Cell-mediated cytotoxicity expressed by lymphoid cells from rats with asbestos-induced peritoneal mesothelioma towards rat fetal cell.

Abstract

Cell-mediated immunity (CMI) directed towards rat fetal cells was evaluated in Fischer F344 young inbred male rats having asbestos-induced peritoneal mesothelioma. The tumors were induced by exposure to Canadian chrysotile B fibers and the CMI delineated by the injury and destruction brought about to 6- to 10-day-old primary fetal cell cultures by the so-called educated peripheral blood lymphoid-cells (PBLC) obtained from the cancer-bearing rats. A significant cytotoxicity was found to be expressed by the PBLCs, suggesting that during the development of mesothelioma, a cellular retrodifferentiation occurs, thereby educating the effectors to recognize a common determinant existing in both the tumor and fetal cells. Educated PBLCs were produced from rats having endodermal tissue cancers (adenocarcinomas of the small bowel, colon and pancreas) and were found to also be cytotoxic to the fetal cultures, yet no injury was apparently inflicted upon cultured mesothelioma target cells by these effectors. These results suggested that the tumor education was specific and that probably a unique and different fetal component was being recognized by the effector cells obtained from the rats with lesions arising either in the mesodermal or endodermal tissue. Further support for this concept was the failure of an antibody, specific to an oncofetal protein existing in endodermal lesions, to apparently recognize any common oncogenic proteins in the mesothelioma. Preliminary studies have also been accomplished which suggests the existence of natural killing immune responses existing to the mesothelioma target cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Nonpulmonary Outcomes of Asbestos Exposure

“…Chrysotile appears to pose a greater threat than crocidolite. However, IARC recently concluded the evidence to support asbestos-induced stomach cancer to be “limited” ( Straif et al, 2009 ). There is a great deal of inconsistency in the studies of the GIT effects of asbestos, making it difficult to come to any strong conclusions (see Table 3 ).…”

“…In addition, the potential for misdiagnosis of primary diffuse malignant peritoneal mesothelioma in women further complicates the issue ( Kerrigan et al, 2002 ), particularly in older studies that did not use specific markers directed toward serous ovarian carcinoma ( Bollinger et al, 1989 ). Nevertheless, IARC recently concluded that the evidence to date is sufficient to consider asbestos an ovarian carcinogen ( Straif et al, 2009 ). Studies include a cohort of East London factory workers from 1933-1980 who reportedly elevated rates of ovarian cancer ( Newhouse et al, 1985 and a confirmation of excessive ovarian cancer in female gas mask assemblers during World War II ( Wignall & Fox, 1982 ; Acheson et al, 1982 ).…”