Functional Genomics Study Of Annexin Ⅰ And CASK And Key Protein Screening In Esophageal Squamous Cell Carcinoma

The esophageal squamous cell carcinoma (ESCC) is a major kind of malignant tumor in China. Its molecular mechanisms are poorly understood. Previous studies showed that the expression of some important proteins have been changed, such as annexin I was down-regulated and CASK, a scaffold protein, was up-regulated during the tumorigenesis of ESCC.In the present study functional genomic analysis of annexin I and CASK proteins in the ESCC had been investigated via semi-quantitative RT-PCR, Western blot, immunohistochemistry staining (IHC) of the multi-tissue arrays (MTAs) and indirected immunofluorescence staining (IIF) techniques. Annexin I protein was lost in ESCC. It decreased very sharply with scattered disappearance on the cellular membrane and translocated to the nuclear membrane. CASK was up-regulated and the localization was also changed in ESCC. The expression of CASK increased on the nuclear membrane and also in cytoplasm surrounding nuclear membrane. The observation suggested that the translocation of annexin I and CASK in ESCC might correlate with the tumorigenesis of ESCC.The IIF staining showed that CASK and annexin I were co-localized in normal esophageal epithelia and partially in ESCC tissues and cells as well. In normal epithelia CASK and annexin I was mainly co-localized on the cell membrane, however they switched from cellular membrane to the nucleus in ESCC.The co-immunoprecipitation study between the two proteins had found that they might interact each other in normal esophageal epithelia and might also partially associate with in the cancer tissue and cell lines. The association between the CASK and annexin I in normal epithelia had been found stronger than that in ESCC. The co-IP between the two proteins had...