RESUMO
OBJECTIVE: To investigate the expression pattern of Numb, a membrane associated protein, in colon cancer and its biological significance. METHODS: Routine immunohistochemistry staining was used to detect the expression of Numb in tissue microarray with 60 cases of colon cancer tissue and 20 normal colon tissue. The clinical data was analyzed. The expression of Numb in SW480, SW620 cell lines were evaluated by immunostaining and Western blot. RESULTS: The positive expression rate of Numb in cytoplasm decreased in poorly differentiated tumor tissue than normal tissue and well and moderately differentiated colon cancer (P < 0.05), and the expression intensity was correlated with the differentiation state of cancer tissue. Westen blot results showed that colon cancer cell line SW480, compared with SW620 has a higher protein expression (P < 0.05). A punctate distribution of Numb in cytoplasm in colon cancer cell under confocal immunofluorescence was observed. A increased expression density in SW480 cell line was noticed when compared with that in SW620 cell line (P < 0.05). CONCLUSION: Numb may has an important regulation in the process of tumor progression and play a protective role against tumor development.