Antigen binding fragments that specifically detect cancer cells, nucleotides encoding the fragments, and use thereof for the prophylaxis and detection of cancers

A composition comprising an antigen binding polypeptide fragment which under suitable conditions inhibits specific binding of an antibody comprising SEQ ID NO:14 to a cell surface antigen present on glioma, melanoma, breast carcinoma, lung carcinoma, ovarian carcinoma, lymphoma, colon carcinoma, gastric carcinoma or prostate carcinoma tumor cells, but not normal non-cancerous cells of at least one of brain, skin, breast, lung, ovary, lymph node, large intestine, stomach and prostate tissues.

A method of inhibiting specific binding of a first antigen binding polypeptide fragment which specifically recognizes an epitope on C-antigen recognized by an scFv comprising the heavy and light chain variable regions of SEQ ID NO:14 to an antigen specifically recognized by the first antigen binding polypeptide fragment, said method comprising the steps of:

• a) obtaining a tumor-specific second antigen binding polypeptide fragment;
• and
• b) demanding whether said second antigen binding polypeptide fragment decreases the binding of said first antigen binding polypeptide fragment to said antigen.