Nicotinamide N-methyltransferase induces cellular invasion through activating matrix metalloproteinase-2 expression in clear cell renal cell carcinoma cells.
Nicotinamide N-methyltransferase (NNMT) was recently identified as one clear cell renal cell carcinoma (ccRCC)-associated gene by analyzing full-length complementary DNA-enriched libraries of ccRCC tissues. The aim of this study is to investigate the potential role of NNMT in cellular invasion. A strong NNMT expression is accompanied with a high invasive activity in ccRCC cell lines, and small interfering RNA-mediated NNMT knockdown effectively suppressed the invasive capacity of ccRCC cells, whereas NNMT overexpression markedly enhanced that of human embryonic kidney 293 (HEK293) cells. A positive correlation between the expression of NNMT and matrix metallopeptidase (MMP)-2 was found in ccRCC cell lines and clinical tissues. The treatment of blocking antibody or inhibitor specific to MMP-2 significantly suppressed NNMT-dependent cellular invasion in HEK293 cells. Furthermore, SP-1-binding region of MMP-2 promoter was found to be essential in NNMT-induced MMP-2 expression. The specific inhibitors of PI3K/Akt signaling markedly decreased the binding of SP1 to MMP-2 promoter as shown by chromatin immunoprecipitation assay. We also demonstrated that PI3K/Akt pathway plays a role in NNMT-dependent cellular invasion and MMP-2 activation. Moreover, short hairpin RNA-mediated knockdown of NNMT expression efficiently inhibited the growth and metastasis of ccRCC cells in non-obese diabetic severe combined immunodeficiency mice. Taken together, the present study suggests that NNMT has a crucial role in cellular invasion via activating PI3K/Akt/SP1/MMP-2 pathway in ccRCC.
Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan.
Sai-Wen
SW
Tang
Tsung-Cheng
TC
Yang
Wei-Chou
WC
Lin
Wen-Hsin
WH
Chang
Chung-Chieh
CC
Wang
Ming-Kuen
MK
Lai
Jung-Yaw
JY
Lin
D000328:Adult; D000368:Aged; D000818:Animals; D002292:Carcinoma, Renal Cell / Q000201:enzymology / Q000473:pathology*; D004789:Enzyme Activation; D006801:Humans; D007680:Kidney Neoplasms / Q000201:enzymology / Q000473:pathology*; D020778:Matrix Metalloproteinase 2 / Q000235:genetics* / Q000502:physiology; D051379:Mice; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D050903:Nicotinamide N-Methyltransferase / Q000502:physiology*; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D011401:Promoter Regions, Genetic; D051057:Proto-Oncogene Proteins c-akt / Q000502:physiology; D016329:Sp1 Transcription Factor / Q000502:physiology
D016329:Sp1 Transcription Factor; D050903:Nicotinamide N-Methyltransferase; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2