[Silencing ERp29 promotes the invasiveness of human PCa cells in vitro: Molecular mechanisms].

Objective: To analyz the correlation of the expression of ERp29 with the clinicopathological characteristics of PCa and investigate the effect of small interfering RNA (siRNA) silencing the ERp29 gene on the biological behavior of PCa LNCaP cells.

Methods: The expression of the ERp29 gene in the BPH and PCa tissues was detected by immunohistochemistry and that of the ERp29 protein in the PCa and adjacent normal tissues of 6 PCa patients determined by Western blot. Human LNCaP cells were transfected with siRNA using LipofectamineTM 2000, and the expressions of ERp29 mRNA and protein in the LNCaP cells detected by quantitative real-time PCR (qRT-PCR) and Western blot, respectively. The proliferation of the LNCaP cells was measured by MTT assay, their in vitro migration and invasiveness evaluated by the Transwell method, and the expressions of E-cadherin and Vimentin determined by qRT-PCR.

Results: The expression of ERp29 was significantly lower in the PCa than in the adjacent normal tissue (73.9% vs 91.9%， P < 0.05), with a significant correlation between the down-regulated ERp29 expression and metastasis (M) staging (P < 0.05). After transfection with siRNA, the LNCaP cells showed dramatically increased proliferation, migration and invasiveness (P < 0.05), and the expression of E-cadherin was markedly down-regulated while that of Vimentin up-regulated as compared with those in the normal control group (P < 0.05).

Conclusions: The ERp29 gene may be a novel repressor of tumor metastasis. Silencing ERp29 can promote the invasiveness of human PCa cells in vitro by down-regulating the expression of E-cadherin and increasing epithelial-mesenchymal transition.