Establishment and characterization of OCUT-1, an undifferentiated thyroid cancer cell line expressing high level of telomerase.

BACKGROUND & OBJECTIVES: Undifferentiated thyroid cancer is one of the most aggressive human malignancies, and the prognoses that have been reported are extremely poor. A number of studies have described the clinicopathologic features of this tumor and analyzed its biologic background to explain the extraordinarily aggressive nature of the tumor. Still the mechanism of cellular aggressiveness in undifferentiated thyroid cancer is not yet fully understood. METHODS: We established and characterized an undifferentiated thyroid cancer cell line, OCUT-1, derived from the surgical specimen obtained from a 74-year-old Japanese woman with advanced undifferentiated thyroid cancer. RESULTS: The cell line had already maintained over 100 passages and was stably cultured for more than a year. The cell line was observed to maintain not only its morphologic similarity to the primary cancer cells, but also its aggressive nature, including high proliferative activity, numerous genetic abnormalities, and cytokine production. Further, we have demonstrated the expression of telomerase activity in the cell, which could represent one of the responsible mechanisms for the cellular aggressiveness of this type of tumor. CONCLUSIONS: This cell line might be useful for further study concerning the correlation between telomerase activation and disease progression or anaplastic change in thyroid cancer.

Decrease in ICAM-1 expression on gastric cancer cells is correlated with lymph node metastasis.

BACKGROUND: Lymph node metastasis is a frequent type of metastasis in patients with gastric cancer. The mechanisms responsible for this type of metastasis, however, are not clearly understood. We hypothesize that the immunosurveillance system between cancer cells and lymphocytes may be associated with the lymph node metastatic process. In this study, we examined the correlation between lymph node metastasis and intercellular adhesion molecule-1 (ICAM-1), which mediates the immunosurveillance system between tumor cells and cytotoxic lymphocytes, in gastric cancer.METHODS: One hundred and forty-three specimens resected from patients with gastric cancer were investigated by staining with a monoclonal antibody against ICAM-1. We studied the correlation between the expression of ICAM-1 and various clinicopathologic factors, as well as infiltration of tumor-infiltrating lymphocytes (TILs).RESULTS: ICAM-1 expression on gastric cancer cells was significantly decreased in patients with lymph node metastasis. The infiltration of TILs was associated with ICAM-1 expression level. The prognosis of patients with ICAM-1-negative tumors was poorer than the prognosis of those with ICAM-1-positive tumors.CONCLUSIONS: These findings suggest that ICAM-1 expression on cancer cells is closely associated with lymph node metastasis in gastric cancer, under the influence of the host immunosurveillance system.