The occurrence of SV40-Neutralizing antibodies in sera of patients with genitourinary carcinoma

Simian virus 40 in humans

Simian virus 40 (SV40) is a monkey virus that was administered to human populations by contaminated vaccines which were produced in SV40 naturally infected monkey cells. Recent molecular biology and epidemiological studies suggest that SV40 may be contagiously transmitted in humans by horizontal infection, independently from the earlier administration of SV40-contaminated vaccines.SV40 footprints in humans have been found associated at high prevalence with specific tumor types such as brain and bone tumors, mesotheliomas and lymphomas and with kidney diseases, and at lower prevalence in blood samples from healthy donors. Contrasting reports appeared in the literature on the circulation of SV40 in humans by contagious transmission and its association, as a possible etiologic cofactor, with specific human tumors. As a consequence of the conflicting results, a considerable debate has developed in the scientific community. In the present review we consider the main results obtained by different groups investigating SV40 sequences in human tumors and in blood specimens, the putative role of SV40 in the onset/progression of specific human tumors, and comment on the hypotheses arising from these data.

Is there a role for SV40 in human cancer?

The question of whether Simian Virus 40 (SV40) can cause human tumors has been one of the most highly controversial topics in cancer research during the last 50 years. The longstanding debate began with the discovery of SV40 as a contaminant in poliovirus vaccine stocks that were used to inoculate approximately 100 million children and adults in the United States between 1955 and 1963, and countless more throughout the world. Concerns regarding the potential health risk of SV40 exposure were reinforced by studies demonstrating SV40's potential to transform human cells and promote tumor growth in animal models. Many studies have attempted to assess the relationship between the potential exposure of humans to SV40 and cancer incidence. Reports of the detection of SV40 DNA in a variety of cancers have raised serious concerns as to whether the inadvertent inoculation with SV40 has led to the development of cancer in humans. However, inconsistent reports linking SV40 with various tumor types has led to conflicting views regarding the potential of SV40 as a human cancer virus. Several recent studies suggest that older detection methodologies were flawed, and the limitations of these methods could account for most, if not all, of the positive correlations of SV40 in human tumors to date. Although many people may have been exposed to SV40 by polio vaccination, there is inadequate evidence to support widespread SV40 infection in the population, increased tumor incidence in those individuals who received contaminated vaccine, or a direct role for SV40 in human cancer.

Serum antibody in patients with prostatic cancer

130 serum specimens were evaluated. None of 24 serum specimens from patients with prostatic cancer yielded precipitation of haemagglutination reactions with extracts of normal human prostatic tissue or with preparations of prostatic fluid. In 1 of 5 patients from whom autologous prostatic tissue was available, precipitation was observed. By indirect immunofluroescence 13 (54%) patients with prostatic cancer possessed antibodies reactive with the cytoplasmic membrane (intercellular area?) of primate prostatic secretory epithelium. Membranous autoantibodies were observed in 2 patients from whom autologous tissue was available as substrate. Antibodies to nuclei were observed but these have been considered in view of their ubiquitous nature, as perhaps being representative of non-specific indicators of other immunologic aberrations. In contrast, only 11 (10%) of 106 patients with other than prostatic cancer possessed membranous antibodies; of these, 11 (73%) possessed a genito-urinary disorder (5 benign prostatic hypertrophy, considered by some as predisposing to prostatic cancer and 3 carcinoma of the bladder). While not possessing sufficient specificity for diagnosis, the high incidence of this antibody, 92% positive in patients with advanced disease (Stage III), suggests it may be useful as a prognostic index of patients with metastatic disease.