The results of the present study demonstrated that celecoxib inhibited the proliferation, migration, invasion and EMT of BC cells. celecoxib inhibited EMT by upregulating microRNA (miR)-145 and downregulating the expression of transforming growth factor receptor 2 and SMAD family member 3. Furthermore, the combination of celecoxib with miR-145 mimics demonstrated an additive migration and invasion-inhibitory effect in BC cell lines. The data indicated that celecoxib in addition to miR-145 mimics (20 nM) exhibited a significantly stronger anti-invasion and anti-migration ability compared with celecoxib alone (P 0.05; Fig. GW791343 trihydrochloride 5). Additionally, the expression levels of EMT associated proteins and miR-145 targeted proteins were measured using a western blot assay. The results indicated that celecoxib in combination with miR-145 mimic resulted in a significant increase in E-cadherin expression levels compared with celecoxib or miR-145 mimic alone (P 0.05; Fig. 6). In contrast, celecoxib and miR-145 mimic in combination resulted in a significant decrease in the expression levels of Vimentin, TGFBR2 and Smad3 compared with celecoxib or miR-145 mimic alone (P 0.05; Fig. 6). Open in a separate window Figure 5 Migration and invasion inhibition of bladder cancer cells by the combined treatment of celecoxib and miR-145 mimic. The 5637 and T24 cells were treated with celecoxib (60 (56) reported that the perioperative inhibition of -adrenergic and COX2 signaling in a clinical trial in patients with breast cancer improves the transcriptome of peripheral blood mononuclear cells (PBMCs) and increases the activity of c-Myb in PBMCs. These results suggest that celecoxib may regulate the expression of miR-145 through p53 and c-Myb. Previously, Dovedi (11) demonstrated that celecoxib has potent anti-tumor effects in combination with BCG immunotherapy in an experimental model of murine BC. Furthermore, the intravesical administration of exogenous miR-145 may inhibit tumor growth in mouse orthotopic human BC xenografts (37). The present study revealed the additive invasion-suppressing effect following the co-treatment of T24 and 5637 cells with celecoxib and miR-145 mimic (Figs. 5 and ?and6).6). Li (57) reported that GW791343 trihydrochloride miR-145 protects cardiomyocytes against hydrogen peroxide (H2O2)-induced apoptosis through targeting the reactive oxygen species (ROS)-activated mitochondrial apoptotic pathway. However, ROS have been identified to mediate p53/p65/miR-145 expressions in alloxan-diabetic rats (58). In urothelial carcinoma cell lines, the ectopic expression of miR-145 induced apoptosis characterized by caspase activation (59). In the present study, it was demonstrated that miR-145 combined with celecoxib exerted a potent invasion-suppressing effect but was not able to counteract the effect of celecoxib (Figs. 5 and ?and6).6). This contradiction may be partly explained by the functional, structural and metabolic differences between mitochondria in malignant and normal cells. Unlike cardiac myocytes, the majority of cancer cells are far less sensitive to the toxicity of ROS (60). In conclusion, the present study demonstrated that celecoxib inhibits migration, invasion and EMT partly via the miRNA-145/TGFBR2/Smad3 axis in BC cells. Co-treatment with celecoxib and miR-145 exerted an additive anti-tumor effect by negatively regulating TGF- signaling pathways in human BC cells, as presented in Figs. 5 and ?and6.6. In a future study, the restoration of miR-145 and an effective drug co-delivery system of celecoxib and miR-145 may be a promising novel approach in BC therapy. Acknowledgments Not applicable. Funding The present study was supported by the National Natural Erg Science Foundation of China (grant no. 81560419), the Natural Science Foundation of Jiangxi (grant no. 20151BAB205047) and the Jiangxi Province Infrastructure Facilities for Scientific Research Institutes (grant nos. 20142BBA13038 and 20151BBA13047). Availability of data and materials Data sharing is not applicable to this article, as no datasets were generated or analyzed during the current study. Authors’ contributions XL, YWu, ZZ and MH performed the experiments and generated data. XL, WD, YWa, XZ, LC and YL analyzed the data. TZ, GW and BF designed the experiments. XL and BF wrote the manuscript. All authors reviewed and approved the manuscript. Ethics approval and consent to participate The present study was approved by the Research Ethics Committee of the First Affiliated Hospital, Nanchang University (Nanchang, China). Patient consent for publication Not applicable. Competing interests The authors declare that.Co-treatment with celecoxib and miR-145 exerted an additive anti-tumor effect by negatively regulating TGF- signaling pathways in human BC cells, as presented in Figs. 5). Additionally, the expression levels of EMT associated proteins and miR-145 targeted proteins were measured using a western blot assay. The results indicated that celecoxib in combination with miR-145 mimic resulted in a significant increase in E-cadherin expression levels compared with celecoxib or miR-145 mimic alone (P 0.05; GW791343 trihydrochloride Fig. 6). In contrast, celecoxib and miR-145 mimic in combination resulted in a significant decrease in the expression levels of Vimentin, TGFBR2 and Smad3 compared with celecoxib or miR-145 mimic alone (P 0.05; Fig. 6). Open in a separate window Figure 5 Migration and invasion inhibition of bladder cancer cells by the combined treatment of celecoxib and miR-145 mimic. The 5637 and T24 cells were treated with celecoxib (60 (56) reported that the perioperative inhibition of -adrenergic and COX2 signaling in a clinical trial in patients with breast cancer improves the transcriptome of peripheral blood mononuclear cells (PBMCs) and increases the activity of c-Myb in PBMCs. These results suggest that celecoxib may regulate the expression of miR-145 through p53 and c-Myb. Previously, Dovedi (11) demonstrated that celecoxib has potent anti-tumor effects in combination with BCG immunotherapy in an experimental model of murine BC. Furthermore, the intravesical administration of exogenous miR-145 may inhibit tumor growth in mouse orthotopic human BC xenografts (37). The present study revealed the additive invasion-suppressing effect following the co-treatment of T24 and 5637 cells with celecoxib and miR-145 mimic (Figs. 5 and GW791343 trihydrochloride ?and6).6). Li (57) reported that miR-145 protects cardiomyocytes against hydrogen peroxide (H2O2)-induced apoptosis through targeting the reactive oxygen species (ROS)-activated mitochondrial apoptotic pathway. However, ROS have been identified to mediate p53/p65/miR-145 expressions in alloxan-diabetic rats (58). In urothelial carcinoma cell lines, the ectopic expression of miR-145 induced apoptosis characterized by caspase activation (59). In the present study, it was demonstrated that miR-145 combined with celecoxib exerted a potent invasion-suppressing effect but was not able to counteract the effect of celecoxib (Figs. 5 and ?and6).6). This contradiction may be partly explained by the functional, structural and metabolic differences between mitochondria in malignant and normal cells. Unlike cardiac myocytes, the majority of cancer cells are far less sensitive to the toxicity of ROS (60). In conclusion, the present study demonstrated that celecoxib inhibits migration, invasion and EMT partly via the miRNA-145/TGFBR2/Smad3 axis in BC cells. Co-treatment with celecoxib and miR-145 exerted an additive anti-tumor effect by negatively regulating TGF- signaling pathways in human BC cells, as presented in Figs. 5 and ?and6.6. In a future study, the restoration of miR-145 and an effective drug co-delivery system of celecoxib and miR-145 may be a promising novel approach in BC therapy. Acknowledgments Not applicable. Funding The present study was supported by the National Natural Science Foundation of China (grant no. 81560419), the Natural Science Foundation of Jiangxi (grant no. 20151BAB205047) and the Jiangxi Province Infrastructure Facilities for Scientific Research Institutes (grant nos. 20142BBA13038 and 20151BBA13047). Availability of data and materials Data sharing is not applicable to this article, as no datasets were generated or analyzed during the current study. Authors’ contributions XL, YWu, ZZ and MH performed the experiments and generated data. XL, WD, YWa, XZ, LC and YL analyzed the data. TZ, GW and BF designed the experiments..