Markers for the development of early prostate cancer

P2X1 and P2X7 Receptor Overexpression Is a Negative Predictor of Survival in Muscle-Invasive Bladder Cancer

Bladder cancer is amongst the most common causes of cancer death worldwide. Muscle-invasive bladder cancer (MIBC) bears a particularly poor prognosis. Overexpression of purinergic P2X receptors (P2XRs) has been associated with worse outcome in several malignant tumors. Here, we investigated the role of P2XRs in bladder cancer cell proliferation in vitro and the prognostic value of P2XR expression in MIBC patients. Cell culture experiments with T24, RT4, and non-transformed TRT-HU-1 cells revealed a link between high ATP concentrations in the cell culture supernatants of bladder cell lines and a higher grade of malignancy. Furthermore, proliferation of highly malignant T24 bladder cancer cells depended on autocrine signaling through P2X receptors. P2X1R, P2X4R, and P2X7R expression was immunohistochemically analyzed in tumor specimens from 173 patients with MIBC. High P2X1R expression was associated with pathological parameters of disease progression and reduced survival time. High combined expression of P2X1R and P2X7R increased the risk of distant metastasis and was an independent negative predictor of overall and tumor-specific survival in multivariate analyses. Our results suggest that P2X1R/P2X7R expression scores are powerful negative prognostic markers in MIBC patients and that P2XR-mediated pathways are potential targets for novel therapeutic strategies in bladder cancer.

Correlation of Periacinar Retraction Clefting in Needle Core Biopsies and Corresponding Prostatectomy Specimens of Patients with Prostatic Adenocarcinoma

One of the underemphasized supportive criteria for the diagnosis of prostatic cancer is the presence of retraction clefting around neoplastic glands. We analyzed a series of 152 prostatic cancer cases to determine the frequency, extent, and correlation of periacinar retraction clefting between needle core biopsies (NCB) and corresponding matched radical prostatectomy (RP) specimens. Clefting was significantly more frequent in neoplastic compared to nonneoplastic acini in NBC and RP (p<0.05). There was no significant difference in the frequency of retraction clefting in neoplastic acini between NCB and corresponding RP (p>O.05). We have also found a concordance in matched RP and NCB (Kappa=0.582). We conclude that periacinar retraction clefting appears more frequently in neoplastic acini and could serve as a reliable criterion in the diagnosis of prostatic adenocarcinoma.

Tenascin-C Protects Cancer Stem-like Cells from Immune Surveillance by Arresting T-cell Activation

Precociously disseminated cancer cells may seed quiescent sites of future metastasis if they can protect themselves from immune surveillance. However, there is little knowledge about how such sites might be achieved. Here, we present evidence that prostate cancer stem-like cells (CSC) can be found in histopathologically negative prostate draining lymph nodes (PDLN) in mice harboring oncogene-driven prostate intraepithelial neoplasia (mPIN). PDLN-derived CSCs were phenotypically and functionally identical to CSC obtained from mPIN lesions, but distinct from CSCs obtained from frank prostate tumors. CSC derived from either PDLN or mPIN used the extracellular matrix protein Tenascin-C (TNC) to inhibit T-cell receptor-dependent T-cell activation, proliferation, and cytokine production. Mechanistically, TNC interacted with α5β1 integrin on the cell surface of T cells, inhibiting reorganization of the actin-based cytoskeleton therein required for proper T-cell activation. CSC from both PDLN and mPIN lesions also expressed CXCR4 and migrated in response to its ligand CXCL12, which was overexpressed in PDLN upon mPIN development. CXCR4 was critical for the development of PDLN-derived CSC, as in vivo administration of CXCR4 inhibitors prevented establishment in PDLN of an immunosuppressive microenvironment. Taken together, our work establishes a pivotal role for TNC in tuning the local immune response to establish equilibrium between disseminated nodal CSC and the immune system.

Vasoactive intestinal peptide behaves as a pro-metastatic factor in human prostate cancer cells

BACKGROUND

There is little known on the involvement of vasoactive intestinal peptide (VIP) in the metastatic cascade of human prostate cancer, that is, cell proliferation, cell-cell adhesion, extracellular-matrix degradation, and migration/invasion. Here we evaluated the expression of related biomarker proteins (cyclin D1, metalloproteinases MMP-2 and MMP-9, and E-cadherin) in human androgen-dependent (LNCaP) and independent (PC3) prostate cancer cells.

METHODS

Reverse transcriptase (RT)-polymerase chain reaction (PCR), gelatin zymography, Western blotting, confocal immunofluorescence microscopy, and assays on cell proliferation, adhesion, wound-healing, migration and random homing were performed.

RESULTS

VIP increased cell proliferation and cyclin D1 expression whereas it decreased cell adhesion and E-cadherin expression in LNCaP and PC3 cells. VIP enhanced the gelatinolytic activity of MMP-2 and MMP-9. Semiquantitative RT-PCR assays showed that VIP stimulated mRNA levels of these MMPs and suppressed mRNA levels of its inhibitory protein RECK. VIP promoted cell invasion and migration, and the responses were faster according to the most aggressive status in cancer progression (androgen-independence). The involvement of nuclear factor-kappaB (NF-kappaB) was demonstrated since the anti-inflammatory agent curcumin blocked VIP effects on the above biomarkers in both cell lines.

CONCLUSIONS

Taken together, these results and the presence of kappaB sites on gene promoter of cyclin D1, MMPs and, possibly, E-cadherin suggest that VIP may act as a cytokine in an early metastatic stage of human prostate cancer through the NF-kappaB/MMPs-RECK/E-cadherin system. Our findings may help to define novel targets and agents with potential usefulness in prostate cancer therapy.

Ovarian normal and tumor-associated fibroblasts retain in vivo stromal characteristics in a 3-D matrix-dependent manner

OBJECTIVE

Due to a lack of experimental systems, little is known about ovarian stroma. Here, we introduce an in vivo-like 3-D system of mesenchymal stromal progression during ovarian tumorigenesis to support the study of stroma permissiveness in human ovarian neoplasias.

METHODS

To sort 3-D cultures into 'normal,' 'primed' and 'activated' stromagenic stages, 29 fibroblastic cell lines from 5 ovarian tumor samples (tumor ovarian fibroblasts, TOFs) and 14 cell lines from normal prophylactic oophorectomy samples (normal ovarian fibroblasts, NOFs) were harvested and characterized for their morphological, biochemical and 3-D culture features.

RESULTS

Under 2-D conditions, cells displayed three distinct morphologies: spread, spindle, and intermediate. We found that spread and spindle cells have similar levels of alpha-SMA, a desmoplastic marker, and consistent ratios of pFAKY(397)/totalFAK. In 3-D intermediate cultures, alpha-SMA levels were virtually undetectable while pFAKY(397)/totalFAK ratios were low. In addition, we used confocal microscopy to assess in vivo-like extracellular matrix topography, nuclei morphology and alpha-SMA features in the 3-D cultures. We found that all NOFs presented 'normal' characteristics, while TOFs presented both 'primed' and 'activated' features. Moreover, immunohistochemistry analyses confirmed that the 3-D matrix-dependent characteristics are reminiscent of those observed in in vivo stromal counterparts.

CONCLUSIONS

We conclude that primary human ovarian fibroblasts maintain in vivo-like (staged) stromal characteristics in a 3-D matrix-dependent manner. Therefore, our stromal 3-D system offers a tool that can enhance the understanding of both stromal progression and stroma-induced ovarian tumorigenesis. In the future, this system could also be used to develop ovarian stroma-targeted therapies.

The role of kallikrein-related peptidases in prostate cancer: potential involvement in an epithelial to mesenchymal transition

Several members of the kallikrein-related peptidase family of serine proteases have proteolytic activities that may affect cancer progression; however, the in vivo significance of these activities remains uncertain. We have demonstrated that expression of PSA or KLK4, but not KLK2, in PC-3 prostate cancer cells changed the cellular morphology from epithelial to spindle-shaped, markedly reduced E-cadherin expression, increased vimentin expression and increased cellular migration. These changes are indicative of an epithelial to mesenchymal transition (EMT), a process important in embryonic development and cancer progression. The potential novel role of kallikrein-related peptidases in this process is the focus of this brief review.

Myofibroblastic stromal reaction and expression of tenascin-C and laminin in prostate adenocarcinoma

The aim of this study was to analyse relationship between changes of the stroma and expression of tenascin-C (TN-C) and laminin in prostate carcinoma. Tenascin-C immunostaining was increased, and laminin decreased in carcinomas compared with peritumoral tissue and benign prostate hyperplasia (P<0.05). Statistical analysis confirmed connection between stromal changes and TN-C expression in prostate carcinoma (P<0.05). Gleason pattern 3 carcinomas showed more pronounced stromal reaction and TN-C expression compared with Gleason pattern 4 carcinomas (P<0.05). The main cells in prostate cancer stroma are myofibroblasts that are also responsible for tenascin production. Degradation of laminin was not connected with myofibroblastic stromal changes.

Differentiating keratoacanthoma from squamous cell carcinoma by the use of apoptotic and cell adhesion markers

AIMS

Keratoacanthomas (KA) are well-differentiated squamoproliferative skin lesions that grow rapidly and regress spontaneously. In contrast, squamous cell carcinomas (SCC) can have variable differentiation, inexorably progress and on occasion metastasize. Distinguishing between KA and SCC using haematoxylin and eosin-stained sections from an initial biopsy can often be difficult. There is also some debate as to whether KA is simply a variety of well-differentiated SCC or a distinct entity.

METHODS AND RESULTS

Initial biopsy sections from 25 cases of SCC and 20 of KA were labelled with markers for both the initiation (the cytolytic receptor P2X7) and end-stage (terminal deoxynucleotidyl transferase biotin-dUTP nick end labelling) of apoptosis, telomerase-associated protein (TP1) and the cell adhesion protein E-cadherin. As this was a retrospective study, the clinical outcome of each case was known. This resulted in a unique labelling pattern of each marker for SCC and KA, allowing a differential diagnosis between the two conditions. The simplest marker to use for this purpose was anti-P2X7. Sections from five cases that were initially very difficult to diagnose were correctly identified as SCC using this method.

CONCLUSIONS

These results support the view that KA has a different pathogenesis and biochemistry from that of SCC, and is a distinct entity. Anti-P2X7 labelling, using routine immunohistochemical techniques, provides a method for differentially diagnosing these conditions.

Expression of the apoptotic calcium channel P2X7 in the glandular epithelium

In the current study, expression of the apoptotic calcium channel receptor P2X(7) and prostate-specific antigen (PSA) levels were studied in biopsy cores from 174 patients as well as 20 radical prostatectomy cases. In clinical biopsies, we have previously demonstrated that P2X(1 )and P2X(2) calcium channel receptors are absent from normal prostate epithelium that does not progress to prostate cancer within 5 years. In cases that did progress to prostate cancer however, P2X(1 )and P2X(2) labeling was observed in a stage-specific manner first in the nucleus, then the cytoplasm and finally on the apical epithelium, as prostate cancer developed. These markers were present up to 5 years before cancer was detectable by the usual morphological criteria (Gleason grading) as determined by H and E staining. In the current study, the apoptotic calcium channel receptor P2X(7) yielded similar results to that of P2X(1) and P2X(2). Using radical prostatectomy tissue sections as well as biopsies, these changes in calcium channel metabolism were noted throughout the prostate, indicating a field effect. This finding suggests that the presence of a prostate tumor could be detected without the need for direct sampling of tumor tissue, leading to detection of false negative cases missed by H or E stain. The reliability of PSA levels as a prognostic indicator has been questioned in recent years. In the current study, PSA levels were correlated with the P2X(7) labeling results. All patients who exhibited no P2X(7) labeling had a prostatic serum antigen (PSA) level of <2. Patients who exhibited stage-specific P2X(7) expression, and who later developed obvious prostate cancer as diagnosed by H and E stain, all had a PSA > 2. This finding suggests that increasing PSA may be an accurate indicator of cancer development.

A visual-quantitative analysis of fibroblastic stromagenesis in breast cancer progression

One fundamental difference between normal and transformed cells is the way they interact with their immediate environment. Exploring this difference is crucial for understanding the pathobiology of cancer progression. Benign epithelial tumors are constrained by a surrounding stroma consisting, among other cells, of fibroblasts embedded within fibrillar three-dimensional matrices. However, at a critical point in tumor progression, tumor cells become altered and overcome the barrier, inducing changes in the stroma, which promote, rather than impede, tumor progression. Inherited or acquired genetic aberrations affecting mammary gland epithelia are usually blamed for promoting neoplasia in individuals at "high risk" for breast cancer. However, in addition to these epithelial aberrations certain individuals possess permissive breast stroma. The occurrence of this permissive stroma results in a predisposition for cancer initiation or progression. Here we review stromagenic stages, experimental 3D systems, and discuss digital imaging analyses suitable for uncovering the mechanisms behind fibroblastic breast stromagenesis.

Spatial Composition of Prostate Cancer Spheroids in Mixed and Static Cultures

Aggregation of neoplastic cells produces multicellular spheroids resembling micrometastases. The objective of this study was to investigate the effects of mixing culture medium on the spatial composition of spheroids prepared from well (LNCaP) and poorly (DU 145) differentiated human prostate cancer cells. Spheroids were cultured in a mixed suspension within a high-aspect rotating wall vessel and static liquid-overlay plate. Results from this study demonstrate that mixed cultures consistently manifested differences in morphology and composition between DU 145 and LNCaP spheroids. For example, 40 +/- 12% of DU 145 cells were Ki-67 positive 100 microm from the surface within mixed spheroids versus 0% for LNCaP cells; there was no significant difference in this spatial profile for static cultures. The results suggest that poorly differentiated spheroids may be more likely to experience a change in composition from mixing culture medium than well-differentiated spheroids, due to low tissue density. Immunostaining for P-glycoprotein is representative of this trend; average staining intensity increased 50% for DU 145 spheroids on mixing but was unchanged for LNCaP spheroids. The effects of mixing on spheroid composition were attributed to faster interstitial mass transport. Applications include drug development and delivery, as well as basic research on drug action and resistance.

Early prostate cancer detected using expression of non-functional cytolytic P2X7 receptors

AIMS

To detect early prostate cancer reliably by monitoring the expression of non-functional P2X(7) cytolytic purinergic receptors.

METHODS AND RESULTS

P2X(7) receptors were absent from normal prostate epithelium obtained from post mortem tissue and tissue from cases of transurethral resection collected from young men (n = 23) who were confirmed to be free of cancer at later procedures 5-10 years after collection of the original samples. However, P2X(7) was present in every case of 116 confirmed prostate cancers regardless of Gleason grade or patient age. P2X(7) was present in apparently normal epithelial cells in acini well outside the tumour margins, but appeared in a distinct stage-specific manner commencing with the nucleus, progressing to the cytoplasm and collecting finally on the apical membrane of the epithelial cells in morphologically distinct cancer. The pattern of P2X(7) receptor localization in the epithelial cells was recorded in earlier biopsies obtained from the same patient cohort. One hundred and fourteen of 116 prostates stained positively for P2X(7) at the earliest biopsy, though generally with a less advanced pattern of distribution.

CONCLUSIONS

The appearance of P2X(7) receptors in normal prostate tissue adjacent to prostate tumours makes direct tumour biopsy less critical for positive cancer diagnosis and enables cancer progression to be monitored.

Human prostate cancer risk factors

Prostate cancer has the highest prevalence of any nonskin cancer in the human body, with similar likelihood of neoplastic foci found within the prostates of men around the world regardless of diet, occupation, lifestyle, or other factors. Essentially all men with circulating androgens will develop microscopic prostate cancer if they live long enough. This review is a contemporary and comprehensive, literature-based analysis of the putative risk factors for human prostate cancer, and the results were presented at a multidisciplinary consensus conference held in Crystal City, Virginia, in the fall of 2002. The objectives were to evaluate known environmental factors and mechanisms of prostatic carcinogenesis and to identify existing data gaps and future research needs. The review is divided into four sections, including 1) epidemiology (endogenous factors [family history, hormones, race, aging and oxidative stress] and exogenous factors [diet, environmental agents, occupation and other factors, including lifestyle factors]); 2) animal and cell culture models for prediction of human risk (rodent models, transgenic models, mouse reconstitution models, severe combined immunodeficiency syndrome mouse models, canine models, xenograft models, and cell culture models); 3) biomarkers in prostate cancer, most of which have been tested only as predictive factors for patient outcome after treatment rather than as risk factors; and 4) genotoxic and nongenotoxic mechanisms of carcinogenesis. The authors conclude that most of the data regarding risk relies, of necessity, on epidemiologic studies, but animal and cell culture models offer promise in confirming some important findings. The current understanding of biomarkers of disease and risk factors is limited. An understanding of the risk factors for prostate cancer has practical importance for public health research and policy, genetic and nutritional education and chemoprevention, and prevention strategies.

Differentiation between Cancerous and Normal Hyperplastic Lobules in Breast Lesions

Determining the risk that a particular area of hyperplastic breast tissue will progress to cancer is difficult and is currently expressed only as a general risk factor within the population. Using an antibody against the apoptotic purinergic receptor P2X7, we examined 40 cases each of the following histological categories: normal, moderate, florid and atypical hyperplasia, lobular carcinoma in situ, ductal carcinoma in situ, invasive lobular and invasive ductal carcinoma. These were previously diagnosed by H&E and supplied by clinical laboratories as tissue sections. Normal and mildly hyperplastic epithelium was devoid of the cytolytic P2X7 receptors whereas all epithelial cells in all cases of in situ or invasive lobular or ductal carcinoma labelled intensely. The lobular and ductal in situ cases labelled intracellularly while the invasive epithelial cancer cells showed intense cell surface label indicating an attempt was being made to induce apoptosis. All these receptors however are non-functional and thus unable to induce apoptosis. Approximately 10% of all hyperplastic lobules examined in the biopsied tissue, regardless of H&E classification, labelled for P2X7, which is suggestive of early metabolic cancerous change. The acini within lobules were either completely labelled with P2X7 or were completely devoid of the receptor. A potential advantage of this method lies in identifying early cancerous change in hyperplastic lobules and in establishing the true extent of cancerous spread in infiltrating lesions, thus facilitating the task of reporting clear surgical margins.

Tenascins: regulation and putative functions during pathological stress

In this review, we discuss the structure and function of the extracellular matrix protein family of tenascins with emphasis on their involvement in human pathologies. The article is divided into the following sections:

INTRODUCTION

the tenascin family of extracellular matrix proteins; Structural roles: tenascin-X deficiency and Ehlers-Danlos syndrome; Tenascins as modulators of cell adhesion, migration, and growth; Role of tenascin-C in inflammation; Regulation of tenascins by mechanical stress: implications for wound healing and regeneration; Association of tenascin-C with cancer: antibodies as diagnostic and therapeutic tools; Conclusion and perspectives.