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Pancreatic cancer has a poor prognosis because of its high invasiveness and recurrence, and these properties closely link to the phenomenon of epithelial-mesenchymal transition (EMT). Recently, it has been reported that Sox4 is indispensable for EMT in vitro and in vivo and regulates various master regulators of EMT including Zeb, Twist and Snail. Moreover, Sox4 induces the transcription of Ezh2 which is the histone methyltransferase, and reprograms the cancer epigenome to promote EMT and metastasis. Therefore, the present study evaluated the importance of Sox4, Ezh2 and miR-335, which regulate Sox4 expression epigenetically, in clinical samples with pancreatic cancer. This retrospective analysis included data from 36 consecutive patients who underwent complete surgical resection for pancreatic cancer and did not undergo any preoperative therapies. We assessed the clinical significance of Sox4/Ezh2 axis and miR-335 expression, using immunohistochemistry and qRT-PCR with laser captured microdissection (LCM). The Sox4 positive patients had significantly worse prognosis as for disease-free survival (DFS) (P=0.0154) and the Ezh2-positive patients had significantly worse prognosis as for overall survival (OS) (P=0.0347). The miR-335 expression was inversely correlated with Sox4 expression in the identical clinical specimens, but it was not related to the prognosis. Sox4/Ezh2 axis was closely associated with the prognosis in pancreatic cancer patients.

Increasing evidence has confirmed that dysregulation of microRNAs (miRNAs) can contribute to the progression and metastasis of human tumors. Previous studies have shown that dysregulation of microRNAs (miRNAs) can contribute to the progression and metastasis of human tumors. However, the precise mechanisms of miR‑132 in osteosarcoma have not been well clarified. Real-time PCR was performed to detect the expression of miR‑132 in osteosarcoma cell lines. miR-132 mimic, miR‑132 inhibitor and negative control were transfected into osteosarcoma cells and the effects of miR‑132 on the cell growth and metastasis were investigated. Furthermore, protein level of Sox4 was measured by western blotting. Luciferase assays were performed to validate Sox4 as miR‑132 target in osteosarcoma cells. We found that miR‑132 was downregulated in osteosarcoma cell lines. Introduction of miR‑132 significantly inhibited proliferation, arrested cell cycle and induced apoptosis in osteosarcoma cells. Besides, invasion and epithelial-mesenchymal transition (EMT) of osteosarcoma cells was suppressed by overexpressing miR‑132. However, downregulation of miR‑132 promoted cell growth and metastasis in osteosarcoma cells. Bioinformatics analysis predicted that Sox4 was a potential target gene of miR‑132. Luciferase reporter assay demonstrated that miR‑132 could directly target Sox4. Moreover, the low level of miR‑132 was associated with increased expression of Sox4 in osteosarcoma cells. Sox4 inhibition suppressed cell malignant behaviors. Overexpression of Sox4 in osteosarcoma cells transfected with miR‑132 mimic partially reversed the inhibitory effect of miR‑132. In conclusion, miR‑132 inhibited cell growth and metastasis in osteosarcoma cells by downregulation of Sox4, and knockdown of Sox4 was essential for the miR-132-inhibited cell growth and metastasis in osteosarcoma cells.

MicroRNA-338-3p (miR‑338-3p), a recently discovered miRNA, has been reported to be downregulated and play tumor suppressor roles in gastric cancer, ovarian cancer, colorectal carcinoma and lung cancer by targeting several genes. However, the role and potential mechanism of miR‑338-3p in breast cancer (BC) is still unclear. In the present study, we investigated the roles and mechanisms of miR‑338-3p in human breast cancer. miR‑338-3p expression was determined by qRT-PCR in human BC cell lines, and clinical significantly of miR‑338-3p expression was further evaluated. Furthermore, the function of miR‑338-3p in breast cancer also was investigated by several in vitro approaches and in nude mouse models. Luciferase assay and western blot analysis were performed to validate the potential targets of miR‑338-3p after the preliminary screening by employing open access software. It was found that miR‑338-3p was significantly downregulated in both BC tissues and cell lines and the low expression of miR‑338-3p was inversely correlated with lymph node metastatic and TNM stage status (P<0.01). Function assay showed that the overexpression of miR‑338-3p in BC cells significantly inhibited cell proliferation, colony formation, migration and invasion, and induced cell apoptosis and cell cycle arrest at G1/G0 stage, as well as suppressed tumor growth in the nude mouse model. Luciferase assay and western blot analysis identified sex-determining region Y-box 4 (SOX4) as a direct and functional target of miR‑338-3p. These findings revealed that miR‑338-3p may act as a tumor suppressor in breast cancer by targeting SOX4, suggesting miR‑338-3p as a novel strategy for breast cancer treatment.