Tumor-promoting phorbol ester down-regulates the androgen induction of prostate-specific antigen in a human prostatic adenocarcinoma cell line.

Prostate-specific antigen (PSA) is the most sensitive marker available for monitoring the progression of prostate cancer and response to therapy. In a previous study, we demonstrated tissue-specific expression of PSA glycoprotein and mRNA and its regulation through the androgen receptor. In this study, we examine the effects of protein kinase A (PKA) and protein kinase C (PKC) on the androgen regulation of PSA in a human adenocarcinoma cell line, LNCaP. Northern blot analysis demonstrated that forskolin, an activator of PKA, had no effect on the androgen regulation of PSA. However, the phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA), a direct activator of PKC, showed a time- and dose-dependent repression of the androgen regulation of PSA glycoprotein and mRNA. The biologically inactive phorbol ester, 4 alpha-phorbol-12,13-didecanoate, had no effect. Staurosporine, a PKC inhibitor, blocked the TPA-mediated repression of the androgenic stimulation of PSA glycoprotein. In addition, the calcium ionophore, A23187, was able to simulate the actions of TPA, presumably through activation of PKC via calcium mobilization. In summary, the androgenic regulation of PSA protein and mRNA is repressed by tumor-promoting phorbol esters through the PKC pathway. This indicates that the effects of TPA may be secondary to repressed gene transcription or altered mRNA stability. In addition, this study emphasizes that the androgenic regulation of PSA is complex and may involve other extracellular transduction signals.

Hormonal regulation of prostate-specific antigen messenger RNA in human prostatic adenocarcinoma cell line LNCaP.

Prostate-specific antigen (PSA) is a member of the kallikrein gene family and is expressed exclusively in human prostatic epithelial cells. PSA protein has been an important biological marker for prostate cancers. Until now, very little was known about the regulation of PSA expression in prostatic cells. In this study, we have developed a specific oligonucleotide probe which recognizes PSA but not the human glandular kallikrein. This is crucial because both PSA and human glandular kallikrein are expressed in the prostate at relatively high levels and have high nucleotide sequence homology (greater than 82%). Utilizing a S-labeled PSA-specific probe, PSA mRNA was localized within the glandular epithelium of the prostate. Northern blot analysis detected a single 1.6-kilobase transcript in LNCaP cells, a cell line derived from a human prostate adenocarcinoma metastasis. Therefore, LNCaP cells were used to study the androgenic effects on PSA mRNA expression. A time course study demonstrated that PSA mRNA was induced by mibolerone (a nonmetabolizable synthetic androgen) and reached maximal levels after 9 h. The induction of PSA mRNA required as little as 0.3 nM mibolerone. In addition to mibolerone, PSA mRNA could be induced by the natural androgen, dihydrotestosterone, but not by the synthetic glucocorticoid, dexamethasone, or the synthetic estrogen, diethylstilbestrol. Moreover, in the presence of dihydrotestosterone, PSA mRNA was depressed by hydroxyflutamide (an antiandrogen). These results suggest strongly that the androgenic effects on PSA mRNA in LNCaP cells may be via the function of the androgen receptor.

Stage B prostate adenocarcinoma. Flow cytometric nuclear DNA ploidy analysis.

Over a 16-year period (1966 to 1981), 349 patients underwent radical retropubic prostatectomy for pathologic stage B adenocarcinoma of the prostate. Nuclear DNA content was measured by flow cytometry on available archival material of 283 patients. Two hundred sixty-one patients (92%) had high-quality histograms. The ploidy distribution was as follows: DNA diploid, 177 (68%); DNA tetraploid, 74 (28%); and DNA aneuploid, 10 (4%). The average follow-up was 9.4 years. At the time of follow-up, 53 patients (20%) within the study group had developed tumor progression: 22 local, 23 systemic, and 8 both. The ploidy distribution of the population that developed tumor progression was 27 DNA diploid (51%), 16 DNA tetraploid (30%), and 10 DNA aneuploid (19%). This ploidy distribution is significantly different from that found for the nonprogression group with stage B disease. Overall, 31% of patients with DNA nondiploid tumors had tumors that progressed compared with 15% of patients with DNA diploid tumors. All (100%) DNA aneuploid tumors progressed. The DNA ploidy distribution of all pathologic stage B prostate cancers differs significantly from that found in more advanced stages (C and D1) previously reported for the same time interval. However, the ploidy distribution of stage B tumors that progressed closely resembles that of the stage C and D1 tumors. These results further support the working hypothesis that nuclear DNA content has marked prognostic significance for patients with adenocarcinoma of the prostate. It seems to us that analysis of ploidy by flow or static cytometry will become an essential tool for treating patients with localized prostate cancer.

Tunica vaginalis free graft for the correction of chordee.

Tunica vaginalis free grafts were used to correct severe chordee not amenable to other surgical maneuvers in 11 boys. Postoperatively, the penis was straight in 10 patients and had some degree of downward angulation in 1 boy. The tunica vaginalis free graft seems to be a useful technique for the correction of severe chordee.

Tissue-specific and hormonal regulation of human prostate-specific glandular kallikrein.

Kallikreins are involved in the posttranslational processing of a number of specific polypeptide precursors. Previously, human glandular kallikrein (hGK-1) mRNA has been identified in the prostate; however, the hGK-1 protein has not been identified and characterized. Therefore, its physiologic function in the prostate is not known. In this study, we have isolated a full-length hGK-1 cDNA from a human adenocarcinoma cell line, LNCaP. In vitro translation experiments demonstrated that the molecular size of the hGK-1 protein generated from this cDNA is similar to that of prostate-specific antigen (PSA), a protein which is produced exclusively in the prostate. In situ hybridization with a hGK-1-specific oligonucleotide probe (77 bases), which can differentiate hGK-1 mRNA from PSA mRNA, demonstrated the hGK-1 mRNA to be located in the prostate epithelium. The hGK-1 mRNA was colocalized with PSA mRNA in prostatic epithelia. Moreover, in situ hybridization studies revealed that the level of hGK-1 mRNA in human benign prostatic hyperplasia tissues is approximately half that of PSA mRNA. Furthermore, we have demonstrated that hGK-1 mRNA is under androgenic regulation in LNCaP cells. Time course analysis revealed that hGK-1 mRNA levels increased significantly at 5 h of mibolerone treatment and reached maximal levels by 9 h. In addition, hGK-1 mRNA levels were increased by dihydrotestosterone, but not by dexamethasone or diethylstilbestrol treatments. Flutamide, a nonmetabolized anti-androgen, repressed the androgenic effects. These studies suggest that expression of hGK-1 mRNA is regulated by androgen via the androgen receptor.

Augmentation cystoplasty utilizing de-epithelialized sigmoid colon: a preliminary study.

The use of bowel segments for bladder replacement or augmentation has been associated with metabolic complications and obstruction due to mucus production. Establishment of a transitional epithelium over the de-epithelialized surface of a segment of intestine might alleviate these complications. Twenty Holstein bull calves underwent sigmoidocystoplasty. Fourteen experimental animals had the epithelium of the sigmoid removed before augmentation. Six calves with intact mucosa served as controls. Fifteen calves survived the study: 11 experimentals and four controls. Cystectomies were performed at four, six, eight, or 12 weeks. Ninety-one percent (10/11) of the experimental calves had almost complete epithelialization of the de-epithelialized graft. All experimental animals had residual colonic mucosa or mucoceles. Nine of 11 experimental calves (82%) had greater than 25% contracture of the sigmoid graft. Two animals had less than 25% graft contracture (1) or formed a wide-mouthed true diverticulum (1) in the grafted segment. All control animals formed a wide-mouthed true diverticulum and had no graft contracture.

Extended followup of bilateral Wilms tumor: results of the National Wilms Tumor Study.

The long-term survival of patients with synchronous bilateral Wilms tumor is not well defined. Retrospective review of 185 patients registered with the National Wilms Tumor Study from January 1974 to July 1986 with stage V tumors suggests that the long-term outcome remains good. Over-all survival is 83%, 73% and 70% at 2, 5 and 10 years, respectively. Unfavorable histology, age at diagnosis and the most advanced stage of the individual tumors remain the most important prognostic variables. No significant difference in survival was noted between patients undergoing initial surgical resection of the tumor and those managed with initial tumor biopsy followed by chemotherapy with or without radiotherapy and subsequent surgical resection. Survival does not appear to be compromised by attempting to conserve native renal function with renal-sparing operations.

Hormonal regulation of prostate-specific antigen (PSA) glycoprotein in the human prostatic adenocarcinoma cell line, LNCaP.

Prostate-specific antigen (PSA) has emerged as the most useful marker for management of patients with prostate cancer. The regulation of this glycoprotein in vivo has important clinical implications. Indirect evidence indicates that the PSA glycoprotein might be regulated by androgens, and previous studies in this laboratory have demonstrated that PSA mRNA is upregulated by androgens. The current work reports a detailed study of PSA glycoprotein expression as influenced by steroid hormones in a human prostatic adenocarcinoma cell line, LNCaP. First, we have examined the steroid binding specificity of the androgen receptor in this cell line. In comparison with wild-type rat androgen receptor in prostate, the receptor in LNCaP cells has altered affinity for a number of steroids or analogs such as progesterone (R5020), antiprogesterone (RU486), two antiandrogens (cyperoterone acetate and hydroxyflutamide), and an androgen metabolite (epitestosterone). However, its affinity for androgens (mibolerone, dihydrotestosterone, and testosterone) is not changed. The receptor does not bind to the synthetic glucocorticoids (triaminolone acetonide and dexamethasone) nor to a synthetic estrogen DES (diethylstilbestrol). The change of the steroid binding specificity of the receptor is correlated with a single mutation (A----G at nucleotide #876 relative to the initiation codon) of the steroid binding domain of the receptor. The mutation and alteration of steroid-binding specificity of the androgen receptor is also correlated with PSA glycoprotein expression affected by different ligands tested. We have demonstrated that the PSA glycoprotein is upregulated by androgens and is affected by neither epidermal growth factor nor basic fibroblast growth factor. Moreover, PSA glycoprotein could be induced by R5020, estradiol, and epitestosterone; but neither glucocorticoids nor DES had any effect on PSA induction. Interestingly, although the antiandrogen, cyperotone acetate, had the ability to induce PSA, both RU486 and hydroxyflutamide could block androgen and progesterone induction of PSA glycoprotein. Therefore, we conclude that the PSA glycoprotein expression is influenced predominantly by androgens via its receptor, and the mutation of the receptor can affect the expression of this cellular gene by the steroids other than androgens.