The Expression Of Musashi-1 (intestinal Stem/progenitor Marker) In Clonic Cancer

Background: The mechanisms of malignant tumor remain unknown by now. There are many hypotheses and one of them is a theory of cancer stem cells. It supposed that cancer originated from a small number of cells, which were called cancer stem cells, or tumor stem cells and or tumor-initiating cells. These special cells had an ability of infinitive proliferation. On the one time they can update themselves and on the other hand they can produce tumor cells, which had the finite ability of proliferation and differentiation. Cancer stem cells are resistant to the radiotherapy and chemotherapy and are responsible for the tumor recurrence. Cancer stem cell maybe the result of the mutation of the normal stem cell. In recent years, the incidence of colon cancer is increasing gradually and until now the marker of the colon cancer stem cell is still not clear. Musashi-1 is a putative marker of the normal intestinal stem/progenitor cell and there are few reports about the expression of Musashi-1 in clonic cancer.Objective: To explore the expression of Musashi-1 in colon cancer tissues and in distal normal tissues, we respectively detect Musashi-1mRNA and Musashi-1 protein in colon cancer tissues and in distal normal tissues.Methods: There are two parts:1 The mRNA expression of Musashi-1 gene in 25 colonic cancer specimens an18 distal normal colon tissues was detected by general RT-PCR and relatively quantitative real-time RT-PCR method. The multiples of expression of Musashi-1 in colonic cancer relative to distal normal colon tissue was calculated by the method of 2-△△CT.2 The colonic cancer tissues and distal normal colon tissues were simultaneously fixed and were made pathology slices, which were detected by immunohistochemistry method to find out how Musashi-1 was expressed. The gross expression amount of Musashi-1 protein in the colonic cancer tissues and in distal normal colon tissues was got by western-blotting method. Results:1 Musashi-1mRNA was expressed both in the colonic cancer tissues and in distal normal colon tissues. Real-time RT-PCR results showed that the expression of Musashi-1 mRNA in colonic cancer was 4.24 (1.95-9.23) times higher than that was in distal normal colon tissue. There was significant difference between them ( P<0.01) . The expression of Musashi-1 mRNA in poorly differentiated colonic cancer was significantly different from high and medium differentiated tissues (P<0.005 and P<0.01) . The expression of Musashi-1 mRNA in poorly differentiated colonic cancer was 5.54 (3.07-9.98) times higher than that was in high differentiated tissues.2 Immunohistochemistry showed that there was Musashi-1 protein expression both in the colonic cancer tissues and in distal normal colon tissues. Musashi-1 protein were expressed in cytoplasm and in nucleus in One-third of the middle and lower recess in normal distal colon tissues, but expressed in all recess in colonic cancer tissues. Western-blotting showed that the expression amounts of Musashi-1 protein were different in the colonic cancer tissues and in distal normal colon tissues(P<0.05). Musashi-1 protein was higher in the colonic cancer tissues than in distal normal colon tissues.Conclusion: Musashi-1mRNA and Musashi-1 protein are both expressed in the colonic cancer tissues and in distal normal colon tissues. Musashi-1mRNA and Musashi-1 protein are higher in the colonic cancer tissues than in distal normal colon tissues. In tumor tissues, the higher expression of Musashi-1 mRNA in colonic cancer especially in poorly differentiated tissues than in distal normal colon tissue suggests that Musashi-1 may play an important role in the initiation and development of colonic cancer.