Newly established Askin tumor cell line and overexpression of focal adhesion kinase in Ewing sarcoma family of tumors cell lines.

Askin tumor is a malignant small round cell tumor that originates from the thoracopulmonary region and is a member of Ewing sarcoma family of tumors (ESFT). Only a few Askin tumor cell lines have been established. An Askin tumor cell line, designated MP-ASKIN-SA, was established from the left thoracic tumor of a 13-year-old Japanese boy. ESFT is known to have a high rate of distant metastases at diagnosis. The genes controlling the spread of ESFT cells, however, have not been elucidated. G-banding chromosome analysis revealed that the MP-ASKIN-SA cell line has complex chromosomal abnormalities including trisomy 8. The EWS/FLI1 chimeric transcript and c-myc overexpression were revealed by the reverse transcriptase-polymerase chain reaction and Northern blot analysis. Furthermore, we investigated the expression of the focal adhesion kinase (FAK) gene in the ESFT cell lines using Northern blot analysis. In addition to the MP-ASKIN-SA cell line, six Ewing sarcoma cell lines, one peripheral nerve sheath tumor cell line, and two Askin tumor cell lines were analyzed. All ESFT cell lines, including MP-ASKIN-SA, expressed five- to twenty-eight-fold-increased values of FAK, as compared with fibroblasts obtained from the bone marrow of a healthy volunteer. These results raise the possibility that the overexpression of c-myc and FAK are involved in the poor prognosis of ESFT.