The MiR-495/Annexin A3/P53 Axis Inhibits the Invasion and EMT of Colorectal Cancer Cells

Abstract

Background/Aims: More and more reports have shown that the dysregulation of miRNAs can contribute to the progression and metastasis of human cancers. Many studies have shown that the down-regulation of the miR-495 level occurs in a variety of cancers, including colorectal cancer (CRC). However, the precise molecular mechanisms of miR-495 in CRC have not been well clarified. In the current study, we investigated the biological functions and molecular mechanisms of miR-495 in CRC cell lines. Methods: qRT-PCR was used to determine the level of miR-495 in CRC cell lines and tissues. A miR-495 mimic and inhibitor were transfected into CRC cells, and the effects of miR-495 on the invasion and EMT were explored by qRT-PCR as well as transwell and Western blot assays. Meanwhile, luciferase assays were performed to validate Annexin A3 as a miR-495 target in CRC cells. Results: In our study, we found that miR-495 is down-regulated in CRC tissues and cell lines. Moreover, the low level of miR-495 was associated with increased expression of Annexin A3 in CRC tissues and cell lines. The invasion and EMT of CRC cells were suppressed by the overexpression of miR-495. However, the down-regulation of miR-495 promoted the invasion and EMT of CRC cells. Bioinformatics analysis predicted that Annexin A3 was a potential target gene of miR-495. Next, the luciferase reporter assay confirmed that miR-495 could directly target Annexin A3. Consistent with the effect of miR-495, the down-regulation of Annexin A3 by siRNA inhibited the invasion and EMT of CRC cells through the up-regulation of p53. The introduction of Annexin A3 in CRC cells partially blocked the effects of the miR-495 mimic. Conclusion: The introduction of miR-495 directly targeted Annexin A3 to inhibit the invasion and EMT of CRC cells by up-regulating p53, and the down-regulation of Annexin A3 was essential for inhibiting the invasion and EMT of CRC cells by overexpressing miR-495. Overall, the re-activation of the miR-495/Annexin A3/ p53 axis may represent a new strategy for overcoming metastasis of CRC.

MEGF6 Promotes the Epithelial-to-Mesenchymal Transition via the TGFβ/SMAD Signaling Pathway in Colorectal Cancer Metastasis

“…The EMT, in which epithelial cells lose polarity and gain the stromal phenotype, has been invoked as a critical component of the metastatic process [35- 38]. Different studies have shown that the suppression of E-cadherin is a vital molecular event involving specific E-boxes located in the proximal elements of promoters [24, 39]. The pattern of E-cadherin loss is currently thought to be transcriptional repression of CDH1 in different malignancies [22].…”

Development of novel predictive miRNA/target gene pathways for colorectal cancer distance metastasis to the liver using a bioinformatic approach

“…Therefore, this study provides new information on the roles of these miRNAs in CRC progression. Other miRNAs, such as miR-495, are known to influence CRC cell proliferation, invasion, migration and EMT [65,66]. MiR-495 was also found to directly affect the expression of invasion-related molecules, including MMP2 [65].…”

MicroRNA‑495 targets Notch1 to prohibit cell proliferation and invasion in oral squamous cell carcinoma

“…In esophageal squamous cell carcinoma, the expression levels of miR-495 were reported to be reduced in tumor tissues and significantly associated with lymph node metastasis, invasion and tumor, node and metastasis (TNM) stage (22). miR-495 was observed to be expressed at low levels in glioma (23,24), osteosarcoma (25), colorectal (35,36), gastric (37-39), prostate (40) and endometrial cancers (41), and renal cell carcinoma (42). miR-495 has been reported to be highly expressed in bladder (43) and breast (44) cancers; miR-495 upregulation in bladder cancer has been strongly correlated with larger tumor sizes, advanced TNM stages and lymph node metastasis (43).…”

“…Another study revealed that restoration of miR-495 expression attenuated cell proliferation and invasion, and promoted the apoptosis of osteosarcoma cells (25). Ectopic expression of miR-495 was demonstrated to prohibit proliferation, colony formation, metastasis and epithelial-mesenchymal transition (EMT), and induce the apoptosis of colorectal cancer cells (35,36). Numerous studies have also demonstrated that miR-495 acts as a tumor suppressor in gastric cancer by regulating cell growth, motility and chemotherapy resistance (37-39,45).…”

“…Numerous miR-495 targets have been previously identified, including: Cyclin-dependent kinase 6 and MYB in glioma (23,24); high mobility group (HMG) nucleosome binding domain 5 in osteosarcoma (25); family with sequence similarity 83 member D and Annexin A3 in colorectal cancer (35,36); phosphatase of regenerating liver-3, HMG AT-hook 2 and ATP binding cassette subfamily B member 1 in gastric cancer (38,39,45); protein kinase B in prostate cancer (40); forkhead box C1 in endometrial cancer (41); stabilin 1 in renal cell carcinoma (42); phosphatase and tensin homolog in bladder cancer (43); and junctional adhesion molecule-A in breast cancer (44). Notch1, a member of the Notch receptors, was predicted as a novel direct target gene of miR-495 in OSCC in the present study.…”