Development and validation of H11B2C2 monoclonal antibody-reactive hyaluronic acid binding protein: overexpression of HABP during human tumor progression

UNIVmAb reactive albumin associated hyaladherin as a potential biomarker for colorectal cancer

Colorectal cancer (CRC) is the third most common cancer; cancer biomarker discovery is important for disease detection and management. It is known that hyaluronic acid and its receptors are ubiquitously expressed in almost all human tissues. Earlier we have shown that a monoclonal antibody H11B2C2, presently known as UNIVmAb, reactive hyaladherin expressed in multiple human cancers mainly using immunohistochemistry. However, the nature of the antigen and its sequence homology are not known. In the current study, a comprehensive investigation was performed to explore the nature of the antigen and its homology using both biochemical and proteomic analysis. Our results showed that UNIVmAb reactive 57 kDa antigen was overexpressed in advanced grade colorectal cancer tissues compared to benign and its hyperplasia. Biochemical investigations including biotinylated hyaluronic acid-pulldown, Immunoprecipitation, HA-oligo competition experiments confirmed that the UNIVmAb reactive 57 kDa antigen is a member of hyaladherin. Further Proteomic analysis showed that the antigen has homology with IGHG1 (Igγ-1 chain C region), a possible IgG superfamily, and is associated with human serum albumin.

Validation and evaluation of a common biomarker in human cancers sera protein detected by a monoclonal antibody UNIVmAb

OBJECTIVE

Management and diagnosis of multiple human cancers remains a challenge and search for a common biomarker is still debatable. In this manuscript we have evaluated the use of monoclonal antibody UNIVmAb, to detect the protein (H11) as a common biomarker for all cancers irrespective of the grade and origin. We have shown by both ELISA and Western Blot that the H11 protein, is a unique hyaluronan binding protein that has not been detected earlier. H11 protein was fractionated in an anion exchange column followed by cibacron blue gel exclusion chromatography. Hyaluronan binding H11 protein reacted with Monoclonal antibody UNIVmAb and b-HA inspite of b-Hyaluronan (biotinylated Hyaluronan) interaction and HA-Oligo (Hyaluronan oligosaccharides) competition from various grades of Human cancers sera.

RESULTS

ELISA, Western blot and b-Hyaluronan interactions clearly showed an over-expression of UNIVmAb reacted H11 protein in all fifty cancer's sera when compared with seventy normal sera. UNIVmAb reactive H11 protein can be used as a common biomarker. We believe, UNIVmAb detected H11 protein, is a unique hyaluronan binding protein, that can be used as a common biomarker for all cancers.