In
colorectal neoplasms, N-myc downstream-regulated gene 1 (NDRG1) is a primarily cytoplasmic
protein, but it is also expressed on the cell membrane and in the nucleus. NDRG1 is involved in various stages of
tumor development in
colorectal cancer, and it is possible that the different subcellular localizations may determine the function of
NDRG1 protein. Here, we attempt to clarify the characteristics of
NDRG1 protein subcellular localization during the progression of
colorectal cancer. We examined NDRG1 expression in 49
colorectal cancer patients in cancerous, non-cancerous, and corresponding lymph node tissues. Cytoplasmic and membrane NDRG1 expression was higher in the lymph nodes with
metastases than in those without
metastases (P<0.01). Nuclear NDRG1 expression in
colorectal neoplasms was significantly higher than in the normal colorectal mucosa, and yet the normal colorectal mucosa showed no nuclear expression. Furthermore, our results showed higher cytoplasmic NDRG1 expression was better for differentiation, and higher membrane NDRG1 expression resulted in a greater possibility of
lymph node metastasis. These data indicate that a certain relationship between the cytoplasmic and membrane expression of NDRG1 in lymph nodes exists with
lymph node metastasis. NDRG1 expression may translocate from the membrane of the
colorectal cancer cells to the nucleus, where it is involved in
lymph node metastasis. Combination analysis of NDRG1 subcellular expression and clinical variables will help predict the incidence of
lymph node metastasis.