Development on Tumor Associated Antigen with Specific Target toward Lung Cancer: Recent Developments

Tumor liberated protein (TLP) has been previously described as a TAA (complex) present in the sera
from lung cancer patients with early stage disease. Since early detection improves overall survival in
lung cancer, identification of screening biomarkers for patients at risk for the development of this
disease represents an important target. Starting from the peptide epitope RTNKEASI previously
isolated from TLP complexes, we generated a rabbit anti-RTNKEASI serum. This antiserum detected
and immunoprecipitated a 55 kDa protein band in the lysate of the lung cancer cell line A549. This
protein band was identified as aldehyde dehydrogenase is form 1A1 through mass spectrometry,
revealing the molecular nature of at least one component of the previously described TLP complex.