The serum levels of suPAR in benign prostate hyperplasia and prostate cancer - a comparative study

Abstract

The  plasminogen  activator  system  is  assumed  to  play  a  key  role  in  the  degradation  of extracellular  matrix  and  basement  membranes.  During  cancer  invasion  and  metastasis,  the activated  plasminogen activator  system  cleaves  plasminogen to the  active plasmin. Plasmin is able to degrade a wide range of extracellular matrix proteins either directly or indirectly by activation of additional proteolytic enzymes.

Accumulating evidence has shown that the urokinase plasminogen activator system might be upregulated in many types of malignancies, including prostate cancer. Previous studies have found  an  association  between  the  soluble  form  of  the  urokinase  plasminogen  receptor, abbreviated as suPAR,  and the  development and  progression of prostate cancer. Furthermore, it has been proposed that the quantification of suPAR in serum might serve as a useful adjunct to current conventional diagnostic tools.

Published  literature  is  limited  regarding  both  the  suPAR  levels  in  patients  diagnosed  with benign prostate hyperplasia (BPH)  and  the  differences in suPAR concentration between BPHand prostate  cancer  patients.  In  the  present  thesis,  the  serum  levels  of  suPAR  in  BPH-  and prostate  cancer  patients  are  therefore  quantified  to  determine  whether  there  is  a  statistically significant difference between the two groups.

The  present thesis concludes  that there is no  statistically significant difference in the suPAR concentration  between  BPH  patients  (median  0.22  ng/mL)  and  prostate  cancer  patients (median 0.17 ng/mL).  However,  methodological  limitations of the  immunoassay  utilized  for suPAR quantification  was  encountered,  and  further  studies  are  warranted  to  give  an  exact estimation of the  suPAR concentration in BPH-  and prostate cancer  patients.  In addition, due to  limited published  literature,  it  was  difficult  to  define  the  normal  or  abnormal  levels  of suPAR.

The serum samples obtained in the present thesis are stored at the Regional Research Biobank of Central Norway and are accessible for future studies.  By  including   samples  from  the HUNT  research  biobank,  it  might  be  achievable  to  obtain  a  larger  cohort  of  serum  samples and further investigate the role of suPAR as a predictor of prostate cancer progression.