNA splicing ..........16

Technologies for gene suppression ......... 17

Antisense oligonucleotides.......17

Transcription factor decoys......18

Aptamers .........18

Ribozymes .......18

Aptazymes .......19

RNA aptamers vs allosteric ribozymes.......19

RNA Lasso........19

Peptide nucleic acid 20

PNA-DNA chimeras.20

Locked nucleic acid.21

Gene silencing ..21

Post-transcriptional gene silencing ...........21

TargeTronÔ technology for gene knockout 21

Definitions and terminology of RNAi ....... 22

RNAi mechanisms ... 22

Piwi-interacting RNAs in germ cell development.......... 24

Relation of RNAi to junk DNA .. 24

RNA editing and RNAi.............. 24

Historical landmarks in the development of RNAi ........ 25

2. RNAi Technologies ...... 27

Introduction...... 27

Comparison of antisense and RNAi.......... 27

Advantages of antisense over siRNAs........27

Advantages of siRNAs over antisense........28

RNA aptamers vs siRNA ..........28

RNA Lassos versus siRNA ........28

Antisense vs DNP-ssRNA and DNP-siRNA 29

LNA and RNAi..... 30

LNA for gene suppression........30

Comparison of LNA and RNAi ...30

Use of siLNA to improve siRNA.30

RNAi versus small molecules... 30

RNAi kits ............ 31

ShortCut™ RNAi Kit 31

HiScribe™ RNAi Transcription Kit..............32

pSUPER RNAi system..............32

Si2 Silencing Duplex...............33

Techniques for measuring RNAi-induced gene silencing .............. 33

Application of PCR in RNAi.......33

Real-time quantitative PCR.34

Assessment of the silencing effect of siRNA by RT-PCR34

Bioinformatics tools for design of siRNAs 35

Random siRNA design.............35

Rational siRNA design .............35

The concept of pooling siRNAs ............36

Criteria for rational siRNA design.........37

BLOCK-iT RNAi Designer ....37

QIAGEN's 2-for-Silencing siRNA Duplexes..37

Designing vector-based siRNA.............37

iRNAChek for designing siRNA.............38

TROD: T7 RNAi Oligo Designer............38

siDirect: siRNA design software...........38

Prediction of efficacy of siRNAs 38

Algorithms for prediction of siRNA efficacy.38

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siRNA database.39

Production of siRNAs .............. 39

Chemical synthesis of short oligonucleotides...39

In vitro transcription...............40

Generation of siRNA in vivo .....40

siRNA:DNA hybrid molecules ...41

Modifications of siRNAs ...........41

Synthetic RNAs vs siRNAs ..42

Specificity of siRNAs ............... 42

Genome-wide data sets for the production of esiRNAs. 42

ddRNAi for inducing RNAi........ 43

ddRNAi technology .43

Advantages of ddRNAi over siRNA ............43

Short hairpin RNAs.. 44

Advantages and limitations of shRNA........45

Expressed interfering RNA ...... 45

RNA-induced transcriptional silencing complex ........... 46

Inhibition of gene expression by antigene RNA ........... 47

RNAi vs mRNA modulation by small molecular weight compounds ... 47

3. MicroRNA.... 49

Introduction...... 49

miRNA and RISC  50

Role of the microprocessor complex in miRNA............. 51

miRNAs compared to siRNAs... 52

Mapping miRNA genes ............ 52

Role of miRNA in gene regulation ........... 53

Control of gene expression by miRNA .......54

miRNA-mediated translational repression involving Piwi ..............54

Role of miRNAs in gene regulation during stem cell differentiation54

Mechanism of miRNAs-induced silencing of gene expression .............54

Detection and expression profiling of miRNA ............... 55

Real-time PCR for expression profiling of miRNAs............55

Use of LNA to explore miRNA...56

Microarrays for analysis of miRNA gene expression..........56

Computational approaches for the identification of miRNAs ........ 57

Biochemical approach to identification of miRNA......... 57

Targeting of miRNAs with antisense oligonucleotides.. 57

Silencing miRNAs by antagomirs............. 58

miRNA-regulated lentiviral vectors ......... 58

miRNAs as drug targets .......... 58

Prediction of miRNA targets.....59

Role of miRNA in human health and disease  60

Role of miRNAs in regulation of hematopoiesis60

Influence of miRNA on stem cell formation and maintenance ............61

Role of miRNA in regulation of aging.........61

Role of miRNA in inflammation.62

Role of miRNA in the cardiovascular system  62

miRNAs as potential therapeutic targets in heart disease..62

miRNA-based approach for reduction of hypercholesterolemia ..........62

Role of miRNA in neurological disorders . 63

Schizophrenia and miRNA .......63

Role of miRNA in viral infections............. 63

Role of miRNA in HSV-1 latency ...............63

miRNA and skin disorders ....... 64

Role of miRNA in inflammatory skin disorders .64

Role of miRNAs in cancer ........ 64

Role of miRNAs in viral oncogenesis..........65

miRNA genes in cancer ...........65

Cancer miRNA signature .........66

miRNA biomarkers in cancer....66

Diagnostic value of miRNA in cancer.........67

miRNA and brain cancer.....67

miRNA and breast cancer ...67

miRNA and colorectal cancer...............68

miRNA and hematological malignancies68

miRNA and lung cancer ......69

miRNA and pancreatic cancer .............69

miRNA and prostatic cancer70

miRNA and thyroid cancer ..70

miRNAs as basis of cancer therapeutics.....70

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miRNA gene as a basis of cancer therapy ..70

Future prospects of miRNA ..... 70

4. Methods of delivery in RNAi............. 73

Introduction...... 73

Methods of delivery of oligonucleotides .. 73

Oral and rectal administration..74

Pulmonary administration........74

Targeted delivery to the CNS...74

High flow microinfusion into the brain parenchyma.....75

Intracellular guidance by special techniques ...75

Biochemical microinjection ......76

Liposomes-mediated oligonucleotide delivery..76

Polyethylenimine-mediated oligonucleotide delivery.........76

Delivery of TF Decoys .............76

Biodegradable microparticles ...77

Microparticles ...77

Nanoparticles....77

siRNA delivery technologies.... 77

Local delivery of siRNA............78

In vivo delivery of siRNAs by synthetic vectors78

Intracellular delivery of siRNAs 79

Protein transduction domains..............79

MPG-based delivery of siRNA ..............79

Delivery of siRNAs with aptamer-siRNA chimeras .......80

Phosphorothioate stimulated cellular delivery of siRNA80

Targeted delivery of siRNAs by lipid-based technologies...80

Systemic in vivo delivery of lipophilic siRNAs .............81

NeoLipid™ technology........81

siFECTamineÔ ..81

Delivery of siRNA-lipoplexes ...............81

Electroporation .82

Nucleofactor technology .....82

Intravascular delivery of siRNA 83

27mer siRNA duplexes for improved delivery and potency83

TransIT-TKOÒ...84

DNA-based plasmids for delivery of siRNA .85

Convergent transcription....85

PCR cassettes expressing siRNAs .............85

Genetically engineered bacteria for delivery of shRNA......86

Viral vectors for delivery of siRNA ............86

Retroviral delivery of siRNA 86

Adenoviral vectors.............86

Lentiviral vectors...............87

Recombinant baculovirus vector..........88

Adeno-associated virus vectors for shRNA expression ......88

Delivery of siRNA without a vector............88

Cell-penetrating peptides for delivery of siRNAs ..............89

Role of nanobiotechnology in siRNA delivery...89

Quantum dots to monitor siRNA delivery ...89

Polyethylenimine nanoparticles for siRNA delivery ......90

Chitosan-coated nanoparticles for siRNA delivery .......90

siRNA delivery by lipid nanoparticles....91

Delivery of siRNA by nanosize liposomes ...91

Lipidic aminoglycoside as siRNA nanocarrier ..............92

Targeted delivery of siRNAs to specific cell populations ....92

siRNA Dynamic PolyConjugates for delivery to hepatocytes .........92

Delivery of siRNA to the CNS ..............92

Control of RNAi and siRNA levels ............ 93

siRNA pharmacokinetics in mammalian cells ............... 93

Mathematical modeling for determining the dosing schedule of siRNA 94

5. RNAi in Research ........ 95

Introduction...... 95

Basic RNAi research95

Genes and lifespan ............95

Antiviral role of RNAi in animal cells.....95

Silencing snoRNA genes .....95

Profiling small RNAs by Massively Parallel Signature Sequencing ..96

Study of signaling pathways ...............96

RNAi for research in neuroscience .......97

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Use of RNAi to study insulin action ......97

Detection of cancer mutations.............97

Loss-of-function genetic screens .........97

Inducible and reversible RNAi .............98

Combination of siRNA with green fluorescent protein ..98

RNAi and environmental research........99

Applied RNAi research............. 99

RNAi for gene expression studies .............99

Microarrays for measuring gene expression in RNAi .........99

RNAi for functional genomic analysis ...... 100

RNAi studies on C. elegans ............... 100

RNAi studies on Drosophila............... 101

RNAi in planaria .............. 102

Testing the specificity of RNAi 102

Tissue-specific RNAi.............. 102

siRNA-mediated gene silencing .............. 103

RNAi libraries.. 103

Universal plasmid siRNA library......... 104

pDual library using plasmid vector..... 104

pHippy plasmid vector library ........... 104

siRNA libary including miRNAs .......... 105

siRNA libraries using pRetroSuper vector. 105

siRNA produced by enzymatic engineering of DNA .... 105

shRNA libraries ............... 105

Enzymatic production of RNAi library . 106

RNAi and alternative splicing . 107

RNAi in animal development .. 107

RNAi for creating transgenic animals.. 107

RNAi for creating models of neurological disorders.... 108

Research support for RNAi in US........... 109

RNAi for toxicogenomics ....... 109

Role of RNAi in the US biodefense research .. 109

The RNAi Consortium............ 109

Research support for RNAi in Europe .... 110

European Union for RNA Interference Technology.......... 110

Research support of RNAi...... 110

Role of RNAi in MitoCheck project........... 111

Genome-Wide RNAi Global Initiative..... 111

6. RNAi in drug discovery .. 113

Basis of RNAi for drug discovery............. 113

Use of siRNA libraries to identify genes as therapeutic targets ........ 113

Role of siRNAs in drug target identification .............. 113

Use of a genome-wide, siRNA library for drug discovery ............ 114

Use of arrayed adenoviral siRNA libraries for drug discovery ...... 114

RNAi as a tool for assay development ..... 114

Targeting human kinases with an siRNAi library ............ 115

Challenges of drug discovery with RNAi... 115

Express TrackSM siRNA Drug Discovery Program ............ 115

Genome-wide siRNA screens in mammalian cells........... 116

Natural antisense and ncRNA as drug targets 116

MicroRNAs as drug targets .... 117

RNAi for target validation ...... 117

Delivering siRNA for target validation in vivo ........... 117

Off-target effects of siRNA-mediated gene silencing.. 119

Bioinformatic approach to off-target effects ............. 120

Selection of siRNA versus shRNA for target validation ............... 120

Application of RNAi to the druggable genome 121

Application of siRNA during preclinical drug development ............... 121

siRNAs vs small molecules as drugs........ 121

siRNAs vs antisense drugs..... 122

RNAi technology in plants for drug discovery and development ....... 123

Application of RNAi to poppy plant as source of new drugs ........ 123

7. Therapeutic applications of RNAi ... 125

Introduction.... 125

Potential of RNAi-based therapies ........ 126

In vitro applications of siRNA 126

In vivo applications of RNAi .. 127

RNAi and cell therapy............ 127

Gene inactivation to study hESCs........... 127

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RNAi and stem cells.............. 128

Cell therapy for immune disorders.......... 129

RNAi gene therapy  129

Drug-inducible systems for control of gene expression... 129

Potential side effects of RNAi gene therapy... 130

Systemic delivery of siRNAs... 130

In vivo RNAi therapeutic efficacy in animal models of human diseases .. 131

Virus infections  131

RNAi approaches to viral infections......... 132

RNAi applications in HIV........ 133

siRNA-directed inhibition of HIV-1 infection ............. 133

Role of the nef gene during HIV-1 infection and RNAi 134

Bispecific siRNA constructs ............... 134

Targeting CXCR4 with siRNAs ........... 135

Targeting CCR5 with siRNAs ............. 135

Synergistic effect of snRNA and siRNA .... 135

Anti-HIV shRNA for AIDS lymphoma .. 136

Influenza....... 136

Inhibition of influenza virus by siRNAs .... 137

Delivery of siRNA in influenza ........... 137

Challenges and future prospects of siRNAs for influenza ............ 138

Respiratory syncytial and parainfluenza viruses............. 138

Coronavirus/severe acute respiratory syndrome............ 139

Herpes simplex virus 2.......... 140

Hepatitis B ..... 140

Hepatitis C virus .. 140

Cytomegalovirus .. 142

siRNA vs antisense oligonucleotides for viral infections... 142

RNAi-based rational approach to antimalarial drug discovery.... 143

RNAi applications in oncology ............... 143

RNAi approach to study TRAIL ............... 145

Modification of alternative splicing in cancer . 145

siRNA for cancer chemoprevention ......... 145

Drug discovery for cancer...... 146

Inhibition of angiogenesis...... 146

Inhibition of oncogenes......... 147

Onconase....... 147

Allele-specific inhibition......... 147

Drug delivery issues in managing cancer