Objective      To study the effect of cytoplasmic transduction peptide (CTP)-mediated nitrogen permease regulator 2-like (NPRL2) fusion protein on the migration and invasion of primary renal cell carcinoma (RCC) cells as well as its impact on epithelial-mesenchymal transition (EMT). Methods     Primary RCC cells were cultured from clinically resected renal tumor tissue. Prokaryotic expression plasmids pET15b-CTP-NPRL2 and pET15b-NPRL2 were constructed and transfected into E. coli BL21. The expression of fusion proteins CTP-NPRL2 and NPRL2 was tested by Western blotting. Primary RCC cells were divided into 3 groups CTP-NPRL2

NPRL2 and blank control by treated with CTP-NPRL2

NPRL2 fusion protein solution and PBS

respectively. Cell invasion and migration ability were evaluated by Transwell assay. The mRNA and protein expression levels of raptor

vimentin

fibronectin and E-cadherin were detected by realtime PCR (RT-PCR) and Western blotting

respectively. Results      Morphologic observation and immunochemical assay confirmed the successful culture of primary RCC cells derived from patient specimens. After plasmid construction and transfection

the expression of fusion proteins CTP-NPRL2 and NPRL2 were detected by Western blotting. Green fluorescence was only detected in the cytoplasm of CTP-NPRL2 group

suggesting that CTP successfully mediated NPRL2 protein into RCC cells. Compared with NPRL2 and control groups

the invasion and migration ability of primary RCC cells in CTP-NPRL2 group was significantly decreased (P0.05). Also

the mRNA and protein expression levels of raptor

vimentin and fibronectin were significantly decreased

while E-cadherin was significantly increased (P0.05) in CTPNPRL2 group. Conclusion     CTP-NPRL2 fusion protein inhibits the migration and invasion ability of RCC. This may partly be associated with decreased activity of mTORC1 mediated by interaction between NPRL2 and raptor

consequently regulating the expression of EMT-correlated E-cadherin

vimentin and fibronectin.