Objective To investigate the effects of exosome-derived miR-1246 on metastasis and autophagy of esophageal squamous cell carcinoma(ESCC).Methods The exosomes of ESCC cells were extracted by exosome extraction kit,the morphology was observed under electron microscope,the particle size was detected by nano-particle size analyzer,and the expression of exosome markers TSG101 and Calnexin was detected by Western blot.The RNA of exosomes of ESCC cells and normal esophageal epithelial cells were sequenced to analyze the differentially expressed miRNAs,which were analyzed by KEGG Pathway enrichment.The expression of miR-1246 in tumor tissues and paracancer tissues of 155 patients with ESCC was evaluated by transcriptome sequencing.The effect of miR-1246 on the migration ability of ESCC cells was detected by Transwell assay and the effect on autophagy was detected by Western blot.Results The exosomes derived from ESCC cells were intact in shape and similar to spherical vesicle-like structure with the particle size of 50～80 nm.The exosome marker TSG101 protein was positive and Calnexin protein was negative.There were 59 common differentially expressed miRNAs between exosomes of ESCC cells and normal esophageal epithelial cells.Exosome miR-1246 was highly expressed in ESCC cells,and the differentially expressed miRNAs were mainly enriched in autophagy metabolic pathway.Exosome miR-1246 was highly expressed in cancer tissues of patients with ESCC.Overexpression of miR-1246 significantly promoted the migration and autophagy of ESCC cells(t=4.119 and 48.150,P <0.05 and <0.001,respectively).Inhibition of miR-1246 expression inhibited the migration and autophagy of ESCC cells(t=9.067 and 51.270,P <0.01 and <0.001,respectively).Conclusion miR-1246 derived from exosomes can significantly affect the metastasis and autophagy of ESCC cells.

Objective To analyze the clinical characteristics and therapy of levofloxacin-induced prolonged Q-T interval in patients with multi-drug resistant tuberculosis ( MDR-TB) . Methods Clinical materials of 6 patients with MDR-TB who developed prolonged Q-T/QTc interval caused by levofloxacin therapy were analyzed. Those cases were collected from the Tuberculosis Prevention and Control of Wuhan City form April 2010 to August 2014. Results The proportion of patients with levofloxacin-induced prolonged Q-T interval was approximately 3.0%.The condition occurred 2-8 months after the administration. The initial value of QTc interval ranged from 397 ms to 439 ms, while the average was (410.17±14.62) ms.The value of QTc interval was extended to 470-486 ms after treatment of levofloxacin, while the average was (476.33±6.16) ms.The increase of QTc interval was 47-85 ms, while the average was ( 66 ± 11. 48 ) ms. None of them developed Tdp. Conclusion The application of high dosage and long treatment course of levofloxacin in patients with MDR-TB could result in the extension of the Q-T/QTc interval, which should arouse our serious attention. In order to detect the abnormal Q-T/QTc interval in early stage, electrolyte level examination as well as ECG examination should be considered as routine tests before initiation of treatment and during the follow-up treatment.

Objective To observe the effect of rotavirus (RV) infection on expression level and bioactivity of Na+-H+ exchanger 3 (NHE3) in Caco-2 cells. Methods Model of NHE3-expressing Caco-2 cells was constructed and studied in terms of intervention: control, RV, clathrin antagonist chlorpromazine (CPZ), and CPZ + RV. NHE3 activity and NHE3 protein amount on cell surface were determined by BCECF-AM and biotinylation, respectively. Expression level of clathrin was assayed by Western blot. Results Compared with control group, NHE3 activity and NHE3 surface protein level significantly decreased when the cells were treated with RV. These effects could not be completely cancelled by clathrin antagonist CPZ. Moreover, RV treatment could increase cellular protein level of clathrin, which was cancelled by CPZ. Conclusions The effect of RV infection on NHE3 expression level and biological activity may be related to clathrin-dependent endocytosis pathway, and may be also affected by other endocytosis pathways.

Objective To investigate the effects of rotavirus ( RV) on the expression and bioactiv-ity of Na+-H+ exchanger 3 ( NHE3 ) in Caco-2 cells and the possible regulatory mechanism. Methods Caco-2 cells expressing NHE3 were constructed and divided into four groups as follows: control ( CTL ) group, RV group, BAPTA-AM ( a Ca2+ chelator) group and BAPTA-AM+RV group. Na+-H+ exchanger ac-tivity and NHE3 expression on cell surface were determined using BCECF-AM and biotinylation assay, re-spectively. Expression of Cdc42 at protein level was measured by Western blot. Results Compared with the control group, RV infection significantly decreased the activity of NHE3 and its expression on cell surface. BATPA-AM antagonized the inhibitory effects on NHE3. Moreover, the expression of Cdc42 at protein level was increased following RV infection, which was also antagonized by BATPA-AM. Conclusions Intracellu-lar Ca2+-mediated Cdc42-dependent endocytosis pathway might be involved in regulating the expression and bioactivity of NHE3 during RV infection.