Abstract. Nasopharyngeal carcinoma (NPC) is one of the most common malignant tumors in southern China and Southeast Asia. It is characterized as a multistep process involved in multiple genetic and epigenetic events. The mechanism of carcinogenesis still needs to be further clarified. In this study, two-dimensional gel electrophoresis, matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), RT-PCR, Western blot and immunohistochemical (IHC) analyses were used to detect Galectin-1 expression in NPC compared with normal nasopharyngeal epithelial tissues (NNET). We found that Galectin-1 was expressed at a significantly higher level in NPC compared with NNET. Our results indicated that high expression level of Galectin-1 might correlate with the development of NPC and Galectin-1 may serve as a potential diagnostic marker or therapeutic target for NPC.
IntroductionNPC is a disease with remarkable racial and geographic distribution, which is one of the most common malignant tumors in southern China and Southeast Asia. The incidence rate is about 25-50 per 100,000 person year and 100-fold higher than that in the Western world (1,2). With the advances in NPC study, many NPC-related molecules have been reported, such as serum antibodies against various EBV proteins (3), cathepsin D (4), stathmin 14-3-3, Annexin I (5), serum amyloid A (6), Bmi-1 (7) and Met protein (8). However, the molecular basis of NPC is still unclear. A better understanding of the molecular basis of NPC is fundamental for developing more effective diagnostic, prognostic, treatment and prevention approaches.High-throughput technologies such as microarrays and proteomics offer the potential ability to find alterations previously unidentified in NPC. Analyses for gene expression profiles of NPC with a cDNA array found that genes with aberrant expressions possibly contributed to the pathogenesis of NPC (9). Proteomics has provided new opportunities to uncover biomarkers and therapeutic targets for NPC as well as reveal the molecular mechanism underlying this disease. Using tissue samples from patients may be the most direct and persuasive way to find biomarkers and therapeutic targets for cancers by a proteomic approach.In the present study, 2-DE and mass spectrometry (MS) were used to identify differential expression proteins between NPC and NNET samples. The differential expression of Galectin-1 was confirmed significantly up-regulated in NPC compared with NNET by RT-PCR and Western blot analysis. Our data will facilitate the better understanding of NPC carcinogenesis and reveal the function of Galectin-1 in NPC. Investigation of protein that occurs during carcinogenesis can provide new insights into the pathogenesis of cancer and is useful in developing new tumor biomarkers for the diagnosis and treatment of the disease.
Materials and methods
Materials and chemicals. Immobiline pH-gradient (IPG)DryStrips (pH 3-10, length 24 cm), IPG buffer (pH 3-10), DryStrip cover fluids, thiourea, urea, CHAPS, DTT, Pharmalyte (pH...
