Anti-Fat1 Antibody Development

As a well-recognized leader with over a decade of experience in antibody preparation, Creative Biolabs is dedicated to the development of new therapeutic agents. Especially, we offer our clients with comprehensive high-quality services for antibody development against giant cadherin Fat1 protein.

Fat1

Pancreatic ductal adenocarcinoma is the most common malignant tumor of the pancreas and is the fourth-ranked cause of cancer-related death worldwide. As one of the most aggressive solid tumors, the mortality rate from pancreatic cancer is high with 5-year survival rates less than 5%. Fat1 belongs to a small subfamily of four vertebrate genes, Fat1 to Fat4. Fat cadherin genes encode extremely large proteins of 500-600 KDa with conservation of structure. Among them, Fat1 is the largest one. Each family member is comprised of up to 34 cadherin repeats, one or two laminin-G domain and several epidermal growth factors (EGF)-like motifs, a single-pass TM domain, and a large cytoplasmic domain. Fat1 is also an upstream regulator of the Hippo pathway and hence plays a role in growth control.

Fig.1 Schematic presentation the domain organization of human Fat4 and Fat1 cadherins. (Sadeqzadeh, 2014)

Ectodomain Shedding

The release of high levels of the ectodomain (ECD) of Fat1 cadherin into the secretomes of human pancreatic cancer cells is mainly mediated by a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10). Fat1 and its sheddase ADAM10 are overexpressed in pancreatic adenocarcinomas. The precise cleavage site(s) has not been identified, but the most distal peptides mapped to regions including the laminin-G-like motifs, revealing the proteolytic processing of Fat1 occurs relatively close to the membrane. In addition to the shed ECD, this process would also generate a membrane-bound C-terminal fragment of about 60 KDa, which would be subject to further proteolysis leading to reduced levels or even absence of this isoform.

Fig.2 Alternative Fat1 processing in pancreatic cancer cells. (Wojtalewicz, 2014)

Antibody Development

ECD is relatively stable, an important prerequisite for candidate biomarkers to find applicability in robust assay formats. Besides being applied as a new biomarker to benefit pancreatic cancer patients, ECD of Fat1 could be regarded as targets to develop antibodies to neutralize itself, thereby preventing any possible ECD-induced activity beneficial to tumor development. Moreover, there is no doubt that the shedding process occurs between the laminin-G domain and EGF-like domain, so antibodies could be developed specifically against the membrane-proximal domain to make antibody-drug conjugate (ADC). That approach will both significantly dampen tumor relapse and prevent aggressive progression of pancreatic cancer.

As the new generation of immunotherapy, antibodies are meticulously constituted bio-macromolecules with high potential in the treatment of cancer and various other diseases. Years of experience and professional technicians provide a guideline for antibody production, optimization, and conjugation. The advanced platform at Creative Biolabs is here to serve the diverse needs of our clients and we can tailor specific analytical service packages to fit your timeline and R&D budget. Please contact us for more information and a detailed quote.

References

1. Sadeqzadeh, E.; et al. FAT1 cadherin is multiply phosphorylated on its ectodomain but phosphorylation is not catalysed by the four-jointed homologue. FEBS letters. 2014, 588(18), 3511-3517.
2. Wojtalewicz, N.; et al. A soluble form of the giant cadherin Fat1 is released from pancreatic cancer cells by ADAM10 mediated ectodomain shedding. PloS one. 2014, 9(3), e90461.

For Research Use Only. NOT FOR CLINICAL USE.