Detection of PSA mRNA from the peripheral blood and pelvic lymph nodes in patients with prostatic cancer by means of reverse transcription-polymerase chain reaction (RT-PCR)

Abstract

To detect prostate cancer cells in the blood circulation and in the lymph nodes by RT-PCR methods, we examined two kinds of prostate specific antigens (PSA) primers and one prostate specific membrane antigen (PSM). PSa primer 1 was established by us, PSA primer 2 by Moreno et al and PSM primer by Israeli et al. Both PSA primers were specific for expression of PSA mRNA because in 12 kinds of urogenital culture cells only LNCaP cells, which produce PSA, expressed PSA mRNA by RT-PCR, PSA 1 was more sensitive than PSA 2 for detection of PSA mRNA in the circulating cells since PSA mRNA was detected in the blood circulating cells in 5 cases of stage D2 prostate cancer using PSA primer 1 but in only one was using PSA primer 2. PSM mRNA was detected in all 12 types of urogenital cancer cells and in the blood circulating cells not of prostate cancer patients but also of renal, bladder, testicular cancer patients and normal volunteers. PSA 1 was used to detect PSA mRNA from the samples of fine needle aspiration biopsy (FNAB) of pelvic lymph node, and PSA mRNA was positive in 10 FNAB samples including not only all 6 cytologically positive and two cytologically class III cases but also 2 of 8 cytologically negative cases. RT-PCR for FNAB samples of all 15 cases of bladder cancer were negative for the detection of PSA mRNA. Detection of PSA mRNA by RT-PCR in FNAB samples may be useful to diagnose pelvic lymph node metastasis and to furnish additional information for the cytological diagnosis of prostate cancer.