Prostate Specific Membrane Antigen Expression in Renal Cell Carcinoma and Transitional Cell Carcinoma

Cho, Sung Tae; Kim, Sung Yong; Lee, Young Goo

Abstract

PURPOSE: Prostate specific membrane antigen (PSMA) has been used in molecular staging of prostatic cancer and known as a more sensitive marker than PSA (prostate specific antigen). Recently it has been known that PSMA is expressed in various tissue including kidney, bladder, testis, duodenum, breast, colon, etc. We performed RT-PCR (reverse transcriptase-polymerase chain reaction) assay for PSMA to evalute whether PSMA is expressed in renal cell carcinoma and bladder transitional cell carcinoma or not.
MATERIALS AND METHODS
RNA was extracted from renal cell carcinoma cell lines (Caki-1, Caki-2, 7860, A498, ACHN, and 769-P), peripheral blood of metastatic renal cell carcinoma patients (7), peripheral blood of metastatic bladder transitional cell carcinoma patients (8), normal urothelium, bladder transitional cell carcinoma cell lines (RT4, 5637, HT1376, T24, TccSup) and prostatic cancer cell lines (LNCaP, DuCaP). These RNAs were analyzed by nested RT-PCR assay for the expression of PSMA. 196 bp nested PCR product was excised from the gel, cloned, and sequenced.
RESULTS
PSMA mRNA was expressed in Caki-1, peripheral blood of metastatic renal cell ca (4/7, P=0.006), peripheral blood of metastatic blader trnasitional cell carcinoma patient (3/8, P=0.032), HT1376, LNCaP, and DuCaP. Automated sequencing analysis showed that all sequences were identical with PSMA mRNA sequence.
CONCLUSIONS
PSMA is expressed in renal cell carcinoma and bladder transitional cell carcinoma besides prostatic cancer. This result suggests the possibility that PSMA expression can be a new biomarker for the renal cell carcinoma and bladder transitional cell carcinoma.