Screening Of The Genes Highly Expressed In Esophageal Cancer By MRNA Fluorescent Differential Display

Esophageal carcinoma is a common digestive tract malignant tumor. China is among the countries with high incidence of esophageal cancer, nearly 150,000 people a year dying of this disease on average. At present,there is no remarkable result in either the surgery or the radioactive treatment or the chemotherapy. One important reason for that is the insufficient knowledge on its pathogenesis. With the rapid development of molecular biology, researchers have realized the importance of studying its mechanism. Objective: This thesis screened the genes highly expressed in esophageal cancer by mRNA fluorescent differential display and held a preliminary discussion about their biological behavior in esophagus cancer. Methods:The study applied mRNA fluorescent differential display to screen the gene fragments with different expression in cancer tissues and their corresponding normal tissues excised by surgery and validating these different gene fragments by RT-PCR; furthermore,the whole span of the highly expressed gene fragments was cloned and sequenced. Results: 1. 6 cDNA fragments in esophageal cancer tissues were obtained by FDD-PCR and through the second PCR amplification, 4 of the 6 fragments showed positive features. These fragments were cloned and sequenced, and 3 cDNA fragments with high reliability were obtained, named 16-0(144 bp), 16-2(216 bp),16-3(227 bp) respectively. 2. The 3 cDNA fragments were validated by fluorescence quantitative PCR, and the result showed that their expression was significantly higher than that in the corresponding normal tissue adjacent to the tumor. Gene 16-0 was highly homologous with homo sapiens immunoglobulin lambda-like polypeptide 3. Gene 16-2 was highly homologous with homo sapiens signal transducer and activator of transcription 2 and 16-3 was homologous with homo sapiens chromosome 10 open reading frame 99. 3.The experiment got 16-0 gene's span. Its ORF was 711 bp, coding 236 amino acids. Conclusion: The 3 cDNA different fragments were highly expressed in esophagus cancer tissues. By analyzing 16-0's span,sequence and the comparison result of homology, it was possibe that Igll3 was one of immunoglobulin family members relevant to esophagus cancer. It may provide theoretical foundation for further clarifying the relevant mechanisms of esophageal carcinoma.