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The possible role of activin in the regulation of malignant prostatic growth was studied using RNAase protection assays of activin receptors, inhibin/activin subunits and follistatin mRNAs in the human prostatic carcinoma cell lines LNCaP-FGC, -R and -LNO, in human prostatic carcinoma xenografts and in human prostatic tissue. Activin receptor types IA (ActRIA), IB (ActRIB), IIA (ActRIIA) and IIB (ActRIIB) mRNAs were generally expressed in prostate epithelial cells, with significantly lower levels of ActRIB mRNA in prostate tumour material when compared to non-malignant tissue (P < 0.05; Mann-WhitneyU-test). Inhibin/activin βA- and βB-subunit mRNA expression was also found in prostate tissue. Androgen-independent xenografts expressed significantly lower amounts of βB-subunit mRNA when compared to androgen-dependent xenografts (P < 0.05). While βB-subunit mRNA was expressed by LNCaP-FGC and -LNO cells, virtually no expression was found in the androgen-independent LNCaP-R line. Inhibina-subunit mRNA levels were low or undetectable in all samples investigated. Follistatin mRNA was undetectable in LNCaP-sublines, while low levels were found in prostatic tissues. In androgen-independent LNCaP-R cells, activin inhibited cell growth in a dose-dependent manner. These results suggest that prostate tumour progression is accompanied by a decrease of the inhibitory effect of locally produced activin by either a decrease in the expression of activin βB-subunit mRNA or by a decrease of ActRIB mRNA levels. [ABSTRACT FROM AUTHOR]

Adenovirus (Ad5) mediated gene therapy for prostate cancer offers a new therapeutic modality. Payloads of various origins (cytotoxic, immunomodulatory, repair genes) have been applied in experimental settings and even in clinical phase I trials to alter tumour growth. We report here on in vitro studies of adenoviral constructs with altered tropism and a new therapeutic gene. Vector Targeting. Currently, intraprostatic injection is used to target vectors to the prostate. Transcriptional targeting of genes under control of prostate specific promoters has been shown to be specific but is limited by a lower expression compared to viral promoters. Increasing the transduction of the vector into the cell might enhance the expression of therapeutic genes. The adenovirus uses the Coxsackie Adenoviral Receptor (CAR) for adhesion to the cell membrane by means of its viral knob, after which internalisation follows. Many tumour cells, including poorly differentiated prostate cancer cells, have limited or absent CAR. We have evaluated possibilities to retarget adenoviral vectors towards the pantumoral EpCAM antigen and prostate specific membrane antigen (PSMA) in order to increase transduction in vitro. [ABSTRACT FROM AUTHOR]

Studies using fresh-frozen tissue samples originating from different centres, as is often the case in EORTC related translational research, can show conflicting research results due to heterogeneity in the quality of samples and associated data from each centre. The development of infrastructure for the European Human Frozen Tumour Tissue Bank (TuBaFrost) anticipated this problem and Standard Operating Procedures (SOPs) have been developed to ensure samples collected are of consistent high quality and variation in research results is minimised. The SOPs drew on the best practice standard workflows and operating procedures employed by members of the TuBaFrost Consortium and key tissue bank initiatives worldwide. It was essential to provide workable solutions that reflect the variety in infrastructure and resources at the potential collecting centres and also the fact that it is not necessary to standardise every step of the collection and storage process in order to collect high quality tissue. Hence, the TuBaFrost SOPs detail the compulsory measures that must be implemented in order to become a TuBaFrost collecting centre and also make advisory recommendations regarding the less critical factors. Accordingly, the TuBaFrost SOPs are very flexible and to illustrate this the complete SOP for collecting, freezing and storing tissue at the Erasmus MC Tissue Bank is included. These TuBaFrost SOPs could equally be applicable to centres collecting samples for EORTC related translational research studies in order to standardise sample quality and produce reliable and reproducible research results.

Developing a tissue bank database has become more than just logically arranging data in tables combined with a search engine. Current demand for high quality samples and data, and the ever-changing legal and ethical regulations mean that the application must reflect TuBaFrost rules and protocols for the collection, exchange and use of tissue. To ensure continuation and extension of the TuBaFrost European tissue bank, the custodianship of the samples, and hence the decision over whether to issue samples to requestors, remains with the local collecting centre. The database application described in this article has been developed to facilitate this open structure virtual tissue bank model serving a large group. It encompasses many key tasks, without the requirement for personnel, hence minimising operational costs. The Internet-accessible database application enables search, selection and request submission for requestors, whereas collectors can upload and edit their collection. Communication between requestor and involved collectors is started with automatically generated e-mails.

Many systems have already been designed and successfully used for sharing histology images over large distances, without transfer of the original glass slides. Rapid evolution was seen when digital images could be transferred over the Internet. Nowadays, sophisticated Virtual Microscope systems can be acquired, with the capability to quickly scan large batches of glass slides at high magnification and compress and store the large images on disc, which subsequently can be consulted through the Internet. The images are stored on an image server, which can give simple, easy to transfer pictures to the user specifying a certain magnification on any position in the scan. This offers new opportunities in histology review, overcoming the necessity of the dynamic telepathology systems to have compatible software systems and microscopes and in addition, an adequate connection of sufficient bandwidth. Consulting the images now only requires an Internet connection and a computer with a high quality monitor. A system of complete pathology review supporting bio-repositories is described, based on the implementation of this technique in the European Human Frozen Tumor Tissue Bank (TuBaFrost).

TuBaFrost is the consortium responsible for the creation of a virtual European human frozen tumour tissue bank: a collection of high quality frozen residual, accurately classified tumour tissue samples, which are stored in European cancer centres and universities. This virtual tissue bank, searchable on the internet, has rules for access and use, and a code of conduct to comply with the various legal and ethical regulations in European countries. The easy accessibility and the European scale of the bank will result in the availability of a large number of samples even of rarer tumour types. Standardisation of collection, storage and quality control throughout the network is achieved minimising inter-institutional variability. A website providing access to upload, search and request samples is a key tool of the tissue bank. The search engine makes use of virtual microscopy. An overview of the development of the European virtual frozen tissue bank infrastructure is described in this paper. The various key aspects are described in more detail in a series of articles to appear in this Journal.

When designing infrastructure for a networked virtual tumour bank (samples remain at the collector institutes and sample data are collected in a searchable central database), it is apparent that this can only function properly after developing an adequate set of rules for use and access. These rules must include sufficient incentives for the tissue sample collectors to remain active within the network and maintain sufficient sample levels in the local bank. These requirements resulted in a key TuBaFrost rule, stating that the custodianship of the samples remains under the authority of the local collector. As a consequence, the samples and the decision to issue the samples to a requestor are not transferred to a large organisation but instead remain with the collector, thus allowing autonomous negotiation between collector and requestor, potential co-authorship in publications or compensation for collection and processing costs. Furthermore, it realises a streamlined cost effective network, ensuring tissue visibility and accessibility thereby improving the availability of large amounts of samples of highly specific or rare tumour types as well as providing contact opportunities for collaboration between scientists with cutting edge technology and tissue collectors. With this general purpose in mind, the rules and responsibilities for collectors, requestors and central office were generated.

The regulatory regimes for research with residual tissue and accompanying data differ widely between countries in the European Union (EU): from specific consent to opt-out or even no consent at all. This could greatly hamper research where the exchange of tissue and accompanying data has become the gold standard, like in TubaFrost. Instead of adhering to international guidelines, which have a democratic deficit, or an attempt for a new set of possible harmonising rules, TubaFrost chose to create a coordinating rule: if tissue may legitimately be used for a certain kind of research in the country where it was taken and under whose jurisdiction the patient falls, it may also be used for such research in the country where it is sent to in the context of a scientific program even if in that other country other regulations would apply for research with residual tissue taken from patients under their jurisdiction. This coordinating rule has a sound basis in EU law in general and will solve the problems related to diverging national regulatory regimes in the case of cross national research with residual tissue.

Tumour Bank Networking presents a great challenge for oncological research as in order to carry out large-scale, multi-centre studies with minimal intrinsic bias, each tumour bank in the network must have some fundamental similarities and be using the same standardised and validated procedures. The European Human Frozen Tumour Tissue Bank (TuBaFrost) has responded to this need by the promotion of an integrated platform of tumour banks in Europe. The operational framework for TuBaFrost has drawn upon the best practice of standard workflows and operating procedures employed by members of the TuBaFrost project and key initiatives worldwide.

Many systems have already been designed and successfully used for sharing histology images over large distances, without transfer of the original glass slides. Rapid evolution was seen when digital images could be transferred over the Internet. Nowadays, sophisticated virtual microscope systems can be acquired, with the capability to quickly scan large batches of glass slides at high magnification and compress and store the large images on disc, which subsequently can be consulted through the Internet. The images are stored on an image server, which can give simple, easy to transfer pictures to the user specifying a certain magnification on any position in the scan. This offers new opportunities in histology review, overcoming the necessity of the dynamic telepathology systems to have compatible software systems and microscopes and in addition, an adequate connection of sufficient bandwidth. Consulting the images now only requires an Internet connection and a computer with a high quality monitor. A system of complete pathology review supporting biorepositories is described, based on the implementation of this technique in the European Human Frozen Tumor Tissue Bank (TuBaFrost).

Background: Adenovirus binds to the coxsackievirus and adenovirus receptor (CAR) as a first step in the process of cellular infection. This dependence on CAR potentially limits the use of adenovirus in gene therapy, since CAR is expressed in many tissues of the body, and expression of CAR may be low or lost upon progression of certain tumors. These limitations may be overcome by transductional targeting of adenovirus towards other cell surface molecules. We have evaluated the pantumoral epithelial cell adhesion molecule (EpCAM) and prostate specific membrane antigen (PSMA) as possible targets for adenoviral transduction of prostate cancer cells., Methods: Bispecific antibodies, constructed as conjugates between an anti-adenovirus fiber knob Fab' fragment and anti-EpCAM or anti-PSMA monoclonal antibodies, were incubated with an eGFP-expressing adenovirus to retarget this vector. A cell panel, that includes two prostate cancer cell lines and four non-prostate control lines, were infected with serial dilutions of the retargeted vector and specificity of infection was determined., Results: Receptor-specific transduction was obtained for both EpCAM and PSMA. PSMA-retargeting was shown to be selective for the prostate cancer cell lines., Conclusions: PSMA serves as a tissue-specific target for adenoviral vectors and may be applicable for gene therapeutical treatment of prostate cancer., (2004 Wiley-Liss, Inc.)