Aided by advanced technologies and long-term scientific expertise in the field of antibody discovery, Creative Biolabs has achieved great success in the in vitro diagnostic (IVD) antibody development against different biomarkers for the diagnosis and prognosis of diversified cancers. Particularly, ABCG5 has become a promising marker for the diagnosis and prognosis of colorectal cancer.
ATP-binding cassette (ABC) transporters G5 (ABCG5), encoded by human ABCG5 gene, functions as a half-transporter to limit intestinal absorption and promote biliary excretion of sterols. Generally, ABCG5 combines with ABCG8 to form an obligate heterodimer that mediates Mg2+- and ATP-dependent sterol transport across the cell membrane. Consistent with their function, ABCG5 and ABCG8 are located on the apical membrane of enterocytes and hepatocytes and gallbladder epithelium, where they limit intestinal absorption and facilitate biliary secretion of cholesterol and phytosterols. Besides lipids and sterols, ABC proteins facilitate translocation of heterogeneous substrates including metabolic products, peptides and proteins, saccharides, amino acids, inorganic and organic ions, metals and drugs. ABCG5 is predicted to contain N-terminal ATP-binding motifs (Walker A and B motifs) and an ABC transporter signature motif (C motif), and 6 transmembrane segments in the C terminus. ABCG5 is shown to play a crucial role in the development of resistance by the efflux of anticancer agents outside of cancer cells.
Fig.1 Structure of ABC transporters. (Wright, J., 2018)
Colorectal cancer (CRC) is the third most common cancer worldwide, with short survival time and highest mortality rates. Recently, tumor budding in colorectal cancer has been regarded as an indicator of lymph node metastasis, distant metastatic disease, local recurrence, worse overall and disease-free survival, and as an independent prognostic factor. In the tumor buds, ABCG5 is over-expressed, which is associated with worse prognosis in node-negative colorectal cancer patients. Especially, ABCG5 plays a role in the efflux transport of sterols and is thus involved in the development of resistance because of the reduction of anticancer agents in cancer cells. In addition, ABCG5 mutations may contribute to the sterol accumulation and atherosclerosis, and have been observed in patients with sitosterolemia. Therefore, ABCG5 has great potential to act as prognostic biomarkers in patients with colorectal cancer, and it is a useful indicator to stratify patients with colorectal cancer into prognostic subgroups.
Fig.2 Schematic of the biological function of ABCG5/8. (Stender, S., 2014)
With high specificity and sensibility, ABCG5 has been combined with other colorectal cancer markers for cancer diagnosis. IVD antibodies against ABCG5 show immeasurable prognostic and diagnostic value in colorectal cancer patients. With years of experience, Creative Biolabs now offers monoclonal, polyclonal, and recombinant antibody discovery and development services for different disease markers, including ABCG5 marker.
Based on our advanced IVD platform, we are proud to develop novel high-quality ABCG5-specific antibody (pairs) and IVD immunoassays of different formats. Bringing in years of experience and expertise, our dedicated team of professionals will help you with every step of the development process, thereby accelerating and bringing your immunoassay to market rapidly. Please contact us for more information and experience the great value of our services.
References
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