Interaction between Viral and Cell Genes in Cervical Tumors

The results of the works carried out in the Laboratory of Molecular Biology of Viruses, CRC in the framework of the Human Genome program and devoted to the study of the activity of cell and viral genes in cervical cancer are summarized. DNA of human papillomaviruses persists in tumors both in episomal and integrated forms. Integration may occur in different regions of chromosomes. Viral transforming genes 6 and 7 are always present in tumor cells, while antibodies to these proteins are detected only in 30% of patients. Loss of heterozygosity is detected on the long and short arms of chromosome 6; some such cases are manifest already at the early stages of tumor progression, while others are typical of the late stages. A number of cell genes potentially involved in tumorigenesis are shown to be hypermethylated in CpG islands. Methylation of several genes at once is observed in 30% of tumors. Tumor progression is associated with increased expression of 16^ink4a, an inhibitor of cyclin-dependent kinases.