Development of Long Asymmetric siRNA Structure for Target Gene Silencing and Immune Stimulation in Mammalian Cells.

Post-transcriptional regulation of transcript abundances by RNA interference (i) is a widely conserved regulatory mechanism to control cellular processes. We previously introduced an alternative siRNA structure called asymmetric siRNA (asiRNA), and showed that asiRNA exhibits comparable gene-silencing efficiency with reduced off-target effects compared with conventional siRNAs. However, to what extent the length of the guide strand affects the gene-silencing efficiency of asiRNAs is still elusive.

RIG-I-Mediated Innate Immune Stimulation by Chemically Synthesized Long Double-Stranded RNAs Is Structure and Sequence Dependent.

Double-stranded RNAs (dsRNAs) longer than 30 bp have not been considered desirable RNA interference (RNAi) triggering structures in mammalian cells as they nonspecifically activate innate immune response. However, in earlier studies, not only dsRNA length but also 5'-triphosphate moiety produced by transcription might have affected the stimulation of innate immune system. Herein, using chemically synthesized long dsRNAs without 5'-triphosphate, we elucidated direct relationship between length of dsRNAs and innate immune stimulation.

L-Type Calcium Channel Blocker Enhances Cellular Delivery and Gene Silencing Potency of Cell-Penetrating Asymmetric siRNAs.

The efficient delivery of small interfering RNAs (siRNAs) to the target cells is critical for the pharmaceutical success of RNA interference (RNAi) drugs. One of the possible strategies to improve siRNA delivery is to identify auxiliary molecules that augment their cellular uptake. Herein, we performed a chemical library screening in an effort to discover small molecules that enhance the potency of cholesterol-conjugated, cell-penetrating asymmetric siRNAs (cp-asiRNAs).

ALPPL2 Is a Potential Diagnostic Biomarker for Pancreatic Cancer-Derived Extracellular Vesicles.

Pancreatic cancer is an aggressive malignancy that often goes undiagnosed in the early stages. Non-invasive, early, and accurate diagnosis is therefore undoubtedly the "holy grail" of pancreatic cancer research. However, despite extensive research efforts, there is no definitive biomarker for this cancer.

Cell-SELEX-Based Identification of a Human and Mouse Cross-Reactive Endothelial Cell-Internalizing Aptamer.

Increased interest and insights gained by researchers on the roles of endothelial cells in the pathophysiology of cancer, inflammatory, and cardiovascular diseases have led to the design of pharmacological interventions aimed at the endothelium lining in the diseased sites. Toward this end, we used established brain microvascular endothelial cell lines mouse (bEND3), human (hCMEC/D3), and Toggle Cell-SELEX to identify a species cross-reactive, endothelial cell-internalizing aptamer R11-3. This 2'F-modified RNA aptamer is specific for endothelial cells as no internalization was seen with cells of nonendothelial origin.

Cell-SELEX Based Identification of an RNA Aptamer for and Its Use in Various Detection Formats.

are important indicator organisms, used routinely for the monitoring of water and food safety. For quick, sensitive and real-time detection of we developed a 2'F modified RNA aptamer Ec3, by Cell-SELEX. The 31 nucleotide truncated Ec3 demonstrated improved binding and low nano-molar affinity to .

ALPPL2 Aptamer-Mediated Targeted Delivery of 5-Fluoro-2'-Deoxyuridine to Pancreatic Cancer.

Nucleoside analogues are the most promising drugs for the treatment of pancreatic cancer to date. However, their use is often limited due to toxic side effects. Aptamer-mediated targeted delivery of these drugs to cancer cells could maximize their effectiveness and concomitantly minimize the toxic side effects by reducing uptake into normal cells.

Long dsRNA-mediated RNA interference and immunostimulation: a targeted delivery approach using polyethyleneimine based nano-carriers.

RNA oligonucleotides capable of inducing controlled immunostimulation combined with specific oncogene silencing via an RNA interference (RNAi) mechanism provide synergistic inhibition of cancer cell growth. With this concept, we previously designed a potent immunostimulatory long double stranded RNA, referred to as liRNA, capable of executing RNAi mediated specific target gene silencing. In this study, we developed a highly effective liRNA based targeted delivery system to apply in the treatment of glioblastoma multiforme.

Alkaline phosphatase ALPPL-2 is a novel pancreatic carcinoma-associated protein.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a very low median survival rate. The lack of early sensitive diagnostic markers is one of the main causes of PDAC-associated lethality. Therefore, to identify novel pancreatic cancer biomarkers that can facilitate early diagnosis and also help in the development of effective therapeutics, we developed RNA aptamers targeting pancreatic cancer by Cell-systematic evolution of ligands by exponential enrichment (SELEX) approach.

The design, preparation, and evaluation of asymmetric small interfering RNA for specific gene silencing in mammalian cells.

RNA interference (RNAi) is a highly efficient endogenous gene silencing mechanism mediated by short double-stranded RNAs termed small interfering RNAs (siRNAs). The current standard siRNA structure, which is used by most researchers to trigger sequence-specific target gene silencing, consists of a double strand region of 19 bp with 2 nt 3'-overhangs at both ends. However, in addition to the desired target gene silencing, this conventional siRNA structure also exhibits several unintended effects that constitute obstacles to the use of siRNA in gene function studies and therapeutics development.

Dual functions of highly potent graphene derivative-poly-L-lysine composites to inhibit bacteria and support human cells.

Dual-function poly(L-lysine) (PLL) composites that function as antibacterial agents and promote the growth of human cell culture have been sought by researchers for a long period. In this paper, we report the preparation of new graphene derivative-PLL composites via electrostatic interactions and covalent bonding between graphene derivatives and PLL. The resulting composites were characterized by infrared spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy.

Enhanced intracellular delivery and multi-target gene silencing triggered by tripodal RNA structures.

Background: The development of gene interfering RNA (iRNA) molecules such as small interfering RNAs (siRNAs) and antagomirs provides promising therapeutic modalities for targeting specific mRNAs and microRNAs (miRNAs) involved in disease mechanisms. Therapeutic iRNA strategy against cancer or hypermutable viruses prefers targeting multiple genes simultaneously to achieve synergistic inhibition and to prevent resistance.

Methods: In the present study, we report chemically synthesized, multi-target gene interfering RNA structures based upon branched, tripodal interfering RNAs (termed T-tiRNAs).

Long double-stranded RNA-mediated RNA interference and immunostimulation: long interfering double-stranded RNA as a potent anticancer therapeutics.

In most applications, small interfering RNAs are designed to execute specific gene silencing via RNA interference (RNAi) without triggering nonspecific responses such as immunostimulation. However, in anticancer therapeutics, immunostimulation combined with specific oncogene silencing could be beneficial, resulting in the synergistic inhibition of cancer cell growth. In this study, we report an immunostimulatory long double-stranded RNA (dsRNA) structure with the ability to trigger RNAi-mediated specific target gene silencing, termed as long interfering dsRNA (liRNA).

Structural diversity repertoire of gene silencing small interfering RNAs.

Since the discovery of double-stranded (ds) RNA-mediated RNA interference (RNAi) phenomenon in Caenorhabditis elegans, specific gene silencing based upon RNAi mechanism has become a novel biomedical tool that has extended our understanding of cell biology and opened the door to an innovative class of therapeutic agents. To silence genes in mammalian cells, short dsRNA referred to as small interfering RNA (siRNA) is used as an RNAi trigger to avoid nonspecific interferon responses induced by long dsRNAs. An early structure-activity relationship study performed in Drosophila melanogaster embryonic extract suggested the existence of strict siRNA structural design rules to achieve optimal gene silencing.

Development of single-stranded DNA aptamers for specific Bisphenol a detection.

The development of reagents with high affinity and specificity to small molecules is crucial for the high-throughput detection of chemical compounds, such as toxicants or pollutants. Aptamers are short and single-stranded (ss) oligonucleotides able to recognize target molecules with high affinity. Here, we report the selection of ssDNA aptamers that bind to Bisphenol A (BPA), an environmental hormone.

A sol-gel-based microfluidics system enhances the efficiency of RNA aptamer selection.

RNA and DNA aptamers that bind to target molecules with high specificity and affinity have been a focus of diagnostics and therapeutic research. These aptamers are obtained by SELEX often requiring many rounds of selection and amplification. Recently, we have shown the efficient binding and elution of RNA aptamers against target proteins using a microfluidic chip that incorporates 5 sol-gel binding droplets within which specific target proteins are imbedded.

Nucleic acid aptamers targeting cell-surface proteins.

Aptamers are chemical antibodies that bind to their targets with high affinity and specificity. These short stretches of nucleic acids are identified using a repetitive in vitro selection and partitioning technology called SELEX (Systematic Evolution of Ligands by EXponential enrichment). Since the emergence of this technology, many modifications and variations have been introduced to enable the selection of specific ligands, even for implausible targets.

Patents on SELEX and therapeutic aptamers.

Aptamers, the oligonucleotides (DNA/RNA) that bind to target molecules with high specificity and affinity, have been a focus of therapeutic research for the last two decades. The magnitude of scientific and commercial interest shown for aptamers is not surprising because aptamers have several advantages over other curative modalities, especially antibodies. Patent activity in this field has also shown an exponential growth.

Pentoxifylline impedes migration in B16F10 melanoma by modulating Rho GTPase activity and actin organisation.

Cancer cell migration is a hallmark of metastatic cascade and compounds that can intervene in this process are clinically important. Pentoxifylline (PTX), a methyl xanthine derivative, inhibits B16F10 melanoma lung homing by inhibiting F10 invasion, MMP secretion and adhesion to matrix components. However, its effect on B16F10 migration remained unexamined, which we investigated in the present study.

Suramin augments the antitumor and antimetastatic activity of pentoxifylline in B16F10 melanoma.

Rapid tumor growth and metastasis are 2 major problems associated with treatment of malignant melanoma. Therefore, drugs that can intervene these processes are of clinical importance. Pentoxifylline (PTX), a methyl xanthine derivative, has been shown to inhibit B16F10 melanoma tumor growth and metastasis.

Antiproliferative and antiproteolytic activity of pentoxifylline in cultures of B16F10 melanoma cells.

Purpose: Pentoxifylline (PTX), a methyl xanthine derivative is widely used as a haemorheological agent in the treatment of peripheral vascular disease. In the present study, we investigated the in vitro effects of PTX on B16F10 melanoma cell proliferation, adhesion and secretion of Matrix metalloproteinases.

Methods: The toxic range of PTX was evaluated using MTT test and colony formation assay.