EFFECTS OF HUMAN PAPILLOMAVIRUS TYPE-18-SPECIFIC ANTISENSE OLIGONUCLEOTIDES ON THE TRANSFORMED PHENOTYPE OF HUMAN CARCINOMA CELL-LINES

DNA of human papillomavirus type 18 is present in several human cancer cell lines thal were derived from oral or cervical tumors, and it is known that several features of the transformed phenotype can be inhibi ted by expression Of antisense RNA to human papillomavirus (HPV). The pre ent study was performed to find out whether antisense oligonucleot ides were also inhibitory. Synthetic oligonucleotides were made that w ere complementary to regions of the start codons of the E6 and E7 gene s of HPV-18. These were added to cultures of the oral cancer cell line 1483 and the cervical cancer cell line C4-1, each of which contain DN A of HP-18. As controls we used the oral cancer cell line 183 and the monkey kidney cell line Vero, which do not contain HPV. Anti-E6 and an ti-E7 oligonucleotides, in concentrations between 1 and 5 muM, signifi cantly inhibited the growth of the 1483 and C4-1 cells, but not the 18 3 or Vero cell lines. Treatment of the 1483 cells with a combination o f 2.5 muM of each of the antisense oligonucleotides was a more effecti ve inhibitor than 5 muM of either one used alone. Antisense oligonucle otides had no effect on the ability of 1483 cells to form foci in soft agar, nor on their plating efficiency or serum requirements. Microsco pic examination of 1483 cells showed that the antisense E7 oligonucleo tide produced cell-rounding, detachment from the surface of the cultur e flask, and cell death, while the antisense E6 oligonucleotide had no ne of these effects. Random-sequence oligonucleotides had no effects o f any type on any cells that were growing in culture. However, if rand om-sequence oligonucleotides were added to cells at the time they were passed to a new culture vessel, they produced severe nonspecific toxi c effects. These results show that the use of synthetic oligonucleotid es is an effective way of producing antisense-mediated changes in the behavior of human cancer cells that contain DNA of HPV-18.