SOX30, a target gene of miR-653-5p, represses the proliferation and invasion of prostate cancer cells through inhibition of Wnt/β-catenin signaling.

Sex-determining region Y-box containing gene 30 (SOX30) is a newly identified tumor-associated gene in several types of cancer. However, whether SOX30 is involved in the development and progression of prostate cancer remains unknown. This study investigated the potential role of SOX30 in prostate cancer. Prostate cancer cell lines and a normal prostate epithelial cell line were used for the experiments. The expression of SOX30 was determined using quantitative real-time PCR and western blot analysis. The malignant cellular behaviors of prostate cancer were assessed using the Cell Counting Kit-8, colony formation and Matrigel invasion assays. The miRNA-mRNA interaction was validated using the dual-luciferase reporter assay. SOX30 expression was lower in cells of prostate cancer lines than in cells of the normal prostate epithelial line. Its overexpression repressed the proliferation and invasion of prostate cancer cells. SOX30 was identified as a target gene of microRNA-653-5p (miR-653-5p), which is upregulated in prostate cancer tissues. MiR-653-5p overexpression decreased SOX30 expression, while its inhibition increased SOX30 expression in prostate cancer cells. MiR-653-5p inhibition also markedly restricted prostate cancer cell proliferation and invasion. SOX30 overexpression or miR-653-5p inhibition significantly reduced β-catenin expression and downregulated the activation of Wnt/β-catenin signaling. SOX30 knockdown significantly reversed the miR-653-5p inhibition-mediated inhibitory effect on the proliferation, invasion and Wnt/β-catenin signaling in prostate cancer cells. These results reveal a tumor suppressive function for SOX30 in prostate cancer and confirmed the gene as a target of miR-653-5p. SOX30 upregulation due to miR-653-5p inhibition restricted the proliferation and invasion of prostate cancer cells, and this was associated with Wnt/β-catenin signaling suppression. These findings highlight the importance of the miR-653-5p-SOX30-Wnt/β-catenin signaling axis in prostate cancer progression.

Fu Q ，Sun Z ，Yang F ，Mao T ，Gao Y ，Wang H ... -  《-》

Capn4 expression is modulated by microRNA-520b and exerts an oncogenic role in prostate cancer cells by promoting Wnt/β-catenin signaling.

Accumulating evidence reports that Capn4 plays an important role in the development and progression of various malignant cancers. However, whether Capn4 is involved in prostate cancer remains unclear. Therefore, the aim of this study was to investigate the expression, biological function and regulatory mechanism of Capn4 in prostate cancer. Herein, we found that Capn4 was highly expressed in prostate cancer cell lines compared with normal prostate cells. Capn4 gene silencing markedly suppressed the growth, invasion and Wnt/β-catenin signaling of prostate cancer cells, whereas Capn4 overexpression showed an oncogenic effect. Moreover, silencing of β-catenin significantly blocked the oncogenic effect of Capn4 overexpression. Bioinformatics analysis predicted that Capn4 was a potential target gene of microRNA-520b (miR-520b), which has been reported as a tumor suppressive miRNA in various cancers. The dual-luciferase reporter assay confirmed that miR-520b directly bound to the 3'-untranslated region of Capn4. Real-time quantitative PCR and Western blot analysis showed that miR-520b negatively regulated Capn4 expression in prostate cancer cells in vitro. Furthermore, we found that miR-520b was significantly downregulated in prostate cancer cell lines and tissues. In addition, miR-520b expression was inversely correlated with Capn4 expression in prostate cancer clinical specimens. Overexpression of miR-520b mimicked the tumor suppressive effect of Capn4 siRNA, whereas inhibition of miR-520b had an oncogenic effect. Restoration of Capn4 significantly blocked the antitumor effect of miR-520b in prostate cancer cells. Overall, our findings demonstrate an oncogenic role of Capn4 in prostate cancer and show that its expression is epigenetically regulated by miR-520b. Our results reveal that suppression of Capn4 by miR-520b inhibits the growth and invasion of prostate cancer cells associated with downregulated Wnt/β-catenin signaling, indicating an important role of the miR-520b/Capn4/Wnt/β-catenin regulation axis in the molecular pathogenesis of prostate cancer. Our study suggests that miR-520b and Capn4 may represent potential and novel therapeutic targets for prostate cancer.

Ren W ，Wang D ，Li C ，Shu T ，Zhang W ，Fu X ... -  《-》

Suppression of microRNA-454 impedes the proliferation and invasion of prostate cancer cells by promoting N-myc downstream-regulated gene 2 and inhibiting WNT/β-catenin signaling.

MicroRNA-454 (miR-454) is emerging as critical regulator in tumorigenesis; it may function as an oncogene or a tumor suppressor. However, the role of miR-454 in prostate cancer remains unknown. In this study, we aimed to investigate the function and molecular mechanisms of miR-454 in prostate cancer. We found that miR-454 was highly expressed in prostate cancer tissues and cell lines (*p<0.05), as detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell counting kit-8 assay, colony formation assay and cell invasion assay showed that the inhibition of miR-454 significantly suppressed prostate cancer cell proliferation and invasion (*p<0.05), whereas the overexpression of miR-454 markedly promoted prostate cancer cell proliferation and invasion (*p<0.05). Bioinformatics analysis showed that N-myc downstream-regulated gene 2 (NDRG2), a well-known tumor suppressor, was identified as a potential target gene of miR-454. Dual-luciferase reporter assay showed that miR-454 directly targeted the 3'-untranslated region of NDRG2. RT-qPCR and western blot showed that miR-454 overexpression significantly decreased NDRG2 expression (*p<0.05), whereas miR-454 inhibition markedly promoted NDRG2 expression (*p<0.05). Spearman's correlation analysis showed that miR-454 expression was inversely correlated with NDRG2 expression in prostate cancer tissues (r=-0.8932; p<0.0001). Moreover, miR-454 inhibition significantly suppressed the protein expression of β-catenin (*p<0.05) and blocked the activation of WNT signaling (*p<0.05). In addition, small interfering RNA mediated NDRG2 knockdown significantly reversed the antitumor effect of miR-454 inhibition on prostate cancer cell proliferation and invasion (*p<0.05). Taken together, these results reveal an oncogenic role of miR-454, which promotes prostate cancer cell proliferation and invasion by downregulation of NDRG2. These results also suggest miR-454 as a potential therapeutic target for the treatment of prostate cancer.

Fu Q ，Gao Y ，Yang F ，Mao T ，Sun Z ，Wang H ，Song B ，Li X ... -  《-》

Downregulation of microR-147b represses the proliferation and invasion of thyroid carcinoma cells by inhibiting Wnt/β-catenin signaling via targeting SOX15.

microRNA-147b (miR-147b) is a newly identified tumor-related miRNA that is dysregulated in multiple cancer types. Yet, the role of miR-147b in thyroid carcinoma remains unknown. Herein, we found that miR-147b expression was upregulated in thyroid carcinoma tissues and cell lines. miR-147b inhibition decreased the proliferation, colony formation, and invasion of thyroid carcinoma cells. The tumor suppressive gene SRY-related high-mobility-group box gene 15 (SOX15) was predicted as a miR-147b target gene. SOX15 expression was markedly decreased in thyroid carcinoma tissues and inversely correlated with the miR-147b expression. SOX15 overexpression repressed the proliferation and invasion of thyroid carcinoma cells associated with downregulation of Wnt/β-catenin signaling. SOX15 knockdown abolished the miR-147b-inhibition-mediated antitumor effect. miR-147b inhibition or SOX15 overexpression retarded the tumor growth of thyroid carcinoma cells in vivo. Overall, our study suggests that miR-147b inhibition restrains the proliferation and invasion of thyroid carcinoma cells through upregulation of SOX15 and inhibition of Wnt/β-catenin signaling.

Xu C ，Liu J ，Yao X ，Bai Y ，Zhao Q ，Zhao R ，Kou B ，Li H ，Han P ，Wang X ，Guo L ，Zheng Z ，Zhang S ... -  《-》

MicroRNA-449b-5p suppresses the growth and invasion of breast cancer cells via inhibiting CREPT-mediated Wnt/β-catenin signaling.

Accumulating evidence has suggested that microRNA-449b-5p (miR-449b-5p) plays an important role in the development and progression of multiple cancers. However, little is known about the role of miR-449b-5p in breast cancer. In this study, we aimed to investigate the expression level, biological function and underlying mechanism of miR-449b-5p in breast cancer. Our results showed that miR-449b-5p expression was frequently down-regulated in breast cancer cell lines and tissues. The overexpression of miR-449b-5p significantly inhibited growth and invasion, and induced the cell cycle arrest of breast cancer cells. In contrast, the inhibition of miR-449b-5p showed the opposite effect. Interestingly, bioinformatic analysis predicted that cell cycle-related and expression-elevated protein in tumor (CREPT), an important oncogene in breast cancer, was a potential target gene of miR-449b-5p. The overexpression of miR-449b-5p decreased CREPT expression while miR-449b-5p inhibition promoted CREPT expression in breast cancer cells. Restoration of CREPT expression in miR-449b-5p mimics transfected cells partially reversed the suppressive effect of miR-449b-5p on breast cancer cell growth and invasion. Notably, our results showed that miR-449b-5p overexpression decreased the expression of β-catenin and suppressed the activation of Wnt/β-catenin/TCF-4 signaling via targeting CREPT. In addition, blocking Wnt/β-catenin partially reversed the promotion effect of miR-449b-5p inhibition on breast cancer cell growth and invasion. Overall, these results reveal a tumor suppressive role of miR-449b-5p that restricts the growth and invasion of breast cancer cells through targeting CREPT and inhibiting CREPT-mediated activation of Wnt/β-catenin signaling. Our study suggests that the miR-449b-5p/CREPT/Wnt/β-catenin axis may play an important role in the pathogenesis of breast cancer and miR-449-5p may serve as a potential therapeutic target for breast cancer.

Jiang J ，Yang X ，He X ，Ma W ，Wang J ，Zhou Q ，Li M ，Yu S ... -  《-》