Tumour-suppressive microRNA-144-5p directly targets CCNE1/2 as potential prognostic markers in bladder cancer.

BACKGROUND: Analysis of a microRNA (miRNA) expression signature of bladder cancer (BC) by deep-sequencing revealed that clustered miRNAs microRNA (miR)-451a, miR-144-3p, and miR-144-5p were significantly downregulated in BC tissues. We hypothesised that these miRNAs function as tumour suppressors in BC. The aim of this study was to investigate the functional roles of these miRNAs and their modulation of cancer networks in BC cells. METHODS: The functional studies of BC cells were performed using transfection of mature miRNAs. Genome-wide gene expression analysis, in silico analysis, and dual-luciferase reporter assays were applied to identify miRNA targets. The association between miR-144-5p levels and expression of the target genes was determined, and overall patient survival as a function of target gene expression was estimated by the Kaplan-Meier method. RESULTS: Gain-of-function studies showed that miR-144-5p significantly inhibited cell proliferation by BC cells. Four cell cycle-related genes (CCNE1, CCNE2, CDC25A, and PKMYT1) were identified as direct targets of miR-144-5p. The patients with high CCNE1 or CCNE2 expression had lower overall survival probabilities than those with low expression (P=0.025 and P=0.032). CONCLUSION: miR-144-5p functions as tumour suppressor in BC cells. CCNE1 and CCNE2 were directly regulated by miR-144-5p and might be good prognostic markers for survival of BC patients.

ICAM-1 expression and cellular injury in cultured endothelial cells under hypoxia/reoxygenation.

Intercellular adhesion molecule 1(ICAM-1) expression and cellular changes in human umbilical vein endothelial cells(HUVEC) and ECV304, an established cultured line derived from HUVEC, under hypoxia and hypoxia(H)/reoxygenation(R) were investigated by immunological, cytochemical, and morphological methods. ICAM-1 expression in HUVEC decreased slightly under hypoxia(92%) and was up-regulated under reoxygenation(114%), but this up-regulation was diminished by superoxide dismutase(SOD). The up-regulation of ICAM-1 expression by interleukin-1 beta(IL-1 beta) was detected at almost equal levels under hypoxia, and H/R. Using lucigenin-chemiluminescence, we demonstrated superoxide generation from HUVEC under H/R. The Ca2+ influx under hypoxia, and the Ca2+ release from the cells under H/R reduced by SOD were detected cytochemically. Vacuole formation as cell injury under hypoxia and H/R was detected by electron microscopy. The present findings provide evidence that superoxide generated from HUVEC is responsible for the up-regulation of ICAM-1 expression under H/R, and the cause of endothelial cellular injury.