Development of hydrophobic tag purifying monophosphorylated RNA for chemical synthesis of capped mRNA and enzymatic synthesis of circular mRNA.

We developed phosphorylation reagents with a nitrobenzyl hydrophobic tag and used them for 5'-phosphorylation of chemically or transcriptionally synthesized RNA. The capability of hydrophobic tags to synthesize 5'-monophosphorylated RNA was evaluated based on the yield of the desired oligonucleotides, stability of protecting groups during cleavage/deprotection, separation ability in reverse-phase HPLC (RP-HPLC), and deprotection efficiency after RP-HPLC purification. The results showed that a nitrobenzyl derivative with a tert-butyl group at the benzyl position was most suitable for RNA 5'-phosphorylation.

Development of PCR primers enabling the design of flexible sticky ends for efficient concatenation of long DNA fragments.

We developed chemically modified PCR primers that allow the design of flexible sticky ends by introducing a photo-cleavable group at the phosphate moiety. Nucleic acid derivatives containing -nitrobenzyl photo-cleavable groups with a -butyl group at the benzyl position were stable during strong base treatment for oligonucleotide synthesis and thermal cycling in PCR reactions. PCR using primers incorporating these nucleic acid derivatives confirmed that chain extension reactions completely stopped at position 1 before and after the site of the photo-cleavable group was introduced.

Complete Chemical Synthesis of Minimal Messenger RNA by Efficient Chemical Capping Reaction.

Site-specific chemical modification of mRNA can improve its translational efficiency and stability. For this purpose, it is desirable to develop a complete chemical synthesis method for chemically modified mRNA. The key is a chemical reaction that introduces a cap structure into the chemically synthesized RNA.

Impact of muscle mass loss assessed by computed tomography on the outcome of allogeneic stem cell transplantation.

The definition of sarcopenia assessed by computed tomography (CT) varies among different reports, and few studies have examined the effect of muscle mass loss on the prognosis of post-hematopoietic cell transplantation (HCT). We retrospectively evaluated 172 patients who underwent an initial allogeneic HCT for acute leukemia at our institution. They were divided into 3 groups according to muscle mass measured at the third lumbar vertebra as assessed by CT.