suggested that circ_0056618 level was enhanced in colorectal cancer (CRC) and promoted CRC cell growth, angiogenesis, and migration by reducing miR-206 and elevating CXCR4 and VEGF-A [29]

suggested that circ_0056618 level was enhanced in colorectal cancer (CRC) and promoted CRC cell growth, angiogenesis, and migration by reducing miR-206 and elevating CXCR4 and VEGF-A [29]. promotional effect of circ_0056618 on cell progression in curcumin-treated GC cells. Additionally, curcumin treatment repressed the tumorigenesis of GC through regulating circ_0056618. Curcumin treatment delayed the development of GC partly through decreasing circ_0056618 and increasing miR-194-5p. = 6/group). For control and curcumin groups, 2 106 MKN-45 cells suspended in PBS (Solarbio) were subcutaneously implanted into the flank of the nude mice, and DMSO (Sigma-Aldrich) or 30?M curcumin (Sigma-Aldrich) was intraperitoneally administered into the mice every 7 days. For curcumin + vector and curcumin + circ_0056618 groups, circ_0056618 or vector transfected MKN-45 cells were implanted into the nude mice and then 30?M curcumin (Sigma-Aldrich) was intraperitoneally administered into the mice every 7 days. Tumor volume was examined every 7 days and computed via the equation: (length width2)/2. The mice were euthanized after 28 days through cervical dislocation and the neoplasms were weighted and preserved for qRT-PCR assay. Ethical approval: The research related to animal use has been complied with all the relevant national regulations and institutional policies for the care and use of animals and was approved by the Ethics Committee of Animal Research of Qilu Hospital (Qingdao), Cheeloo College of Medicine, Shandong University. 2.13. Statistical analysis Each experiment was conducted in triplicate. The data were analyzed with GraphPad Prism 7 and exhibited as mean standard deviation. The differences in two groups and three groups were estimated using Students 0.01. 3.2. circ_0056618 overexpression ameliorated the effects of curcumin treatment on GC cell colony formation, cell cycle process, and apoptosis As shown in Figure 2a, circ_0056618 level was elevated in GC cell lines (HGC-27 and MKN-45) compared to that in GES-1 cell line. Then PF-4989216 HGC-27 and MKN-45 cells were subjected to 30?M curcumin for 24?h followed by qRT-PCR assay for circ_0056618 expression level. As a result, curcumin treatment led to an inhibition in circ_0056618 level in HGC-27 and MKN-45 cells compared to control groups, but curcumin did not affect the expression of circ_0056618 in GES-1 cells (Figure 2b). Next, the transfection of circ_0056618 increased the level of circ_0056618 in HGC-27 and MKN-45 cells, suggesting the successful transfection of circ_0056618 (Figure 2c). To explore the PF-4989216 association between curcumin and circ_0056618 in the regulation of GC progression, HGC-27 and MKN-45 cells were treated with control, curcumin, curcumin + vector, or curcumin + circ_0056618. As shown in Figure PF-4989216 2d, curcumin-mediated downregulation on circ_0056618 expression was reversed by circ_0056618 overexpression vector transfection. The results of colony formation assay indicated that the colony formation ability of HGC-27 and MKN-45 cells was suppressed following curcumin exposure, while circ_0056618 overexpression overturned the effect (Figure 2eCg). Flow cytometry analysis showed that the proportion of HGC-27 and MKN-45 cells was increased in the G0/G1 phase and reduced in the S phase after curcumin treatment, whereas the impacts were reversed by elevating circ_0056618 (Figure 2hCk). In addition, flow cytometry analysis also exhibited that curcumin treatment facilitated the apoptosis of HGC-27 and MKN-45 cells, while PF-4989216 circ_0056618 overexpression abated this effect (Figure 2l). Collectively, circ_0056618 overexpression weakened the effects of curcumin on the malignant behaviors of GC cells. Open in a separate window Figure 2 Curcumin relieved the malignant cell phenotypes of GC cells by downregulating circ_0056618. (a) qRT-PCR assay was conducted for circ_0056618 level in GES-1, HGC-27, and MKN-45 cells. (b) The expression level of circ_0056618 in curcumin-treated GES-1, HGC-27, and MKN-45 cells was determined by qRT-PCR assay. (c) The expression of circ_0056618 in HGC-27 and MKN-45 cells transfected with circ_0056618 or vector was examined by qRT-PCR assay. (dCl) HGC-27 and MKN-45 cells were assigned to four groups: control, curcumin, curcumin + vector, and curcumin + circ_0056618. (d) The expression of circ_0056618 in HGC-27 and MKN-45 cells was detected by qRT-PCR assay. (fCg) The colony formation HAS3 ability of HGC-27 and MKN-45 cells was examined by colony formation assay. (hCl) The cell cycle process and apoptosis of HGC-27 and MKN-45 cells were analyzed through flow cytometry analysis. ** 0.01, * 0.05. 3.3. Overexpression of circ_0056618 reversed the inhibitory effects of curcumin on GC cell migration and invasion To investigate whether curcumin affected the migration and invasion of GC cells through regulating circ_0056618, wound healing assay and transwell assay were carried out. Wound healing assay exhibited that curcumin treatment suppressed the ability of wound closure, indicating that the PF-4989216 migration ability of HGC-27 and MKN-45 cells was suppressed, which was rescued by increasing circ_0056618 (Figure 3a and b). Moreover, transwell assay showed that the migration and invasion capacities of HGC-27 and MKN-45 cells were repressed by.