1.Expression Of NNMT In Human Renal Carcinoma 2.The Impact Of PLK1 MRNA Knockdown By SiRNA In Colorectal SW480 Cells

Nicotinamide N-methyltransferase (NNMT), an enzyme highly expresses in normal liver tissue, was found to be highly expressed in renal carcinoma tissue by genechip in our previous study. The expression level of NNMT in human renal cancer tissues was 100 times as that in nomal renal tissues. The results suggest that the different expression of NNMT in human renal cancer may play an important role in the pathological process of kidney cancer.In this study, the sequence of NNMT cDNA from renal cancer tissue was cloned and the expression of both mRNA and protein of this gene in renal carcinoma tissues were investigated.Method and results:The mRNA of NNMT was detected in human renal cancer tissues by RT-PCR. Our results showed that NNMT expression level in cancer tissue was higher than that in normal adjacent tissue. By using TA clone technology, we have successfully cloned the full-length cDNA of NNMT. Our data indicated that the sequence of NNMT from renal cancer tissue was 100% identity with the that from normal liver tissue. (Genbank NM₀06169).The NNMT protein was detected in human renal cancer tissues and normal renal tissues using western blot method. The results suggested that NNMT is diffusely highly expressed in renal cancer tissues, whereas it only lowerly expressed in the epithelial cell of renal tubules. The intracellular distribution of NNMT protein in cancer tissue also showed an different pattern from that in normal renal tissue. NNMT protein was found to be positive both in cytoplasm and nucleus. However, it only found to be positive in the cytoplasm of tubular cells.Conclusion:1. RT-PCR results confirmed the higher expression of NNMT mRNA in renal carcinoma. And The full-length NNMT mRNA from renal carcinoma was 100% identify with that from normal liver tissue.2. The results of western blot suggest that the renal cancer tissues have higher NNMT protein expression level than normal tissues.3. NNMT protein is mainly expressed in the cytoplasm of epithelia cells of parconvoluted tubule in normal renal tissue, but it is highly expressed both in cytoplasm and nucleus of cancer cells.