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Oral squamous cell carcinoma (OSCC) constitutes over 90% of all cancers in the oral cavity. The prognosis for patients with invasive OSCC is poor; therefore, it is important to understand the molecular mechanisms of invasion and subsequent metastasis not only to prevent cancer progression but also to detect new therapeutic targets against OSCC. Recently, extracellular vesicles-particularly exosomes-have been recognized as intercellular communicators in the tumor microenvironment. As exosomic cargo, deregulated microRNAs (miRNAs) can shape the surrounding microenvironment in a cancer-dependent manner. Previous studies have shown inconsistent results regarding miR-200c-3p expression levels in OSCC cell lines, tissues, or serum-likely because of the heterogeneous characters of the specimen materials. For this reason, single-cell clone analyses are necessary to effectively assess the role of exosome-derived miRNAs on cells within the tumor microenvironment. The present study utilized integrated microarray profiling to compare exosome-derived miRNA and exosome-treated cell-derived mRNA expression. Data were acquired from noninvasive SQUU-A and highly invasive SQUU-B tongue cancer cell clones derived from a single patient to determine candidate miRNAs that promote OSCC invasion. Matrigel invasion assays confirmed that hsa-miR-200c-3p was a key pro-invasion factor among six miRNA candidates. Consistently, silencing of the miR-200c-3p targets, CHD9 and WRN, significantly accelerated the invasive potential of SQUU-A cells. Thus, our data indicate that miR-200c-3p in exosomes derived from a highly invasive OSCC line can induce a similar phenotype in non-invasive counterparts.

A real-time cell-monitoring analysis (RTCA) system was previously developed based on the change in impedance when cells attach and spread in a culture dish coated with a gold microelectrode array. However, the potential applications of this system have not yet been fully demonstrated. The purpose of this study was to test the utility of the RTCA system to determine the cytotoxicity of four anticancer agents in carcinoma cells. The results were compared with those of the conventional WST-8 assay at the endpoint to determine the potential of the RTCA system as a new real-time assay method to evaluate cytotoxicity. iCELLigence was used as the RTCA system in this study. Suspensions of oral squamous cell carcinoma (OSCC) cell lines were seeded (2x10 4 cells/well) onto the E-plate (the culture plate of the iCELLigence system). After 24 h of culture, anticancer agents were added to each well, and changes in electrical impedance (cell index, CI) were recorded for another 72 h of culture. Cell proliferation was detected in real-time by the RTCA device in an automated, high throughput manner. Then, the IC 50 profiles of the four anticancer agents were calculated based on the real-time cell index values. The results indicated that the RTCA system was useful in evaluating cytotoxic reactions immediately after the addition of the anticancer agents as it was able to record the data in real-time. Furthermore, the IC 50 levels measured by the real-time assay were lower than those measured by the endpoint assay. Thus, RTCA systems can be used to evaluate chemotherapeutic agents in cancer cells as well as their side effects in normal cells.

Sodium 4-phenylbutyrate (PBA) exhibits anti-inflammatory effects by suppressing nuclear factor-κB (NF-κB) activation. In the present study, the effects of PBA on a mouse model of dextran sulfate sodium (DSS)-induced colitis were investigated. The therapeutic efficacy of PBA (150 mg/kg body weight) in DSS-induced colitis was assessed based on the disease activity index (DAI), colon length, the production of inflammatory cytokines and histopathological examination. The results showed an increase in the median survival time in the PBA-treated group compared with that of the untreated DSS control group. DAI scores were lower in the PBA-treated group than in the DSS control group during the 12 days of the experiment. Additionally, PBA treatment inhibited shortening of the colon and the production of the inflammatory cytokines tumor necrosis factor-α, interleukin-1β and IL-6, which were measured in the colonic lavage fluids. Histopathological examination of the DSS control group showed diffused clusters of chronic inflammatory cells infiltrating the lamina propria, partial exfoliation of the surface epithelium and decreased numbers of mature goblet cells. By contrast, in the PBA-treated group the histopathological findings were the same as those of the normal healthy controls. These results suggest that PBA strongly prevents DSS-induced colitis by suppressing the mechanisms involved in its pathogenesis.

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