Silencing of DJ-1 reduces proliferation, invasion, and migration of papillary thyroid cancer cells in vitro, probably by increase of PTEN expression.

AIMS

To explore the function of DJ-1 on cell proliferation, migration, and invasion in human papillary thyroid carcinoma (PTC) cells.

MATERIALS AND METHODS

DJ-1 was knocked out by siRNA in K1 and TPC-1 cells and the efficiency of siRNA was examined by qRT-PCR and western blot. Cell proliferation, cell cycle, migration, and invasion were measured by CCK-8 assay, flow cytometry, colony formation assay and trans-well assay, respectively.

RESULTS

K1 and TPC-1 cells that were transfected with siRNA of DJ-1 had significantly lower expression levels of DJ-1 mRNA and protein. Down-regulation of DJ-1 significantly suppressed the cell proliferation, migration, and invasion. siRNA-mediated knock-down of DJ-1 increased the number of cells in the G0/G1 phase but reduced it in the S phase, while the G2/M phase was not affected. Moreover, the expression level of PTEN (Phosphatase and Tensin Homolog, PTEN) was found up-regulated in DJ-1-null cells.

CONCLUSIONS

This work suggested that DJ-1 implicated in cell proliferation, migration, and invasion of papillary thyroid cancer cells, possibly by the DJ-1/PTEN/PI3K/Akt signal pathway.