MiR-218-5p Suppresses the Killing Effect of Natural Killer Cell to Lung Adenocarcinoma by Targeting SHMT1

PURPOSE: Lung adenocarcinoma (LA) is one of the major types of lung cancer. MicroRNAs (miRNAs) play an essential role in regulating responses of natural killer (NK) cells to cancer malignancy. However, the mechanism of miR-218-5p involved in the killing effect of NK cells to LA cells remains poorly understood. MATERIALS AND METHODS: The expression of miR-218-5p was examined by quantitative real-time polymerase chain reaction (qRT-PCR). Serine hydroxymethyl transferase 1 (SHMT1) level was detected by qRT-PCR or western blots. Cytokines production of interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) were detected by ELISA. The killing effect of NK cells to LA cells was investigated using lactate dehydrogenase cytotoxicity assay kit. The interaction of miR-218-5p and SHMT1 was probed by luciferase activity assay. Xenograft model was established to investigate the killing effect of NK cells in vivo. RESULTS: miR-218-5p was enhanced and SHMT1 was inhibited in NK cells of LA patients, whereas stimulation of interleukin-2 (IL-2) reversed their abundances. Addition of miR-218-5p reduced IL-2-induced cytokines expression and cytotoxicity in NK-92 against LA cells. Moreover, SHMT1 was negatively regulated by miR-218-5p and attenuated miR-218-5p-mediated effect on cytotoxicity, IFN-γ and TNF-α secretion in IL-2-activated NK cells. In addition, miR-218-5p exhaustion inhibited tumor growth by promoting killing effect of NK cells. CONCLUSION: miR-218-5p suppresses the killing effect of NK cells to LA cells by targeting SHMT1, providing a potential target for LA treatment by ameliorating NK cells function.

Interaction between transcriptional factor E26 transformation specific 1 and peroxiredoxin 1 in nicotine-induced oral precancerous lesion cells / 中华口腔医学杂志

Objective@#To investigate the interaction between nuclear transcriptional factor E26 transformation specific 1 (Ets1) and peroxiredoxin 1 (Prx1) in nicotine-induced oral precancerous lesion cells.@*Methods@#Human oral precancerous lesion dysplastic oral keratinocyte (DOK) cells were cultured and divided into nicotine group, control group, knockdown group and knockdown control group. The nicotine group, knockdown group and knockdown control group were treated with 1 μmol/L nicotine for 7 days while the control group was untreated. Western blotting, co-immunoprecipitation (Co-IP) and chromatin immunoprecipitation (ChIP) were performed to detect Prx1 and Ets1 protein expression, Prx1 and Ets1 protein interaction, combined activity of Ets1 with PRDX1 gene promoter region in nicotine group and control group DOK cells. In nicotine group, DOK cells were transfected with siRNA or lentivirus to knockdown Ets1 and Prx1 expression. Prx1 and Ets1 protein expression was examined by Western blotting.@*Results@#Nicotine increased the expression of Prx1 and Ets1 protein in DOK cells. The relative expression of Prx1 and Ets1 was 0.71±0.02, 0.12±0.01 in nicotine group and 0.53±0.06, 0.01±0.01 in control group (P=0.009, P=0.000). Co-IP showed that Prx1 could form protein complex with Ets1. The expression of Prx1 and Ets1 complex protein was increased in nicotine group. ChIP revealed that nicotine upregulated the combination of transcriptional factor Ets1 with PRDX1 gene promoter region, and the enrichment fold was 80.9±19.7 in nicotine group and 13.8±1.2 in control group (P=0.004). Ets1 and Prx1 protein expression was knocked down. The relative expression of Ets1 and Prx1 was 0.60±0.06, 0.48±0.03 in knockdown group and 0.83±0.08, 0.80±0.06 in knockdown control group (P=0.016, P=0.002). Ets1 knockdown suppressed the expression of Prx1 (P=0.002). Conversely, Prx1 knockdown also inhibited the expression of Ets1 significantly (P=0.000).@*Conclusions@#In oral precancerous lesion cells, Ets1 directly regulates Prx1 expression and nicotine might promote the development of oral precancerous lesion by magnifying the positive feedback signal pathway between Ets1 and Prx1.

Clinical value of virtual touch tissue quantification and PGA index in evaluation of alcoholic liver fibrosis / 中南大学学报(医学版)

OBJECTIVE@#To explore the clinical value of virtual touch tissue quantification (VTQ) technique and the PGA index [prothrombin time (P), γ-glutamyl transpeptadase (GG) and apolipoprotein A1 (ApoAl)] in evaluating the degree of liver fibrosis in alcoholic patients.
@*METHODS@#A total of 64 patients with long-term alcohol history were enrolled for this study. The liver ultrasonography elasticity was examined by VTQ techniques, the VTQ value was assessed in the liver target region, and then the PGA index was calculated. According the liver biopsy biological results, a golden standard, the patients were divided into a non-fibrosis group (n=11), a fibrosis group (n=10), a significant fibrosis group (n=14) and a cirrhosis group (n=29). The diagnostic value of VTQ and PGA index were compared in alcoholic patients following the classification of liver fibrosis.
@*RESULTS@#The elastography VTQ values were (1.38±0.33), (1.49±0.30), (1.76±0.22) and (2.28±0.53) m/s; while the PGA indexes were 2.09±0.94, 2.30±1.06, 3.57±1.09, and 2.21±1.99 in the non-fibrosis group, the fibrosis group, the significant fibrosis group and the cirrhosis group, respectively. The VTQ value and PGA index were positively correlated with the classification of liver fibrosis (VTG: r=0.719, PGA: r=0.683; both P<0.01).
@*CONCLUSION@#The alcoholic liver fibrosis can be assessed by noninvasive VTQ technology and PGA index. As a real-time ultrasound elastography technique, VTQ is more accurate than the PGA index. Combination of the two methods is helpful for early diagnosis and treatment in the patients with alcoholic liver fibrosis.

IFN-γup-regulates Th17/IL-17 response against Chlamydia trachomatis lung infection / 中华微生物学和免疫学杂志

Objective To investigate the regulation of IFN-γ to Th17 response in Chlamydia muridarum (Cm) lung infection in mice. Methods A murine model of pneumonia induced by intranasal inoculation of Cm was used for this study. Anti-mouse IFN-γ McAbs were used to neutralize endogenous IFN-γfollowing Cm lung infection. Control group received the same dose of isotype antibody (IgG2a). Mice were sacrificed at day 7 postinfection. Chlamydial growth in the lung was assessed by immunoenzyme technique.IL-17 and IL-23 mRNA expression in the lung was assayed by RT-PCR and the proliferation of IL-17 + CD4 +T cells in the spleen was assayed by intracellular cytokine staining. Results IFN-γ-neutralized mice exhibited serious disease course, include greater body weight loss, higher organism growth and much more severe pathological changes in the lung compared with control mice. The mRNA expression of IL-17 and IL-23 in the lung and the proliferation of IL-17 + CD4 + T cells in the spleen significantly decreased in the IL-17- neutralized mice. Conclusion IFN-γ was protective in Cm lung infection through up-regulating the antigen specific Th17 responses.