Androgen receptor-interacting protein HSPBAP1 facilitates growth of prostate cancer cells in androgen-deficient conditions.

Hormonal therapies targeting androgen receptor (AR) are effective in prostate cancer (PCa), but often the cancers progress to fatal castrate-resistant disease. Improved understanding of the cellular events during androgen deprivation would help to identify survival and stress pathways whose inhibition could synergize with androgen deprivation. Toward this aim, we performed an RNAi screen on 2,068 genes, including kinases, phosphatases, epigenetic enzymes and other druggable gene targets. High-content cell spot microarray (CSMA) screen was performed in VCaP cells in the presence and absence of androgens with detection of Ki67 and cleaved ADP-ribose polymerase (cPARP) as assays for cell proliferation and apoptosis. Thirty-nine candidate genes were identified, whose silencing inhibited proliferation or induced apoptosis of VCaP cells exclusively under androgen-deprived conditions. One of the candidates, HSPB (heat shock 27 kDa)-associated protein 1 (HSPBAP1), was confirmed to be highly expressed in tumor samples and its mRNA expression levels increased with the Gleason grade. We found that strong HSPBAP1 immunohistochemical staining (IHC) was associated with shorter disease-specific survival of PCa patients compared with negative to moderate staining. Furthermore, we demonstrate that HSPBAP1 interacts with AR in the nucleus of PCa cells specifically during androgen-deprived conditions, occupies chromatin at PSA/klk3 and TMPRSS2/tmprss2 enhancers and regulates their expression. In conclusion, we suggest that HSPBAP1 aids in sustaining cell viability by maintaining AR signaling during androgen-deprived conditions.

Dual role of FoxA1 in androgen receptor binding to chromatin, androgen signalling and prostate cancer.

High androgen receptor (AR) level in primary tumour predicts increased prostate cancer-specific mortality. However, the mechanisms that regulate AR function in prostate cancer are poorly known. We report here a new paradigm for the forkhead protein FoxA1 action in androgen signalling. Besides pioneering the AR pathway, FoxA1 depletion elicited extensive redistribution of AR-binding sites (ARBs) on LNCaP-1F5 cell chromatin that was commensurate with changes in androgen-dependent gene expression signature. We identified three distinct classes of ARBs and androgen-responsive genes: (i) independent of FoxA1, (ii) pioneered by FoxA1 and (iii) masked by FoxA1 and functional upon FoxA1 depletion. FoxA1 depletion also reprogrammed AR binding in VCaP cells, and glucocorticoid receptor binding and glucocorticoid-dependent signalling in LNCaP-1F5 cells. Importantly, FoxA1 protein level in primary prostate tumour had significant association to disease outcome; high FoxA1 level was associated with poor prognosis, whereas low FoxA1 level, even in the presence of high AR expression, predicted good prognosis. The role of FoxA1 in androgen signalling and prostate cancer is distinctly different from that in oestrogen signalling and breast cancer.

PSA forms complexes with α1-antichymotrypsin in prostate.

BACKGROUND: PSA is the most useful prostate cancer marker. However, its levels are increased also in some non-malignant conditions. In circulation, the majority of PSA is complexed with protease inhibitors, including α(1) -antichymotrypsin (ACT). The proportion of the PSA-ACT complex is higher in patients with prostate cancer than in controls without cancer. The expression of ACT has been shown to be higher in prostate cancer than in benign prostatic hyperplasia. However, results regarding the extent which PSA forms complexes within the prostate and whether there are differences in complex formation between normal and malignant prostatic tissue are inconsistent and limited. METHODS: We studied complex formation of PSA secreted by cultured human prostate tissues and in the tissue by in situ proximity ligation assay (PLA). Free, total and active PSA, and the PSA-ACT complex were determined in tissue culture media by immunoassays, immunoblotting, and chromatographic methods. RESULTS: The majority of PSA in tissue culture medium was free and enzymatically active. However, a significant proportion (1.6 ± 0.5%) of immunoreactive PSA was found to be complexed with ACT. Complex formation was confirmed by in situ PLA, which showed more intense staining of PSA-ACT in cancers with Gleason grade 3 than in adjacent benign tissues from the same patients. CONCLUSIONS: These results show that PSA forms complexes already within the prostate and that PSA-ACT levels are increased in moderately differentiated prostate cancer tissue. This may explain, at least partially, why the ratio of serum PSA-ACT to total PSA is increased in prostate cancer.

Contrasting DNA damage checkpoint responses in epithelium of the human seminal vesicle and prostate.

BACKGROUND: Prostate and seminal vesicle are two similar hormone responsive human organs that differ dramatically in their cancer incidence. DNA damage response (DDR) is required for maintenance of genomic integrity. METHODS: In this study we investigated the DDR and cell cycle checkpoint activation of these organs using orthotopic cultures of human surgery-derived tissues and primary cultures of isolated prostate and seminal vesicle cells. RESULTS: We find that the activation of ATM signaling pathway by ionizing radiation (IR) was comparable in both tissues. Previously, we have shown that the prostate secretory cells express low levels of histone variant H2AX and phosphorylated H2AX (γH2AX) after IR. Here we demonstrate that H2AX levels are low also in the secretory seminal vesicle cells suggesting that this is a common phenotype of postmitotic cells. We consequently established primary epithelial cell cultures from both organs to compare their DDR. Interestingly, contrary to human prostate epithelial cells (HPEC), primary seminal vesicle epithelial cells (HSVEC) displayed effective cell cycle checkpoints after IR and expressed higher levels of Wee1A checkpoint kinase. Furthermore, HSVEC but not HPEC cells were able to activate p53 and to induce p21 cell cycle inhibitor. DISCUSSION: Our results show that during replication, the checkpoint enforcement is more proficient in the seminal vesicle than in the prostate epithelium cells. This indicates a more stringent enforcement of DDR in replicating seminal vesicle epithelial cells, and suggests that epithelial regeneration combined with sub-optimal checkpoint responses may contribute to high frequency of genetic lesions in the prostate epithelium.

High expression of antizyme inhibitor 2, an activator of ornithine decarboxylase in steroidogenic cells of human gonads.

High activity of ornithine decarboxylase (ODC), the rate-limiting enzyme of polyamine synthesis, is typically present in rapidly proliferating normal and malignant cells. The mitotically inactive steroidogenic cells in rodent testis and ovaries, however, also display high ODC activity. The activity of ODC in these cells responds to luteinizing hormone, and inhibition of ODC reduces the production of steroid hormones. Polyamines and ODC also control proliferation of germ cells and spermiogenesis. The activity of ODC, especially in proliferating cells, is regulated by antizyme inhibitor (AZIN). This protein displaces ODC from a complex with its inhibitor, antizyme. We have previously identified and cloned a second AZIN, i.e. antizyme inhibitor 2 (AZIN2), which has the highest levels of expression in brain and in testis. In the present study, we have used immunohistochemistry and in situ hybridization to localize the expression of AZIN2 in human gonads. We found a robust expression of AZIN2 in steroidogenic cells: testicular Leydig cells and Leydig cell tumors, in ovarian luteinized cells lining corpus luteum cysts, and in hilus cells. The results suggest that AZIN2 is not primarily involved in regulating the proliferation of the germinal epithelium, indicating a different role for AZIN1 and AZIN2 in the regulation of ODC. The localization of AZIN2 implies possible involvement in the gonadal synthesis and/or release of steroid hormones.

Treatment of prostate cancer with Ad5/3Delta24hCG allows non-invasive detection of the magnitude and persistence of virus replication in vivo.

Hormone refractory metastatic prostate cancer is a deadly disease that currently lacks curative treatments. Conditionally replicating adenoviruses (CRAds) are promising new agents against cancer due to their innate capability to cause oncolysis of tumor cells. Their antitumor effect is determined in part by their capacity for infecting cancer cells. However, the respective primary receptor, the coxsackie-adenovirus receptor (CAR), is variably expressed in many cancer types. We created Ad5/3Delta24hCG, a novel CRAd retargeted to the adenovirus serotype 3 receptor, which has been reported to be highly expressed in tumors. Furthermore, we added a transgene for the beta-chain of human chorionic gonadotropin (hCGbeta), whose expression was tightly coupled to virus replication. Ad5/3Delta24hCG was found effective in killing prostate cancer cells, and oncolysis was seen in concordance with hCGbeta production. In a s.c. in vivo model of hormone refractory prostate cancer, Ad5/3Delta24hCG treatment resulted in statistically significant tumor growth inhibition. Moreover, i.v. injection of Ad5/3Delta24hCG prolonged the survival of mice with hormone refractory prostate cancer metastatic to the lung. Detection of hCGbeta in serum samples confirmed viral replication in vivo. Infection of human clinical samples of cancerous and normal prostatic tissue resulted in effective hCGbeta production in cancer tissue, whereas it remained low in nonmalignant tissue, suggesting cancer-specific replication. These results suggest that Ad5/3Delta24hCG is a potent virus for the treatment of hormone refractory prostate cancer in vitro and in vivo. These preclinical data set the stage for translation into clinical studies.

Expression of human chorionic gonadotropin in testicular germ cell tumors.

BACKGROUND: We have shown that most patients with seminomas have elevated serum concentrations of the free ß subunit of human chorionic gonadotropin (hCGß) and that in nonseminomatous testicular cancer, most of the hCG in the serum is hyperglycosylated (hCG-h). However, the tissue expression of hCG-h or hCGß in germ cell tumors (GCTs) has not been reported. Our objective was to study the expression and diagnostic value of hCG-h and hCGß in testicular GCTs. METHODS: We studied the immunohistochemical expression of hCG, hCG-h, hCGß, and the free α subunit of hCG (hCGα) in GCTs from 154 patients. We compared the tissue expression with serum concentrations and evaluated the correlation between staining intensity, established prognostic variables, and outcome. RESULTS: The expression varied between tumor types. All forms of hCG, including hCG-h, were detected in embryonal carcinomas (22%) and mixed GCTs (48%). Polyclonal hCG and monoclonal hCGß antibodies detected immunoreactivity in some seminomas (7%). No form of hCG was found in spermatocytic seminomas, pure teratomas, or a yolk sac tumor. The serum concentrations correlated with the corresponding tumor expression. The staining intensities of hCG, hCGß, hCG-h, and hCGα correlated with disease stage but not significantly with relapse, disease-related mortality, or progression-free survival. CONCLUSION: Trophoblastic tissue expresses hCG, hCG-h, and free subunits together whereas seminoma tissue occasionally expresses hCGß. This difference might aid in differential diagnosis of some difficult-to-classify cases.

Comparison of intermittent and continuous androgen deprivation and quality of life between patients with locally advanced and patients with metastatic prostate cancer: a post hoc analysis of the randomized FinnProstate Study VII.

OBJECTIVE: The aim of the study was to compare intermittent (IAD) and continuous (CAD) androgen deprivation therapy (ADT) between locally advanced (M0) and metastatic (M1) prostate cancer, and the effect of ADT on the quality of life. MATERIAL AND METHODS: In total, 852 men with advanced prostate cancer were enrolled to receive goserelin acetate for 24 weeks. Of these, 554 patients whose prostate-specific antigen (PSA) decreased to less than 10 ng/ml or by at least 50% (<20 ng/ml at baseline) were randomized to IAD or CAD. In the IAD arm, ADT was resumed for at least 24 weeks whenever PSA increased to greater than 20 ng/ml or above baseline. RESULTS: Median follow-up time was 65 months. Median times from randomization to progression, death, prostate cancer death and treatment failure in M0 and M1 patients were 46.8 and 21.4, 57.6 and 40.3, 59.5 and 40.7, and 41.9 and 20.0 months, respectively (p < 0.001). No significant differences emerged between IAD and CAD. ADT showed a beneficial effect on pain, activity limitation and social functioning in M1 patients, and a deleterious effect on physical capacity in M0 patients and on sexual functioning in both groups. IAD offered extra benefit for activity limitation, social functioning and recovery of sexual functioning. CONCLUSIONS: IAD is as efficient as CAD in treatment of locally advanced and metastatic prostate cancer. ADT improves quality of life in M1 patients, with IAD offering extra benefit.

Phospholipase PLA2G7, associated with aggressive prostate cancer, promotes prostate cancer cell migration and invasion and is inhibited by statins.

Prostate cancer is the second leading cause of cancer mortality in men in developed countries. Due to the heterogeneous nature of the disease, design of novel personalized treatments is required to achieve efficient therapeutic responses. We have recently identified phospholipase 2 group VII (PLA2G7) as a potential drug target especially in ERG oncogene positive prostate cancers. Here, the expression profile of PLA2G7 was studied in 1137 prostate cancer and 409 adjacent non-malignant prostate tissues using immunohistochemistry to validate its biomarker potential and putative association with disease progression. In order to reveal the molecular alterations induced by PLA2G7 impairment, lipidomic and gene expression profiling was performed in response to PLA2G7 silencing in cultured prostate cancer cells. Moreover, the antineoplastic effect of statins combined with PLA2G7 impairment was studied in prostate cancer cells to evaluate the potential of repositioning of in vivo compatible drugs developed for other indications towards anti-cancer purposes. The results indicated that PLA2G7 is a cancer-selective biomarker in 50 % of prostate cancers and associates with aggressive disease. The alterations induced by PLA2G7 silencing highlighted the potential of PLA2G7 inhibition as an anti-proliferative, pro-apoptotic and anti-migratorial therapeutic approach in prostate cancer. Moreover, the anti-proliferative effect of PLA2G7 silencing was potentiated by lipid-lowering statins in prostate cancer cells. Taken together, our results support the potential of PLA2G7 as a biomarker and a drug target in prostate cancer and present a rationale for combining PLA2G7 inhibition with the use of statins in prostate cancer management.

Low proportion of false-negative smears in the Finnish program for cervical cancer screening.

BACKGROUND: We assessed the performance and validity of cytology in the Finnish screening program by considering high-grade neoplasia and cervical cancer (CIN3+) rates as detected in the program and by reevaluating cases observed after a negative screening test. METHODS: This retrospective study included 915 screen-detected CIN3+ cases and 421 cases observed after a negative screen. Randomized and blinded reevaluation of potential false-negative screening tests covered 345 archival case smears from women without a referral to colposcopy, as well as 689 control smears for estimating performance and validity measures. RESULTS: The false-negative rate at the cutoff of low-grade squamous intraepithelial lesion or worse was 35% (95% confidence interval, 30-40%). In the subpopulation with original screening result of Pap I, the false-negative rate was 23% (18-28%). Sensitivity of screening laboratory rereading for detecting low-grade lesions or worse as atypical was 75% (67-82%) and specificity 93% (91-94%). Reproducibility of specific cytologic diagnoses was only fair. False negatives constituted 11% of all CIN3+ diagnoses in the screened population; those false negatives with an original Pap I screening result constituted 5%. CONCLUSIONS: Although screen failures in the form of diagnostic false negatives occur within the Finnish screening program, their effect on cancer incidence is fairly small and cannot be readily decreased without sacrificing the high specificity of screening or without high incremental costs. Feedback for the screening laboratories is needed, however, to improve the reproducibility of cytologic diagnoses to optimize the burden of intensified follow-up and treatment of precancerous lesions.

DNA damage recognition via activated ATM and p53 pathway in nonproliferating human prostate tissue.

DNA damage response (DDR) pathways have been extensively studied in cancer cell lines and mouse models, but little is known about how DNA damage is recognized by different cell types in nonmalignant, slowly replicating human tissues. Here, we assess, using ex vivo cultures of human prostate tissue, DDR caused by cytotoxic drugs (camptothecin, doxorubicin, etoposide, and cisplatin) and ionizing radiation (IR) in the context of normal tissue architecture. Using specific markers for basal and luminal epithelial cells, we determine and quantify cell compartment-specific damage recognition. IR, doxorubicin, and etoposide induced the phosphorylation of H2A.X on Ser(139) (γH2AX) and DNA damage foci formation. Surprisingly, luminal epithelial cells lack the prominent γH2AX response after IR when compared with basal cells, although ATM phosphorylation on Ser(1981) and 53BP1 foci were clearly detectable in both cell types. The attenuated γH2AX response seems to result from low levels of total H2A.X in the luminal cells. Marked increase in p53, a downstream target of the activated ATM pathway, was detected only in response to camptothecin and doxorubicin. These findings emphasize the diversity of pathways activated by DNA damage in slowly replicating tissues and reveal an unexpected deviation in the prostate luminal compartment that may be relevant in prostate tumorigenesis. Detailed mapping of tissue and cell type differences in DDR will provide an outlook of relevant responses to therapeutic strategies.

Long-term efficacy of maintenance bacillus Calmette-Guérin versus maintenance mitomycin C instillation therapy in frequently recurrent TaT1 tumours without carcinoma in situ: a subgroup analysis of the prospective, randomised FinnBladder I study with a 20-year follow-up.

BACKGROUND: The long-term prospective data on bacillus Calmette-Guérin (BCG) and mitomycin C (MMC) instillation therapy are limited. OBJECTIVE: To compare the long-term benefit of BCG and MMC maintenance therapy in patients with recurrent bladder carcinoma. DESIGN, SETTING, AND PARTICIPANTS: Eighty-nine patients with frequently recurrent TaT1 disease without carcinoma in situ (CIS) were eligible. Originally, the patients were enrolled in the prospective FinnBladder I study between 1984 and 1987 and randomised to receive BCG or MMC. Both regimens involved five weekly instillations, followed by monthly instillations for 2 yr. Because of alkalinising the urine and adjusting the dose to bladder capacity, the average concentration of MMC was low: 30-40 mg in 150-200 ml of phosphate buffer. Overall median follow-up time was 8.5 yr, whereas the median follow-up time of the patients who were still alive was 19.4 yr. MEASUREMENTS: Primary end points were time to first recurrence and overall mortality. Secondary end points were progression and disease-specific mortality. RESULTS AND LIMITATIONS: Thirty-six of 45 patients (80.0%) in the MMC group experienced recurrence in contrast to 26 of 44 patients (59.1%) in the BCG group. This finding was reflected in significantly lower cumulative incidence estimates in the BCG group (p=0.005). There was a weak trend for fewer progressions (p=0.1) and cancer-specific deaths (p=0.2) in the cumulative incidence analysis, as 4 patients versus 10 patients progressed and 4 patients versus 9 patients died from the disease in the BCG group versus the MMC group, respectively. No difference existed in the overall mortality. The study population, however, was too small for conclusive evidence about progression or survival. CONCLUSIONS: An intensive intravesical BCG immunotherapy results in a sustained and significant long-term reduction in recurrence in frequently recurrent bladder carcinoma. The relatively low progression rate during the long follow-up suggests that it may be difficult to show significant differences in overall mortality with a substantially larger but otherwise similar study population. TRIAL REGISTRATION: Registration was not considered to be necessary at this stage of the follow-up because the study was initiated as early as 1984 and the last randomisation took place in July 1987, that is, long before the current requirements concerning study registrations were implemented.

Adenocarcinoma in isolated rectal bladder after treatment of bladder exstrophy.

We report the first Finnish patient with carcinoma in an augmented intestinal bladder, where urine and stools are not in contact. The patient had undergone rectal bladder reconstruction at the age of 2 years because of bladder exstrophy. When the patient was aged 46 years, a 2-cm, papillar, well-differentiated adenocarcinoma was detected and removed, preserving the rectal bladder.

Laparoscopic radical prostatectomy: surgical, oncological and functional outcomes.

OBJECTIVE: To report the first results of laparoscopic radical prostatectomy (LRP) at our institution. MATERIAL AND METHODS: The surgical, functional and oncological outcomes of all patients who underwent LRP at Helsinki University Central Hospital between May 2002 and May 2006 were prospectively evaluated. The first eight patients were operated transperitoneally and the next 72 extraperitoneally. RESULTS: The mean operative time was 328+/-73 min (range 210-510 min). The mean estimated blood loss was 769+/-906 ml (range 50-5500 ml), and 18 patients (22.5%) had transfusions. The mean catheterization time was 13.2+/-4.0 days (range 9-35 days). Mean hospital stay was 5.7+/-3.1 days (range 3-15 days). Nineteen patients (23.8%) had perioperative complications. The conversion rate to open surgery was 11.3% and 6.3% required an immediate re-operation. Three anastomotic strictures (5.7%) and two cases of ileus (3.8%) were observed. The cancer was intracapsular (pT1-2) in 68 patients (85.0%) and extracapsular (pT3-4) in 12 (15.0%). Positive surgical margins were noted in 20 patients (25.0%) in total: 17.6% of pT1-2 cases and 66.7% of pT3-4 cases. Prostate-specific antigen recurrence (> or =0.2 ng/ml) was noted in 5/53 patients (9.4%), who were followed for >12 months. The continence rate (no daily pad use) was 86.8% and the potency rate was 34.6% at 12 months. CONCLUSIONS: The surgical, functional and oncological results of our first LRPs compare fairly well with the early experience of others. LRP is feasible outside high-volume centers but the learning curve is expected to be long.

Clinical significance of widespread gastric metaplasia in the duodenal bulb.

BACKGROUND: All the risk factors of peptic ulcer disease are not thoroughly understood. GOALS: To assess duodenal gastric metaplasia (DGM) in relation to Helicobacter pylori status and endoscopy findings with special reference to the effects of highly selective vagotomy. STUDY: The study population consisted of 1056 adult patients and an additional 154 patients who had had a highly selective vagotomy. Their clinical and endoscopy records as well as the histology of gastric and duodenal biopsies were evaluated retrospectively. H. pylori infection had been determined by serology and culture. RESULTS: Widespread (more than 20%) DGM was strongly associated with H. pylori positive duodenal ulcer disease (in 59.7% of patients). The prevalence of DGM diminished progressively the more proximally the ulcer was located in the stomach, and was 2.5% in proximal gastric ulcers patients. In vagotomized patients, the prevalence of widespread DGM (8.4% of patients, median 14 years after operation and the majority still H. pylori positive) was close to that of patients with H. pylori gastritis without peptic ulcer disease (4.5%). CONCLUSIONS: Widespread DGM is an indicator for an increased risk of duodenal ulcer among H. pylori positive patients and it could be used to select patients for eradication therapy.