The Area And Significance Of Y-box Binding Protein1Expressed In Colorectal Cancer Tissue

Y-box binding protein is a transcription factor, which is widely expressed in all cells from bacteria to humans, is also a kind of highly conservative regulatory elements. The y-box binding proteins including dbA、dbB and Y-box binding protein1(YB-1), etc. But on the relationship between tumor research still wildly is YB-1, the molecular weight is43-kDa, it combines in human MHC Class Ⅱ gene promoter region which is Y-box DNA sequence(GTGATTGGCCAA), these sequence of center back to CCAAT box, is a for all Y-box binding proteins identification and combined with highly conservative district. Y-box binding proteins have three typical structural:end of anmino acid N, rich proline and alanine, is the structure of the transcriptional activation domain; hydrophilic structure domain C terminal, is the structure of the interaction between protein and protein domains; cold shock domain (CSD):the highly conserved nucleotide domain structure, in combination with DNA damage and nonspecific DNA, participate in the CSD protein itself or heterogeneous polymerization, through the analysis of the gene mutation, CSD is the structure domain combined DNA and mRNA. YB-1is a highly conserved DNA binding protein, a member of the CSD, wildly exist in mammals of cytoplasm and nucleus, with a variety of cellular functions, participate in gene transcription, translation DNA damage induced by repair, anticancer drug resistance, and so on. The present study showed that YB-1participate in a wide variety of tumor into the level, the transformation of the degenerative development, has been confirmed in such as thyroid tumor, breast tumor, lung cancer cells and so on.This study using Immunohistochemical method and Western blot experiment detect the area and significance of Y-box protein1expressed in colorectal cancer tissue.Objective: To explore the amount of YB-1protein which expressed in colorectal cancer tissue and normal colon tissue, in colon cancer cell lines and normal colonic cell lines. And research its relationship with clinical pathological colon cancer patients.Methods:Using immunohistochemical method to detect YB-1protein in103cases of colon cancer tissue and corresponding tissue adjacent to carcinoma, the expression in30cases of normal colon tissue; using Western blot method to detect the amount of YB-1protein expressed inside nucleus in colorectal cancer tissues, tissue adjacent to carcinoma and normal colon tissue, LS-174T cell lines and NCM460cell lines.Results: Immunohistochemical results shows YB-1protein expression mainly in cytoplasm, the positive rate in cancer tissues (75.73%,78/103) are more higher than tissue adjacent to carcinoma (37.86%,39/103) and normal tissue (30%,9/30). The difference was statistical significance (P<0.05).37cases (35.92%,37/103) shows YB-1protein expressed inside nucleus, and the positive expression inside nucleus are related to the tumor diameter size, lymph node metastasis, distant metastasis or direct invasion and the degree of cell differentiation (P<0.05). Western blot results also confirmed that YB-1protein expressed inside nucleus in cancer tissue (0.382±0.095) are significantly higher than the tissue adjacent to carcinoma (0.251±0.043) and normal tissue (0.238±0.045). The difference was statistical significance (F=21.268, P<0.05). And YB-1protein expressed inside nucleus in LS-174T (0.548±0.031) is significantly higher than NCM460cell lines (0.269±0.017). The difference was statistical significance (F=64.273, P<0.05).Conclusion: In colon cancer tissues, YB-1expressed in the cytoplasm and nuclear translocation phenomenon is significantly higher than the tissue adjacent to carcinoma and normal colon tissue. The change of the amount of YB-1protein and the transfer to nucleus is closely related to colon cancer cell proliferation differentiation, could become the new target for colon cancer treatment.