Improved Synthesis Strategy for Peptide Nucleic Acids (PNA) appropriate for Cell-specific Fluorescence Imaging

Abstract

Progress in genomics and proteomics attended to the door for better understanding the recent rapid expanding complex research field of metabolomics. This trend in biomedical research increasingly focuses to the development of patient-specific therapeutic approaches with higher efficiency and sustainability. Simultaneously undesired adverse reactions are avoided. In parallel, the development of molecules for molecular imaging is required not only for the imaging of morphological structures but also for the imaging of metabolic processes like the aberrant expression of the cysteine protease cathepsin B (CtsB) gene and the activity of the resulting product associated with metastasis and invasiveness of malign tumors. Finally the objective is to merge imaging and therapy at the same level. The design of molecules which fulfil these responsibilities is pivotal and requires proper chemical methodologies. In this context our modified solid phase peptide chemistry using temperature shifts during synthesis is considered as an appropriate technology. We generated highly variable conjugates which consist of molecules useful as diagnostically and therapeutically active molecules. As an example the modular PNA products with the complementary sequence to the CtsB mRNA and additionally with a cathepsin B cleavage site had been prepared as functional modules for distinction of cell lines with different CtsB gene expression. After ligation to the modular peptide-based BioShuttle carrier, which was utilized to facilitate the delivery of the functional modules into the cells' cytoplasm, the modules were scrutinized.

Biological role of metabolic reprogramming of cancer cells during epithelial‑mesenchymal transition (Review)

“…This phenomenon is more pronounced during tumor metastasis. With the development of molecular imaging technology, alterations in cell morphology can be observed and detection of nucleic acid synthesis during tumor cell metastasis can be conducted (143). During metastasis, the rapid proliferation of cells includes the transmission of genetic information, transcription, translation and other process, inevitably leading to increased synthesis of DNA and RNA.…”

Solid-Phase Synthesis of Difficult Purine-Rich PNAs through Selective Hmb Incorporation: Application to the Total Synthesis of Cell Penetrating Peptide-PNAs

“…Following completion of the 22-mer PNA synthesis, it was cleaved from solid phase and analyzed by RP-HPLC (Scheme 1 —Compound 1a and Figure 2A ). The RP-HPLC analysis of 22-mer PNA showed a broad peak which is characteristic of long PNAs (Pipkorn et al, 2012 ). However, as soon as the PNA is conjugated to the cell-penetrating peptides, the RP-HPLC peaks are well-defined and it can be easily purified (Figures 2B,C ).…”

“Clicking” Gene Therapeutics: A Successful Union of Chemistry and Biomedicine for New Solutions

“…In one body of work, Pipkort et al ., applied a similar approach to Diels Alder click, for cell-specific fluorescence imaging using PNA probes. 22 Using modular PNA probes allowed for the combination of the imaging and therapeutic activities in one PNA molecule. The mRNA product of the cysteine protease cathepsin B (CtsB) gene was imaged and simultaneously degraded using the peptide-PNA conjugate.…”