Gene Therapy
	Growth Factors
	Gliomas

	Targeted Therapy for Small Cell Lung Cancer
	Identification of tumor suppressor gene candidates in SCLC, which alone or combined with p53 reactivating molecules can be used in cancer gene therapy

Using this knowledge, our aim is to develop an effective targeted non-viral gene therapy vector, which can be used for systemic treatment of patients with SCLC.
Development of this gene therapy vector requires the following:

1. Expression of the therapeutic gene must be high and cancer specific.
   Transcriptional targeting can be obtained using highly active cancer specific promoters to control the expression of a therapeutic gene.
   
2. The therapeutic gene must efficiently cause tumour regression.
   The most effective therapeutic genes should generate products that are toxic for both dividing and non-dividing cells and the toxic products should diffuse to neighbouring cells.
   
3. Delivery of the therapeutic gene must be efficient.
   This can be obtained using non-viral delivery vehicles, which confer efficient cellular uptake, have a high ability for carrying the gene and which display so little toxicity and immunogenicity, that they can be applied repetitively. The efficacy and specificity may further be enhanced by coupling the vector to molecules, which target the cancer cell surface.

The regulation and expression patterns of many SCLC specific genes identified by the gene expression analysis as very highly and specifically expressed in SCLC were analysed. Selected from these we have identified, cloned and tested several promoters. One of these is a 1.7 kb promoter region from the Insulinoma Associated-1 (INSM1, IA-1) gene - a gene that is normally exclusively expressed during early embryogenesis and is inactive in the adult. This gene is highly reactivated in SCLC and neuroendocrine tumours due to expression of activating transcription factors. We have demonstrated that expression from this INSM1 promoter region is very high in most SCLC cell lines and absent in other cancer and normal cell lines. When regulating a therapeutic gene, we have demonstrated that the INSM1 promoter is sufficiently active to confer efficient SCLC specific cell death in vitro after transient transfections. We have recently shown that the human INSM1 promoter also is active in an in vivo SCLC tumour model system and causes significant tumour regression upon treatment. After systemic treatment with a novel liposomal gene delivery vector with a therapeutic gene regulated by the INSM1 promoter, we observed significant tumor growth delay of xenografted SCLC tumors. We are currently testing promoter regions from other genes, which mediate high and SCLC specific gene expression and specific SCLC cell death in vitro for comparison and for selection of the most optimal promoter for transcriptionally targeted gene therapy for SCLC.

To ensure the best efficacy of transcriptionally targeted gene therapy we are in the process of determining the most effective therapeutic gene for SCLC. Tumour suppressor gene restoration (of e.g. wild type p53) is a commonly used gene for cancer gene therapy, but we find only a minimal effect of this strategy in SCLC. In contrast, the suicide gene Herpes Simplex Virus Thymidine Kinase (HSV-TK) in combination with ganciclovir treatment (a prodrug converted to a toxic nucleotide by the enzyme) was found to effectively eradicate SCLC cells in vitro and in vivo . The potency of other suicide gene strategies (using other genes with other prodrugs) and other forms of therapeutic genes are therefore in testing.

One of the major hurdles in gene therapy so far has been the lack of efficient and non-toxic gene delivery vehicles. Recently a new formulation of cationic liposomes consisting of extruded DOTAP:cholesterol nanoparticles has been demonstrated as very efficient for systemic delivery of genes. These particles can deliver large amounts of DNA to tumours, are non-toxic and protect the DNA from degradation in the bloodstream. We are utilising these particles for systemic delivery of various plasmids for verification of the cancer specificity and activity of the selected cancer specific promoters and the effect of various therapeutic genes in an in vivo mouse tumour model system with xenografted human SCLC tumours. Another advantage of the particles is that they can be coupled to targeting molecules such as ligands or antibodies. In the gene expression analysis of SCLC we have identified a number of highly expressed surface molecules. This opens the possibility of further enhancing specificity and/or efficacy by targeting to various types of surface molecules. Back to top  

Identification of tumor suppressor gene candidates in SCLC, which alone or combined with p53 reactivating molecules can be used in cancer gene therapy
Small cell lung cancer (SCLC) is a deadly disease with no current satisfactory treatments. There is therefore an urgent need for development of more efficient treatment modalities for patients with this cancer type. One intriguing modality is cancer gene therapy and one the most common approaches is tumour-suppressor-restoration therapy. Tumour-suppressor-genes (TSGs) are directly involved in the regulation of various cellular processes including cell proliferation, differentiation and apoptosis. They can protect a tissue from uncontrollable proliferation by inducing apoptosis at any stage of malignancy and they are often inactivated in cancer cells. Thus, in tumour suppressor restoration therapy, a wild-type TSG is introduced into cancer cells, in which the gene is inactivated, to restore the cell's normal gene function. Such introduction of TSGs in the cancer cells generally induces apoptosis and/or cell cycle arrest. However, as different types of cancers have different tumour suppressor deficiencies, the strategy must be customized to each cancer type. This can be achieved either by using tumour specific TSG or by combing different TSG in order to achieve the most optimal effect. p53 is a TSG often mutated in human cancers. Within the last several years, small molecules that are able to reactivate mutant p53 and thereby induce massive cell death have been identified. The combination of p53 with other TSG has recently been shown to be more effective in inducing cancer cell death than either used alone. The aim of this project is therefore to identify TSG candidates in SCLC, which either alone or in combination with p53 reactivating molecules can be used for the development of cancer gene therapy. Back to top  

Growth Factors

	Role of Different Signalling Pathways Downstream of a Truncated Epidermal Growth Factor Receptor.
	The Role of EphA2 in EGFR/EGFRvIII Mediated Tumor Transformation.

	Establishment of in vitro and in vivo models of glioblastomas
	Effects of EGFR and VEGF inhibition in human glioblastoma cells using cetuximab in combination with bevacizumab
	Cross-talk between EGFR signaling and the Notch pathway in glioblastoma multiforme
	The role of Notch signaling in brain cancer stem-like cells and glioblastoma multiforme