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.

Detection of a specific pattern of hyaluronan oligosaccharides and their binding proteins in human ovarian tumour.

UNLABELLED: Tumour cells generate hyaluronan (HA) oligomers (O-HA) by an autocrine mechanism to regulate their own behaviour through receptor interaction, necessitating analysis of HA sizes and its receptor expression in tumour progression. In this study for the first time, we identified specific size of HA in malignant ovarian tumour compared to benign tumour tissue. Therefore, we prepared the identified HA probes and conducted multiplex and monoplex ligand blot analysis and Immunohistochemistry to identify their receptor expression and distribution. Although, HA recognized CD44 as principle receptors despite of size, multiplex analysis showed multiple receptor expression with distribution at the tumour cell surface. Furthermore, the HA 6-mer (major O-HA of ovarian tumour) pull down of tumour tissue proteins showed 120 kDa protein along with CD44 with over expression in the malignant tumour. Upon depletion of CD44 protein HA 6-mer showed a major 120 kDa protein with distribution at nuclear membrane, suggesting that this protein may play an important role in ovarian tumour progression. In summary, ovarian tumour cells of different grade showed heterogeneity in generation of HA oligomers and their interaction with specific receptors. Therefore, simultaneous analysis of O-HA and their receptors expression could serve as a prognostic indicator during tumorigenesis. Copyright © 2016 John Wiley & Sons, Ltd. SIGNIFICANCE OF THE STUDY: Down regulation of hyaluronan (HA) at tumour epithelial cells results in the generation of O-HA. Increasing evidence about O-HA biological functions (mainly in vitro) are available, but we lack information of O-HA sizes generated during tumorigenesis and less information is available about their receptor interaction. We used biochemical approaches and identified that tumour cells of different grade possessing heterogeneity in generation of O-HA and specificity towards receptor binding. We identified a new receptor for HA 6-mer that over express in cancer tissue that shows its role in tumour progression. Collectively, simultaneous identification of HA sizes and their receptors could serve as a prognostic marker.

Bioactive hyaluronan fragment (hexasaccharide) detects specific hexa-binding proteins in human breast and stomach cancer: possible role in tumorogenesis.

Hyaluronan (HA) is a component of extracellular matrix that influences cell-proliferation, migration, development, regeneration, normal tissue remodeling, tissues undergoing malignancy and tumor cell interaction. The widespread occurrence of HA binding proteins, their involvement in tissue organization and the control of cellular behavior are well documented. The low molecular mass HA fragments can also induce a variety of biological events, including chemokine gene expression, transcription factor expression and angiogenesis. It is believed that these fragments are more potent in cellular activities than high molecular mass HA. In this study, we isolated the various fragments by gel permeation chromatography of hyaluronidase digested HA and characterized by fluoro assisted carbohydrate electrophoresis (FACE) and matrix assisted laser desorption ionization analysis (MALDI). Detection and distribution of cellular receptors in invasive tumor tissues for HA polymer and HA fragments were determined both by Western blot and histochemistry. The study demonstrated the overexpression of HA-hexa binding protein in human tumors of breast and stomach and its involvement in tumorogenesis.