Chronic kidney disease and clinical outcomes in patients with COVID-19 in Japan

Clinical and Experimental Nephrology - Identifying predictive factors for coronavirus disease 2019 (COVID-19) is crucial for risk stratification and intervention. Kidney dysfunction contributes to...     

Gene amplification of YB‐1 in castration‐resistant prostate cancer in association with aberrant androgen receptor expression

Although Y‐box binding protein‐1 (YB‐1) is known to be overexpressed in prostate cancer, especially castration‐resistant prostate cancer (CRPC), the mechanism of its overexpression remains unclear. We aimed to elucidate the mechanism of YB‐1 overexpression in CRPC. Gene amplification in CRPC cells and tissues was examined by public database analysis, and digital PCR. The significance of YB‐1 amplification for the YB‐1/androgen receptor (AR) axis and prognosis was examined by public database analysis and immunohistochemistry. YB‐1 amplification was mainly observed in CRPC tissues by public database analysis and confirmed in CRPC cells and tissues by digital PCR. Expression of YB‐1 was increased in CRPC tissues compared with treatment‐naïve tissues. Furthermore, YB‐1 and phosphorylated YB‐1 levels were associated with AR and AR V7 expression levels. Finally, YB‐1 amplification was associated with poor outcomes in CRPC. Taken together, the present findings suggest that YB‐1 amplification contributes to progression to CRPC through regulation of AR and AR V7 expressions, and that YB‐1 is a promising therapeutic target in CRPC.     

Spatiotemporal metabolic dynamics of the photosensitizer talaporfin sodium in carcinoma and sarcoma

Photodynamic therapy (PDT) using the photosensitizer talaporfin sodium (talaporfin) is a new mode of treatment for cancer. However, the metabolic mechanism of talaporfin has not been clarified. Thus, we investigated the uptake, transportation, and elimination mechanisms of talaporfin in carcinoma and sarcoma. The results showed that talaporfin co‐localized in early endosomes and lysosomes. Talaporfin uptake was via clathrin‐ and caveolae‐dependent endocytosis and a high amount of intracellular ATP was essential. Inhibition of lysosomal enzymes maintained intracellular talaporfin levels. Inhibition of K‐Ras signaling reduced talaporfin uptake in carcinoma and sarcoma cell lines. Talaporfin was taken up by clathrin‐ and caveolae‐dependent endocytosis, translocated from early endosomes to lysosomes, and finally degraded by lysosomes. We also demonstrated that ATP is essential for the uptake of talaporfin and that activation of K‐Ras is involved as a regulatory mechanism. These results provide new insights into the metabolism of talaporfin in cancer cells for the enhancement of PDT for carcinoma and sarcoma.     

Changing Blue Fluorescent Protein to Green Fluorescent Protein Using Chemical RNA Editing as a Novel Strategy in Genetic Restoration

Using the transition from cytosine of BFP (blue fluorescent protein) gene to uridine of GFP (green fluorescent protein) gene at position 199 as a model, we successfully controlled photochemical RNA editing to effect site‐directed deamination of cytidine (C) to uridine (U). Oligodeoxynucleotides (ODNs) containing 5′‐carboxyvinyl‐2′‐deoxyuridine (^CVU) were used for reversible photoligation, and single‐stranded 100‐nt BFP DNA and in vitro‐transcribed full‐length BFP mRNA were the targets. Photo‐cross‐linking with the responsive ODNs was performed using UV (366 nm) irradiation, which was followed by heat treatment, and the cross‐linked nucleotide was cleaved through photosplitting (UV, 312 nm). The products were analyzed using restriction fragment length polymorphism (RFLP) and fluorescence measurements. Western blotting and fluorescence‐analysis results revealed that in vitro‐translated proteins were synthesized from mRNAs after site‐directed RNA editing. We detected substantial amounts of the target‐base‐substituted fragment using RFLP and observed highly reproducible spectra of the transition‐GFP signal using fluorescence spectroscopy, which indicated protein stability. ODNc restored approximately 10% of the C‐to‐U transition. Thus, we successfully used non‐enzymatic site‐directed deamination for genetic restoration in vitro. In the near future, in vivo studies that include cultured cells and model animals will be conducted to treat genetic disorders.