Tumor Biology Research Group

General

Prostate cancer is the most common form of cancer occurring among men. The Scandinavian countries have a high incidence of prostate cancer compared with most other areas in the world. The disease can develop slowly and be relatively "harmless", while in other patients it may manifest itself as an aggressive and deadly disease. Only a small minority of patients can be offered curative treatment. The diagnostic tools that are available (mainly histological grading and serum level of prostate-specific antigen, PSA) are not currently able to predict the course of the disease. As a result, there is a great deal of uncertainty about whether the disease should be treated, or whether it makes more sense to take a "watchful waiting" approach. Since the treatment entails considerable discomfort for patients, it would be a major step forward if a more accurate means of predicting disease development were to be found, because this would enable doctors to be able to select the appropriate treatment.

Initially, most prostate cancers depend on male sex hormones to grow, so that treatment that interferes with these hormones can to some extent slow the progression of the disease. Most tumours, however, gradually develop androgen resistance, so that this type of treatment eventually becomes ineffective. The prognosis is poor for patients with inoperable and hormone independent tumours, which in time will often spread to the skeleton. Patients with skeletal metastases will typically experience a degraded quality of life due to pain, limitations in movements, and disability due to a gradually worsened general condition. We do not know today which mechanisms favour the spread of prostate cancer to the skeleton. It seems obvious that changes in the expression of proteins that may affect infiltration and metastasis must play a vital role. For example, changes in the production of proteins responsible for the degradation of the extracellular matrix (so-called proteolytic enzymes) can favour the migration of cancer cells. In turn, malignant cells must also attach themselves to bone tissue, a process that can reasonably thought to be facilitated by the increased expression of adhesion molecules. Over the years, our research group has conducted basic research on prostate cancer in the morphological unit in the Faculty of Medicine in Trondheim. During this time, we have developed expertise in a number of fields, and have also built strong contacts with the Urological unit at St. Olavs hospital, as a means of linking basic research with clinical practices. Our main work has been conducted on cell lines established from prostate carcinomas, to map out the mechanisms that control the cell's propensity and ability to grow invasively. More recently, we have also taken up human prostate tissue for use as a research model.

Current research projects

Immune histochemical characterization of primary cultures (available)

Stromal and epithelial tissue components have a strong mutual relationship with each other. There is evidence that this interaction makes important contributions in the development of progressive prostate cancer. This study aims to determine the immunological profile of two different types of fibroblast cultures (primary cultures), respectively, from cancer lesions and from hyper-plastic areas. It may also be appropriate to include PIN lesions in the study. In brief, the study starts with the culturing of fibroblasts from prostatectomy preparations, with subsequent preparation for histological colouring and antibody labelling. Five to eight antibodies are used.

What role do retroviruses play in the development of prostate cancer? (available)

TMA from prostate tissue, primary culture materials and established prostate carcinoma cell lines are used in immunohistochemical studies of the protein expression of HERV-specific antibodies. Between 5-8 antibodies are used. New antibodies from HPR project are also used, particularly HERV-W, which is also called syncytin (and which might play a role in cell fusion), HERV-K (suspected to be involved in melanoma development along with testicular teratomas) and HERV-R (which is connected to macrophage function and placenta development)

Beta integrin’s role in invasiveness (available)

Invasiveness is an important characteristic of malignancy. The migrating phenotype is expected to be affected by adhesion molecules, including integrins. In an earlier project, we examined whether tyrosine kinase inhibitors affected the prostate cancer cell’s ability to invade through an artificial basal membrane.

We found strong inhibition of beta integrins. Unfortunately, tyrosine kinase inhibition is also associated with toxic effects, so it is difficult to confirm beta integrins’ role in infiltration and metastasizing. More recently, an alternative to tyrosine kinase inhibition has been found, the use of inhibitory RNA (SiRNA). In this project, we want to selectively extinguish the beta integrin with the least possible side effects, and then study the cells’ invasive ability in a 3D-invasion model that has already been establish as a part of a master’s student’s project.

Studies of micro-RNA (miRNA) in prostate cancer cells (available)

MiRNA is a class of evolutionary conserved non-coding RNA sequences. These sequences contain approximately 22 nucleotides. There is evidence that miRNA regulates gene expression by inhibiting translation, and that miRNA has mRNA as a target sequence. What is better known is that miRNA seems to affect the functional expression of several genes that are involved in tumour cell growth and survival, which means it may be that miRNA can be a target for future cancer therapies.

The project is mapping out miRNA status in the two cell lines from adenocarcinoma (PC-3 and LNCaP). Cell lines are isolated from a bone metastasis and a lymphatic node metastasis, respectively. Phenotypically, the two are quite different in terms of their aggressive behaviour, and it is therefore important to map out the miRNA status of these much-used cell lines. QRT-PCR and RNA micro-array are the methods used in this work.

Why does prostate cancer metastasize to the skeleton? (Nathalie Niyonzima)

In a previous master project, we have shown that osteoblast cells induce certain changes in prostate cancer cells when the two cell types grown together, so they can exchange signal material through the culture media. The changes can be measured as the changed expression of a number of genes, by measuring mRNA using micro arrays. Some of the changes can be interpreted as expressions of stimulation of cancer cells’ aggressive behaviour. An important support for this interpretation would be if we were able to show that cancer cells show greater invasive capacity, measured in a quantitative in vitro invasion model (a matrigel invasion chamber). The cells we have used in multicell culture research show a strong tendency to be invasive, such that we have to adapt the system to this problem. If the model shows that culturing cells with osteoblasts results in higher invasiveness, it would be very interesting to try to suppress expression of one or more of the proteins that stimulates the production of osteoblasts, to see if any of these are critical for the behaviour changes we observe. This type of repression can be achieved by using siRNA technology.

Why does prostate cancer metastasize to the skeleton? Gene expression analyses with prostate cancer cells cultured with prostate fibroblasts (primary cultures) (Tove Reinertsen )

We still have not identified the nature of the mechanisms that favour the spread of prostate cancer to the skeleton. Our research has shown that contact between prostate cancer cells and bone tissue cells triggers the expression of metastasis-related proteins.

In this project we want to investigate the contact between prostate cancer cells and bone tissue cells and how they work together to amplify the influence of bone tissue cells. The project uses a model that makes it possible to study the mechanisms that affect prostate cancer cells’ ability to develop metastases. We use an in vitro cell model where prostate cancer cells are grown together with prostate fibroblasts in the laboratory. The interaction between the two cell types is studied by examining the types of gene expression changes that are caused by culturing the two cell lines together. Gene expression analyses are performed using Illumina microarrays and QRT-PCR.

Factors that influence RNA quality in frozen tissue material. An examination of biopsies from mice. (Marius Bakken )

One challenge in working with materials from biobanks is the quality of the research material itself. This will vary depending on the procedure that the laboratory has followed when the tissue is collected. The purpose of this study is to examine the differences caused by collection and storage methods, particularly with respect to RNA quality. The project will also focus on the importance of RNA quality for gene technology methods such as real-time PCR and microarrays. Such knowledge will be useful in optimizing procedures for the collection of biopsies by biobanks.

New prognostic markers of prostate cancer (Helena Bertilsson)

Prostate cancer is the most common form of cancer occurring among men. The Scandinavian countries have a high incidence of prostate cancer compared with most other areas in the world. The disease can develop slowly and be relatively "harmless", while in other patients it may manifest itself as an aggressive and deadly disease. Only a small minority of patients can be offered curative treatment. The diagnostic tools that are available (mainly histological grading and serum level of prostate-specific antigen, PSA) are not currently able to predict the course of the disease. As a result, there is a great deal of uncertainty about whether the disease should be treated, or whether it makes more sense to take a "watchful waiting" approach. Since the treatment entails considerable discomfort for patients, it would be a major step forward if a more accurate means of predicting disease development were to be found, because this would enable doctors to be able to select the appropriate treatment.

A Gleason grade is a histological image that provides information about a prostate cancer patient’s prognosis. Patients with a Gleason grade of 4 have a significantly poorer prognosis than those with a grade of 3. It is therefore important, from a molecular biology perspective, to understand what distinguishes the two Gleason grades. The project aims to identify the molecular and genetic differences found in Gleason grades 3 and 4. Central to this effort is the optimization of a protocol for RNA extraction from fresh prostate preparations. Tissue arrays (immunohistochemistry) are used to map protein expression. Microarrays (Affymetrix) with micro dissected material will be analysed to find specific gene expression patterns.

Title: Down-regulation of E-cadherin with siRNA: changes in invasiveness and protein expression (Åse Kristin Skain Andersen )

E-cadherin is a cell-cell adhesion molecule that is often down-regulated in carcinomas. It is conceivable that this down-regulation contributes to an invasive phenotype.

The project aims to take advantage of RNA interference technology to extinguish E-cadherin expression with a low-invasive cell line from LNCaP prostate carcinoma. If E-cadherin plays a role in invasiveness, one could expect that the low-invasive cell line would increase its ability to infiltrate and migrate after siRNA treatment. To measure the cells’ invasive ability, we use a standardized invasion assay that makes use of an artificial basal membrane.

Primary Cultures from prostate cancer (Linn Haug Moen )

There is a complex relationship of interactions between epithelial cells and the extracellular matrix (ECM) surrounding them, such as basal membranes, interstitial collagen, proteoglycans and stromal cells. The ability of different cells to break down extracellular components is of great importance in physiological and pathological processes.

The project uses cultured cell material from prostate biopsies. Fibroblasts are grown from cancer lesions and from benign areas. The cells are compared in terms of protein expression and ultra structure. The project aims to identify chemotactical substances that can affect carcinoma cells’ invasive capability.