Detection of viral DNA and RNA by in situ hybridization

Abstract

Using cloned restriction endonuclease fragments of Herpes simplex virus (HSV), human papillomavirus (HPV), and cytomegalovirus (CMV) DNA as probes, viral DNA and RNA sequences have been detected in human tissues. The probes were labeled either with a radioactive isotope, for subsequent detection by autoradiography, or with biotin. This latter technique has been successfully used to visualize HPV DNA in tissues that have been fixed in formalin and embedded in paraffin, and is therefore of value in retrospective studies of histological specimens. HPV DNA was detected under non-stringent conditions (Tm = -42 degrees C) with heterologous probes in plantar and common warts, laryngeal papillomas, and anogenital condylomas. The specific type of HPV was established using stringent hybridization conditions (Tm = - 17 degrees C). Results from these and from malignant tissues show the distribution and localization of HSV and HPV RNA and DNA sequences in malignancies of squamous cell origin in the anogenital region. Both HSV and HPV DNA sequences have occasionally been detected in the same tumor, providing a further impetus to test the hypothesis that an initiator-promoter relationship might involve these common human viruses in the development of some tumors.