Using autologous serum for the serological analysis of recombinantly expressed clones (SEREX) from a cDNA derived from a human mela

Using autologous serum for the serological analysis of recombinantly expressed clones (SEREX) from a cDNA derived from a human mela noma, several new melanoma antigens were identified that are immuno genic in the autologous host. Sequence analysis revealed that one of these antigens, HOM-MEL-40, was coded for by the SSX2 gene, which has recently been described to be involved in the t(X;18) translocation of human synovial sarcomas. Expression analysis performed by Northern blot and RT-PCR demonstrated the presence of HOM-MEL-40 tran scripts in a significant proportion of human melanomas (50%), colon cancers (25%), hepatocarcinomas (30%), and breast carcinoma (20%) but not in normal tissues except for testis. Sequence comparison with tran scripts cloned from testis ruled out mutations in the melanoma-derived HOM-MEL-40. Antibodies against HOM-MEL-40 were found in 10 of 89 patients with melanoma, including 3 of 8 patients with HOM-MEL-40positive tumors, but not in 41 apparently healthy controls. In view of the specific expression pattern and hnmunogeniclty In cancer patients, HOM MEL-MIholds promise as a target for immune interventions in a consid erable population of patients with HOM-MEL-40-positive tumors.