Antisense oligonucleotides and prevention of tumor growth: a different approach and proposal for a new method.

There have been several attempts to prevent tumor formation and growth. However, none of the developed methods gives a completely satisfying result for the treatment of tumor masses. The most often used therapies against tumor cells are radiotherapy and chemotherapy. However, utilization of these methods to treat cancer generally result in generation of undesired side effects. In recent years, the antisense oligonucleotide technology has been employed, with success to an extent, in prevention of tumor growth. However, this method has its limitations. One of the most important limitation is that all of the crucial genes that play certain roles and are specifically expressed in tumor cells have not yet been identified. Therefore, only a few numbers of genes that are shown to play a role in tumor cells are targeted by the antisense oligonucleotide method. The aim of the present study is to propose a hypotheses and outline the involved procedure which could be used to generate oligonucleotides that are antisense to genes or mRNAs that display certain specific functions in tumor cells but are yet to be identified. The proposed hypotheses involves first, a careful isolation of differentially expressed mRNAs by using the tumor and the corresponding normal cells. These mRNAs should represent the genes that operate in tumor cells but not in the corresponding normal cells. Following the isolation of the differentially expressed mRNAs, they will be reverse transcribed and the desired amounts of cDNA copies will be obtained. The cDNA copies will then be used differentially as a source for oligonucleotides that are antisense to genes or mRNAs. To obtain the desired length oligonucleotides that will be used as antisense oligonucleotides the cDNA copies will be subjected to Maxam-Gilbert fragmentation and/or controlled enodonuclease digestion. These two mentioned procedures could be optimized and used together or separately to obtain the desired length oligonucleotides that will be used against tumor cells.