SV40 and human cancers

New Perspectives on Diagnosis and Therapy of Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is a rare, but severe form of cancer, with an incidence that varies significantly within and among different countries around the world. It develops in about one to two persons per million of the general population, leading to thousands of deaths every year worldwide. To date, the MPM is mostly associated with occupational asbestos exposure. Asbestos represents the predominant etiological factor, with approximately 70% of cases of MPM with well-documented occupational exposure to asbestos, with the exposure time, on average greater than 40 years. Environmental exposure to asbestos is increasingly becoming recognized as a cause of mesothelioma, together with gene mutations. The possible roles of other cofactors, such as viral infection and radiation exposure, are still debated. MPM is a fatal tumor. This cancer arises during its early phase without clinical signs. Consequently, its diagnosis occurs at advanced stages. Standard clinical therapeutic approaches include surgery, chemo- and radiotherapies. Preclinical and clinical researches are making great strides in the field of this deadly disease, identifying new biomarkers and innovative therapeutic approaches. Among the newly identified markers and potential therapeutic targets, circulating microRNAs and the Notch pathway represent promising avenues that could result in the early detection of the tumor and novel therapeutic approaches.

Absence of Epstein-Barr Virus, Human Papillomavirus, and Simian Virus 40 in Patients of Central European Origin With Lymphoepithelioma-like Carcinoma of the Skin

The authors report 10 cases of lymphoepithelioma-like carcinoma (LELC) of the skin and the results of a molecular biological study for HPV, EBV, and SV40 in lesional tissues. All patients originated from Central Europe. There were seven men and three women, ranging in age from 57 to 86 years. Locations included the face (n = 4), scalp (n = 2), penis (n = 2), and retroauricular area (n = 1); location was unknown for one subject. All but two patients presented with a tumor confined to the skin; in both patients with the penile carcinoma, the tumors had metastasized to an inguinal lymph node. Six patients with available follow-up included four individuals with no evidence of tumor metastasis or recurrences at 2, 3, 4, and 5 years, one patient who died with metastatic disease 7 years after diagnosis, and one patient who died of an unrelated course. Microscopically, all cases showed distinctive features of LELC characterized by variably sized and shaped nodules or syncytial sheets of epithelial cells that contained vesicular chromatic and prominent nucleoli and that were permeated and surrounded by small, well-differentiated lymphocytes and plasma cells. Because all 10 cases studied proved negative for EBV, HPV, and SV40, these viruses seem to play no causal role in LELC of the skin in patients from Central Europe.

Quantitative real-time PCR assay for detection of human polyomavirus infection

The human polyomaviruses BK (BKV) and JC (JCV) affect immunosuppressed patients and are associated with urogenital tract (BKV) and CNS disorders (JCV) and in humans, the pathogenic role of the rhesus monkey virus, Simian virus 40 (SV40), is uncertain. These three viruses have somewhat overlapping tissue pathogenicity and detection of all three polyomaviruses is desirable. A broadly targeted, simple, single tube real-time degenerated quantitative PCR (QPCR) technique for detection of JCV, BKV and SV40 DNA was developed. To avoid false positive results, due to contamination with commonly used SV40 T-antigen plasmids, a conserved region of the VP2 gene was targeted. Down to 1-10 copies of target DNA per PCR reaction were detected. The QPCR was compared with a nested PCR on 41 clinical samples (urine, serum and plasma): 24 (58.5%) tested positive by nested PCR, whereas 31 (75.6%) were positive with QPCR. One CSF sample, from a patient with progressive multifocal leukoencephalopathy, was negative with the nested PCR but determined as positive by QPCR. Sera from 24 blood donors were negative with QPCR. The QPCR described had a high sensitivity. Its specificity was confirmed sequencing. The QPCR is simple to perform and is valuable for diagnosis of polyomavirus infection.