Prostate Cancer (PCa) is one of the leading medical issues faced by men worldwide and is the
most prevalent cancer diagnosed in men in both Europe and the United States. The vast
majority of current literature concerning PCa diagnosis concludes that better PCa markers are
needed to reduce over-diagnosis of low risk disease and widespread over-treatment.
The primary objective of this research entails the generation and characterisation of antiprostate specific antigen (PSA) isoform-specific recombinant antibody fragments. Selective
screening of avian single chain antibody fragment (scFv) libraries was carried out for the
isolation of high-affinity, anti-fPSA and anti-cPSA specific antibody fragments. These antibodies
were kinetically evaluated using surface plasmon resonance-based instrumentation and
incorporated into an enzyme-linked immunosorbent assay (ELISA) that can detect PSA in the
ng/mL range. Anti-fPSA scFvB8 is a nanomolar affinity antibody fragment that contains highly
conserved cysteine residues. High resolution X-ray crystallography of this antibody fragment
and mutant variants was successfully carried out and revealed interesting structural attributes
of avian antibody fragments.
Glycan expression patterns change with the cellular modifications that accompany the onset of
tumourigenesis. Hence, as a secondary objective, whole serum N-glycan profiling was carried
out on 117 prostate cancer patient’s serum using a robotised, high-throughput analysis
platform for glyco-profiling which utilises ultra-performance liquid chromatography (UPLC) to
obtain high resolution separation of N-linked glycans released from serum. A specific glycomic
signature identified from this analysis can distinguish between indolent and aggressive
prostate cancer with high accuracy.
The reagents generated and the results obtained from this body of work provide significant
insight into antibody and glycomic-approaches that can potentially deliver the much sought
after cancer-specific biomarker analysis for improved PCa diagnosis.