Absence of jaagsiekte sheep retrovirus DNA and RNA in bronchioloalveolar and conventional human pulmonary adenocarcinoma by PCR and RT-PCR analysis

Bronchioloalveolar adenocarcinoma (BAC) morphologically resembles sheep pul monary adenomatosis (SPA), a contagious ovine pulmonary adenocarcinoma caus ed by the jaagsiekte sheep retrovirus (JSRV). Previously, positivity for JS RV by immunostaining, reverse-transcription polymerase chain reaction (RT-P CR), and Western blot was reported in most nonmucinous BACs. Our objective in this study was to analyze additional BAC subtypes and conventional adeno carcinomas (CA) to further substantiate this association. Tumor tissue was microdissected from unstained paraffin sections of 26 cases of formalin-fix ed, paraffin-embedded BAC (7 mucinous, 17 nonmucinous, 2 sclerosing) and 29 cases of CA. Positive controls consisted of 2 separate paraffin blocks of known SPA. Primer sequences were derived that were capable of hybridizing t o all reported strain variants of both the DNA (endogeneous) and RNA (exoge nous) forms of JSRV. Each sample was tested using both PCR (DNA) and RT-PCR (RNA). All BAC and CA cases were negative for JSRV. Positive controls yiel ded PCR products that were sequenced and precisely matched the published pr ototype stain of JSRV. To control for negative effects of tissue fixation, dilutions of positive control tissue were added to BAC and CA samples. Dete ction of JSRV was evident at 1:50 dilution. Although the possibility of a v iral association with BAC cannot be excluded, this study shows that the ass ociation with JSRV is probably very weak, if present at all. Hum PATHOL 32: 1039-1042. Copyright (C) 2001 by W.B. Saunders Company.