Distribution of stromelysin-3 mRNA transcripts and microvessels in human breast carcinomas.

Several proteinases, implicated in tumor invasion, are expressed in fibroblastic cells surrounding neoplastic cells, and are believed to be induced by paracrine stimulation. Such stimulation, by the local release of angiogenic factors, is also responsible for the induction of new capillary blood vessels, a crucial aspect of tumor growth and metastasis. We have here compared the expression of a matrix metalloproteinase, stromelysin-3 (ST3), with the distribution of tumor microvessels in invasive breast carcinomas. The highest level of ST3 mRNA in each tumor was recorded and compared to the highest microvessel density. No correlation between these two parameters was observed by analysis of 63 tumors. Detailed examination of 19 individual tumors did not reveal any correlation between the distribution of ST3 mRNA and microvessels. In the material studied here, ST3 expression was observed to correlate with long-term survival of the patients, whereas microvessel density did not correlate.