nd mock 11733457 PE/CA-PJ15 cells were subcutaneously injected on the left and right backs of athymic BALB/c nu/nu mice and 4 NNMT Silencing Decreases Cell Tumorigenicity tumor growth was monitored weakly. After 8 weeks, the mean size of tumors developing in mice injected with transfected PE/CAPJ15 cells was significantly different from that in mice injected with mock PE/CA-PJ15 cells. As shown in is 
still unclear. In order to explore the involvement of NNMT in oral cancer cell metabolism, we analyzed NNMT expression in seven human oral cancer cell lines and the effect of enzyme knockdown on cell growth in vitro and in vivo. NNMT catalyzes the N-methylation of nicotinamide, pyridines and other structural analogs. N-methylation is one method by which drug and other xenobiotic compounds are metabolized Discussion Oral squamous cell carcinoma is the most common malignancy of the oral cavity. Despite latest innovations in both basic and clinical research, the overall survival rate for OSCC still remains low. The high mortality associated with oral cancer is usually due to the detection of late-stage disease after the primary tumor has metastasized. The optimal management of cervical lymph node metastases is very important to improve survival, and comprehensive gene expression profiling is essential for the identification of reliable and clinically applicable markers, which allow their preoperative detection. In the present study, we focused on the 12603839 expression of NNMT, an enzyme belonging to Phase II Metabolizing Enzymes and involved in the biotransformation and detoxification of many xenobiotics. Although NNMT overespression has been reported in several kinds of tumors, the cellular effect of NNMT upregulation NNMT Silencing Decreases Cell Tumorigenicity by the liver and the enzyme NNMT is responsible for this activity which uses S-adenosyl-L-methionine as methyl donor. In the liver, where the enzyme is predominantly expressed, NNMT activity has a bimodal frequency distribution and variation in its activity might result in differences among individuals in the metabolism and therapeutic effect of drugs and in the formation of potentially toxic pyridine metabolites. Although NNMT is mainly expressed in the liver, a low NNMT expression has been also detected in the kidney, lung, skeletal muscle, placenta, heart, bladder and brain. Interestingly, an enhanced expression of NNMT has been reported in a number of cancers, such as glioblastoma, stomach adenocarcinoma, papillary thyroid cancers, renal, and oral squamous cell carcinomas, colorectal cancer, bladder, lung and pancreatic cancers. BCTC web Moreover, it has been suggested that NNMT expression can be used as a prognostic marker for tumor. Among nonneoplastic diseases, an overexpression of NNMT was also detected in atherosclerosis, chronic obstructive pulmonary disease , and Parkinson’s disease. We have been studying the expression of NNMT in several types of malignancies for many years. In fact, the metabolism of drugs, hormones, toxic chemicals, and micronutriens is an important topic in the fields of pharmacology and endocrinology, and it is often implicated in many pathophysiological processes and diseases, such as tumorigenesis and resistance to chemotherapy. In our previous reports, we analysed NNMT expression in renal cell carcinoma, OSCC, bladder cancer and non-small cell lung cancer. Our results revealed an overexpression of NNMT in ccRCC, OSCC, bladder UC and NSCLC samples compared with adjacent nonc
