The fibrinolytic enzyme system is thought to play an integral part in the invasion of extracellular matrix by malignant cells. We systematically examined the immunohistochemical distribution of plasminogen activators (t-PA, u-PA and u-PA receptor) and their inhibitors (PAI-1 and PAI-2) in topographically distinct regions within resected squamous cell lung carcinomas. Within tumours there were marked regional differences in the expression of plasminogen activators and plasminogen activator inhibitors by tumour cells, implying variations in fibrinolytic phenotype. In all tumours studied, the presence of tumour macrophages was associated with expression of PAI-1. The striking intra-tumoural variation observed has implications for the interpretation of clinical samples taken to study fibrinolytic phenotype, and supports the concept that fibrinolytic phenotype is critically dependent upon prevailing conditions in the tumour microenvironment.
|Number of pages||8|
|Publication status||Published - 1 Jan 2001|
- Plasminogen activator inhibitors
- Plasminogen activators
- Squamous cell lung cancer