Preoperative p27 status is an independent predictor of prostate specific antigen failure following radical prostatectomy

miR-196a-mediated downregulation of p27kip1 protein promotes prostate cancer proliferation and relates to biochemical recurrence after radical prostatectomy

BACKGROUND

Dysregulation of microRNAs has performed vital gene regulatory functions in the genesis, progression, and prognosis of multiple malignant tumors. This study aimed to elucidate the regulatory mechanism of miR-196a in prostate cancer (PCa) and explore its clinical significance.

METHODS

Quantitative real-time polymerase chain reaction was implemented to examine miR-196a and p27^kip1 messenger RNA expression in PCa. Cell proliferation was evaluated via Cell Counting Kit-8, colony formation, and nude mouse tumorigenicity assays. Luciferase reporter assay was applied to identify target genes. p27^kip1 protein expression in PCa was investigated using Western blot analysis and immunohistochemistry.

RESULTS

There was a dramatic upregulation of miR-196a in PCa. Upregulated miR-196a was related to worse Gleason score (GS), later pathological stage, and poor biochemical recurrence (BCR)-free survival. In vivo and in vitro experiments exhibited that miR-196a promoted PCa proliferation and expedited G1/S-phase progression through the downregulation of p27^kip1 protein. Additionally, p27^kip1 protein was distinctly downregulated in PCa. Low p27^kip1 protein expression had a strong correlation with increased GS and was an independent predictor of BCR after radical prostatectomy (RP).

CONCLUSIONS

Excessive expression of miR-196a and subsequent downregulation of p27^kip1 protein play essential roles in promoting PCa proliferation and leading to BCR after RP. miR-196a and its target p27^kip1 may become novel molecular biomarkers and therapeutic targets for PCa.

Comprehensive analysis of biomarkers for prostate cancer based on weighted gene co-expression network analysis

BACKGROUND

Prostate cancer (PCa) is one of the leading causes of cancer-related death. In the present research, we adopted a comprehensive bioinformatics method to identify some biomarkers associated with the tumor progression and prognosis of PCa.

METHODS

Differentially expressed genes (DEGs) analysis and weighted gene co-expression network analysis (WGCNA) were applied for exploring gene modules correlative with tumor progression and prognosis of PCa. Clinically Significant Modules were distinguished, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to Annotation, Visualization and Integrated Discovery (DAVID). Protein-protein interaction (PPI) networks were used in selecting potential hub genes. RNA-Seq data and clinical materials of prostate cancer from The Cancer Genome Atlas (TCGA) database were used for the identification and validation of hub genes. The significance of these genes was confirmed via survival analysis and immunohistochemistry.

RESULTS

2688 DEGs were filtered. Weighted gene co-expression network was constructed, and DEGs were divided into 6 modules. Two modules were selected as hub modules which were highly associated with the tumor grades. Functional enrichment analysis was performed on genes in hub modules. Thirteen hub genes in these hub modules were identified through PPT networks. Based on TCGA data, 4 of them (CCNB1, TTK, CNN1, and ACTG2) were correlated with prognosis. The protein levels of CCNB1, TTK, and ACTG2 had a degree of differences between tumor tissues and normal tissues.

CONCLUSION

Four hub genes were identified as candidate biomarkers and potential therapeutic targets for further studies of exploring molecular mechanisms and individual therapy on PCa.

Molecular alterations associated with prostate cancer

Introduction

The amount of information and knowledge about pathways and genetic alterations regarding prostate cancer, including the tools available for its study has been recently increasing. Additionally, a variety of molecular signaling pathways control cell proliferation, however, this incompletely understood process is disturbed in cancer cells.

Materials and methods

A literature review was made using the MEDLINE, Embase and LILACS databases searching for the following keywords: prostate neoplasms, prostate cancer, molecular medicine, genomics, pathways, and cell cycle.

Results

Different biological mechanisms have been associated with the development of prostate cancer, such as alterations in tumor suppressor genes, oncogenes (TP53, RB1, among others) and CDKIs; DNA methylation; chromosomal alterations and rearrangements; changes in PTEN and PI3K / mTOR; global defects in apoptosis; alterations in the androgen receptor (AR); and epigenetic mechanisms.

Conclusions

Good clinical practice and a practical approach have to be based on basic knowledge, thus, in this article, the main genetic alterations, mutations and pathways involved in prostate cancer development were reviewed.

Long non-coding RNA GAS5 and ZFAS1 are prognostic markers involved in translation targeted by miR-940 in prostate cancer

Identification of prognostic biomarkers helps facilitate the prediction of patient outcomes as well as guide treatments. Accumulating evidence now suggests that long non-coding RNAs (lncRNAs) play key roles in tumor progression with diagnostic and prognostic values. However, little is known about the biological functions of lncRNAs and how they contribute to the pathogenesis of cancer. Herein, we performed weighted correlation network analysis (WGCNA) on 380 RNA-seq samples from prostate cancer patients to create networks comprising of microRNAs, lncRNAs, and protein-coding genes. Our analysis revealed expression modules that associated with pathological parameters. More importantly, we identified a gene module that is involved in protein translation and is associated with patient survival. In this gene module, we explored the regulation axis involving GAS5, ZFAS1, and miR-940. We show that GAS5, ZFAS1, and miR-940 are up-regulated in tumors relative to normal prostate tissues, and high expression of either lncRNA is an indicator of poor patient outcome. Finally, we constructed a co-expression network involving GAS5, ZFAS1, and miR-940, as well as the targets of miR-940. Our results show that GAS5 and ZFAS1 are targeted by miR-940 via NAA10 and RPL28. Taken together, co-expression analysis of gene expression profiling from RNA-seq can accelerate the identification and functional characterization of novel prognostic markers in prostate cancer.

Antitumoral action of icaritin in LNCaP prostate cancer cells by regulating PEA3/HER2/AR signaling

Human epidermal growth factor receptor type 2 (HER2) and androgen receptor (AR) are critical factors for prostate cancer (PCa) progression. These factors regulate tumor cell survival and proliferation, and remain as crucial drivers of castration-resistant PCa progression. Icaritin (ICT) is a prenyl flavonoid derived from the Epimedium genus, which has many biological and pharmacological effects. Using androgen-sensitive human prostate carcinoma LNCaP cell lines, we found that 35 μg/ml of ICT could inhibit more than 50% of cell proliferation, induce cell apoptosis, and lead to a strong G1 phase arrest by targeting cyclin-related proteins and suppressing the ability of cell invasion. Moreover, ICT exerts its potent anticancer efficacy by inducing polyomavirus enhancer activator 3 (PEA3) to inhibit the aberrantly activated HER2/AR signaling. In addition, after PEA3 expression was silenced by specific small-interference RNA, we found that both the ICT-inhibited effect on LNCaP cell proliferation and the ICT-induced cell apoptosis rate decreased. These results provide alternative mechanisms for the antitumor actions of ICT, indicating that ICT might be a promising therapeutic agent, as well as a preventive agent, for hormone therapy-resistant PCa.

Biomarkers for evaluation of prostate cancer prognosis

Prostate cancer, with a lifetime prevalence of one in six men, is the second cause of malignancy-related death and the most prevalent cancer in men in many countries. Nowadays, prostate cancer diagnosis is often based on the use of biomarkers, especially prostate-specific antigen (PSA) which can result in enhanced detection at earlier stage and decreasing in the number of metastatic patients. However, because of the low specificity of PSA, unnecessary biopsies and mistaken diagnoses frequently occur. Prostate cancer has various features so prognosis following diagnosis is greatly variable. There is a requirement for new prognostic biomarkers, particularly to differentiate between inactive and aggressive forms of disease, to improve clinical management of prostate cancer. Research continues into finding additional markers that may allow this goal to be attained. We here selected a group of candidate biomarkers including PSA, PSA velocity, percentage free PSA, TGFβ1, AMACR, chromogranin A, IL-6, IGFBPs, PSCA, biomarkers related to cell cycle regulation, apoptosis, PTEN, androgen receptor, cellular adhesion and angiogenesis, and also prognostic biomarkers with Genomic tests for discussion. This provides an outline of biomarkers that are presently of prognostic interest in prostate cancer investigation.

Low dosed interferon alpha augments the anti-tumor potential of histone deacetylase inhibition on prostate cancer cell growth and invasion

We evaluated whether low-dosed interferon alpha (IFNa) may augment the anti-tumor potential of the histone deacetylase (HDAC)-inhibitor valproic acid (VPA) on prostate cancer cells in vitro and in vivo. PC-3, DU-145, or LNCaP prostate cancer cells were treated with VPA (1 mM), IFNa (200 U/ml), or with the VPA-IFNa combination. Tumor cell growth, cell cycle progression, and cell cycle regulating proteins were then investigated by the MTT assay, flow cytometry, and western blotting. Tumor cell adhesion to endothelium or to immobilized extracellular matrix proteins, as well as migratory properties of the cells, were evaluated. Integrin α and β adhesion molecules and alterations of cell signaling pathways were analyzed. Finally, effects of the drug treatment on prostate cancer growth in vivo were determined in the NOD/SCID mouse model. VPA reduced tumor cell adhesion, migration, and growth in vitro. A much stronger anti-cancer potential was evoked by the VPA-IFNa combination, although IFNa in itself did not block growth or adhesion. The same effect was seen when tumor growth was evaluated in vivo. Molecular analysis revealed distinct elevation of histone H3 acetylation caused by VPA which was further up-regulated by VPA-IFNa, whereas IFNa alone did not alter H3 acetylation. The combinatorial benefit became obvious in Akt phosphorylation, p21 and p27 and integrin α1, α3, and β1 expression. Application of low-dosed IFNa to a VPA based regimen profoundly boosts the anti-tumor properties of VPA. The combined use of VPA and low-dosed IFNa may therefore be an innovative option in treating advanced prostate cancer.

The role of treatment modality on the utility of predictive tissue biomarkers in clinical prostate cancer: a systematic review

BACKGROUND

Tissue biomarkers could pivotally improve clinical outcome prediction following prostate cancer therapy. Clinically, prostate cancer is managed by diverse treatment modalities whose individual influence on a biomarker's predictive ability is not well understood and poorly investigated in the literature.

OBJECTIVE

We conducted a systematic review to assess the predictive value of biomarkers in different treatment contexts in prostate cancer.

STUDY METHODOLOGY

A literature search was performed using the MeSH headings "prostate neoplasms" and "biological markers". Rigorous selection criteria identified studies correlating expression with clinical outcomes from primary androgen deprivation therapy (ADT), radical prostatectomy and radiotherapy (± neoadjuvant ADT).

STUDY RESULTS

Of 10,668 studies identified, 481 papers matched initial inclusion criteria. Following rescreening, 384 studies identified 236 individual tissue biomarkers, of which 29 were predictive on multivariate analysis in at least 2 independent cohorts. The majority were only tested in surgical cohorts. Only 8 predictive biomarkers were tested across all 3 treatments with Ki67 identified as universal predictive marker. p16 showed potential for treatment stratification between surgery and radiotherapy but needs further validation in independent studies.

CONCLUSIONS

Despite years of research, very few tissue biomarkers retain predictive value in independent validation across therapy context. Currently, none have conclusive ability to help treatment selection. Future biomarker research should consider the therapy context and use uniform methodology and evaluation criteria.

[Prostate cancer: promising biomarkers related to aggressive disease]

BACKGROUND

Although a rapidly growing number of candidate biological markers of prognosis and/or response to specific treatments in prostate cancer, none have to date showed ability to completely prognosticate prostate cancer on evidence based urology.

OBJECTIVE

To review the pertinent literature on the issue.

ACQUISITION OF EVIDENCE

A comprehensive review of the current literature was done focusing on promising biomarkers related to aggressive prostate cancer.

SUMMARY OF EVIDENCE

Combined with the heterogeneous nature of the disease, mixed case series are the most common study design, impeding robust results and the development of an effective therapeutic strategy. Improvement in prostate cancer patient survival requires not only the identification of new therapeutic target based on detailed understanding of the biological mechanisms involved in metastatic dissemination and tumor growth but strong clinical studies as well.

CONCLUSION

Better study design involving potential markers and including well-classified and staged patients with robust methodology and adequate outcomes (mainly survival) are necessary to the field evolution.

Inhibition of cyclin-dependent kinase phosphorylation of FOXO1 and prostate cancer cell growth by a peptide derived from FOXO1

Increasing evidence suggests that FOXO1 possesses a tumor suppressor function. Inactivation of FOXO1 has been documented in many types of human cancer, and restoring the activity of FOXO1 holds promise for cancer treatment. In this study, we identified a FOXO1-derived peptide termed FO1-6nls that inhibits cyclin-dependent kinases 1 and 2 (CDK1/2)-mediated phosphorylation of FOXO1 at the serine 249 residue in vitro and in vivo. Overexpression of FO1-6nls in prostate cancer (PCa) cells not only blocked CDK1-induced cytoplasmic localization of FOXO1 but also augmented FOXO1's transcriptional activity. This effect of FO1-6nls requires its binding to CDK1 and CDK2. Moreover, the ectopic expression of FO1-6nls inhibited the growth of PTEN-positive DU145 PCa cells. Importantly, the growth-inhibitory function of FO1-6nls is dependent on FOXO1. Finally, the ectopic expression of FO1-6nls overcame CDK1-mediated inhibition of FOXO1-induced apoptosis of PCa cells. These results indicate that the FOXO1-derived peptide FO1-6nls can restore FOXO1's tumor suppressor function by specifically opposing CDK1/2-mediated phosphorylation and inhibition of FOXO1 and hence may have a therapeutic potential for the treatment of PCa.

Is there a role for chemotherapy in nonmetastatic prostate cancer?

PURPOSE OF REVIEW

Prognostic clinical, pathological, and molecular parameters identify patients with nonmetastatic prostate cancer that are at risk for the development of future metastatic disease and shorter survival. In metastatic castration-resistant prostate cancer, docetaxel-based chemotherapy prolongs survival and improves quality of life, and is the standard of care. It may be rational to hypothesize that early utilization of chemotherapy may delay the onset of distant metastasis and prolong survival in the earlier nonmetastatic disease. A discussion on ongoing clinical trials and natural history aspects applicable to clinical trials design in this setting are presented herein.

RECENT FINDINGS

Preliminary data suggest that chemotherapy is well tolerated, feasible, and potentially active in nonmetastatic prostate cancer. However, results from prospective randomized trials were not published yet.

SUMMARY

In nonmetastatic prostate cancer, application of chemotherapy remains an open question awaiting prospective validation and should be routinely applied outside of clinical trials. In view of the long natural history, evaluation of conventional endpoints as time to distant metastasis and survival are challenging even in the high-risk patients. Appropriate patient selection based on predictive biomarkers and surrogate endpoints may provide critical information for patient selection and study design.

Cysteine-rich secretory protein 3 and β-microseminoprotein on prostate cancer needle biopsies do not have predictive value for subsequent prostatectomy outcome

OBJECTIVES

• To investigate whether cysteine-rich secretory protein 3 (CRISP-3) and/or β-microseminoprotein (β-MSP) expression in diagnostic prostate needle biopsies have predictive value for prostate cancer (PC) on radical prostatecomy (RP). • To evaluate their potential clinical implementation in a preoperative setting.

PATIENTS AND METHODS

• In total, 174 participants from the European Randomized Study of Screening for Prostate Cancer, Rotterdam section, treated by RP for PC were included in the present study. • CRISP-3 and β-MSP immunohistochemistry was performed on corresponding diagnostic needle biopsies. • Outcome was correlated with clinicopathological parameters (prostate-specific-antigen, PSA; number of positive biopsies; Gleason score, GS; pT-stage; surgical margins at RP) and significant PC at RP (pT3/4, or GS > 6, or tumour volume ≥ 0.5 mL) in the total cohort (n= 174) and in a subgroup with low-risk features at biopsy (PSA ≤ 10 ng/ml, cT ≤ 2, PSA density <0.20 ng/mL/g, GS < 7 and ≤ 2 positive biopsy cores; n= 87).

RESULTS

• β-MSP and CRISP-3 expression in PC tissue was heterogeneous, with variable staining intensities occurring in the same tissue specimen. • High expression of β-MSP significantly correlated with GS < 7 at RP; it was not a predictor for significant PC at RP neither in the total group (n= 174; odds ratio, OR, 0.319; 95% confidence interval, CI, 0.060-1.695; P= 0.180), nor in the low-risk group (n= 87; OR, 0.227; 95% CI, 0.040-1.274; P= 0.092). • CRISP-3 expression was not related to clinicopathological parameters, and did not predict significant PC at RP in the total group (n= 174; OR, 1.056; 95% CI, 0.438-2.545; P= 0.904) or the low-risk group (n= 87; OR, 1.856; 95% CI, 0.626-5.506; P= 0.265).

CONCLUSIONS

• High β-MSP expression correlated with low GS in subsequent RP specimens, supporting the view that β-MSP exerts a tumour-suppressive effect. • No significant prognostic value of β-MSP or CRISP-3 in prostate needle biopsies for significant PC at RP was found. • β-MSP or CRISP-3 do not have additional value in the therapeutic stratification of patients with PC.

Biomolecular markers of outcome prediction in prostate cancer

Prostate cancer has a variable clinical outcome and, therefore, there is a clear need for novel molecular markers that are specifically associated with biologically aggressive disease to improve staging and prognostication and also to provide mechanistic information to facilitate treatment selection. Different candidate biomarkers have been identified that are linked to patient prognosis and/or response to specific treatments. Such molecules are involved in diverse cellular processes (including cell cycle regulation, cell death and apoptosis, signal transduction, cell adhesion, and angiogenesis) within which aberrant activity of several regulatory pathways has been seen in prostate cancer. Although the number of molecular markers continues to grow, mainly because of the advent of high-throughput methods, more work needs to be done to develop uniform standards for their characterization to enable comparison of markers across studies. Moreover, a rate-limiting step in the development of molecular markers is large-scale clinical assessment and their evaluation in the context of prediction model improvement. In fact, thus far, only a few studies have tested and demonstrated whether the addition of new biological markers improves the accuracy of standard clinical models (nomograms) in predicting biochemical progression in patients with clinically localized prostate cancer who underwent radical prostatectomy. Cancer 2009;115(13 suppl):3058-67. (c) 2009 American Cancer Society.

The impact of Skp2 overexpression on recurrence-free survival following radical prostatectomy

BACKGROUND

In several human cancers, overexpression of Skp2 (S-phase kinase associated protein 2), which targets p27 for degradation, portends a poorer prognosis. We examined whether Skp2 overexpression is associated with recurrence following radical prostatectomy (RP) for prostate cancer.

METHODS

Immunohistochemical staining for Skp2, p27, and MIB-1 was performed on 109 men with node-negative prostate cancer surgically managed from 1985-1996. Associations between the stains were tested and Cox regression was used to determine the association between Skp2 expression and time to biochemical recurrence following RP.

RESULTS

The 12 tumors (11%) with Skp2 overexpression all had correspondingly low p27 expression (P=0.006), and a similar inverse Skp2/p27 relationship was seen in vitro in LNCap cells. Skp2 overexpression in tissue was associated with higher Gleason score (P=0.002), more advanced pathological stage (P=0.01), and higher MIB-1 index (P=0.03), but a more favorable PSA profile (P=0.04). Five men received a TURP. Among 104 who received RP, median follow-up was 67 months (range: 0.2-218). After adjusting for PSA, pathologic stage, and Gleason score, Skp2 overexpression remained significantly associated with a shorter time to biochemical recurrence (adjusted hazard ratio 4.8 (95% C.I. 1.6-14, P=0.004)). The median time to recurrence with high vs. low Skp2 was 4 vs. 54 months.

CONCLUSIONS

Skp2 overexpression was seen in a significant minority of surgically-managed men and was independently associated with a higher risk of recurrence, raising the possibility that Skp2 could be useful as a prognostic biomarker and as a potential molecular target for novel systemic agents in prostate cancer.

The elevated expression of a mismatch repair protein is a predictor for biochemical recurrence after radical prostatectomy

PURPOSE

The inability to predict clinical outcome of prostate cancer is a major impediment to effective treatment decisions and patient counseling. New markers of recurrence are needed to improve the accuracy of risk assessment and treatment of prostate cancer. Our previous studies identified a mismatch repair protein, PMS2, to be elevated in prostate cancer; here, we investigate the prognostic potential of this marker. We hypothesized that the elevation of PMS2 would correlate with disease outcome.

EXPERIMENTAL DESIGN

Retrospective quantitative immunohistochemistry was done to measure PMS2 in high-grade cancers of 166 men treated by radical prostatectomy with a biochemical recurrence rate of 56%. Associations between PMS2 levels, pathologic variables, and biochemical recurrence over time were determined.

RESULTS

The mean level of PMS2 protein was consistently higher in both cancer-associated benign epithelium and cancer cells of patients who recurred, compared with nonrecurrent patients. PMS2 was an independent predictor of time-to-recurrence in Cox multivariate analyses and significantly stratified patients based on outcome. PMS2 was able to improve the sensitivity of total percent Gleason 4/5 as a risk factor for recurrence in this cohort.

CONCLUSIONS

PMS2 protein levels were shown to be a predictor of time-to-recurrence after surgery. This study is the first to document that the elevation of a mismatch repair protein negatively correlates with prognosis and has implications in patient diagnosis and molecular profiling.

The Cdk inhibitor p27 in human cancer: prognostic potential and relevance to anticancer therapy

The cyclin-dependent kinase (Cdk) inhibitor p27 (also known as KIP1) regulates cell proliferation, cell motility and apoptosis. Interestingly, the protein can exert both positive and negative functions on these processes. Diverse post-translational modifications determine the physiological role of p27. Phosphorylation regulates p27 binding to and inhibition of cyclin-Cdk complexes, its localization and its ubiquitin-mediated proteolysis. In cancers, p27 is inactivated through impaired synthesis, accelerated degradation and by mislocalization. Moreover, studies in several tumour types indicate that p27 expression levels have both prognostic and therapeutic implications.

Expression of p27((Kip1)), cyclin D3 and Ki67 in BPH, prostate cancer and hormone-treated prostate cancer cells

p27((Kip1)), cyclin D3 and Ki67 are the markers of DNA damage and cell proliferation. The goal of the current study was to analyze expression of the markers in benign and malignant prostate cancer tissues. Activity of p27((Kip1)), cyclin D3 and Ki67 was immunohistochemically evaluated in different cells of BPH, prostate cancer (PCa) and hormonally treated prostate cancer (HTPCa) tissues. The tissue samples were derived by means of TURP or radical prostatectomy. Intensity of the expression was compared between the groups, and association was sought with clinical parameters. Total expression of p27((Kip1)) was significantly higher in BPH as compared with PCa. Epithelial marker expression was higher in HTPCa than in PCa. Intensity of the expression in epithelial, vascular and ductal cells was negatively associated with the tumor stage and Gleason grades. Total Ki67 activity was positively correlated with patient age and serum PSA level. There was significantly higher expression in PCa and hormone-escaped PCa (HEPCa) as compared with BPH. Epithelial and vascular marker expression was positively associated with tumor stage and Gleason grades. There was a positive correlation between cyclin D3 and serum PSA level. With the increase of Gleason grades, cyclin D3 expression increased significantly. Expression of p27((Kip1)) negatively correlated with Ki67 and cyclin D3, while the latter two markers correlated positively. p27((Kip1)) is down-regulated, whereas Ki67 and cyclin D3 are up-regulated in PCa. Intensity of the markers' expression is associated with tumor stage and grades. Hormonotherapy of PCa causes activation of p27((Kip1)). HEPCa is characterized by increased Ki67 expression.

Prognostic significance of p27Kip1 expression in bladder cancer

The importance of markers in urological cancer is well recognised and many attempts are being made to find one which will be of prognostic significance. Authors from New York found that low expression of p27Kip1 in patients with bladder cancer was a significant predictor of pelvic recurrence, progression to metastasis and death. Authors from Switzerland examined patients with a primary solitary distal ureteric TCC; they found that distal ureteric resection in such patients is feasible, and that the long-term oncological outcome appears to be comparable to more radical treatment of this condition.

OBJECTIVE

To define the prognostic significance of p27(Kip1) expression in bladder cancer for overall, disease-specific, metastasis-free and pelvic recurrence-free survival, and to identify clinical and pathological correlates of p27(Kip1) immunophenotypes.

PATIENTS AND METHODS

Tumour samples from 128 evaluable patients with bladder cancer were assessed by immunohistochemistry for p27(Kip1) and E2F-1 expression. Immunoreactivity of p27(Kip1) was correlated with clinicopathological variables, E2F-1 immunoreactivity, and outcome. Multivariate analysis was used to assess predictors of outcome. The median follow-up was 30.9 months overall and 105.7 months in the 32 patients alive at the last follow-up.

RESULTS

The fraction of tumour cells with p27(Kip1) nuclear immunoreactivity was <5% in 15, 5-25% in 30, 25-50% in 19, 50-75% in 51, and > or = 75% in 13 patients. High-grade tumours and those with lower E2F-1 nuclear reactivity had a lower mean percentage p27(Kip1) reactivity (P = 0.047 and 0.011, respectively). On multivariate analysis, the percentage p27(Kip1) reactivity was a significant independent predictor of pelvic recurrence (P = 0.017), progression to metastases (P = 0.046), death from disease (P = 0.008), and death from any cause (P = 0.017), with a low expression portending a worse prognosis. Suspicion of vascular invasion was a significant independent predictor of progression to metastases (P = 0.002), death from disease, and death from any cause (both P < 0.001). Lymph node involvement was a significant independent predictor of progression to metastases (P = 0.006).

CONCLUSIONS

Low expression of p27(Kip1) was a significant independent predictor of pelvic recurrence, progression to metastasis, death from disease and death from any cause, in patients with bladder cancer.

Molecular staging of prostate cancer in the year 2007

Numerous attempts towards improving patient management by molecular staging have been fruitless so far. No single molecular parameter is routinely analyzed in prostate cancer tissue. This may be partly due to genuine properties of prostate cancer that may make this tumor a difficult target. Furthermore, inherent logistical problems result in a shortage of prostate cancer tissue for research purposes. For the future, it can be hoped that the availability of more powerful molecular techniques in combination with better tissue archives will allow more rapid progress. Powerful DNA array and proteomics methods allow the systematic analysis of virtually all genes of a cancer on the DNA, RNA, and protein level. Although such approaches are sometimes labeled as "fishing expeditions," it cannot be totally disregarded that the simultaneous analysis of all genes has a high likelihood of identifying significant new information. In future, one of the major scientific challenges will be the validation of several potential biomarkers in large enough and clinically well-characterized patient cohorts. In particular, studies on needle core biopsies and hormone refractory cancers are imperatively needed for investigating the natural history of the disease or to discover potential predictive markers for radiation therapy and new therapeutic target genes to answer the clinically most important questions for optimal clinical decision making in prostate cancer patients: which patients will not require local therapy? If local therapy is needed, what is the treatment of choice? What medications should be given if metastases are present?

A novel anticancer agent, icaritin, induced cell growth inhibition, G1 arrest and mitochondrial transmembrane potential drop in human prostate carcinoma PC-3 cells

Icariin and icaritin with prenyl group have been demonstrated for their selective estrogen receptor modulating activities. We screened their effects on cell growth in human prostate carcinoma PC-3 cell line (estrogen receptor positive) in vitro. PC-3 cell line was used for the measurement of anti-carcinoma activities of 0-100 micromol/l icaritin and 30 micromol/l icariin. 1 micromol/l 17-beta estradiol (E(2)) served as the estrogen positive control, and 1 micromol/l ICI 182,780 [7 alpha-[9 (4,4,5,5,5-pentafluoropentyl) sulfinyl] nonyl]-estra-1,3,5(10)-triene-3,17h-diol]] served as the specific estrogen receptor antagonist. Primary cultured rat prostate basal cells used as cell growth selective control. The growth-inhibitory effects were analyzed using MTT assay, and fluorochrome staining, flow cytometry, and immunoblotting were employed to illustrate the possible mechanisms. When treated with icaritin for 24 to 72 h, cell growth was strongly inhibited (at 48 h IC(50) was 10.74+/-1.59 micromol/l, P<0.001) companied with a mitochondrial transmembrane potential (_Psim) drop. Meanwhile, few changes in IC(50) could be observed when co-incubated with ICI 182,780. Icaritin-induced growth inhibition was associated with G(1) arrest (P<0.05), and G(2)-M arrest depending upon doses. Consistently with G(1) arrest, icaritin increased protein expressions of pRb, p27(Kip1) and p16(Ink4a), while showed decrease in phosphorylated pRb, Cyclin D1 and CDK4. Comparatively, icariin has much lower effects on PC-3 cells and showed only weak G(1) arrest, suggesting a possible structure-activity relationship. These findings suggested a novel anticancer efficacy of icaritin mediated selectively via induction of cell cycle arrest but not associated with estrogen receptors in PC-3 cells.

Single nucleotide polymorphisms: early diagnosis and risk assessment in genitourinary malignancy

Genetic screening for malignancy has been limited to high-risk individuals with a strong hereditary predisposition to cancer. With the cloning of the human genome, it has become apparent that genetic anomalies are not limited to high-risk individuals; more than 10 million genetic variants exist. Because the vast majority of these genetic variants have no functional significance, current efforts are focused on identification of which impact cancer development and/or progression. Here, we review the rationale for studying polymorphic variants in urologic malignancies, prior studies in the field, and future avenues of research.

Molecular markers in the diagnosis of prostate cancer

The genetic alterations leading to prostate cancer are gradually being discovered. A wide variety of genes have been associated with prostate cancer development as well as tumor progression. Knowledge of gene polymorphisms associated with disease aid in the understanding of important pathways involved in this process and may result in the near future in clinical applications. Urinary molecular markers will soon be available to aid in the decision of repeat prostate biopsies. Recent findings suggest the importance of androgen signaling in disease development and progression. The further understanding of interaction of inflammation, diet, and genetic predisposition will improve risk stratification in the near future.

Biological Correlates of p27 Compartmental Expression in Prostate Cancer

PURPOSE

As one of the cyclin-dependent kinase inhibitors, p27 has been associated with biological behavior and disease progression in malignancies.

MATERIALS AND METHODS

Tissue microarrays were constructed using 640 radical prostatectomy specimens. Normal prostate tissue, benign prostatic hyperplasia and index tumor were cored in triplicate at 0.6 mm. Slides were stained with an antibody to p27 and digitized. The expression of p27 was quantified. SPSS 11.0 (SPSS, Chicago, Illinois) was used to perform the Spearman correlation test, Kaplan-Meier analysis and Cox proportional hazard regression.

RESULTS

We noted p27 expression predominately located in the epithelial nuclei of benign and cancer tissues. In PCa p27 was decreased compared to that in normal tissue, while p27 cytoplasmic expression was increased in PCa. Moderate nuclear p27 and cytoplasmic displacement of p27 were associated with worse disease-free survival compared with high or low p27. The cytoplasmic presence of p27 was an independent indicator for predicting the probability of biochemical recurrence in PCa.

CONCLUSIONS

We report that p27 expression is consistently high in the normal prostate. Moderate levels of nuclear p27 and/or cytoplasmic entrapment of p27 are associated with increased proliferation and worse biochemical recurrence-free survival. These findings suggest that PCa may enhance its growth and progression by decreasing nuclear p27 via cytoplasmic displacement and other molecular mechanisms.

Recent advances in the field of urology

Advances have been made in every aspect of urology that strengthen the scientific underpinning of current urologic practices and that hopefully will encourage further scientific investigation into the source, mechanisms, and cure of urologic diseases. This article reviews some of the advances that have been detailed in the recent urologic literature.

A Simple Inexpensive Method for the Production of Tissue Microarrays from Needle Biopsy Specimens

The use of tissue microarrays has become an efficient method for the high-throughput analysis of tissues with molecular markers, yet these studies have not been used to leverage the limited materials present in needle biopsies of human tissues. The use of these biopsy tissues is crucial to study diseases in patients who are treated by nonsurgical methods such as radiation, chemotherapy, or palliative care. The authors present a simple, inexpensive method for using needle biopsy specimens in tissue microarrays. Using this process with prostate cancer specimens, the authors demonstrate that over 150 slides can be produced from a single area of cancer in a needle biopsy and that the length of the core involved by cancer in the needle biopsy determines the number of available tissue microarray slides. The authors also note the optimal number of samples (three) needed from a single patient biopsy to guarantee sufficient material for analysis and perform an immunohistochemical correlation between needle biopsy and surgical resection tissue microarray samples for the quantitative marker Ki-67. This process can be extended to any type of needle biopsy specimen, increasing the number of studies and potential use of these tissues as a practical reality.

A Novel Anticancer Agent, Decursin, Induces G1 Arrest and Apoptosis in Human Prostate Carcinoma Cells

We isolated a coumarin compound decursin (C19H20O5; molecular weight 328) from Korean angelica (Angelica gigas) root and characterized it by spectroscopy. Here, for the first time, we observed that decursin (25-100 μmol/L) treatment for 24 to 96 hours strongly inhibits growth and induces death in human prostate carcinoma DU145, PC-3, and LNCaP cells. Furthermore, we observed that decursinol [where (CH3)2-C=CH-COO- side chain of decursin is substituted with -OH] has much lower effects compared with decursin, suggesting a possible structure-activity relationship. Decursin-induced growth inhibition was associated with a strong G1 arrest (P &lt; 0.001) in DU145 and LNCaP cells, and G1, S as well as G2-M arrests depending upon doses and treatment times in PC-3 cells. Comparatively, decursin was nontoxic to human prostate epithelial PWR-1E cells and showed only moderate growth inhibition and G1 arrest. Consistent with G1 arrest in DU145 cells, decursin strongly increased protein levels of Cip1/p21 but showed a moderate increase in Kip1/p27 with a decrease in cyclin-dependent kinases (CDK); CDK2, CDK4, CDK6, and cyclin D1, and inhibited CDK2, CDK4, CDK6, cyclin D1, and cyclin E kinase activity, and increased binding of CDK inhibitor (CDKI) with CDK. Decursin-caused cell death was associated with an increase in apoptosis (P &lt; 0.05-0.001) and cleaved caspase-9, caspase-3, and poly(ADP-ribose) polymerase; however, pretreatment with all-caspases inhibitor (z-VAD-fmk) only partially reversed decursin-induced apoptosis, suggesting the involvement of both caspase-dependent and caspase-independent pathways. These findings suggest the novel anticancer efficacy of decursin mediated via induction of cell cycle arrest and apoptosis selectively in human prostate carcinoma cells.

Molecular Markers and Prostate Cancer Prognosis

Prostate cancer is the most common malignancy among American men and is the second-leading cause of cancer-related mortality. Although radical prostatectomy and radiation therapy offer hope for cure for the majority of men with localized tumors, we continue to lack the tools to definitively determine which cancers need to be treated, which cancers will recur after treatment, and which cancers will behave aggressively when they have metastasized. Recent breakthroughs in molecular biology have led to the identification of a number of potential biomarkers for prostate cancer, many of which have been suggested to have prognostic significance. Eventually, combinations of these markers will hopefully enable us to more rationally facilitate counseling and direct management for men with prostate cancer.

Genetic alterations in prostate cancer

Prostate cancer is the number one malignancy among men. The search for causative factors has proven to be difficult and, accordingly, treatment options for advanced prostate cancer remain limited. However, technologic breakthroughs in the fields of genetics and molecular biology have advanced our understanding of the mechanisms involved in prostate carcinogenesis. The aim of this article is to review the most recent evidence for the role of various genetic insults at specific steps in tumor formation and to suggest potential therapeutic targets.

Update of staging and risk assessment for prostate cancer patients

PURPOSE OF REVIEW

This paper will review the current staging system for prostate adenocarcinoma patients, and will also review new information that can be combined with clinical and pathological staging in order to assess a patient's risk of success or failure of treatment.

RECENT FINDINGS

There has been significant stage migration of prostate cancer patients in the past 15 years, such that patients are currently being diagnosed younger, with lower clinical stages and serum prostate-specific antigen levels, and a lower risk of metastatic disease than previously. The incorporation of the results of extended prostate biopsy schemes, with stage, grade and serum prostate-specific antigen levels, improves the risk assessment of newly diagnosed prostate cancer patients. New imaging techniques, such as transrectal ultrasound Doppler flow and magnetic resonance spectroscopy hold promise for improving risk assessment. Molecular biomarkers may improve risk assessment in the future, although none are currently approved by the US Food and Drug Administration for this indication. Gene chip arrays may further refine risk assessment and assist with the identification of therapeutic targets.

SUMMARY

There has been significant stage migration of prostate cancer patients in the prostate-specific antigen era. Incorporating biopsy information into nomograms and risk assessment equations improves upon clinical staging and risk assessment. New imaging techniques, molecular markers and gene chip arrays hold promise for future risk assessment.

Reduction of PTEN and p27kip1 expression correlates with tumor grade in prostate cancer. Analysis in radical prostatectomy specimens and needle biopsies

The extreme variability of prostate cancer implies latent disease with missing clinical symptoms in some cases. Tumor suppressors PTEN (phosphatase and tensin homolog deleted on chromosome ten) and p27kip1 are frequently mutated in various human cancers. PTEN negatively influences cell growth and induces apoptosis, while p27kip1 binds to cyclin-E-Cdk2 and counteracts mitosis. This study investigated the expression of PTEN and p27kip1 in prostatectomies and needle biopsies in order to determine whether protein localization or expression levels are correlated with tumor grade and whether PTEN and p27kip1 expression in biopsies are valuable predictive tumor markers. Analysis of PTEN demonstrated that weak expression levels were significantly more prevalent in high-grade tumors. Analysis of p27kip1 revealed that high-grade tumors had a higher percentage of cytoplasmic localization of the protein than low-grade tumors, where nuclear localization was more frequent. Furthermore, this study indicated a positive association between PTEN and p27kip1 levels. An increase of high-grade tumors corresponded to a progressive loss of both tumor suppressors in needle biopsies and prostatectomies. p27kip1 and PTEN did not show a higher predictive accuracy of the tumor grade in the surgical specimen than the Gleason score. However, p27kip1 had the same predictive value as the Gleason score in needle biopsies.

Molecular markers to identify patients at risk for recurrence after primary treatment for prostate cancer

Accurate prognostication is a prerequisite for accurate therapeutics and management of prostate cancer because indolent tumors may require no intervention, whereas aggressive tumors lead to patient mortality. There is a critical need to define these subgroups of patients with prostate cancer differing in clinical outcome. Prognostic nomograms based on clinical data provide useful predictions of clinical states and outcomes, but they need further refinements to improve accuracy and universality. Genomic and proteomic analyses have provided many novel markers that may help define prognostic parameters based on the underlying biology of prostate cancer progression at the molecular level. These molecular markers are likely to augment traditional prognostic modalities by providing a set of molecularly defined and quantifiable variables. Encompassing the genome, transcriptome, and proteome of prostate cancer will likely provide "molecular signatures" that will bridge prognostication, prediction, and treatment in a single continuum.

The reporting of prostate cancer on needle biopsy: prognostic and therapeutic implications and the utility of diagnostic markers

Prostate needle biopsy remains the gold standard for diagnosing prostate cancer. Prostate cancer on needle biopsy can be evaluated by numerous techniques of quantifying tumour extent, Gleason score, and the presence of perineural invasion (PNI). These modalities can help clinicians in assessing the risk of extraprostatic disease, progression likelihood, and in helping men with prostate cancer choose among therapeutic options. This review details the information that should be included in the routine pathology report. Recent advances in molecular biology of prostate carcinogenesis have identified many molecular markers for prostate cancer. While several are extremely promising as diagnostic immunohistochemical markers, other prognostic markers are not yet ready to be used in routine practice until they are validated by large prospective studies.

Predicting biochemical recurrence after radical prostatectomy for patients with organ-confined disease using p27 expression

OBJECTIVES

It is unclear why men who undergo radical prostatectomy (RP) and are found to have pathologically organ-confined disease develop prostate-specific antigen (PSA) recurrences. We previously found that patients with less than 45% of cells in the prostate needle biopsy specimen (PNBx) staining positive for the cell cycle regulator p27 had a significantly increased risk of biochemical recurrence after RP. We sought to determine whether p27 staining in the PNBx specimen might serve as a molecular marker for PSA failure in the subset of patients who develop PSA recurrence despite organ-confined disease at RP.

METHODS

The PNBx specimens of 161 men treated with RP between 1991 and 2000 were examined for p27 expression using immunohistochemistry. The p27 cutpoint of less than 45% expression was used to define the high and low-risk categories. Patients were separated into two groups for analysis: organ-confined (pT2 and negative surgical margins) and non-organ-confined (pT2 with positive surgical margins, pT3, pT4, or lymph node involvement). The mean and median follow-up for patients with organ-confined and non-organ-confined disease was 47 and 43 months and 42 and 38 months, respectively. Multivariate Cox proportional hazards analysis was used to examine the preoperative clinical variables that were the strongest predictors of biochemical recurrence after RP among each group.

RESULTS

Among organ-confined patients, p27 expression was the only significant independent predictor of the time to biochemical recurrence after RP (hazard ratio 5.15, 95% confidence interval 1.41 to 18.83, P = 0.013). Among patients with non-organ-confined disease, the percentage of biopsy tissue with cancer, biopsy Gleason score, and PSA level were independent predictors of PSA recurrence. p27 expression was not a significant independent predictor of PSA recurrence among men with non-organ-confined disease.

CONCLUSIONS

p27 expression in the PNBx was a significant independent predictor of PSA failure for patients with pathologically organ-confined disease, but not for those with non-organ-confined disease. Patients with organ-confined disease but low p27 expression had a greater than fivefold risk of developing PSA recurrence than were men with high p27 expression, suggesting that p27 may be a molecular marker associated with micrometastatic disease at the time of RP.