Carcinogenic Effect of Human Tumors-Derived Cell Free-Filtrates in Nude Mice

Abstract

Cancer remains as a worldwide cause of death. Investigational research efforts have included the administration of tumors-derived extracts to healthy animals. Having previously demonstrated that administration of non-transmissible, human cancers-derived homogenates induced malignant tumors in mice; we examined here the consequences of administering 50 or 100 µg of protein of crude homogenates from samples of mammary carcinoma, pancreatic adenocarcinoma, and melanoma. The protocol conceived six inoculations per week during three months. Concurrent control group received homogenates of healthy donor skin cosmetic surgery fragments. Mammary carcinoma homogenate administration did not provoke animals’ deterioration or mortality. Multiple foci of lung adenocarcinomas with broad expression of malignity histomarkers, coexisting with small cell-like carcinomas were found. Disseminated cells, positive to classic epithelial markers were detected in lymphoid nodes. Pancreas tumor and melanoma homogenates administrations severely deteriorated animals’ health. Pancreas tumor induced lung poorly-differentiated adenocarcinomas, as a remarkable pancreatic islets hyperplasia. Melanoma affected lungs with atypical adenomatous hyperplasia and solid pseudopapillary adenocarcinoma. Giant atypical hepatocytes with variegated nuclei were also observed. Kidney parenchyma exhibited dispersed foci of neoplastic cells within a desmoplastic matrix. A noticeable nuclear overlapping with hyperchromatic nuclei, mitotic figures, and prominent nuclear atypia was identified in epidermal cells. None of these changes were ever detected in any mouse of the control groups. This study confirms and extends our hypothesis that tumor homogenates contain and may act as a vector for “malignancy drivers”, which ultimately implement a carcinogenesis process in otherwise healthy mice.