Testicular tumors antigens

The second most common tumor in LE is testicular germ cell cancer [43], and these patients usually harbor antibodies to the Ma2 protein. Antibodies to Ma2 antigen alone are usually associated with testicular cancer. Similar to many other onconeural antibodies, Ma2 is associated with clinical multi-focality. Many patients have symptoms of brain stem and hypothalamic dysfunction, and only one-fourth of Ma2 positive patients exhibit classical LE [45]. Patients with antibodies to the major antigen Ma2 and antibodies to Mai or Ma3 have different tumors [43, 46], and are more likely to have additional neurological signs [45],... 

There is considerable antigen diversity in brain stem encephalitis, with a number of associated antibodies, in particular the Ma, Hu, and Ri antibodies [60]. The Ma2 antibody is associated with brain stem dysfunction, isolated or in combination with diencephalic encephalitis or LE [45]. Vertical gaze palsy is common in these patients [58]. If testicular cancer is not found, lung cancer should be suspected in these patients [61]. One-third of the patients with Ma2 antibodies have narcoleptic-like symptoms, and immune-mediated hypocretin dysfunction has been suggested in such cases [61]. OM with Ri antibodies has traditionally been associated with breast cancer, but the most common tumor in these patients is actually SCLC [62], SCLC is also the predominant tumor in Hu antibody positive patients with brain stem encephalitis. 

Marks A, Sutherland DR, Bailey D, et al. Gharacterization and distribution of an oncofetal antigen (M2A antigen) expressed on testicular germ cell tumors. Br J Cancer. 1999 80 569-578. 

The GAGE gene family encodes another tumor-associated antigens expressed in many tumors such as malignant melanoma, neuroblastoma, and other carcinomas and sarcomas but not in normal tissue with the exception of testicular tissue. 

A further interesting protein characteristic for breast tissue is NY-BR-1. NY-BR-1 is a differentiation antigen expressed in normal breast tissue and epithelial breast tumors in addition to testicular parenchyma and brain tissue. NY-BR-1 is a nuclear polypeptide functioning as transcription factor encoded by a gene located on chromosome lOpll-12. 

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