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Aims—Insulin-like growth factor type I (IGF-I) antisense cellular gene therapy of tumours is based on the following data: rat glioma or hepatoma cells transfected with the vector encoding IGF-I antisense cDNA lose their tumorigenicity and induce a tumour specific immune response involving CD8+ T cells. Recently, using the IGF-I triple helix approach in studies of tumorigenicity, major histocompatibility complex class I (MHC-I) antigens were demonstrated in rat glioma transfected cells. This study used comparative IGF-I antisense and triple helix technologies in human primary glioma cells to determine the triple helix strategy that would be most appropriate for the treatment of glioblastoma. Methods—The cells were transfected using the IGF-I triple helix expression vector, pMT-AG, derived from the pMT-EP vector. pMT-AG contains a cassette comprising a 23 bp DNA fragment transcribing a third RNA strand, which forms a triple helix structure within a target region of the human IGF-I gene. Using pMT-EP, vectors encoding MHC-I or B7 antisense cDNA were also constructed. Results—IGF-I triple helix transfected glioma cells are characterised by immune and apoptotic phenomena that appear to be related. The expression of MHC-I and B7 in transfected cells (analysed by flow cytometry) was accompanied by programmed cell death (detected by dUTP fluorescein terminal transferase labelling of nicked DNA and electron microscopic techniques). Cotransfection of these cells with MHC-I and B7 antisense vectors suppressed the expression of MHC-I and B7, and was associated with a pronounced decrease in apoptosis. Conclusion—When designing an IGF-I triple helix strategy for the treatment of human glioblastoma, the transfected tumour cells should have the following characteristics: the absence of IGF-I, thepresence of both MHC-I and B7 molecules, and signs of apoptosis.

The authors would like to make the following corrections. In page 2, paragraph 2, Materials and Methods, first column, 34th line, it should be Cartagena's University Hospital del Caribe (preclinical study) instead of Cartagena's University, second column, 29th line, it should be Bogota, instead of Cartagena.

The aim of this study was to establish the criteria for methodology of cellular “anti-IGF-I” therapy of malignant tumours and particularly for glioblastoma multiforme. The treatment of primary glioblastoma patients using surgery, radiotherapy, and chemotherapy was followed by subcutaneous injection of autologous cancer cells transfected by IGF-I antisense/triple helix expression vectors. The prepared cell “vaccines” should it be in the case of glioblastomas or other tumours, have shown a change of phenotype, the absence of IGF-I protein, and expression of MHC-I and B7. The peripheral blood lymphocytes, PBL cells, removed after each of two successive vaccinations, have demonstrated for all the types of tumour tested an increasing level of CD8+ and CD8+28+ molecules and a switch from CD8+11b+ to CD8+11. All cancer patients were supervised for up to 19 months, the period corresponding to minimum survival of glioblastoma patients. The obtained results have permitted to specify the common criteria for “anti-IGF-I” strategy: characteristics sine qua non of injected “vaccines” (cloned cells IGF-I(−) and MHC-I(+)) and of PBL cells (CD8+ increased level).

Background Health research is increasing in Africa, but most resources are currently chanelled towards infectious diseases and health system development. While infectious diseases remain a heavy burden for some African countries, non-communicable diseases (NCDs) account for more than half of all deaths globally and WHO predicts 27% increase in NCDs in Africa over the next decade. We present findings of a European-Africa consultation on the research agenda for NCDs. Methods A workshop was held in Yaoundé, Cameroon, organized by the Network for the Coordination and Advancement of Sub-Saharan Africa-European Union Science and Technology Cooperation (CAAST-Net). Drawing on initial presentations, a small expert group from academic, clinical, public-health and administrative positions considered research needs in Africa for cardiovascular disease, cancer and diabetes. Results Research in Africa can draw from different environmental and genetic characteristics to understand the causes of the disease, while economic and social factors are important in developing relevant strategies for prevention and treatment. The suggested research needs include better methods for description and recording, clinical studies, understanding cultural impacts, prevention strategies, and the integrated organisation of care. Specific fields proposed for research are listed. Conclusions Our paper contributes to transparency in the process of priority-setting for health research in Africa. Although the European Union Seventh Framework Research Programme prioritises biomedical and clinical research, research for Africa should also address broader social and cultural research and intervention research for greatest impact. Research policy leaders in Africa must engage national governments and international agencies as well as service providers and research communities. None can act effectively alone. Bringing together the different stakeholders, and feeding the results through to the European Union research programme is a valuable contribution of CAAST-Net.

Alterations in the expression of growth factors and their receptors are associated with the growth and development of human tumors. One such growth factor is IGF-I (insulin-like growth factor I ), a 70-amino-acid polypeptide expressed in many tissues, including brain. IGF-I is also expressed at high levels in some nervous system-derived tumors, especially in glioblastoma. When using IGF-I as a diagnostic marker, 17 different tumors are considered as expressing the IGF-I gene. Malignant glioma, the most common human brain cancer, is usually fatal. Average survival is less than one year. Our strategy of gene therapy for the treatment of gliomas and other solid tumors is based on: 1) diagnostic using IGF-I gene expression as a differential marker, and 2) application of "triple-helix anti-IGF-I" therapy. In the latter approach, tumor cells are transfected with a vector, which encodes an oligoribonucleotide--an RNA strand containing oligopurine sequence which might be capable of forming a triple helix with an oligopurine and/or oligopyrimidine sequence of the promotor of IGF-I gene (RNA-IGF-I DNA triple helix). Human tumor cells transfected in vitro become down-regulated in the production of IGF-I and present immunogenic (MHC-I and B7 expression) and apoptotic characteristics. Similar results were obtained when IGF-I antisense strategy was applied. In both strategies the transfected cells reimplanted in vivo lose tumorigenicity and elicit tumor specific immunity which leads to elimination of established tumors.

The triplex-based strategy as the well-known antisense strategy seems to be a pow-erful approach to control gene expression in malignant cells. Few examples of the inhibitory activity of triplex-forming oligonucleotides on target genes involved in tumori-genesis are now available (for reviews see (Chan and Glazer, 1997; Giovannangeli and Helene, 1997; Maher III, 1996; Vasquez and Wilson, 1998)). Most of the TFOs are tar-geted to polypurine-polypyrimidine sequences located in control regions of the gene of interest and are cell delivered via transaction with various chemical carriers. An alternative way to introduce TFOs in cells is to use a plasmid vector that can drive the synthesis of an RNA triplex-forming oligonucleotide inside the cells. This TFO generated in situ is therefore protected from degradation by nucleases and could reach its DNA target without being trapped in lysosomal vesicles. Obviously, it could be trans-fected in cells via either standard cell transfection procedures or via ways similarly used in virus-based gene therapy. An application of this triplex-based approach has been used for the inhibition of the Insulin-like growth factor I protein which plays a major role in tumorigenesis of glioblastoma and hepatocarcinoma (Shevelev et al., 1997; Upegui-Gonzalez et al., 1998b). The inhibition of IGF-I using antisense or triple-helix tech-nologies in these cells induced an immune response of syngenic animals (Lafarge-Frayssinet et al., 1997; Shevelev et al., 1997; Trojan et al., 1993; Upegui-Gonzalez et al., 1998a; Upegui-Gonzalez et al., 1998b). These results obtained with IGF-I familly may ultimately lead to the use of the antisense and triplex-based approaches in clinical trials for anticancer gene therapy.

IGF-I antisense gene therapy has been applied successfully to animal models of glioma, hepatoma and teratocarcinoma. The antisense strategy has shown that tumor cells transfected with vectors encoding IGF-I antisense RNA lose tumorigenicity, become immunogenic and are associated with tumor specific immune response involving CD8+ lymphocytes. An IGF-I triple helix approach to gene therapy for glioma was recently described. The approach we have taken is to establish parameters of change using the IGF-I triple helix strategy. PCC-3 embryonal carcinoma cells derived from murine teratocarcinoma which express IGF-I were used as a model. The cells were transfected with vector which encodes an oligoribonucleotide that forms RNA-IGF-I DNA triple-helix structure. The triple-helix stops the production of IGF-I. Cells transfected in this manner underwent changes in phenotype and an increase in MHC-I and B-7 cell surface molecules. They also showed enhancement in the production of apoptotic cells (60-70%). The "triple helix" transfected cells lost the ability to induce tumor when injected subcutaneously in syngeneic 129 Sv mice. When co-transfected in vitro with expression vectors encoding both MHC-I and B-7 cDNA in antisense orientation, the "triple-helix" transfected cells were down-regulated in expression of MHC-I and B-7 and the number of apoptotic cells was significantly decreased. Injection of the doubly co-transfected cells into 129 Sv mice was associated with induction of teratocarcinoma. Comparison between antisense and triple-helix transfected cells strategies showed similar immunogenic and apoptotic changes. The findings suggest that triple-helix technology may offer a new clinical approach to treatement of tumors expressing IGF-I.

Insulin-like growth factor I (IGF-I), has a role in cellular differentiation and is also expressed in neoplastic transformation of glioma cells. We recently demonstrated inhibition in expression of cellular IGF-I after transfection with vectors that incodes a segment of the human IGF-I RNA in antisense orientation. The transfected cells expressed increased levels of both MHC-I and B7 molecules. In this paper we show that IGF-I antisense transfected cells also become apoptotic. Moreover, the phenomenon of programmed cell death is related to the phenomenon that results in increased expression of MHC-I and B7 molecules. Co-transfection of rat glioma cells with the vector expressing IGF-I antisense RNA and with vectors encoding the expression of MHC-I and B7 antisense cDNA suppressed the expression of both of these molecules and was associated with a decrease in apoptosis.