Shiba S, et al. - In view of the observation that a glycoprotein, mucin1 (MUC1) is often expressed in malignant cells, researchers studied the functional roles of core protein [MUC1-C] in duodenal adenocarcinoma (DAC). For this purpose, they assessed proliferation, migration, invasion, ALDH activity using a human duodenal cancer cell line, HuTu80, by cell counting kit–8, scratch wound healing, matrigel invasion, and ALDEFUOR assays, respectively. RT-PCR and flow cytometry confirmed the positive expression of MUC1 in HuTu80. The addition of 50-100 μM GO203 as well as treatment with siRNA for MUC1-C led to inhibition of in vitro cell growth. furthermore, a significant reduction in migration, invasion, ALDH activity was observed with silencing of MUC1-C. The growth of subcutaneous HuTu80 tumors in nude mice significantly suppressed when locally injected with GO-203 (14 mg/kg). Immunohistochemically, seven DAC cases strongly showed MUC1, but 11 others did not have MUC1. They observed significantly worse outcome among patients with high MUC1 expression than those without MUC1 expression. Results thereby suggest the functional association of MUC1 with the malignant potential of DAC and that it could be a novel therapeutic target for this rare tumor.