MiR-503 promotes the migration and invasion of colorectal cancer cells by regulating PDCD4.

PURPOSE

MicroRNAs are expressed abnormally in colorectal cancer (CRC) and could participate in its development. In this study we aimed to explore the molecular mechanisms of miR-503 in the genesis of CRC.

METHODS

The relative expression of miR-503 and programmed cell death 4 (PDCD4) tumor suppressor in CRC tissues and cell lines were detected by qRT-PCR and Western blot. Cell migration and cell invasion were assessed by transwell assay. Moreover, the confirmation of the direct target of miR-503 in CRC was performed by luciferase reporter assay.

RESULTS

The expression of miR-503 was increased remarkably in CRC, while PDCD4 decreased. Moreover, PDCD4 was verified as a specific target of miR-503 in CRC and it could reverse the effect of miR-503 on CRC cells. Furthermore, the abnormal expression of miR-503 played an important role in regulating of the development of CRC cells. In addition, PDCD4 protein expression and miR-503 mRNA expression were negatively correlated in CRC tissues.

CONCLUSION

The inhibitory effect of miR-503 in CRC was realized by the upregulation of PDCD4, suggesting that miR-503/PDCD4 axis might play a critical role in CRC and could possibly be a therapeutic target.