Spliceosome-Mediated RNA Trans-Splicing Facilitates Targeted Delivery of Suicide Genes to Cancer Cells

Abstract

Patients suffering from recessive dystrophic epidermolysis bullosa (RDEB), a hereditary blistering disease of epithelia, show susceptibility to develop highly aggressive squamous cell carcinoma (SCC). Tumors metastasize early and are associated with mortality in the 30th-40th years of life in this patient group. So far, no adequate therapy is available for RDEB SCC. An approach is suicide gene therapy, in which a cell deathinducing agent is introduced to cancer cells. However, lack of specificity has constrained clinical application of this modality. Therefore, we used spliceosome-mediated RNA trans-splicing technology, capable of replacing a tumor-specific transcript with one encoding a cell death-inducing peptide/toxin, to provide tumorrestricted expression. We designed 3 0 pre-trans-splicing molecules (PTM) and evaluated their efficiency to trans-splice an RDEB SCC-associated target gene, the matrix metalloproteinase-9 (MMP9), in a fluorescencebased test system. A highly efficient PTM was further adapted to insert the toxin streptolysin O (SLO) of Streptococcus pyogenes into the MMP9 gene. Transfection of RDEB SCC cells with the SLO-PTM resulted in cell death and induction of toxin function restricted to RDEB SCC cells. Thus, RNA trans-splicing is a suicide gene therapy approach with increased specificity to treat highly malignant SCC tumors.

Safety and Efficacy of Suicide Gene Therapy with Adenosine Deaminase 5-Fluorocytosine Silmutaneously in in Vitro Cultures of Melanoma and Retinal Cell Lines

“…In the study by Gruber C. et al 87 the efficiency of 3` pre-trans-splicing molecules (PTM) was investigated and high efficiency was observed against highly malignant tumors. In the study by Di Stasi et al 88, the inducible caspase 9 (iCasp9) gene was investigated.…”

Suicide Gene Therapy for Cancer; Old Dog New Tricks

“…This technology has the ability to replace a tumor-specific transcript with one encoding a cell death-inducing peptide/toxin. The group of Gruber C et al [96] investigated the efficiency of 3′ pre-trans-splicing molecules (PTM) and the results indicated that this method is efficient against highly malignant tumors. Another novel suicide gene therapy system was developed by Di Stasi et al [97].…”

Development of cabozantinib for the treatment of prostate cancer

“…Bone metastases in prostate cancer are more likely to express MET than other soft tissue metastases 10. Preclinical studies in prostate cancer xenografts reported responses to cabozantinib therapy in nude mouse tibia (minimal bone lesions seen) as compared with development of multiple osteoblastic and osteolytic lesions in vehicle-treated controls 20. It is hypothesized that the osteoclast differentiation induced by cabozantinib may be responsible for the bone scan responses seen; however, the exact mechanism via which this occurs is unknown at present 20.…”

“…Preclinical studies in prostate cancer xenografts reported responses to cabozantinib therapy in nude mouse tibia (minimal bone lesions seen) as compared with development of multiple osteoblastic and osteolytic lesions in vehicle-treated controls 20. It is hypothesized that the osteoclast differentiation induced by cabozantinib may be responsible for the bone scan responses seen; however, the exact mechanism via which this occurs is unknown at present 20. Treatment with cabozantinib appeared to decelerate both osteoblastic and osteolytic progression of prostate xenograft tumors in bone.…”