Analysis of the papillomavirus type 16 DNA amplification by PCR in SiHa and SLT cell lines

The tumoral cell line SiHa had incorporated in its genome a small part of the viral DNA of the human papillomavirus type 16 (HPV-16), an aetiological agent of cancer of cervix. The genetic transfection in SiHa cells with the plasmid LTneo by the technique of coprecipitation of calcium phosphate followed by selection with G-418 produced a new cell called SLT. The SLT cells were different from SiHa, the parental cell line. Analysis of the amplification of the viral DNA by the polymerase chain reaction showed that HPV-16 was amplified in SiHa cells and was not amplified in SLT cells. This result confirmed that HPV-16 DNA was deleted from the cellular genome and that in this context the polyomavirus LT antigen known as an immortalizing oncogene in the process of carcinogenesis in multiple steps had produced an antioncogenic effect.