CA215, A New Pan Cancer Biomarker, and its Clinical Applications

The antigen recognized by RP215, CA215, can be detected in the shed media from a number of cultured cancer cells [2,5]. Therefore, Matrix-Assisted Laser Desorption/Ionization TimeOf-Flight Mass Spectrometry (MALDI-TOF MS) analysis was performed to determine the molecular identity of affinityisolated CA215 from the shed media of OC-3-VGH ovarian and C-33A cervical cancer cell lines [2,5]. Following tryptic digestion of CA215, the peptide fragments were subjected to analysis by MALDI-TOF MS. It was observed that as many as 50% of the peptide fragments derived from the shed media of cultured cancer cells were found to have a high degree of homology to antigen receptors, including immunoglobulins (42%) and T cell receptors (6%) expressed by cancer cells [5]. Many other different glycoproteins generally categorized as immunoglobulin superfamily proteins (IgSF) were also detected in such analyses [11].