TUMOR COLLAGENASE STIMULATORY FACTOR (TCSF) EXPRESSION AND LOCALIZATION IN HUMAN LUNG AND BREAST CANCERS

Tumor cell-derived collagenase stimulatory factor (TCSF) stimulates in vitro the biosynthesis of various matrix metalloproteinases involved in tumor invasion, such as interstitial collagenase, gelatinase A, and stromelysin 1. The expression of TCSF mRNAs was studied in vivo, usin g in situ hybridization and Northern blotting analysis, in seven norma l tissues and in 22 squamous cell carcinomas of the lung, and in seven benign proliferations and in 22 ductal carcinomas of the mammary glan d. By in situ hybridization, TCSF mRNAs were detected in 40 of 44 carc inomas, in pre-invasive and invasive cancer cells of both lung and bre ast cancers. TCSF mRNAs and gelatinase A mRNAs were both visualized in the same areas in serial sections in breast cancers, and were express ed by different cells, tumor cells, and fibroblasts. The histological results were confirmed by Northern blot analysis, which showed a highe r expression of TCSF mRNAs in cancers than in benign and normal tissue s. These observations support the hypothesis that TCSF is an important factor in lung and breast tumor progression.