Prostatic Antigen Research Articles

Optimised electroporation mediated DNA vaccination for treatment of prostate cancer

BackgroundImmunological therapies enhance the ability of the immune system to recognise and destroy cancer cells via selective killing mechanisms. DNA vaccines have potential to activate the immune system against specific antigens, with accompanying potent immunological adjuvant effects from unmethylated CpG motifs as on prokaryotic DNA. We investigated an electroporation driven plasmid DNA vaccination strategy in animal models for treatment of prostate cancer.MethodsPlasmid expressing human PSA gene (phPSA) was delivered in vivo by intra-muscular electroporation, to induce effective anti-tumour immune responses against prostate antigen expressing tumours. Groups of male C57 BL/6 mice received intra-muscular injections of phPSA plasmid. For phPSA delivery, quadriceps muscle was injected with 50 μg plasmid. After 80 seconds, square-wave pulses were administered in sequence using a custom designed pulse generator and acustom-designed applicator with 2 needles placed through the skin central to the muscle. To determine an optimum treatment regimen, three different vaccination schedules were investigated. In a separate experiment, the immune potential of the phPSA vaccine was further enhanced with co- administration of synthetic CpG rich oligonucleotides. One week after last vaccination, the mice were challenged subcutaneously with TRAMPC1/hPSA (prostate cancer cell line stably expressing human PSA) and tumour growth was monitored. Serum from animals was examined by ELISA for anti-hPSA antibodies and for IFNγ. Histological assessment of the tumours was also carried out. In vivo and in vitro cytotoxicity assays were performed with splenocytes from treated mice.ResultsThe phPSA vaccine therapy significantly delayed the appearance of tumours and resulted in prolonged survival of the animals. Four-dose vaccination regimen provided optimal immunological effects. Co - administration of the synthetic CpG with phPSA increased anti-tumour responses, preventing tumour occurrence in 54% of treated animals. Vaccination with phPSA resulted in anti-hPSA Abs production and a significant production of IFNγ was observed in immunised animals (p < 0.05). Immune responses were tumour specific and were transferable in adoptive T cell transfer experiments.ConclusionsThis phPSA plasmid electroporation vaccination strategy can effectively activate tumour specific immune responses. Optimisation of the approach indicated that a four-dose regimen provided highest tumour protection. In vivo electroporation mediated vaccination is a safe and effective modality for the treatment of prostate cancer and has a potential to be used as a neo-adjuvant or adjuvant therapy.

Crucial Role of Interferon-γ in Experimental Autoimmune Prostatitis

An autoimmune etiology is proposed in some patients with chronic nonbacterial prostatitis since they show interferon-gamma secreting lymphocytes specific to prostate antigens in the periphery and increased interferon-gamma in seminal plasma. We investigated the involvement of interferon-gamma in an animal model of autoimmune prostatitis. Experimental autoimmune prostatitis was studied in the no-obese diabetic and C57Bl/6 (Harlan, Zeist, The Netherlands) susceptible mouse strains, and in the IRF-1 KO and STAT-1 KO mouse strains deficient in transcription factors involved in interferon-gamma signaling. Experimental autoimmune prostatitis was characterized by prostate specific interferon-gamma secreting cells in the periphery and by T-helper 1 related cytokines in the target organ. Increased interferon-gamma and interleukin-12 were observed in the prostate of autoimmune animals while interleukin-10 and interleukin-4 were decreased and unaltered, respectively. The absence of transcription factors involved in the interferon-gamma signaling cascade, IRF-1 and STAT-1, made mice resistant to experimental autoimmune prostatitis. IRF-1 KO and STAT-1 KO mice immunized with prostate antigens did not show infiltration or alterations in the prostate. They did not have the typical prostate specific autoimmune response and showed decreased interferon-gamma, interleukin-12 and interleukin-10, and augmented interleukin-4 in the prostate. Our results argue for a crucial role of interferon-gamma as a key factor in the pathogenesis of the disease. Intense research is promptly required to identify the pathogenic mechanisms underlying chronic prostatitis/chronic pelvic pain syndrome to find a more rational therapy.

Immunohistochemical Expression of Prostatic Antigens in Adenocarcinoma and Villous Adenoma of the Urinary Bladder

Immunohistochemical Expression of Prostatic Antigens in Adenocarcinoma and Villous Adenoma of the Urinary Bladder

Évaluation des pratiques des médecins généralistes du Maine et Loire concernant l’hypertrophie bénigne de la prostate

To assess the diagnosis and therapeutic management of the benign prostatic hyperplasia (BPH) by the general practitioners (GPs) in the Maine-et-Loire. A questionnaire evaluating the management of BPH was sent to the 686 GPs of the Maine-et-Loire between March and June 2008. One hundred and seventy-one GPs answered. Among them 24% were women, 35.1% worked in urban areas, 34.5% worked in semi-urban areas and 30.4% worked in rural areas. 17.5 % had been working less than 10 years, 29.2% had been working between 10 and 20 years and 53.2% had been working more than 20 years. The medical interview, the digital rectal examination (DRE) and the assay of the prostatic serum antigen (PSA) were performed by more than 90% of the GPs whereas the ultrasound scan and the international prostatic score symptom (IPSS) were respectively used by only 15,2 and 69,6% of them. Phytotherapy, alphablockers and inhibitors of 5 alpha reductase were respectively prescribed by 85.4, 95.3 and 53.8% of the GPs. 96.5% of the GPs addressed the patient to a urologist after the failure of the first line treatment. There were no differences according to the working environment. Women performed less DRE (p<0.0001) and sent more patients to urologist than men (p=0.0197). Finally, 88.9% of the GPs were interested in having an update on the last recommendations. The GPs diagnosed BPH and initiated the first line treatment. In case of failure, they sent the patients to a urologist. Their primary treatment management was not really in adequation with the recommendations. The recent therapeutic innovations may explain this discordance between the clinical practice and the recommendations. It is noteworthy that most of the GPs who answered this survey were keen in having an update on the recent advances in the BPH management.

Residual Vein Thrombosis Improves Screening for Occult Cancer: Results On 537 Patients with Idiopathic Deep Vein Thrombosis.

Abstract 3999Poster Board III-935 BackgroundClinical advantage of extensive screening for occult cancer in patients with idiopathic Deep Vein Thrombosis (DVT) is unknown. We have demonstrated that the Residual Vein Thrombosis (RVT)-based screening for occult cancer improves early detection as well as cancer-related mortality (Siragusa S et al. Blood 2007;110(699):OC). Here we report on final analysis of 537 patients over a period of 8 years. Objective of the studyWe conducted a prospective study evaluating whether a RVT-based screening for cancer is sensitive and influences cancer-related mortality. Study designProspective with two cohorts of DVT patients: the first cohort was monitored for clinical overt cancer only (Group A), while the second (Group B) received complete screening for occult neoplasm and subsequent surveillance. Materials and methodsConsecutive patients with a first episode of DVT who presented RVT after 3 month of anticoagulation and without signs and/or symptoms for overt cancer. Screening for occult cancer was based on: ultrasound and/or CT scan of the abdomen and pelvis, gastroscopy, colonoscopy or sigmoidoscopy, hemoccult, sputum cytology and tumor markers. These tests were extended with mammography and Pap smear for women and ultrasound of the prostate and total specific prostatic antigen (PSA) for men. All investigations had to be completed within four-weeks from the assessment of RVT. All patients were followed-up for at least 2 years. Incidence and cancer-related mortality was compared between the two groups by survival curves (Kaplan-Mayer) and related Breslow test for statistics. ResultsOver a period of 8 years, 537 patients were included in the analysis: first cohort included 346 patients (Group A), second cohort 191 (Group B). Clinical characteristics between groups were homogenous. During the follow-up, 8.3% of patients developed overt cancer in group A; in group B, 7.8% of patients had diagnosed cancer at the moment of extensive screening while 2 new cases (0.7%) occurred during the follow-up (Table). The sensitivity of this approach was 92.1% (95% confidence intervals 75.2-104.2). Cancer-related mortality was 7.5% in group A and 3.6% in group B (p< 0.001). ConclusionsThe RVT-based screening for occult cancer is highly effective for improving early detection as well as cancer-related mortality in a cohort of 537 patient with DVT of the lower limbs.TableCancer eventsCharacteristicGroup A (n= 346)Group B (N= 191)Cancer, No (%) at screening time- -15 (7.8)Cancer, No (%) during clinical surveillance29 (8.3)2 (1.0)Density incidence (cases x 1000 p/y)42.339.6Median time of diagnosing cancer, months (range)7.2 (1.3-21.5)3.2 (0-13.2)Cancer-related mortality, No (%)26 (7.5)6 (3.6)Cancer-related mortality, median time (range)19 (3.9-28.2)18 (3.2-6.4) Disclosures:Off Label Use: Hydroxyurea use in myelofibrosis.

7015 Degarelix versus leuprolide in patients with metastatic prostate cancer: assessment of serum alkaline phosphatase over time

Degarelix is a gonadotropin-releasing hormone antagonist (GnRH receptor blocker) with immediate onset of action, suppressing gonadotropins, testosterone, and prostate-specific antigen (PSA) in prostate cancer.To determine the efficacy and safety of initial doses of 200 mg or 240 mg of degarelix and thereafter monthly subcutaneous maintenance doses of 80 mg, 120 mg, or 160 mg of degarelix for the treatment of prostate cancer.The 1-yr study was of open-label, randomised design and involved 187 patients (range: 52–93 yr, median: 72 yr) with histologically confirmed adenocarcinoma of the prostate and a baseline PSA >2 ng/ml.At baseline, median serum testosterone was 4.13 ng/ml (range: P25–P75, 3.37–5.19 ng/ml) and PSA was 27.6 ng/ml (range: P25–P75, 11.9–55.0 ng/ml). On day 3, 88% and 92% of patients in the groups to whom 200-mg and 240-mg initial doses of degarelix were administered, respectively, had testosterone levels ≤0.5 ng/ml. For patients with testosterone levels ≤0.5 ng/ml at 1 mo, the testosterone levels remained ≤0.5 ng/ml until the end of the study in 100% of the patients treated with a monthly maintenance dosage of 160 mg of degarelix. No evidence of testosterone surge was detected. PSA decreased by 97–98% after 1 yr and the median time to 90% reduction in PSA was 8 wk in all but one patient (from the 80-mg dosage treatment group at the intial 200-mg dose of degarelix). Thirteen patients (6%) withdrew from the study due to adverse events, largely related to androgen deprivation.Degarelix treatment for 1 yr resulted in a fast, profound, and sustained suppression of testosterone and PSA, with no evidence of testosterone surge. Degarelix was well tolerated.

Adenocarcinoma incidental de próstata en resección transuteral por causa benigna: Hospital de San José, julio 2006 a marzo 2008

La resección transuretral de próstata es un procedimiento común para tratar patologías urinarias obstructivas benignas.',2 Al material obtenido se le practica estudio histológico para confirmar la naturaleza benigna, pero en algunos casos se ha encontrado como hallazgo incidental un adenocarcinoma en estadios tempranos. No se sabe con claridad cuánto material debe procesarse o si la cantidad de tejido examinado aumenta la posibilidad de encontrar cáncer. El objetivo de este trabajo es determinar la frecuencia de adenocarcinoma incidental de próstata en pacientes sometidos a RTU por causa benigna. Reune 196 casos de RTU en los que se procesó en una segunda fase todo el tejido restante obtenido, describiendo las variables edad, peso del espécimen, número de láminas procesadas, niveles de PSA y categoría diagnóstica, la cual fue clasificada como negativa para maglinidad, PIN alto de grado y adenocarcinoma de próstata estadios Tla y Tlb. Se encontró que la frecuencia de cáncer próstata en pacientes a quienes se les realizó RTU por hiperplasia prostática benigna en el Hospital de San José fue muy baja, dos pacientes de 71 y 80 años, además de otro que corresponde a una neoplasia intraepitelial de alto grado (PIN de AG) con niveles normales de PSA, lo que evidencia que la frecuencia es menor que la reportada en la literatura internacional. 3 '4 Abreviaturas: CIP, carcinoma incidental de próstata; RTU, resección transuretral de próstata; PIN AG neoplasia intraepitelial prostática de alto grado; PSA, antigeno especifico prostático; TNM, sistema de clasificación de estadio tumoral (T: tumor, N : ganglios linfáticos, M: metástasis).

An aberrant prostate antigen–specific immune response causes prostatitis in mice and is associated with chronic prostatitis in humans

Chronic prostatitis is a common disease of unclear etiology and has no specific treatment. Mice deficient in the expression of the autoimmune regulator (Aire) gene, which are defective in thymic expression of self antigens and central tolerance, develop spontaneous prostatitis. In this study, we found that Aire-deficient mice developed spontaneous B and T cell immune responses to a prostate autoantigen, seminal vesicle secretory protein 2 (SVS2), which we believe to be novel. We show that thymic expression of this self antigen was Aire dependent. Moreover, prostatitis was induced in WT mice through immunization with SVS2, demonstrating that immunity to SVS2 was sufficient to induce prostatitis. The clinical relevance of this antigen was highlighted by our observation that patients with chronic prostatitis possessed specific autoantibodies against the human SVS2-like seminal vesicle protein semenogelin. These results provide direct evidence that spontaneous chronic prostatitis is an autoimmune disease and is regulated by both central and peripheral tolerance. Moreover, SVS2 and semenogelin are among the relevant autoantigens in mice and humans, respectively.

Benign Prostatic Hyperplasia-associated Free Prostate-specific Antigen Improves Detection of Prostate Cancer in an Artificial Neural Network

To show discriminative power between patients with prostate cancer (PCa) and those with "no evidence of malignancy" using "benign" prostate-specific antigen (bPSA) and the new automated Access benign prostatic hyperplasia-associated (BPHA) research assay within a percent free PSA (%fPSA)-based artificial neural network (ANN) model. The sera from 287 patients with PCa and 254 patients with no evidence of malignancy were measured using the BPHA, total PSA (tPSA), and fPSA assays with Access immunoassay technology, with a 0-10 ng/mL tPSA range. Two ANN models with Bayesian regularization and leave-one-out validation using the 4 input parameters of tPSA, %fPSA, age, and prostate volume and 1 containing BPHA/tPSA were constructed and compared by receiver operating characteristic curve analysis. The BPHA/tPSA-based ANN reached the significant greatest area under the receiver operating characteristic curve (AUC 0.81; P = .0004 and P = .0024) and best specificity (53.9% and 44.5%) compared with the ANN without BPHA/tPSA (AUC 0.77; specificity 50% and 40.6%) and %fPSA (AUC 0.77; specificity 40.9% and 27.2%) at 90% and 95% sensitivity, respectively. The AUCs for tPSA (0.58), BPHA (0.55), BPHA/fPSA (0.51), prostate volume (0.69), and BPHA/tPSA (0.69) were significantly lower. Although BPHA as single marker or ratio to tPSA did not improve the diagnostic performance of %fPSA or tPSA, the incorporation of BPHA/tPSA into an ANN model increased the specificity compared with %fPSA by 13% and 17% at 90% and 95% sensitivity, respectively. Thus, the automated BPHA research assay might improve PCa detection when incorporating this new marker into an ANN.

Monoclonal antibody to the prostate specific antigen: Monoklonaler Antikörper gegen das Prostata-spezifische Antigen

Somatic cell hybrids were made from mouse myeloma cells and spleen cells derived from BALB/c mice immunized with homogenized epithelial fractions of BPH. The screening by immunoperoxidase staining on human prostate and non-prostate tissue resulted in one monoclonal antibody identifying a prostate specific antigen. Upon SDS-PAGE and Western blot this antigen exhibited a single band at the position of 34 kDa molecular weight. The immunoreactivity of the prostate antigen was found to be localized exclusively in the epithelial lining of ducts and secretions of normal prostate, BPH and prostate cancer. Anti-p34 antibody reacted with an antigenic determinant on the PSA molecule cancer. Anti-p34 antibody reacted with an antigenic determinant on the PSA molecule and inhibited the binding of Anti-PSA antibody to PSA by about 80 to 90% in the RIA.

Critical Appraisal of Prostate-specific Antigen in Prostate Cancer Screening: 20 Years Later

Prostate-specific antigen (PSA) is secreted by all types of prostate epithelial cells and has been used for 2 decades as a biologic marker for prostate cancer (PCa). Since the implementation of PSA screening in the United States, the detection of PCa has increased, accompanied by a decrease in the incidence of high-grade cancer and PCa-specific mortality rates. It has been suggested that these decreases have resulted from the enhanced detection of PCa while still curable. These data have been the impetus for early detection programs, which have recommended the initiation of screening as early as 40 years of age. Despite widespread use, PSA screening remains controversial, principally because of the lack of evidence from randomized controlled trials demonstrating a mortality benefit that could outweigh the concerns of the costs of overdiagnosis and overtreatment. Two ongoing, randomized controlled trials are examining whether screening reduces the risk of PCa-related mortality, and the results of these studies are expected soon. Although it has its limitations, PSA still remains the best-studied marker for the detection of PCa.

Characterization of T cell responses specific for a self-antigen expressed in the mouse prostate (40.23)

Abstract OBJECTIVE: Examine if functional prostate-specific T cells exist in mice and determine if such T cells might be harnessed for prostate cancer therapy. METHODS: Studies were performed in transgenic mice (POET) expressing ovalbumin (OVA) under control of a prostate-specific promoter and double transgenic POETxOTI and POETxOTII mice, which contain OVA-specific CD8 or CD4 T cells, respectively. RESULTS: Double transgenic mice revealed incomplete central deletion of OTI and OTII cells, with functional prostate-specific T cells still present in the periphery. To model the fate of prostate-specific T cells in which the self-protein is not expressed during development, we transferred OTI or OTII cells into POET mice. While most transferred OTI cells were deleted, the persisting OTI cells were antigen experienced and capable of expanding and inducing prostate inflammation. Transferred OTII cells by contrast maintained a naïve and responsive phenotype. CONCLUSIONS: Antigen experienced prostate-specific CD8 T cells persist, can be induced to expand and infiltrate the normal prostate, and thus may prove useful for cancer therapy. CD4 T cells specific for the same prostate antigen remain naïve, suggesting limited presentation by APC. We are generating TRAMPxPOET mice, which develop OVA-expressing prostate cancer, to study targeting self-antigens for tumor therapy. Supported by the NCI &amp; a CRI Predoctoral Fellowship

Impact of vitamin D receptor activity on experimental autoimmune prostatitis

Chronic non bacterial prostatitis is a chronic inflammatory syndrome. Its etiology and physiopathology are unclear and treatments are empirical and ineffective in most cases. Autoimmunity has been proposed as an etiology. In the present report, we investigated the impact of vitamin D receptor silencing, by use of VDR-KO NOD mice and the immune-modulating effect of the vitamin D3 analog TX527 on the development of Experimental Autoimmune Prostatitis in NOD mice. VDR-KO NOD mice developed a more aggressive form of autoimmune prostatitis characterized by a greater lymphoproliferative response against prostate antigen in vitro (6.92 ± 4.77 vs. 2.47 ± 0.41 21 days after disease induction, p < 0.05) and higher levels of specific INFγ secretion (471 ± 6 vs. 386 ± 5 pg/ml, p < 0.01). This was accompanied in vivo by more severe lesions and augmented mononuclear cell infiltration in the prostate gland. On the other hand, although analog-treated mice showed a significant reduction in the spleen T-cell specific proliferative response against prostate antigen in vitro, no effect on disease development was observed. We conclude that vitamin D receptor modulation holds the promise of interfering with autoimmune prostatitis. Introduction of more powerful analogs, or combinations with anti-T-cell reagents may represent therapeutic solutions for these group of patients.

Production of Antibodies against Multipass Membrane Proteins Expressed in Human Tumor Cells Using Dendritic Cell Immunization

Antibody mediated therapeutic strategies against human malignant tumors have been widely authorized and clinically applied to cancer patients. In order to develop methods to generate antibodies reactive to the extracellular domains of multipass plasma membrane proteins specifically expressed in malignant tumors, we examined the use of dendritic cells (DCs) for immunization. DCs were transduced with genes encoding the human six transmembrane epithelial antigen of prostate 1 (STEAP1), STEAP4, and seven transmembrane prostate specific G-protein coupled receptor (PSGR). Mice were immunized with these DCs and followed by repeated booster immunization with plasmids expressing each protein. The immunized mice produced significant amounts of antibodies against these proteins. Our results suggest that DC immunization is an effective method to produce antibodies reactive to extracellular regions of plasma membrane proteins with multiple-transmembrane domains, and may be useful to develop antibody mediated antitumor therapies.

Proteome-based epitopic peptide scanning along PSA

The specific definition of the immunogenic peptide repertoire from tumor-associated-antigens (TAAs) is of crucial importance for designing effective immunotherapeutical treatments. Multiple mechanisms, at different levels and in complementary manners, contribute to the generation of immunogenic peptides. Using as an experimental model the prostate specific antigen (PSA) and a murine monoclonal antibody (MAb) raised against human PSA, the role of PSA peptide 1) similarity to the murine proteome, 2) affinity to H2-Ad/Ed molecules, and 3) proteasomal cleavage pattern were investigated. We report that the core of the interaction between the anti-PSA MAb ER-PR8 and the prostatic antigen is located in the pentapeptide motif PSA 27–31GGWEC. The pentapeptide motif is characterized by having no sequence similarity to the murine proteome and a low number of potential proteolytic sites.

The biomarker revolution: a step toward personalized medicine.

Any drug-based treatment, be it prophylactic or therapeutic, is bound to suffer from two limitations. The fi rst one is that the drug will never be active in 100% of individuals. In fact, even in classes of drugs such as prophylactic vaccines, which exhibit very high levels of effi cacy, a full effi cacy rate is very rarely obtained. In the case of small chemical drugs, the range of effi cacy is approximately 50‐70% and overall, 30% of patients do not benefi t from current medicines. The second limitation of any drug is its safety profi le. An ‘active’ drug is likely to induce side effects that will vary in severity from one individual to another. It is noteworthy in this context that the number of reported serious adverse

Abstract A12: Increased expression of STEAP1 gene as potential poor prognostic marker of prostate cancer

Abstract A12 Prostate cancer is a public health problem due to its high incidence and mortality rates. STEAP1 and STEAP2 genes (six-transmembrane epithelial antigen of prostate 1 e 2) are mapped at 7q21.13 region, where we have previously described genomic gains by array comparative genomic hybridization (aCGH) of primary prostate adenocarcinomas (PCa). The involvement of these genes in PCa development and progression remains to be clarified. They express tumor antigens and are putative molecular markers. The objective of this study was to determine STEAP1 and STEAP2 genes expressions by real time quantitative PCR (qPCR) and STEAP1protein expression by immunohistochemistry in samples of PCa, in surrounding non-neoplastic tissues, and in prostate nodular hyperplasia. Patients were classified in three groups of recurrence risk depending on serum PSA levels, Gleason scores, and tumor stages for qPCR analysis. Increased STEAP1 and STEAP2 genes expressions were registered in 16% and 21% of the 55 samples, respectively; both genes presented simultaneous increased expression in three high-risk cases. Similar pattern of expression of these genes were detected in the majority of PCa and in surrounding non-neoplastic tissues. Compared to surrounding non-neoplastic tissues, there was significant increase of STEAP1 expression in tumor samples with Gleason scores ≥ 7(4+3) and in cases with vascular invasion. There was a trend for increased STEAP1 expression in high-risk cases when compared to the moderate-risk group. In accordance with gene expression, higher levels of STEAP1 protein were expressed in PCa compared to surrounding non-neoplastic tissues. Our data suggest that increased STEAP1 expression is related to clinical and pathological parameters of PCa patients and it use as a poor prognostic marker should be considered. Citation Information: Cancer Prev Res 2008;1(7 Suppl):A12.

Autoanticuerpos séricos en pacientes con prostatitis crónica/ síndrome de dolor pélvico crónico

IntroductionChronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is an inflammatory condition that affects the prostate gland without evidence of infection in the urinary tract. Evidence reported during last decade supports a role for an autoimmune response to prostate antigens as a cause of this pathology. In fact, the presence of a specific cellular immune response against prostate antigens was demonstrated in CP/CPPS patients, but little is known about the humoral immune response. Therefore, we decided to study the presence of serum specific antibodies to prostate antigens, expressed in the human prostatic cell line DU- 145, and other serum autoantibodies that are markers of different autoimmune diseases. Materials and Methods25 patients with CP/CPPS and 13 normal controls were studied and underwent the determination of serum antibodies anti-DU-145 cells, Rheumatoid Factor, anti-Thyroperoxidase, anti- Thyroglobuline, anti-islet cells, anti-nuclear, anti-smooth muscle, antiliver and kidney microsomes, and anti-parietal cell antibodies. ResultsThere were non significant differences between controls and patients for anti-DU-145 antibodies (p=0,71). Thirty-six percent of the patients and 0% of the controls showed positive levels of Rheumatoid Factor (p=0,016). Three patients but none of the normal controls were positive for anti-Tyroperoxidase antibodies (p=0,54). One patient and one normal control presented anti-islet cell antibodies (p=0,99). No positive results were observed, either in patients or in controls, for the remaining autoantibodies assayed. ConclusionThese results show an association between the inflammatory autoimmune marker Rheumatoid Factor and CP/CPPS. Although no significant differences in the remaining assayed autoantibodies were observed, a tendency to higher positive incidence in patients compared with controls was seen. Additional studies with an enlarged population of patients are needed to elucidate the exact role of the humoral autoimmune response in CP/CPPS.

High frequency of prostate antigen‐directed T cells in cancer patients compared to healthy age‐matched individuals

In order to obtain a sustained cytotoxic T lymphocyte (CTL) response against cancer cells it is preferable to have CTLs directed against multiple peptide epitopes from numerous tumor-associated antigens. We used a Flow Cytometry-based interferon (IFN)-gamma secretion assay with peptide-pulsed C1R-A2 as antigen-presenting cells to analyze whether CD8+ T cells directed against any of 24 HLA-A*0201-binding peptides from 15 prostate-associated proteins can be found in the peripheral blood of patients with localized prostate cancer. We also investigated whether multiple prostate antigen-specific CD8+ T cells can be generated simultaneously, from a naïve T cell repertoire. In that case, dendritic cells (DCs) from peripheral blood of healthy donors were divided in six portions and separately pulsed with six peptides. The peptide-pulsed DCs were then pooled and used to stimulate autologous T cells. The T cells were re-stimulated with peptide-pulsed monocytes. We found prostate antigen-restricted CD8+ T cells in the peripheral blood in 48 out of 184 (26.1%) analyzed samples from 25 cancer patients. This is significantly higher than 17 out of 214 analyzed samples (7.9%) from 10 healthy age-matched male individuals (P = 0.0249). In the cases when antigen-specific T cells could not be detected, we were able to generate IFN-gamma-producing CD8+ T cells specific for up to three prostate antigens simultaneously from a naïve T cell repertoire. CD8+ T cells directed against prostate antigen peptides can be found in, or generated from, peripheral blood. This indicates that such T cells could be expanded ex vivo for adoptive transfer to prostate cancer patients.

Immunohistochemical Expression of Prostatic Antigens in Adenocarcinoma and Villous Adenoma of the Urinary Bladder

Adenocarcinomas of the bladder are rare, with the diagnosis dependent on exclusion of secondary involvement by direct extension or metastatic spread from other sites. The recent description of an unusual form of urothelial-type mucinous prostatic adenocarcinoma raises a novel differential diagnosis between adenocarcinomas of the prostate and bladder, and investigation into the utility of classic prostatic immunohistochemical antigens in bladder adenocarcinoma is warranted. We identified 37 primary infiltrating adenocarcinomas of the bladder, which included signet ring cell carcinomas (n=11), urachal adenocarcinomas (n=5), and enteric adenocarcinoma (n=21). Also included for comparison were 3 cases, each of bladder villous adenomas and bladder adenocarcinoma in situ. Tissue microarrays were constructed from each case, with each specimen represented by multiple 1.0-mm cores to assess for tumor protein heterogeneity. Immunohistochemistry for prostate-specific antigen (PSA), prostate specific acid phosphatase (PSAP), P501S (prostein), and prostate specific membrane antigen (PSMA) was performed, and moderate to strong immunoreactivity was considered a positive result. Of the 37 adenocarcinomas, all were negative for PSA and PSAP (0/37; 0%). In contrast, a minority of bladder adenocarcinomas was labeled with the prostate antigens P501S and PSMA. P501S showed moderate diffuse cytoplasmic staining in 4/37 cases (11%), including 3 enteric-type adenocarcinomas and 1 mucinous adenocarcinoma. Additionally, 1 case of adenocarcinoma in situ demonstrated diffuse cytoplasmic staining for P501S. The granular perinuclear staining pattern of P501S typically seen in prostatic adenocarcinoma was absent in all cases of bladder adenocarcinoma. PSMA showed diffuse cytoplasmic staining in 4/37 (11%) infiltrating adenocarcinomas (including 1 signet ring carcinoma and 3 enteric-type adenocarcinomas), and in 1 case of adenocarcinoma in situ. Membranous PSMA staining was evident in an additional 3 tumors, 1 urachal mucinous adenocarcinoma, 1 nonurachal mucinous and signet ring cell adenocarcinoma, and 1 nonurachal villous adenoma. In conclusion, although all cases of bladder adenocarcinoma examined were negative for PSA and PSAP, the surprising finding that a subset of invasive and in situ adenocarcinomas of the bladder demonstrated immunoreactivity for P501S and PSMA should warrant caution when using these markers in differentiating prostatic from bladder adenocarcinomas. The lack of granular perinuclear staining for P501S and the absence of membranous PSMA staining both favor a bladder adenocarcinoma, although rare cases of villous adenoma and adenocarcinoma did show PSMA membranous staining indistinguishable from that seen in prostate cancer. Although the novel antigens P501S and PSMA are fairly specific and more sensitive in the differential diagnosis of prostate and urothelial carcinoma, care must be taken when adenocarcinomas of the bladder are considered within this differential diagnosis.