LOCALIZATION OF THE 92 KD GELATINASE MESSENGER-RNA IN SQUAMOUS-CELL AND ADENOCARCINOMAS OF THE LUNG USING IN-SITU HYBRIDIZATION

We have used in situ hybridization for RNA to localize cells containin g mRNA for the 92 kd gelatinase in carcinomas of the lung. We used arc hival material to analyze sections from 12 cases of squamous cell carc inomas of the lung including six stage I and three stage II and from t hree cases of adenocarcinoma of the lung. Presence of mRNA in the tiss ue was verified by in situ hybridization for gamma actin. The 92 kd ge latinase mRNA was found in all 12 squamous cell carcinomas tumors and was highly expressed in the tumor cells themselves. In addition, it wa s found in host stromal cells surrounding the tumor, but not in normal lung fibroblasts. In contrast it was not found in the adenocarcinomas of the lung or in the stroma surrounding these tumors. The mRNA for t he 92 kd gelatinase was present ill normal pulmonary tissue, bronchial epithelium, basal cell hyperplasia of bronchial epithelium, alveolar macrophages, and focally in bronchial mucous glands. It was not presen t in normal alveoli, vascular cells, cartilage, or most lymphocytes. W e corroborated the presence of the mRNA for the 92 kd gelatinase by ri bonuclease protection assay. The levels of mRNA for the 92 kd gelatina se in two specimens of squamous cell carcinoma were 6- to 10-fold grea ter than in the nonneoplastic tissue and two adenocarcinoma specimens.