RESUMO
Cancer is the second-leading cause of death worldwide. Cancer mortality is largely caused by the absence of recognizable early signs and a poor prognosis. Therefore, developing efficient diagnostic and prognostic biomarkers is crucial to reducing the incidence of cancer and improving its prognostic accuracy. tRNA-derived fragments are a new class of non-coding RNAs with important regulatory roles in cancer biology. In this paper, the research progress of tRNA-derived fragments as biomarkers in tumorigenesis, development, and prognosis was reviewed to provide a theoretical basis for cancer diagnosis and prognostic assessment.
RESUMO
Objective:To investigate the regulatory effects of nuclear factor-κB (NF-κB) on dendritic cell (DC) maturation and function through solute carrier family 1 member 2 (Slc1a2).Methods:Mouse bone marrow-derived DCs were transfected with Slc1a2-specific siRNA and an overexpression Slc1a2 eukaryotic expression vector. The real-time fluorescence quantitation (RT-PCR) and Western Blot methods were used to detect knockdown and overexpression efficiency. The expression of surface molecules (CD40, CD80) and major histocompatibility complex Ⅱ (MHCⅡ) of DCs was detected by flow cytometry. ELISA was used to detect the secretion of the cytokines interleukin (IL)-12, IL-6, and transforming growth factor-β (TGF-β). The effects of knockdown of Slc1a2 on DC maturation and function and the effects of overexpression of Slc1a2 on DC maturation and function were reflected by the above assay results. A mixed lymphocyte culture assay was used to investigate the effect of Slc1a2 on T cell proliferation, and an ELISA was used to detect the lavel of IL-17A. Changes in the relative fluorescence intensity of FITC in DCs were analyzed by flow cytometry to investigate the ability of Slc1a2 overexpression on antigen phagocytosis. Finally, DCs were pretreated with an NF-κB inhibitor, toluoylphenylalanine chloromethyl ketone (TPCK), and the effect of TPCK on the expression of Slc1a2 in DCs and DC maturation was examined.Results:Slc1a2 expression was found to be high in DC treated with lipopolysaccharides (LPS) ( P<0.001). The knockdown of Slc1a2 decreased DC maturation and ability to stimulate the proliferation of CD4 + T cells ( P<0.001) and inhibited IL-17 secretion ( P<0.01). Overexpression of Slc1a2 promoted DC maturation and ability to stimulate the proliferation of CD4 + T cells(all P<0.01) Pretreatment of DC with the NF-κB inhibitor TPCK inhibited the expression of Slc1a2 at mRNA and protein levels induced by LPS. Conclusions:NF-κB regulates Slc1a2 expression, which affects the maturation and function of DC.