Integration of SV40 in human osteosarcoma DNA

Abstract

Simian virus 40 (SV40) has been demonstrated in several types of tumors, including osteosarcoma, by polymerase chain reaction (PCR). We detected SV40 sequences by PCR, followed by hybridization, in nine of 35 osteosarcoma tumors and one of 11 osteosarcoma explants. PCR can detect fewer than one virus per cell but gives little detail of the gross structure and abundance of the virus. Analysis by Southern blotting of total DNA from ten osteosarcomas, positive for SV40 by PCR, found viral integration in half of these. Analysis showed integration of one to four copies per cell of rearranged SV40. No SV40 was detectable on blots of the remaining ®ve SV40 + osteosarcomas, perhaps because of the lesser sensitivity of direct hybridization. Inactivation of the p53 and Rb tumor suppressors is a key activity of SV40 T-antigen. Unexpectedly, correlation of these ®ndings with our prior studies indicated that ®ve of ten osteosarcomas positive for SV40 DNA had mutations of p53, and two had deleted Rb. Apparently clonal integration with pre-existing alteration of a tumor suppressor gene, suggests that SV40 may play a role in the ®nal conversion to malignant osteosarcoma.

Tissue-specific expression of SV40 in tumors associated with the Li–Fraumeni syndrome

“…Based on previous reports of SV40-like DNA sequences in childhood choroid plexus tumours (Bergsagel et al, 1992), in osteosarcoma (Carbone et al, 1996;Mendoza et al, 1998), and its tropism to renal epithelium, we asked whether the presence of SV40 T-antigen could account for the`second-hit' in both patients' CPCs and the RCC and osteosarcoma in Patient 2. The degraded nature of the DNA from Patient 2's osteosarcoma made it uninformative.…”

“…Based on previous ®ndings of polyomavirus (e.g. SV40) DNA in CPC and OS tumors (Bergsagel et al, 1992;Carbone et al, 1996;Mendoza et al, 1998), our studies were directed at viral oncoprotein mechanisms of second hits in the loss of normal p53 function. We found that both genetic and epigenetic mechanisms of p53 inactivation occur in LFS patients.…”

Different simian virus 40 genomic regions and sequences homologous with SV40 large T antigen in DNA of human brain and bone tumors and of leukocytes from blood donors

“…S V40 Tag sequences have been detected at different prevalence by polymerase chain reaction (PCR) followed by filter hybridization in human brain tumors, [1][2][3][4][5] pleural mesotheliomas, 6 -10 bone tumors, [11][12][13][14][15] pituitary 16 and thyroid neoplasms, 17 and in lymphoproliferative disorders. 18 -20 Southern blot hybridization experiments with bone and papillary thyroid tumor DNAs confirmed the SV40 specificity of these sequences and assessed that the viral DNA can be present in a free episomal form as well as integrated into the human genome.…”

“…18 -20 Southern blot hybridization experiments with bone and papillary thyroid tumor DNAs confirmed the SV40 specificity of these sequences and assessed that the viral DNA can be present in a free episomal form as well as integrated into the human genome. 13,17 Moreover, SV40 Tag DNA sequences were detected in normal lung and pituitary tissues, 8,16 in peripheral blood mononuclear cells (PBMCs) of patients affected by osteosarcomas, 14 in PBMCs from blood donors, 2,3,14,18,20 and in sperm fluids of healthy individuals. 3 SV40 DNA was detected in PBMCs and brain tissue of monkeys, 21 and SV40 neutralizing antibodies were found in human sera.…”

SV40 in human brain cancers and non-Hodgkin's lymphoma

“…Studies have shown the expression of SV40 mRNA and/or T-ag in cancer cells, the integration of SV40 sequences in some cancers, and that SV40 T-ag protein was complexed with p53 and pRb in some tumor specimens (Bergsagel et al, 1992;Carbone et al, 1997a;De Luca et al, 1997;Mendoza et al, 1998;Zhen et al, 1999;Arrington and Butel, 2001). These are important findings because SV40 oncogenesis is mediated in large part by T-ag.…”