142P - Development of an ELISA to detect tumor-associated antigen tNASP in urine

Date 10 October 2016
Event ESMO 2016 Congress
Session Poster display
Topics Translational Research
Presenter Oleg Alekseev
Citation Annals of Oncology (2016) 27 (6): 15-42. 10.1093/annonc/mdw363
Authors O. Alekseev1, J. Vaughn2, B. Taylor2, L. Barba2, J. Greiner2, C. Dickson2, C. Anderson2, J. Fullmer2, Z. Vaskalis3
  • 1Physiology And Pathophysiology, Campbell University, 27506 - Buies Creek/US
  • 2Medical Student, Campbell University, Buies Creek/US
  • 3School Of Osteopathic Medicine, Campbell University, Buies Creek/US

Abstract

Background

Tumor-associated antigens (TAAs) are proteins that elicit a humoral immune response when their expression is elevated in tumor progression. tNASP is one of two splice variants of Nuclear Autoantigenic Sperm Protein. In addition to its normal testicular expression, it is also aberrantly expressed in cancer cells. We have previously demonstrated that immunohistochemical detection of tNASP has high diagnostic sensitivity and specificity in ovarian cancer. We have discovered that tNASP is also aberrantly expressed in prostate cancer cells and tissues. In the current study, we developed an ELISA to detect specific anti-tNASP serum antibodies as well as tNASP protein in urine for early diagnosis of prostate cancer.

Methods

tNASP protein expression was assayed by immunohistochemistry (IHC) in prostate cancer biopsy samples from different disease stages, using affinity-purified goat anti-tNASP serum, which specifically recognizes only tNASP protein. A recombinant tNASP-specific fragment was used as bait to produce a standard curve for detection of anti-tNASP antibodies by ELISA. Serum and urine samples from patients with prostate cancer, and otherwise healthy control patients, were obtained from the Tissue Procurement Facility of the University of North Carolina at Chapel Hill, Roswell Park Cancer Institute, and Fox Chase Cancer Center. Correlation between serum anti-tNASP antibody levels, urine tNASP protein level and Prostate Specific Antigen (PSA) was analyzed by Spearman's coefficient.

Results

ELISA measurements demonstrated a significant increase in tNASP protein levels in the urine of prostate cancer patients, as compared to control group urine. Spearman's rank correlation demonstrated that the concentration of anti-tNASP antibodies and tNASP levels in urine co-varied with PSA levels. Urine tNASP protein was detected by ELISA with anti t-NASP antibody as bait, whereas anti-tNASP antibodies were not detected in urine samples.

Conclusions

Combined detection of serum anti-tNASP antibody and urine tNASP protein could be used for diagnosis of prostate cancer and has the potential to improve early diagnostic confidence.

Clinical trial identification

Legal entity responsible for the study

This study was supported by Campbell University School of Osteopathic Medicine, North Carolina, 27506, USA. Associate Professor Oleg Alekseev, MD, PhD is a principal investigator on this project.

Funding

This study was funded by School of Osteopathic Medicine of the Campbell University (CUSOM). Principal investigator Dr. Oleg Alekseev is a full-time faculty in CUSOM and research activity is his duty along with teaching.

Disclosure

All authors have declared no conflicts of interest.