Bladder cancer cells secrete while normal bladder cells express but do not secrete AGR2.

Area of Science:

• Biochemistry
• Oncology
• Urology

Background:

• Anterior gradient 2 (AGR2) is a cancer-associated secreted protein prevalent in adenocarcinomas.
• AGR2's utility as a biomarker is questioned due to expression in normal organs, like the bladder urothelium.
• Normal urothelial cells exhibit uniform AGR2 expression but minimal secretion into urine.

Purpose of the Study:

• To investigate the diagnostic potential of AGR2 as a urinary biomarker for urothelial carcinoma.
• To differentiate AGR2 secretion patterns between normal urothelial cells and urothelial carcinoma cells.

Main Methods:

• Analysis of AGR2 expression in normal bladder urothelium and urothelial carcinoma tissues.
• Detection of AGR2 levels in the urine of cancer patients and healthy individuals.
• Comparison of urinary AGR2 levels with tumor expression status.

Main Results:

• AGR2 expression is often lost in urothelial carcinoma, with only 25% of primary tumors retaining it.
• AGR2 is secreted by urothelial carcinoma cells, detectable in 25% of patient urine samples.
• Urinary AGR2 detection correlated with tumor expression, suggesting cancer-specific secretion.

Conclusions:

• Cancer cells, unlike normal cells, actively secrete AGR2.
• Urinary AGR2 measurement is a promising indicator for the presence of urothelial carcinoma.
• AGR2 secretion and cell surface presence are key cancer characteristics, not just expression.