Label-Free Detection of Zeptomol miRNA via Peptide Nucleic Acid Hybridization Using Novel Cyclic Voltammetry Method.

To harness the applicability of microribonucleic acid (miRNA) as a cancer biomarker, the detection sensitivity of serum miRNA needs to be improved. This study evaluated the detection sensitivity of miRNA hybridization using cyclic voltammograms (CVs) and microelectrode array chips modified with peptide nucleic acid (PNA) probes and 6-hydroxy-1-hexanethiol. We investigated the PNA probe modification pattern on array chips using fluorescently labeled cDNA.

Effective capture of proteins inside living cells by antibodies indirectly linked to a novel cell-penetrating polymer-modified protein A derivative.

Antibodies against cytoplasmic proteins are useful tools that can control cellular function and clarify signaling mechanisms. However, it is difficult to capture proteins inside living cells, and thus appropriate methods for antibody delivery to the cytoplasm of living cells are required. Cell-penetrating materials, such as the TAT-peptide, have received attention for their ability to deliver various cargos into living cells.

Development of real time imaging of specific messenger RNA in a living cell using artificial antisense nucleic acids.

Real time imaging of mRNA in living cell is powerful tool in investigating the role of mRNA. Here we developed the method for visualizing specific mRNAs in living cell. The proposed method contains hybridization of antisense nucleic acids with mRNA transcripted inside cell.

Design of a molecular beacon PNA.

We have designed a novel dual-labeled PNA oligomer, having both a fluorescent dye and a quencher, by utilizing key compounds 1 and 2. We showed that the designed dual-labeled PNA oligomer works as a molecular beacon PNA. We also investigated the optimization of a stem-loop structure which can supersensitize the function as a molecular beacon PNA.

Application of peptide nucleic acid (PNA) for detection of transcription factors binding probes.

We designed novel PNA monomer units that could post-synthetically and quantitatively introduce photo-functionalized molecules into PNA oligomers. Designed photo-functionalized PNAs were applicable to wide fields such as genome based analysis. In this study, we applied a photo-functionalized PNA oligomers for the detection of transcription factors binding probes.

Development of novel whole-mount in situ hybridization (WISH).

We have designed a novel fluorescent PNA probe which can be rapidly introduced into the living cell without any complicated pretreatment. We could post-synthetically incorporate amino acid derivatives having membrane permeability function into the PNA probe by utilizing key compound 1 which we have already developed. We show that the PNA probe will be a candidate for a rapidly penetrating and non-degrading probe for WISH.

Pin1 and Par14 peptidyl prolyl isomerase inhibitors block cell proliferation.

Disruption of the parvulin family peptidyl prolyl isomerase (PPIase) Pin1 gene delays reentry into the cell cycle when quiescent primary mouse embryo fibroblasts are stimulated with serum. Since Pin1 regulates cell cycle progression, a Pin1 inhibitor would be expected to block cell proliferation. To identify such inhibitors, we screened a chemical compound library for molecules that inhibited human Pin1 PPIase activity in vitro.