Document 0235 DOCN M9620235 TI Mycoplasmas and oncogenesis: persistent infection and multistage malignant transformation. DT 9602 AU Tsai S; Wear DJ; Shih JW; Lo SC; American Registry of Pathology, Department of Infectious and; Parasitic Disease Pathology, Armed Forces Institute of Pathology,; Washington, DC 20306-6000, USA. SO Proc Natl Acad Sci U S A. 1995 Oct 24;92(22):10197-201. Unique Identifier : AIDSLINE MED/96036051 AB Oncogenic potential of human mycoplasmas was studied using cultured mouse embryo cells, C3H/10T1/2 (C3H). Mycoplasma fermentans and Mycoplasma penetrans, mycoplasmas found in unusually high frequencies among patients with AIDS, were examined. Instead of acute transformation, a multistage process in promotion and progression of malignant cell transformation with long latency was noted; after 6 passages (1 wk per passage) of persistent infection with M. fermentans, C3H cells exhibited phenotypic changes with malignant characteristics that became progressively more prominent with further prolonged infection. Up to at least the 11th passage, all malignant changes were reversible if mycoplasmas were eradicated by antibiotic treatment. Further persistent infection with the mycoplasmas until 18 passages resulted in an irreversible form of transformation that included the ability to form tumors in animals and high soft agar cloning efficiency. Whereas chromosomal loss and translocational changes in C3H cells infected by either mycoplasma during the reversible stage were not prominent, the onset of the irreversible phase of transformation coincided with such karyotypic alteration. Genetic instability--i.e., prominent chromosomal alteration of permanently transformed cells--was most likely caused by mutation of a gene(s) responsible for fidelity of DNA replication or repair. Once induced, chromosomal alterations continued to accumulate both in cultured cells and in animals without the continued presence of the transforming microbes. Mycoplasma-mediated multistage oncogenesis exhibited here shares many characteristics found in the development of human cancer. DE Animal AIDS-Related Opportunistic Infections/*MICROBIOLOGY Cell Division Cell Line *Cell Transformation, Neoplastic Cells, Cultured Chromosome Deletion Chromosome Mapping Clone Cells Embryo Human Karyotyping Mice Mice, Inbred C3H Mice, Nude *Mycoplasma fermentans *Mycoplasma penetrans Mycoplasma Infections/*PHYSIOPATHOLOGY Support, U.S. Gov't, P.H.S. Translocation (Genetics) JOURNAL ARTICLE SOURCE: National Library of Medicine. NOTICE: This material may be protected by Copyright Law (Title 17, U.S.Code).