RNA-mediated Gene Silencing NNMT Decreases Tumorigenity In OSCC Cells
Objective: Oral squamous cell carcinoma (OSCC) is the most common phenotype of oral cancer. Despite the progress in the treatment of OSCC, the overall survival has not improved substantially for the last three decades due to the resistance to conventional chemo or radiotherapy.Therefore, the identification of reliable biomarkers becomes essential to develop effective anti-cancer therapy.In this study we focused on the enzyme Nicotinamide N-methyltransferase (NNMT), which catalyses the transmethylation from S-adenosyl-L-methionine to nicotinamide and to some other azaheterocycles, playing a fundamental role in the biotransformation of many xenobiotics. Several tumors have been associated with abnormal NNMT expression, however its role in cancer cell metabolism remains largely unknown.
Method: 7 human oral cancer cell lines were examined for NNMT expression by Real-Time PCR, Western blot and HPLC-based catalytic assay. Subsequently, we evaluated the effect of shRNA-mediated silencing of NNMT on cell proliferation in vitro and in vivo. NNMT mRNA was detected in all cancer cell lines tested, showing a very high expression level in the PE/CA PJ-15 cells, in keeping with the results of Western blot and catalytic activity assay. PE/CA PJ-15 cell line was stably transfected with shRNA plasmids against NNMT and analyzed by MTT and Soft agar Assay. Transfected and control cells were injected into athymic mice in order to evaluated the effect of NNMT silencing on tumor growth. ShRNA vectors targeted against NNMT efficiently suppressed gene expression, at both the mRNA and protein levels.
Result: Downregulation of NNMT expression by shRNA resulted in a decrease in cell proliferation and colony formation ability on soft agar. In athymic mice, NNMT silencing induced a marked reduction in tumour volume.
Conclusion: Our results seem to suggest that NNMT is involved in cell proliferation and its inhibition could represent a potential molecular approach to the treatment of oral carcinoma.
Continental European Division Meeting
2013 Continental European Division Meeting (Florence, Italy) Florence, Italy
2013 378 Scientific Groups
Mascitti, Marco
( Universita di Ancona, Ancona, N/A, Italy
)
Emanuelli, Monica
( Universita di Ancona, Ancona, N/A, Italy
)
Santarelli, Andrea
( Universita di Ancona, Ancona, N/A, Italy
)
Pozzi, Valentina
( Universita di Ancona, Ancona, N/A, Italy
)
Sartini, Davide
( Universita di Ancona, Ancona, N/A, Italy
)
Morganti, Stefano
( Universita di Ancona, Ancona, N/A, Italy
)
Giuliante, Rachela
( Universita di Ancona, Ancona, N/A, Italy
)
Rocchetti, Romina
( Universita di Ancona, Ancona, N/A, Italy
)
Rubini, Corrado
( Universita di Ancona, Ancona, N/A, Italy
)
Lo Muzio, Lorenzo
( University of Foggia, Foggia, N/A, Italy
)
Poster Session
Oral Medicine and Pathology-Posters
09/06/2013
