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We report the case of a 65-year-old man who gradually developed numbness in both hands, lower limb muscle weakness and atrophy, and orthostatic hypotension over two and a half years. These symptoms indicated hereditary ATTR amyloidosis (ATTRv amyloidosis), and the final diagnosis was established through proof of TTR gene mutation (V30M). We initiated patisiran therapy, and a continuous 6-minute walking test performed 3 weeks from the start of therapy demonstrated improvement in the walking distance. This is a single case report showing the improvement in the motor and sensory function on administration of patisiran monotherapy from an early stage.

The role of β-estradiol (E 2 ) in lipoprotein metabolism in mammary tumors remains unknown. Therefore the effect of E 2 on secretion of lipoprotein lipase (LPL) from mouse mammary tumor FM3A cells was examined. The E 2 -treated FM3A cells increased active LPL secretion in a time- and dose-dependent manner. The activity of mitogen-activated protein kinase (MAPK) was elevated in the tumor cells treated with E 2 , and E 2 -stimulated secretion of LPL was suppressed by the MAPK kinase 1/2 inhibitor PD98059, extracellular signal-regulated kinase (ERK) 1/2 inhibitor FR180204, p38 MAPK inhibitor SB202190, and phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002. In addition, the effect of E 2 on active LPL secretion was markedly suppressed by an inhibitor of mammalian target of rapamycin complex (mTORC) 1 and 2, KU0063794, but not by the mTORC1 inhibitor, rapamycin. Furthermore, a small interfering RNA (siRNA)-mediated decrease in the expression of rapamycin-insensitive companion of mTOR (Rictor), a pivotal component of mTORC2, suppressed the secretion of LPL by E 2 . Stimulatory secretion of LPL by E 2 from the tumor cells is closely associated with activation of mTORC2 rather than mTORC1, possibly via the MAPK cascade.

Medium-sized peptides are expected as a next-generation drug discovery modality because they combine the properties of conventional small-molecule drugs and biopharmaceuticals. Nonetheless, peptides are easily degraded by digestive enzymes such as protease in the body, which could be problematic for the development of peptide-based drugs. To overcome such a problem, peptide-based foldamers containing non-proteinogenic amino acids or cyclized peptides have been reported. In addition, peptides must form stable secondary structures and their side chains should be correctly positioned to exert their bioactivity. In our lab, bioactive peptides have been developed based on regulation of secondary structures by introducing non-proteinogenic amino acids such as acyclic α,α-disubstituted amino acids (dAAs), cyclic dAAs, cyclic β-amino acids, and side-chain stapling. Based on these knowledges, I have been performing research on the development of bioactive peptides based on the secondary structural control of peptides as categorized in the following manner: (1) rational design of antimicrobial foldamers; (2) post-functionalization of helical peptides; (3) development of carrier peptides for intracellular delivery of siRNA utilizing the helical template peptides.

Acute myeloid leukemia (AML) remains a devasting disease. Progress has been made to define molecular mechanisms underlying disease pathogenesis due, in part, to the near-complete understanding of AML genome. Nonetheless, functional studies are necessary to assess the significance of AML-associated mutations and devise urgently needed therapies. Genome-wide knockout screening, employing CRISPR-Cas9 genome editing, is a powerful tool in functional genomics. In this study, genome-wide CRISPR screening was performed using mouse leukemia cell lines developed in our Center, followed by in vivo screening. Among 20,611 genes, 130 AML essential genes were identified, including clinically actionable candidates. It was shown that mRNA decapping enzyme scavenger (DCPS), an enzyme implicated in mRNA decay pathway, is essential for AML survival. ShRNA-mediated gene knockdown and DCPS inhibitor (RG3039) were employed to validate findings. RG3039 induced cell-cycle arrest and apoptosis in vitro. Furthermore, mass spectrometry analysis revealed an association between DCPS and RNA metabolic pathways, and RNA-Seq showed that RG3039 treatment induced aberrant mRNA splicing in AML cells. Importantly, RG3039 exhibited anti-leukemia effects in PDX models. These findings identify DCPS as a novel therapeutic target for AML, shedding new light on the nuclear RNA metabolic pathway in leukemogenesis.

In general, the blood-brain barrier (BBB) poses a major challenge to drug development efforts targeting brain/central nervous system (CNS) diseases, since it limits the distribution of systemically administered therapeutics to the brain/ CNS. Therefore, the development of effective strategies for enhancing drug delivery to the brain has been a topic of great interest in both the clinical and pharmaceutical fields. Intranasal administration has been noted as a method for noninvasive delivery of a drug to the brain/CNS by bypassing the BBB via the "nose-to-brain" route. This nose-to-brain delivery system has the potential to be highly versatile, and a combination of this system with new drugs and siRNA shows promise in the treatment of CNS diseases. Cell-penetrating Tat peptide-modified block copolymer micelles have the potential for improving mucosal permeability and nose-to-brain transport efficiency. In addition, nano-sized drug carriers can improve nose-to-brain delivery through their ability to increase the stability of encapsulated drugs against biological degradation in the nasal cavity and brain/CNS. In this review, we introduce the assessment of and mechanisms for delivery to the brain after intranasal drug/siRNA administration with our cell-penetrating peptide-modified nano-sized polymer micelles. Our findings show that the use of polymer micelles with surface modification by cell-penetrating peptides for intranasal administration enables the noninvasive delivery of therapeutic agents to the brain/CNS by increasing the nose-to-brain transfer of the drug or siRNA administered from the nasal cavity.

The adenovirus (Ad) genome encodes two small noncoding RNAs, VA-RNA I and II, which support Ad replication by antagonizing the antiviral action associated with the Ad-induced activation of double-stranded RNA-dependent protein kinase (PKR). VA-RNAs are also processed in a manner similar to microRNAs (miRNAs), resulting in the production of VA-RNA-derived miRNAs (mivaRNAs). mivaRNAs are incorporated into the RNA-induced silencing complex (RISC) and exhibit posttranscriptional silencing in a manner similar to miRNAs. However, it remained to be clarified whether Dicer-mediated processing of VA-RNAs and the subsequent production of mivaRNAs were crucial for Ad replication. Recently, we have found that Dicer efficiently suppresses Ad replication via cleavage of VA-RNAs to mivaRNAs. Based on these findings, we have developed an oncolytic Ad that shows tumor cell-specific replication and carries an expression cassette of short-hairpin RNA (shRNA) against Dicer (shDicer). The oncolytic Ad expressing shDicer exhibited more efficient replication and oncolytic activity both in vitro and in vivo. In addition, we demonstrated that shRNA-mediated RNA interference is competitively inhibited by VA-RNAs. A replication-incompetent Ad vector lacking VA-RNA expression (AdΔVR vector) exhibited superior knockdown efficiencies compared with a conventional Ad vector, indicating that an shRNA-expressing AdΔVR vector is a powerful framework for shRNA-mediated knockdown. We believe that functional analyses of Ad-encoded genes, including VA-RNAs, could lead to the development of novel recombinant Ads.

Nucleic acid-based drugs (NABDs) have recently attracted considerable attention as next-generation medicines, following the development of low molecular-weight and antibody drugs, because it is likely that they will have fewer side effects and greater target specificity than conventional medicines. Short double-stranded RNAs contain a 2-nucleotide overhang at the 3'-end of each strand. Small interfering RNAs (siRNAs) and microRNAs (miRNAs) inhibit gene expression by RNA interference (RNAi) and thus have great potential as NABDs. However, naked RNA strands have many problems that hinder their application as therapeutics, such as their rapid degradation in biological fluids, poor cellular uptake, and off-target effects. Therefore, artificially modified siRNAs and miRNAs have been studied extensively in an effort to overcome these problems. In this review, I summarize my recent studies on the synthesis of nucleic acid mimics and their application in RNAi-based medicine. The following two topics are specifically discussed: 1) the design and synthesis of chemically modified functional RNAs bearing nucleic acid mimics at their 3'-overhang region, which plays a key role in RNAi; and 2) the practical, reliable synthesis of nucleic acid mimics containing ethynyl groups.

Over the past decade, oligonucleotide-based therapeutics such as antisense oligonucleotides and small interfering RNAs (siRNAs) have been developed extensively. For example, mipomersen (Kynamro; ISIS Pharmaceuticals), which is a second-generation antisense oligonucleotide administered by subcutaneous injection, has recently been approved by the FDA for the treatment of homozygous familial hypercholesterolemia. On the other hands, methods for the evaluation of quality, efficacy and safety of oligonucleotide therapeutics have not been fully discussed. Furthermore, the regulatory guidance specific for oligonucleotide therapeutics has not been established yet. Under these circumstances, we started to collaborate with Osaka University and PMDA to discuss regulatory science focused on oligonucleotide therapeutics. Through the collaboration, we would like to propose the possible design of quality evaluation and preclinical safety-evaluation of oligonucleotide therapeutics.

A number of modified oligonucleotides prepared using a general chemical approach with the corresponding phosphoramidite units have been synthesized to evaluate their functions. An alternative enzymatic method using the corresponding nucleoside triphosphates could also be used. Since this approach affords long-chain sequences from readily available natural DNA templates, if successful it would be useful in numerous biotechnologies. This review summarizes our current results of polymerase chain reaction (PCR) amplification of 4'-thioDNA using 4'-thio-dNTPs and gene silencing using the resulting 4'-thioDNAs as a template arising from 4'-thioDNA-directed transcription in mammalian cells.

First-generation adenovirus vectors (FG-AdVs) are widely used because transduction efficiency of the vectors is very high. However, severe immune responses especially to the liver have been a serious problem of this vector. We succeeded to identify a viral protein that cause the immune responses and reported ''low-inflammatory AdVs'' that mostly solve this problem. However, to develop the ultimate form of this vector, it is necessary to remove virus-associated RNA (VA RNA) genes from the AdV vector genome. VA RNAs are transcribed by polymerase III; they are not essential for viral growth but have important roles to make appropriate circumstances for this virus. Large amount of VA RNAs are required in the late phase to support viral growth. Hence it is difficult to establish 293 cell lines that can support replication of AdVs lacking VA RNA genes (VA-deleted AdVs) supplying sufficient amount of VA RNA in trans. Recently we have developed a method for efficient production of VA-deleted AdVs and succeeded to obtain a high titer of VA-deleted AdVs. Then we construct VA-deleted AdVs expressing shRNA that knockdown the replication of hepatitis C virus (HCV). In fact, VA-deleted AdVs expressing these shRNAs suppressed HCV replication more effectively than conventional FG-AdV. Therefore, we showed that VA RNAs expressed from FG-AdVs probably compete with shRNA in the maturation pathway and reduce the effect of shRNAs. We think that VA-deleted AdV may substitute for current FG-AdVs and become a standard AdV.

Astrocytes, the most abundant cells in the central nervous system (CNS), play diverse roles in the regulation of neuronal activity, vascular function and gliotransmitter release. In neurodegenerative diseases, pathologically activated astrocytes show astrogliosis, which is clinically characterized by an abnormal cell morphology and excessive astrocyte proliferation. Thrombin, a crucial factor for brain injury after intracerebral hemorrhage, activates astrocytic Ca2+ signaling through a specific subtype of the thrombin receptor, termed the proteinase-activated receptor (PAR). In this study, we demonstrate a novel pathophysiological role for transient receptor potential canonical 3 (TRPC3) Ca2+-permeable nonselective cation channels in thrombin-activated astrocytes. In 1321N1 human astrocytoma cells and cultured rat cortical astrocytes, thrombin induced heterogeneous Ca2+ responses with asynchronous repetitive peaks. These oscillations were found to be the result of repetitive Ca2+ release from intracellular stores followed by replenishment of the stores with Ca2+ from the extracellular region. The oscillations occurred without a direct [Ca2+]i increase and were inhibited by the selective TRPC3 inhibitor pyrazole-3. Pharmacological manipulation with BAPTA-AM, cyclopiazonic acid, 2-aminoethoxydiphenyl borate and pyrazole-3 indicated that Ca2+ mobilization through TRPC3 was involved in thrombin-induced changes in the morphology of astrocytes. Moreover, thrombin-induced upregulation of S100B, a marker of reactive astrocytes, at 20 h and increased astrocytic proliferation at 72 h were inhibited by Ca2+ signaling blockers and knockdown of TRPC3 with specific siRNA. Taken together, these results suggest that TRPC3 may constitute a new therapeutic target for brain injury after intracerebral hemorrhage.

Osteopontin (OPN) is the major constituent of calcium-containing urinary stones and is involved in the inhibition of nucleation and aggregation of calcium oxalate (CaOx) crystals, promotion of the adherence of CaOx crystals to cultured renal epithelial cells, and regulation of inflammatory cells as chemokine. OPN has different effects (inhibitor and promoter) at each stage of stone formation in vitro and these multifunctional actions of OPN have not been fully elucidated. We developed a modified crystal method using collagen granules (CG) and immobilized OPN. OPN had strong inhibitory activity on the aggregation/growth of CaOx crystals, but the inhibitory activity decreased by use of OPN-immobilized CG. OPN is also a critical promoter of adherence for CaOx crystals to cultured renal epithelial cells in an in vitro experimental system. We examined the effect of OPN in vivo, by OPN siRNA transfection in rats. Hydrodynamic intravenous and renal subcapsular injections with lipofection were performed on days 1 and 8. The calcium concentration in the kidney was significantly lower and the frequency of CaOx crystal deposits in the tubules was lower in the OPN siRNA transfection group (drinking 1.5% ethylene glycol (EG)), than in the EG drinking group (sham operation) at day 15. We examined the effect of candesartan, an angiotensin II (Ang II) type 1 receptor blockers (ARB) in hyperoxaluric rats. ARB reduced crystal formation and calcium concentrations in the whole kidney. Hyperoxaluria leads to CaOx crystallization and the development of tubulointerstitial lesions in the kidney. AngII mediates OPN synthesis, which is involved in both macrophage recruitment and CaOx crystallization. OPN synthesis and production increased with hyperoxaluria but to a lesser extent in ARB-treated hyperoxaluric rats. These results show that oxalate can activate the renal renin-angiotensin system and that oxalate-induced upregulation of OPN is in part mediated via the renal renin-angiotensin system.

This review describes studies on drug discovery using a rational formulation design and innovative, drug delivery systems (DDS) for biomaterials such as therapeutic peptides and nucleotides. The microcapsules of the LH-RH superagonist leuprorelin acetate prepared using the new in-water drying method and biodegradable polymers, such as PLGA and PLA, could achieve a long-term sustained release for 1-6 months thereby facilitating easily treatment of hormone-dependent diseases, prostate cancer, endometriosis, and precocious puberty. This DDS technology showed an improvement in patient QOL and highly promoted the clinical value of the agonist. Moreover, PLGA microcapsules of siRNAs against VEGF, cFLIP, Raf-1, and Int6 have also been developed to treat various cancers and arteriosclerosis obliterans. To develop therapeutic nucleotides, a particle design is created using functional peptides, such as cell penetrating peptides (CPP), nuclear localizing signals (NLS), tight junction reversible openers (AT1002), bombesin, and dynein light chain-associated sequences. siRNA use should lead to a paradigm shift in drug discovery against various diseases. Tat analog with NLS could enhance the potency of a vaginal DNA vaccine. The artificial Tat CPP of STR-CH(2)R(4)H(2)C synthesized in our laboratory could efficiently deliver siRNAs into many types of cells and enhance the therapeutic effects for treating sarcoma, atopic dermatitis, allergic rhinitis, and asthma by intratumor injection and inhalation of the nanoparticles. Tat and AT1002 analogs used to treat atopic dermatitis in mice increased cell membrane permeability to siRelA, a siRNA against a subclass of NF-κB, and exhibited striking therapeutic and preventive effects.

RNA interference (RNAi) is a phenomenon of sequence-specific gene silencing in mammalian cells and its discovery has lead to its wide application as a powerful tool in post-genomic research. Recently, short interfering RNA (siRNA), which induces RNAi, has been experimentally introduced as a cancer therapy and is expected to be developed as a nucleic acid-based medicine. Selection of appropriate gene targets is an important parameter in the potential success of siRNA cancer therapies. Candidate targets include genes associated with cell proliferation, metastasis, angiogenesis, and drug resistance. Importantly, silencing of such genes must not affect the functions of normal cells. Development of suitable drug delivery systems (DDSs) is also an important issue. Numerous methods to transfect siRNAs into cells have been developed, and the use of non-viral DDSs is preferred because it offers greater safety for clinical application than does the use of viral DDSs. In this article, we briefly review the mechanism of RNAi and non-viral DDSs. Next, we discuss some of the most recent findings concerning the administration of siRNAs against polo-like kinase-1 (PLK-1), which regulates the mitotic process in mammalian cells. Finally, several current clinical trials of RNAi therapies against cancers are discussed. Results of current studies and clinical trials demonstrate that manipulation of the RNAi mechanism by use of targeted siRNA offers a novel and attractive therapeutic option against cancer.

Many lines of recent evidence indicate that non-coding RNAs including micro RNAs (miRNAs) and small interfering RNAs (siRNAs) play an important role in the control of gene expression in diverse cellular processes and in defense responses against molecular parasites such as viruses and transposons. Viruses also use many different types of non-coding RNAs for regulating expression of their own genome or host genome temporally and spatially to ensure efficient virus proliferation and/or latency in the host cell. Here, we introduce the generation mechanisms and functions of novel non-coding RNAs generated from both animal and plant RNA viruses, after a brief review of non-coding RNAs of DNA viruses.

Chitosan is one of the attractive non-viral carriers for gene delivery including siRNA. However, common chitosan, which has a relatively high molecular weight, is insoluble in water, which might make it difficult to apply clinically. In this study, we investigated the efficacy of low-molecular-weight chitosan (LMWC), which is soluble in water, as a carrier for siRNA delivery. To evaluate the binding affinity and RNA interference (RNAi) of LMWC/siRNA complexes, a multi-well imaging system (IVIS) was adapted. CT26 cells stably expressing firefly luciferase (CT26/Luc cells) were established to evaluate RNAi. Evaluation of RNAi using lipofectamine(TM) 2000 was carried out by employing a luminometer with cell lysis and IVIS without cell lysis. The results were closely correlated, suggesting the advantages of the multi-well imaging system regarding screening, the visualization of results, and nondestructive evaluation. Fluorescence generated by ethidium bromide intercalated in the double strand of siRNA was markedly quenched at a higher ratio of LMWC to siRNA (N/P) and lower pH. Evaluation of the particle size and zeta potential of LMWC/siRNA complexes also indicated the higher binding affinity of LMWC with siRNA. At N/P=300 and pH 6.5, which satisfied the high-level binding affinity of LMWC with siRNA, significantly lower luminescence was detected in CT26/Luc cells treated with LMWC/siRNA compared with those treated with LMWC alone, suggesting the presence of RNAi. These results suggested that LMWC may be an effective carrier for siRNA delivery, and that the multi-well imaging system may be a powerful tool to evaluate the binding affinity and RNAi.

Recently several systems including viral and non-viral carriers that can be used to transfer foreign genetic material into cells have been developed with the aim of enhancing gene transfer in vivo. Non-viral vectors are relatively easy to produce in clinically relevant quantities, and associated with fewer safety concerns. Furthermore, synthetic non-viral vectors provide flexibility in formulation design and can be tailored to interact efficiency with DNA cargo and the specific route of vector injection, and can enhance delivery to specific tissues or cells through incorporation of a targeting ligand. Applying cell-specific targeting technology to liposomes would improve in vivo gene transfection efficacy and reduce any unexpected side-effects. Among the various receptors, asialoglycoprotein receptors and mannose receptors are the most promising for gene targeting since they exhibit high affinity and are rapidly internalized. Receptor-mediated delivery systems are able to introduce foreign DNA into specific cell types in vivo. Our group succeeded in the development of glycosylated cationic liposomes for cell-selective targeting of plasmid DNA, siRNA, and NFkappaB decoy based on the optimization of physicochemical properties of glycosylated liposome complex.

Small RNAs play a critical role in the regulation of gene expression in diverse cellular processes. This mechanism, termed RNA silencing or RNAi, also functions as a defense mechanism against molecular parasites such as virus and transposon. Whereas RNA silencing is triggered by viral infection, viruses suppress RNA silencing to establish infection, and sometimes even exploit it for their infection. In this mini review, we describe intimate interactions between viruses and host organisms in RNA silencing.

Non-viral vectors need to overcome several barriers such as the plasma membrane, the endosomal membrane and the nuclear membrane for efficient gene delivery to the nucleus of target cells. To overcome these obstacles, the delivery system must be equipped with various functional devices. However, it is difficult to package all these needed devices into a single system to exert each of their functions at the appropriate time and at the correct location. Thus, our group proposed a new packaging concept, "Programmed Packaging". A multifunctional envelope-type nano device (MEND) was developed for use as an efficient non-viral system for the delivery of plasmid DNA (pDNA), oligodeoxynucleotide (ODN) and siRNA. Various types of MEND were developed as to strategy and situations. For example, the octaarginine (R8)-modified MEND (R8-MEND) encapsulating pDNA showed significantly high transfection activity comparable to adenovirus, and the up-take pathway of the R8-MEND was macropinocytosis, which can avoid lysosomal degradation. The R8-MEND successfully delivered a gene to hair follicles of mouse skin by in vivo topical application. Consequently, our group succeeded in the development of the MEND based on the Programmed Packaging, and found this to be a promising new delivery system of pDNA and functional nucleic acids.

For efficient gene delivery to the nucleus, nonviral vectors need to overcome several barriers such as the plasma membrane, endosomal membrane, and nuclear membrane. To overcome these obstacles, it is necessary to equip the delivery system with various functional devices. However, it is difficult to package all such functional devices into a single system to exert each of their functions at the appropriate time and at the correct location. Thus our group proposed a new packaging concept, "programmed packaging." A multifunctional envelope-type nano device (MEND) was developed for use as an efficient nonviral system for the delivery of plasmid DNA (pDNA), oligodeoxynucleotide (ODN), and siRNA using octaarginine (R8) as an internalizing ligand based on the programmed packaging. The R8-modified MEND (R8-MEND) encapsulating pDNA showed significantly high transfection activity comparable to that of adenovirus, and the uptake pathway of R8-MEND was macropinocytosis, which can avoid lysosomal degradation. R8-MEND successfully delivered gene to hair follicles after in vivo topical application to mouse skin. Moreover, R8-MEND encapsulating anti-luciferase ODN using protamine showed a 90% antisense effect, and R8-MEND encapsulating siRNA condensed with stearylated R8 significantly silenced luciferase activity. Our group thus succeeded in the development of R8-MEND based on programmed packaging, and MEND is a promising new delivery system for pDNA and functional nucleic acids.

Cardiac valves are recognized as avascular tissue as well as cartilage and eye. We recently identified chondromodulin-I as crucial anti-angiogenic factor for maintaining cardiac valvular function. chondromodulin-I was first detected at developmental stage E9.5 in outflow tract, valvular primordium, and left ventricle, but was restricted to cardiac valves from late embryogenesis to adult. In ApoE(-/-) mice and human valvular heart diseases such as atherosclerosis, rheumatic heart diseases, and infective endocarditis, vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP) expression and neovascularization were observed in the area of down-regulation of chondromodulin-I. Conditioned medium from cultured-valvular interstitial cells strongly inhibited tube formation and migration of endothelial cells, and these effects were partially blocked by chondromodulin-I siRNA in vitro. Gene targeting of chondromodulin-I caused VEGF expression, neovascularization, lipid deposition, and calcification in cardiac valves of aged mice. Echocardiography showed aortic valve thickening and turbulent flow suggesting early stage of aortic stenosis. These findings provide evidence that chondromodulin-I is a crucial factor for maintaining normal cardiac valvular function by preventing angiogenesis that may lead to valvular heart diseases.

In this review article, supramolecular nanocarriers for gene and siRNA delivery were introduced. They were formed through the multimolecular assembly of block copolymers, containing the DNA or siRNA inside the core of the micelle structure. Due to the excellent stability under the physiological conditions, low toxic effect, and controllable gene functions, this system should be a promising candidate for in vivo therapeutic applications including the non-lethal diseases and the tissue engineering.

Two types of specific anti-influenza virus drugs are available in Japan; amantadine and neuraminidase inhibitors(zanamivir and osertamivir). Because of emerging of drug-resistant viruses, we have to develop new types of antiviral reagents. New type anti-influenza virus reagents are developed against viral specific growth steps other than M2 ion channel or NA. Cleavage and activation, attachment, and fusion steps are unique to HA. Transcription initiation step is unique to the viral RNA polymerase. The capped short RNA inhibited the viral RNA polymerase. The peptide derived from matrix protein inhibited the RNA polymerase activity. Antisense oligonucleotide, DNA enzyme and RNAi are also available to inhibit gene expression of influenza virus.