CD34+ fibrocytes in chronic cystitis and noninvasive and invasive urothelial carcinomas of the urinary bladder.
CD34+ fibrocytes are constitutive elements of the connective tissue where they play a role in matrix synthesis and tumor-associated stromal remodeling. Secreted protein, acidic, and rich in cysteine (SPARC) is a pivotal mediator of stromal remodeling precipitated by invasive carcinomas. The present study was undertaken to investigate CD34+ fibrocytes in the stroma of the tumor-free urinary bladder, chronic cystitis, and urothelial carcinomas together with stromal expression of alpha-smooth muscle actin (alpha-SMA), CD117, and SPARC. In tumor-free urinary bladder and chronic cystitis, CD34+ fibrocytes were found in the deep lamina propria and tunica muscularis, whereas the superficial lamina propria disclosed a CD34-negative and alpha-SMA-positive fibrocyte-like cell. Invasive urothelial carcinomas revealed a complete loss of CD34+ fibrocytes and concomitant appearance of alpha-SMA-reactive myofibroblasts which showed strong expression of SPARC. CD117 expression of tumor-free and tumor-associated stroma revealed no differences. We in this study for the first time describe CD34+ fibrocytes in the urinary bladder and an up-to-now unknown population of alpha-SMA-positive fibrocytes exclusively occurring in the superficial lamina propria. Stromal remodeling associated with invasive carcinomas in the urinary bladder is characterized by a loss of CD34+ fibrocytes paralleled by a gain of alpha-SMA-positive myofibroblasts and increased expression of SPARC.
Nimphius
Wilhelm
W
Institute of Pathology, University Hospital Giessen and Marburg GmbH, Location Marburg, Medical Faculty of Philipps-University Marburg, Baldingerstrasse, 35033 Marburg, Germany.
Moll
Roland
R
Olbert
Peter
P
Ramaswamy
Annette
A
Barth
Peter J
PJ
D051722:ADAM Proteins / Q000032:analysis; D000072198:ADAM17 Protein; D000199:Actins / Q000032:analysis; D000368:Aged; D000369:Aged, 80 and over; D018952:Antigens, CD34 / Q000032:analysis*; D002908:Chronic Disease; D003239:Connective Tissue Cells / Q000473:pathology*; D003556:Cystitis / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis; D017154:Stromal Cells / Q000473:pathology; D001749:Urinary Bladder Neoplasms / Q000737:chemistry / Q000473:pathology*
D000199:Actins; D018952:Antigens, CD34; D019009:Proto-Oncogene Proteins c-kit; D051722:ADAM Proteins; D000072198:ADAM17 Protein