Radiocontrast medium induces histamine release in association with upregulation of miR­19a­3p and miR­362­3p expression.

In Taiwan, the use of radiocontrast medium for clinical image diagnosis recently surpassed one million times and the overall prevalence of radiocontrast hypersensitivity was ~7%. A microRNA (miRNA/miRs) is a small non-coding RNA molecule that mostly plays a suppressor role in cells. However, the roles of miRNA expression in radiocontrast-induced mast cells activation remains to be elucidated. The aim of the present study was to investigate the role of miRNA on radiocontrast-induced mast cell activation. Computed tomography radiocontrast, ultravist and mouse mast cell line, P815, were used in the present study. Cell viability was detected by CCK-8 experiment. Levels of histamine and ß-hexosaminidase were measured by ELISA. miRNA expression was detected by miRNA sequencing and reverse transcription-quantitative PCR. The results showed that ultravist could increase histamine release and reduce intracellular ß-hexosaminidase levels of mast cells. A total of 102 miRNAs could be significantly upregulated by ultravist stimulation. Selected candidate miRNAs for the validation included miR-19a-3p and miR-362-3p which were also increased expression following stimulation with ultravist. In conclusion, ultravist could induce mast cell activation through upregulation of miR-19a-3p and miR-362-3p. Thus, miR-19a-3p and miR-362-3p could be promising candidates for development as novel targets for preventing radiocontrast-induced allergy in the future.

Regulating TKT activity inhibits proliferation of human acute lymphoblastic leukemia cells.

Among pediatric blood cancers, acute lymphoblastic leukemia (ALL) is the most common hematologic malignancy. Within ALL, T-cell acute lymphoblastic leukemia (T-ALL) accounts for 10 to 15% of all pediatric cases, and ~25% of adult cases. For T-ALL, its recurrence and relapse after treatment remain problematic. Therefore, it is necessary to develop new therapies for T-ALL. Recent studies suggested regulating energy metabolism is a novel approach to inhibit tumor growth, likely a promising treatment. Transketolase (TKT) is an important enzyme for modulating glucose metabolize in the pentose phosphate pathway (PPP). In this study, we treated T-ALL cells with different doses of niclosamide and primary T-ALL PBMCs were analyzed by RNA sequencing. T-ALL cells treated with niclosamide were analyzed with the Western blotting and TKT activity assay. Metabolism of T-ALL cells was evaluated by ATP assay and seahorse analyses. Lastly, we used a T-ALL xenograft murine model to determine effects of TKT knockdown on T-ALL tumor growth. Tumor samples were analyzed by H&E and IHC stainings. We found that niclosamide reduced T-ALL cell viability, and reduced expressions of TKT, Transketolase-Like Protein 1/2 (TKTL1/2) and transaldolase. In addition, niclosamide inhibited TKT enzyme activity, aerobic metabolism and glycolysis, finally leading to lower production of ATP. TKT knockdown inhibited tumor growth of xenograft T-ALL mice. Findings showed that niclosamide inhibits T-ALL cell growth by inhibiting TKT and energy metabolism.