Tumor genotype-specific growth inhibition in vivo by antisense oligonucleotides against a polymorphic site of the large subunit of human RNA polymerase II.

Loss of heterozygosity (LOH) reduces genes to hemizygosity in cancer cells and presents an absolute difference between normal and cancer cells. The regions of LOH are usually much larger than the tumor suppressor gene, which is lost, and are expected to contain genes that are essential for cell survival. Single nucleotide polymorphisms (SNPs) are the most common type of genetic variation in man, often giving rise to two or more allelic forms of most genes.

The involvement of human ribonucleases H1 and H2 in the variation of response of cells to antisense phosphorothioate oligonucleotides.

We have analyzed the response of a number of human cell lines to treatment with antisense oligodeoxynucleotides (ODNs) directed against RNA polymerase II, replication protein A, and Ha-ras. ODN-delivery to the cells was liposome-mediated or via electroporation, which resulted in different intracellular locations of the ODNs. The ODN-mediated target mRNA reduction varied considerably between the cell lines.