Prostate-specific Antigen Immunoreactivity Research Articles

Individual risk prediction of high grade prostate cancer based on the combination between total prostate-specific antigen (PSA) and free to total PSA ratio.

Clinical practice guidelines endorse the stratification of prostate cancer (PCa) risk according to individual total prostate-specific antigen (tPSA) values and age to enhance the individual risk-benefit ratio. We defined two nomograms to predict the individual risk of high and low grade PCa by combining the assay of tPSA and %free/tPSA (%f/tPSA) in patients with a pre-biopsy tPSA between 2 and 10μg/L. The study cohort consisted of 662 patients that had fPSA, tPSA, and a biopsy performed (41.3% with a final diagnosis of PCa). Logistic regression including age, tPSA and %f/tPSA was used to model the probability of having high or low grade cancer by defining 3 outcome levels: no PCa, low grade (International Society of Urological Pathology grade, ISUP<3) and high grade PCa (ISUP≥3). The nomogram identifying patients with: (a)high vs. those with low grade PCa and without the disease showed a good discriminating capability (∼80%), but the calibration showed a risk of underestimation for predictive probabilities >30% (a considerable critical threshold of risk), (b)ISUP<3 vs. those without the disease showed adiscriminating capability of 63% and overestimates predictive probabilities >50%. In ISUP 5 a possible loss of PSA immunoreactivity has been observed. The estimated risk of high or low grade PCa bythe nomograms may be of aid in the decision-making process, in particular in the case of critical comorbidities andwhen the digital rectal examinations are inconclusive. The improved characterization of the risk of ISUP≥3 might enhance the use for magnetic resonance imaging in this setting.

Clinicopathological and genetic analyses of small cell neuroendocrine carcinoma of the prostate: Histological features for accurate diagnosis and toward future novel therapies

Differentiating small cell neuroendocrine (NE) carcinoma (SCNC) of the prostate from adenocarcinoma with NE differentiation based on morphological features alone sometimes can be challenging. Given that treatment strategies vary depending on histological type, an accurate diagnosis is critical. This study aimed to identify the accurate diagnostic factors for SCNC of the prostate. Furthermore, the possibility of novel treatment strategies through genetic analysis was also investigated. Prostate biopsies conducted in our hospital between January 2017 and May 2020 were included. Consequently, seven cases of SCNC and four cases of adenocarcinoma with NE differentiation were identified. No significant differences in the serum neuron-specific enolase, pro-gastrin-releasing peptide, and prostate-specific antigen (PSA) levels were observed between both tumors. The Ki-67 labeling index was significantly higher, and PSA immunoreactivity tended to be lower in SCNC. Although the morphology was undetectable, genetic analysis confirmed several mutations, including those of PIK3CA and TP53. The fact that morphological findings are not apparent indicates that genetic investigation rather than only morphological findings would be important in the future. In conclusion, given the heterogeneity of serum NE markers in SCNC, diagnosis based on these markers alone is challenging. A high Ki-67 labeling index and low PSA immunoreactivity may be useful for diagnosis, but p53 immunoreactivity is insufficient in distinguishing. Although further studies are required to interpret the results of the genetic analysis involving ALK, PIK3CA, and TP53 mutations, the results of our genetic analysis suggest that PIK3CA mutations in SCNC of the prostate may provide a novel therapeutic strategy.

Immunoreactivity for prostate specific antigen and Ki67 differentiates subgroups of prostate cancer related to outcome

Based on gene-expression profiles, prostate tumors can be subdivided into subtypes with different aggressiveness and response to treatment. We investigated if similar clinically relevant subgroups can be identified simply by the combination of two immunohistochemistry markers: one for tumor cell differentiation (prostate specific antigen, PSA) and one for proliferation (Ki67). This was analyzed in men with prostate cancer diagnosed at transurethral resection of the prostate 1975–1991 (n = 331) where the majority was managed by watchful waiting. Ki67 and PSA immunoreactivity was related to outcome and to tumor characteristics previously associated with prognosis. Increased Ki67 and decreased PSA were associated with poor outcome, and they provided independent prognostic information from Gleason score. A combinatory score for PSA and Ki67 immunoreactivity was produced using the median PSA and Ki67 levels as cut-off (for Ki67 the upper quartile was also evaluated) for differentiation into subgroups. Patients with PSA low/Ki67 high tumors showed higher Gleason score, more advanced tumor stage, and higher risk of prostate cancer death compared to other patients. Their tumor epithelial cells were often ERG positive and expressed higher levels of ErbB2, phosphorylated epidermal growth factor receptor (pEGF-R) and protein kinase B (pAkt), and their tumor stroma showed a reactive response with type 2 macrophage infiltration, high density of blood vessels and hyaluronic acid, and with reduced levels of caveolin-1, androgen receptors, and mast cells. In contrast, men with PSA high/Ki67 low tumors were characterized by low Gleason score, and the most favorable outcome amongst PSA/Ki67-defined subgroups. Men with PSA low/Ki67 low tumors showed clinical and tumor characteristics intermediate of the two groups above. A combinatory PSA/Ki67 immunoreactivity score identifies subgroups of prostate cancers with different epithelial and stroma phenotypes and highly different outcome but the clinical usefulness of this approach needs to be validated in other cohorts.

Gene expression profiles define molecular subtypes of prostate cancer bone metastases with different outcomes and morphology traceable back to the primary tumor.

Bone metastasis is the lethal end‐stage of prostate cancer (PC), but the biology of bone metastases is poorly understood. The overall aim of this study was therefore to explore molecular variability in PC bone metastases of potential importance for therapy. Specifically, genome‐wide expression profiles of bone metastases from untreated patients (n = 12) and patients treated with androgen‐deprivation therapy (ADT, n = 60) were analyzed in relation to patient outcome and to morphological characteristics in metastases and paired primary tumors. Principal component analysis and unsupervised classification were used to identify sample clusters based on mRNA profiles. Clusters were characterized by gene set enrichment analysis and related to histological and clinical parameters using univariate and multivariate statistics. Selected proteins were analyzed by immunohistochemistry in metastases and matched primary tumors (n = 52) and in transurethral resected prostate (TUR‐P) tissue of a separate cohort (n = 59). Three molecular subtypes of bone metastases (MetA‐C) characterized by differences in gene expression pattern, morphology, and clinical behavior were identified. MetA (71% of the cases) showed increased expression of androgen receptor‐regulated genes, including prostate‐specific antigen (PSA), and glandular structures indicating a luminal cell phenotype. MetB (17%) showed expression profiles related to cell cycle activity and DNA damage, and a pronounced cellular atypia. MetC (12%) exhibited enriched stroma–epithelial cell interactions. MetB patients had the lowest serum PSA levels and the poorest prognosis after ADT. Combined analysis of PSA and Ki67 immunoreactivity (proliferation) in bone metastases, paired primary tumors, and TUR‐P samples was able to differentiate MetA‐like (high PSA, low Ki67) from MetB‐like (low PSA, high Ki67) tumors and demonstrate their different prognosis. In conclusion, bone metastases from PC patients are separated based on gene expression profiles into molecular subtypes with different morphology, biology, and clinical outcome. These findings deserve further exploration with the purpose of improving treatment of metastatic PC.

Prostate Cancer Risk-Associated Single-Nucleotide Polymorphism Affects Prostate-Specific Antigen Glycosylation and Its Function.

Genetic association studies have reported single-nucleotide polymorphisms (SNPs) at chromosome 19q13.3 to be associated with prostate cancer (PCa) risk. Recently, the rs61752561 SNP (Asp84Asn substitution) in exon 3 of the kallikrein-related peptidase 3 (KLK3) gene encoding prostate-specific antigen (PSA) was reported to be strongly associated with PCa risk (P = 2.3 × 10-8). However, the biological contribution of the rs61752561 SNP to PCa risk has not been elucidated. Recombinant PSA protein variants were generated to assess the SNP-mediated biochemical changes by stability and substrate activity assays. PC3 cell-PSA overexpression models were established to evaluate the effect of the SNP on PCa pathogenesis. Genotype-specific correlation of the SNP with total PSA (tPSA) concentrations and free/total (F/T) PSA ratio were determined from serum samples. Functional analysis showed that the rs61752561 SNP affects PSA stability and structural conformation and creates an extra glycosylation site. This PSA variant had reduced enzymatic activity and the ability to stimulate proliferation and migration of PCa cells. Interestingly, the minor allele is associated with lower tPSA concentrations and high F/T PSA ratio in serum samples, indicating that the amino acid substitution may affect PSA immunoreactivity to the antibodies used in the clinical immunoassays. The rs61752561 SNP appears to have a potential role in PCa pathogenesis by changing the glycosylation, protein stability, and PSA activity and may also affect the clinically measured F/T PSA ratio. Accounting for these effects on tPSA concentration and F/T PSA ratio may help to improve the accuracy of the current PSA test.

The Proteome of Prostate Cancer Bone Metastasis Reveals Heterogeneity with Prognostic Implications.

Purpose: Bone is the most predominant site of distant metastasis in prostate cancer, and patients have limited therapeutic options at this stage.Experimental Design: We performed a system-wide quantitative proteomic analysis of bone metastatic prostate tumors from 22 patients operated to relieve spinal cord compression. At the time of surgery, most patients had relapsed after androgen-deprivation therapy, while 5 were previously untreated. An extended cohort of prostate cancer bone metastases (n = 65) was used for immunohistochemical validation.Results: On average, 5,067 proteins were identified and quantified per tumor. Compared with primary tumors (n = 26), bone metastases were more heterogeneous and showed increased levels of proteins involved in cell-cycle progression, DNA damage response, RNA processing, and fatty acid β-oxidation; and reduced levels of proteins were related to cell adhesion and carbohydrate metabolism. Within bone metastases, we identified two phenotypic subgroups: BM1, expressing higher levels of AR canonical targets, and mitochondrial and Golgi apparatus resident proteins; and BM2, with increased expression of proliferation and DNA repair-related proteins. The two subgroups, validated by the inverse correlation between MCM3 and prostate specific antigen immunoreactivity, were related to disease prognosis, suggesting that this molecular heterogeneity should be considered when developing personalized therapies.Conclusions: This work is the first system-wide quantitative characterization of the proteome of prostate cancer bone metastases and a valuable resource for understanding the etiology of prostate cancer progression. Clin Cancer Res; 24(21); 5433-44. ©2018 AACR.

Discovery of the Long Interspersed Nuclear Element-1 activation product [Open Reading Frame-1 (ORF1) protein] in human blood

Long Interspersed Nuclear Element 1 is the only autonomous mobile DNA capable of self-propagation, and is an environmental biomarker that is activated upon an environmental trigger. We have developed an ELISA method to detect and measure Open Reading Frame-1 (ORF1) and have applied it to interrogate serum samples from men with equivocal prostate specific antigen (PSA) results. Polyclonal antibodies were developed using the first 14-amino acid peptide of N-terminal-ORF1 protein. Remnant serum samples from a total of 53 men, ages>50 yr, were analyzed for immunoreactive ORF1 (iORF1) and PSA concentrations; outcomes for the non-biopsied and biopsied groups were also recorded. The dynamic range of the ELISA was between (CV): 2.0 (14%) to 30 ng/mL (1.2%). The total imprecision (within-run/inter-day) was: QC3 = 2.7%/21%, QC6 = 1.1%/18%, and QC20 = 0.33%/11%. The median iORF1 concentration in the non-biopsy group was 14.7 ng/mL (Q1 – Q3: 10.5 – Q3:18.4), which was significantly lower than the Biopsy group at 25.0 ng/mL (Q1 – Q3: 20.0–33.1), P-value = .003. In conclusion, we have developed a competitive ELISA and discovered the presence of iORF1 in serum, which could be used to advance future studies involving ORF1 measurement from blood. In addition, iORF1 may be a complement with the PSA screen to better detect prostate cancer.

A rare lesion of the vagina: tubulo-squamous polyp

Vaginal polyps are uncommon and consist of a heterogeneous group of lesions. Most of vaginal polypoid lesions are fibroepithelial polyps. However, a variety of lesions (leiomyoma, superficial myofibroblastoma of the lower female genital tract, rhabdomyoma, and embryonal rhabdomyosarcoma etc.) may present macroscopically as a polypoid mass. Tubulo-squamous polyp of the vagina is a rare benign lesion that has been described recently. Histologically, it is characterized by both epithelial and mesenchymal component, consisting of squamous nests and tubules, embedded in a fibrous stroma. Focal immunoreactivity for prostate-specific antigen (PSA) and/or prostatic acid phosphatase (PSAP) may be observed in some lesions, supporting the possibility that it originates from paraurethral Skene’s glands. Herein, we report a 60-year-old female with a tubulo-squamous polyp of the vagina. A brief review of the literature on this novel entity is also provided.

Proteomic identification of galectin-3 binding ligands and characterization of galectin-3 proteolytic cleavage in human prostasomes

Galectin-3 is a multifunctional carbohydrate-binding protein that was previously characterized as a proteolytic substrate for prostate-specific antigen (PSA) and was shown to be associated with prostasomes in human semen. Prostasomes are exosome-like vesicles that are secreted by the prostatic epithelium and have multiple proposed functions in normal reproduction and prostate cancer. In the current study, galectin-3 binding ligands in human prostasomes were identified and characterized with the goal to investigate galectin-3 function in prostasomes. Galectin-3 binding proteins were isolated by affinity column chromatography. Candidate ligands identified by MS/MS were PSA, prostatic acid phosphatase (PAP), zinc alpha-2-glycoprotein (ZAG), dipeptidyl peptidase-4 (CD26), aminopeptidase N (CD13), neprilysin, clusterin, antibacterial protein (FALL-39) and alpha-1-acid glycoprotein (ORM1). Biochemical methods were used to characterize the ability of galectin-3 to bind to selected ligands, and galectin-3 cleavage assays were utilized to investigate the protease(s) in prostasomes that cleaves galectin-3. CD26, CD13, PSA, PAP and ZAG immunoreactivity were detected in extracts of purified prostasomes. One-dimensional electroblot analysis of prostasomes demonstrated that CD26, PAP and CD13 immunoreactivity co-migrated with galectin-3-reactive protein bands. PSA and ZAG were found to be associated with the surface of prostasomes. Both intact and cleaved galectin-3 were detected in prostate and prostasome extracts. Cleavage and inhibition assays indicated that PSA in prostasomes proteolytically cleaves galectin-3. The identification of these glycoproteins as galectin-3 ligands lays the groundwork for future studies of galectin-3 and prostasome function in reproduction and prostate cancer.

Complex formation between human prostate‐specific antigen and protease inhibitors in mouse plasma

When secreted from the prostate, most of prostate-specific antigen (PSA) is free and enzymatically active. Upon reaching circulation, active PSA is inactivated by complex formation with protease inhibitors. To justify the use of mouse models for evaluation of the function of PSA and for studies on therapeutic modalities based on modulation of PSA activity, it is important to know whether PSA complexation is similar in mouse and man. To characterize the circulating forms of PSA in mouse, we used subcutaneous LNCaP and 22RV1 human prostate cancer cell xenograft tumor models. We also added PSA directly to mouse serum. Free and total PSA were measured by immunoassay, and PSA complexes were extracted by immunopurification followed by SDS-PAGE, in-gel trypsin digestion and identification of signature peptides by mass spectrometry. In mice bearing xenograft tumors, 68% of the immunoreactive PSA occurred in complex, and when added to mouse serum, over 70% of PSA forms complexes that comprises alpha(2)-macroglobulin and members of the alpha(1)-antitrypsin (AAT) family. In mouse plasma, PSA forms complexes similar to those in man, but the major immunoreactive complex contains AAT rather than alpha(1)-antichymotrypsin, which is the main complex forming serpin in man. The complex formation of PSA produced by xenograft tumor models in mice is similar to that of human prostate tumors with respect to the complexation of PSA.

Marcadores moleculares relacionados con cáncer de próstata: 3-nitrotirosina y expresión génica y protéica de la Mn-superóxido dismutasa (Mn-SOD)

Recent reports place prostate cancer (PCa) as third cause of death in the World among males, in Mexico it is the leading cause of male death. In this study, we studied molecular markers and one genetic marker related in tissues with PCa and benign prostatic hyperplasia (BPH): The Mn-superoxide dismutase (Mn-SOD) gen and protein, prostate specific antigen (PSA) and 3-nitrotyrosine (3-NT). It was evaluated if various markers of oxidative stress show altered expression in prostate cancer and BPH. 80 biopsies were obtained. The conditions to amplify and evaluate the immunoreactivity of the genes of interest (Mn-SOD and 3-NT) and the correlation between PSA and Mn-SOD immunoreactivity in prostate cancer and benign prostatic hyperplasia were standardized. Gene overexpression and Mn-SOD and 3-NT immunoreactivity were greater in prostate cancer with respect to the BPH group. Correlation between levels of PSA and the Mn-SOD immunoreactivity was not observed. The above results suggest that the parameters evaluated can be used as tumor markers making the determinations in biopsies of patients suspected of prostate cancer.

Sarcomatoid Carcinoma of the Prostate: A Study of 42 Cases

Sarcomatoid carcinoma of the prostate is a rare type of prostatic cancer. With the exception of 1 study, the morphologic features and patient outcomes have been reported only in relatively small case series and individual reports. We examined transurethral resection, needle biopsy, and radical prostatectomy specimens from 42 patients with sarcomatoid carcinoma of the prostate, all of which were received in consultation. Clinical information on 32 patients was obtainable. Five patients were lost to follow-up and information on the 5 remaining patients could not be obtained. Prior prostatic adenocarcinoma: The majority of patients (n=21; 66%) had a prior history of acinar adenocarcinoma of the prostate. Of the 14 men with available data, reported Gleason scores were 6 (n=7), 8 (n=4), and 10 (n=3). Of the remaining patients for whom this information was known, 11 patients presented with de novo sarcomatoid carcinoma. The time between the original diagnosis of acinar adenocarcinoma and diagnosis of sarcomatoid carcinoma ranged from 6 months to 16 years (mean 6.8 y). Concurrent adenocarcinoma: The majority of patients demonstrated a concurrent high grade acinar carcinoma of Gleason score 7 (n=3), 8 (n=9), 9 (n=10), and 10 (n=10). A subset of patients contained an admixed ductal adenocarcinoma (n=4), small cell carcinoma (n=3), squamous cell carcinoma (n=3), or other unusual pattern of prostate carcinoma (n=3). In 1 case, the diagnosis was based on immunohistochemical evidence of epithelial differentiation along with the history of prior adenocarcinoma. Morphology of the sarcomatoid component: The percentage of sarcomatoid growth ranged from 5% to 99% (mean 65%). Bizarre atypia with giant cells was present in 55% of cases. Admixed heterologous elements were identified in 10 cases (29%), including osteosarcomatous (n=7), chondrosarcomatous (n=5), and rhabdomyosarcomatous (n=2) elements. Of the 12 cases with received immunostains of the sarcomatoid component, 5/7 cases were at least focally positive for cytokeratin, 1/1 case was focally positive for Cam5.2, and 3/6 cases were focally positive for prostate acid phosphatase. The sarcomatoid component did not demonstrate immunoreactivity for prostate-specific antigen in 8 cases. approximately half of all patients developed metastatic disease either at time of presentation or subsequently. Of patients with meaningful follow-up, 6/7 died within 1 year of the diagnosis of sarcomatoid carcinoma; 20 were alive yet with very short follow-up (median 1 y; mean 2.3 y). Kaplan-Meier analysis revealed that the actuarial risk of death at 1 year after diagnosis of sarcomatoid carcinoma was 20%. No correlation was identified between patient survival and morphologic features, before radiation or hormone therapy, or concurrent high-grade prostate cancer. Sarcomatoid carcinoma demonstrates diverse spindle and epithelial cell morphologies. The sarcomatoid component often has heterologous elements and, in 1 case, no epithelial component was seen on hematoxylin and eosin-stained sections. The epithelial component is typically high-grade acinar adenocarcinoma, yet other aggressive tumor subtypes such as ductal adenocarcinoma and small cell carcinoma may also be seen. Sarcomatoid carcinoma is an aggressive form of prostate cancer, the prognosis of which is dismal regardless of other histologic or clinical findings.

A case of Sister Mary Joseph's nodule from prostatic cancer

The metastasis of a visceral malignancy to the umbilicus is known as "Sister Mary Joseph's nodule" (SMJN). We recently encountered an 80-year-old man in whom umbilical metastasis of prostatic cancer was revealed during the course of treatment. The lesion was a red, firm, elastic nodule, 2.5 cm in diameter, with a bumpy, irregular surface, but without subjective symptoms. In histopathological examination, atypical cells with intensely stained, small quasi-circular nuclei and weakly eosinophilic cytoplasm were found in all layers of the dermis. In some parts of these tumor cells, a gland-like structure was observed. Immunohistochemical investigation of the invading tumor cells disclosed immunoreactivity for prostate specific antigen and prostatic acid phosphatase, supporting a diagnosis of SMJN from prostatic cancer. His general condition gradually deteriorated, and he died 2 months later. Prostate cancer often metastasizes to bones and lymph nodes, but rarely to the skin. Of all the cases of cutaneous metastasis of prostate cancer reported in Japan, only three metastases have occurred to the umbilical region. The present case is therefore an example of a very rare condition.

Apocrine Cysts of the Breast

Up to one-third of women aged 30-50 years have cysts in their breasts and are presumed to be at increased risk of developing breast cancer. Here we present an extensive proteomic and immunohistochemistry (IHC) study of breast apocrine cystic lesions aimed at generating specific biomarkers and elucidating the relationship, if existent, of apocrine cysts with cancer phenotype. To this end we compared the expression profiles of apocrine macrocysts obtained from mastectomies from high risk cancer patients with those of cancerous and non-malignant mammary tissue biopsies collected from the same patients. We identified two biomarkers, 15-hydroxyprostaglandin dehydrogenase and 3-hydroxymethylglutaryl-CoA reductase, that were expressed specifically by apocrine type I cysts as well as by apocrine metaplastic cells in type II microcysts, terminal ducts, and intraductal papillary lesions. No expression of these markers was observed in non-malignant terminal ductal lobular units, type II flat cysts, stroma cells, or fat tissue as judged by IHC analysis of matched non-malignant tissue samples collected from 93 high risk patients enrolled in our cancer program. IHC analysis of the corresponding 93 primary tumors indicated that most apocrine changes have little intrinsic malignant potential, although some may progress to invasive apocrine cancer. None of the apocrine lesions examined, however, seemed to be a precursor of invasive ductal carcinomas, which accounted for 81% of the tumors analyzed. Our studies also provided some insight into the origin, development, and enlargement of apocrine cysts in mammary tissue. The successful identification of differentially expressed proteins that characterize specific steps in the progression from early benign lesions to apocrine cancer opens a window of opportunity for designing and testing new approaches for pharmacological intervention, not only in a therapeutic setting but also for chemoprevention, to inhibit cyst development as both 15-hydroxyprostaglandin dehydrogenase and 3-hydroxymethylglutaryl-CoA reductase are currently being targeted for chemoprevention strategies in various malignancies.

Pleomorphic Giant Cell Carcinoma of the Prostate

We report the clinical and pathologic features of 2 cases of pleomorphic giant cell carcinoma of the prostate. One case was found at autopsy in a 77-year-old man and was composed of high-grade prostatic adenocarcinoma with prominent anaplastic giant cells. The patient presented with metastases to multiple retroperitoneal lymph nodes, liver, and lumbar vertebrae. The second case occurred in a 45-year-old man who underwent transurethral resection of the prostate and was found to have high-grade prostatic adenocarcinoma with an extensive anaplastic giant cell component. The patient presented with distant metastases and died within 9 months. Both regular adenocarcinoma and anaplastic giant tumor cells displayed cytoplasmic immunoreactivity for prostate-specific antigen, prostatic acid phosphatase, and keratin AE1/AE3; in one case, scattered cells were also positive for chromogranin and epithelial membrane antigen. Pleomorphic giant cell carcinoma is a rare variant of prostatic adenocarcinoma with a poor prognosis that should be considered in the differential diagnosis of prostatic pleomorphic tumors.

Villous Adenoma of the Urachus: A Case with Prostate Specific Antigen Immunoreactivity

We report a case of a villous adenoma of the urachus discovered incidentally during suprapubic prostatectomy, and discuss a novel immunohistochemical finding that could be diagnostically useful. CASE REPORT A 68-year-old man underwent simultaneous right ureterolithotomy and suprapubic prostatectomy because of hydronephrosis (due t oa2c mcalculus in the ipsilateral lower ureter) and acute urinary retention due to prostatic enlargement, respectively. During prostatectomy an ovoid cystic mass (not diagnosed before surgery by imaging techniques) was noted in the bladder dome without involvement of the adjacent structures. Partial cystectomy with excision of the mass was performed. Postoperative recovery was uneventful. No recurrence of the tumor was noted at 19 months following excision. Gross examination of the specimen showed a mucus filled cystic structure 8 cm in diameter associated with a portion of bladder wall 5 cm in diameter. The lining of the cyst demonstrated an exophytic papillary area 0.8 cm in diameter, which was clearly separated from the surrounding epithelium. Histological examination revealed a cyst lined by transitional epithelium containing a neoplasm with villoglandular architecture (fig. 1, A). The neoplastic cells displayed slight nuclear stratification and crowding, mild nuclear hyperchromatism and occasional prominent nucleoli, while the tumor cell cytoplasm contained acidic mucin (fig. 1, B). Mitotic figures were rare. In the adjacent smooth muscle there were urachal remnants. Tumor invasion was not observed. The pathological diagnosis was villous adenoma that had developed in a urachal cyst. The neoplastic cells exhibited immunoreactivity for cytokeratin 20 and carcinoembryonic antigen. In addition, there was prostatic specific antigen (PSA) immunostaining in the tumor cells and the epithelium of the urachal remnants (fig. 2). Preoperatively, serum PSA was within normal range, while the prostatic specimen showed benign nodular hyperplasia.

Occurrence and localization of uroguanylin in the aging human prostate.

Uroguanylin, a peptide hormone highly expressed in the gastrointestinal tract, is implicated in the regulation of epithelial salt and water transport processes. Since little is known about a possible role of uroguanylin in the reproductive system, we investigated for the first time the occurrence of this peptide in the human prostate using specimens of benign prostatic hyperplasia. Northern blot analyses detected a single uroguanylin transcript of approximately 600 bp in prostate RNA. The uroguanylin expression was further investigated by reverse transcriptase polymerase chain reaction of prostate RNA with uroguanylin-specific primers. Sequencing of the fragments obtained indicated the presence of a uroguanylin molecule with a sequence identical to its intestinal counterpart. Furthermore, in situ hybridization and immunohistochemistry revealed that uroguanylin mRNA and peptide are confined to epithelial cells of the prostate glands. Comparison with the distribution pattern of immunoreactivity for prostate-specific antigen (PSA) showed a high degree of colocalization of uroguanylin- and PSA-immunoreactive cells. In addition, by western blotting techniques we detected the presence of high molecular weight uroguanylin-immunoreactive material in prostatic fluid. In conclusion, our study indicates that the human prostate glands synthesize and secrete (pro-)uroguanylin. We hypothesize that this hormone may play a novel role in the male reproductive tract.

Regulation of prostate-specific antigen (PSA) gene expression and release in LNCaP prostate cancer by antagonists of growth hormone-releasing hormone and vasoactive intestinal peptide.

Prostate-specific antigen (PSA) is the best tumor marker for diagnosis and prognosis of prostatic carcinoma. The secretion of PSA from LNCaP human prostate cancer cells is influenced by acute stimuli such as vasoactive intestinal peptide (VIP), growth hormone-releasing hormone (GHRH), and chronic stimuli like androgens. To study the regulation of basal and VIP/GHRH or androgen-stimulated secretion from LNCaP cells, we used a superfusion system, which allowed us to simultaneously measure PSA gene expression, PSA secretion, and cAMP release from the same cancer cells. LNCaP cancer cells were also implanted orthotopically into nude mice. VIP (30 pM-3 nM), GHRH (3 nM-300 nM), and dihydrotestosterone (100 nM) induced a significant increase in PSA gene expression, PSA secretion, and cAMP release. The dose and time-dependent effects of peptides were manifested only in the presence of androgens. At the end of continuous stimulation of cells with 1 nM VIP for 2 hr, large amounts of stored immunoreactive PSA still remained in the cells. Adenylate cyclase activator, forskolin (FSK), significantly increased PSA secretion and gene expression, and potassium, which causes nonspecific depolarization of membranes, augmented gene expression, and secretion of PSA, but did not influence cAMP release. This suggests that PSA secretion is regulated by cAMP-dependent as well as cAMP-independent pathways. In superfusion system, stimulatory effects of VIP and GHRH on PSA secretion were inhibited by VIP antagonist JV-1-53, and less by GHRH antagonist JV-1-38. In cell cultures, JV-1-38 had a stronger inhibitory effect on proliferation, indicating an involvement of the recently discovered tumoral GHRH receptors in this process. In nude mice, with orthotopically implanted LNCaP cancer cells, GHRH antagonist JV-1-38 alone or androgen ablation by castration had no effect on tumor growth and PSA levels. However, castration combined with treatment with GHRH antagonist, significantly decreased tumor growth and PSA secretion. Our findings suggest that the secretion of PSA is regulated rather than constitutive, contrary to previous reports. In addition, the effect of GHRH and VIP antagonists on PSA secretion from prostate cancer cells is not correlated with their antiproliferative action.

Immunohistochemical analysis of prostate specific antigen in breast cancer.

The presence of immunoreactive prostate-specific antigen (IR-PSA) has been reported in breast cancers and has been suggested to confer a positive prognosis. However, recent large, well-controlled studies have found no significant prognostic value when IR-PSA positivity is examined as an independent variable, even when ultrasensitive immunofluorometric techniques are utilized. The present study, using indirect immunohistochemistry on 75 formalin-fixed, paraffin-embedded breast cancers shows PSA immunoreactivity in only seven of 75 cases (9%), suggesting that PSA positivity in breast carcinoma is not useful as a prognostic or tumor marker with hospital-based methods.

Prostaglandin D Synthase Does Not Produce Prostate-specific Antigen Cross-Reactivity in Renal Cell Carcinoma

Immunoreactive prostate-specific antigen (PSA) has been detected in the sera of female and male renal cell carcinoma (RCC) patients in several studies (1)(2)(3). These measurements were attributed to the tumor because PSA reverted to undetectable concentrations after nephrectomy. However, attempts to definitively ascribe this increase to PSA were not successful either by immunohistochemistry with PSA monoclonal antibodies (1)(2) or by amplification of PSA by reverse transcription-PCR (RT-PCR) (3), suggesting cross-reaction with a PSA-like protein. Prostaglandin D synthase (PGDS) in amniotic fluid has been found to cross-react with a PSA polyclonal antibody, but not with PSA monoclonal antibodies (4). PGDS is present …