TY - JOUR
T1 - Secretion of prostate-specific antigen-suppressing activity by two human prostate carcinoma cell lines
AU - Abdul, Mansoor
AU - Hsieh, Jer Tsong
AU - Logothetis, Christopher J.
AU - Hoosein, Naseema M.
N1 - Funding Information:
This work was supported by NIH grant CA63225 to NMH, NIH grant CA59939 to flH and CaPCURE Award to CJL.
PY - 1995
Y1 - 1995
N2 - The well-differentiated human prostatic carcinoma cell line LNCaP has often been used as a model to study the modulation of prostate-specific antigen (PSA) expression. In this study, we examined the effect of conditioned medium from two androgen-unresponsive, PSA-negative human prostatic carcinoma cell lines, PC-3 and DU-145, on PSA expression by the LNCaP cells. Our results show, for the first time, that the undifferentiated PC-3 and DU-145 cells secrete a factor that lowers PSA mRNA and protein levels in LNCaP cells. Further characterization of the PSA-suppressing activity indicated that it was trypsin as well as acid sensitive, heat-stable, and ammonium sulfate precipitable. The activity was present in the 30-100-kd fraction of PC-3 and DU-145 conditioned media. This PSA-suppression factor could act in an autocrine manner to render undifferentiated prostatic carcinoma cells PSA negative. It may also be responsible for the lack of increase in serum PSA levels observed in a subset of patients with hormone-resistant prostatic carcinoma.
AB - The well-differentiated human prostatic carcinoma cell line LNCaP has often been used as a model to study the modulation of prostate-specific antigen (PSA) expression. In this study, we examined the effect of conditioned medium from two androgen-unresponsive, PSA-negative human prostatic carcinoma cell lines, PC-3 and DU-145, on PSA expression by the LNCaP cells. Our results show, for the first time, that the undifferentiated PC-3 and DU-145 cells secrete a factor that lowers PSA mRNA and protein levels in LNCaP cells. Further characterization of the PSA-suppressing activity indicated that it was trypsin as well as acid sensitive, heat-stable, and ammonium sulfate precipitable. The activity was present in the 30-100-kd fraction of PC-3 and DU-145 conditioned media. This PSA-suppression factor could act in an autocrine manner to render undifferentiated prostatic carcinoma cells PSA negative. It may also be responsible for the lack of increase in serum PSA levels observed in a subset of patients with hormone-resistant prostatic carcinoma.
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U2 - 10.1016/1078-1439(95)00003-Z
DO - 10.1016/1078-1439(95)00003-Z
M3 - Article
AN - SCOPUS:0029137785
SN - 1078-1439
VL - 1
SP - 38
EP - 41
JO - Urologic Oncology: Seminars and Original Investigations
JF - Urologic Oncology: Seminars and Original Investigations
IS - 1
ER -