One interesting study is called, Adenovirus-mediated wild-type p53 overexpression reverts tumourigenicity of human mesothelioma cells. By Giuliano M, Catalano A, Strizzi L, Vianale G, Capogrossi M, Procopio A. Int J Mol Med. 2000 Jun;5(6):591-6. Department of Oncology and Neuroscience, Clinical Pathology Section, Gabriele D’Annunzio University, 66013 Chieti, Italy. Here is an excerpt: Abstract – Pleural malignant mesothelioma (MM) shows poor survival, regardless of tumour stage at diagnosis. MM is unresponsive to present treatment regimens and new protocols are desperately needed. The localised nature, the potential accessibility, and the relative lack of distant metastases make MM a particularly attractive candidate for somatic gene therapy. A common target for cancer gene therapy is the tumour suppressor protein p53. p53 does not seem to be mutated or deleted in MM, but it can be inactivated by binding to other proteins, like mdm2 and SV40 large T antigen. We tested the effects of a replication-deficient adenoviral vector carrying wild-type p53 cDNA in human MM cells. Our results show that >95% of MM cells were efficiently infected with 25 multiplicity of infection (MOI) of vector. Wild-type p53 was effectively expressed resulting in >80% inhibition of proliferation in MM cells. AdCMV.p53 infection induced apoptosis while controls did not show any evident morphological alterations. Ex vivo p53 gene transfer experiments inhibited tumourigenesis in nude mice. In vivo, direct intratumour injection of AdCMV.p53 arrested tumour growth and prolonged survival of treated mice. These results indicate that p53-gene therapy should be strongly exploited for clinical trials in MM patients.
Another study is called, Congenital polycystic tumor of the atrioventricular node (endodermal heterotopia, mesothelioma): A histogenetic appraisal with evidence for its endodermal origin – Human Pathology Volume 18, Issue 8, August 1987, Pages 791-795 by MD Gerald Fine and MD Usha Raju. Here is an excerpt: The small, variously designated, primary atrioventricular node tumor has been considered to be of endothelial, endodermal, or mesothelial origin. To identify its derivation, we studied seven tumors using silver staining and immunocytochemical labeling with a variety of antibodies. Cytoplasmic argyrophil granules but not argentaffin granules were found in isolated cells among the more numerous bubule-lining cells in four tumors. Serotonin and calcitonin were demonstrable in seven and six tumors, respectively, in a similar distribution to that of the argyrophil cells. A positive reaction of different distribution from that of the argyrophil cells was noted in a varying number of tubule-lining cells for carcinoembryonic antigen, epithelial membrane antigen, and blood group antigen in seven, four, and seven tumors, respectively. No activity was noted in the tumor cells for factor VIII-related antigen or a number of peptides. An endodermal rather than mesothelial or epithelial origin for the tumor is substantiated by the presence of neuroendocrine cells in the midst of the more numerous carcinoembryonic-antigen-positive lining cells of the tumor tubules.
Another study is called, SV40 expression in human neoplastic and non-neoplastic tissues: perspectives on diagnosis, prognosis and therapy of human malignant mesothelioma. By Procopio A, Marinacci R, Marinetti MR, Strizzi L, Paludi D, Iezzi T, Tassi G, Casalini A, Modesti A. Dev Biol Stand. 1998;94:361-7. Department of Oncology and Neuroscience, Gabriele D’Annunzio University, Chieti, Italy. Here is an excerpt: Abstract – We have recently demonstrated the association of SV40 and human pleural malignant mesothelioma. Here, we have investigated whether SV40 viral sequences may be associated with other human tumours or other non-neoplastic pathology and whether SV40 DNA or protein expression may be of diagnostic, prognostic or therapeutic relevance. DNA was extracted from paraffin embedded tissues. SV40, JC and BK viral sequences were detected by the polymerase chain reaction and molecular hybridization with specific probes. The screening with three different sets of SV40-related primers demonstrated that 7/18 (38.8%) mesothelioma specimens were SV40 positive as well as 5/18 (27.7%) tubercular pleural lesions. None of the 18 lung cancers, nor the 20 pleural non-specific inflammatory specimens tested were positive. Twenty-five blood samples and 18 urinary sediments from MM patients were also negative. We have also found that SV40 Tag proteins are present in mesothelioma cells and tumours. Tag proteins may interfere with tumour suppressor gene products, such as p53. Preliminary results suggest that wild type p53 transgene expression, obtained after infection with recombinant adenovirus (AdCMV.p53), inhibited in vitro and in vivo proliferation, inducing apoptosis of mesothelioma cells. Infections with control viruses were ineffective. Thus, SV40 DNA and Tag expression in mesothelioma tumour cells, though probably not relevant for diagnostic or prognostic purposes, may be crucial for innovative gene therapy strategies.
If you found any of these excerpts interesting, please read the studies in their entirety.
Monty Wrobleski is the author of this article. For more information please click on the following links