Background: Patients with solo tumour malignancy are at higher risk of developing venous thromboembolism. When prophylactic anticoagulation (and in particular heparin) is used during cancer therapy however, patients appear to have a prolonged survival. Tumours express large quantities of procoagulant molecules, which predispose patients to these conditions. Tissue Factor (TF) is an important example, which may have a role in the biology of malignant disease. Intra-tumour vessel coagulation however is not a common phenomenon. Our hypothesis is that cancer cells produce anticoagulant molecules, which may prevent intra-tumour vessel auto-coagulation. Our results show that one such factor--Tissue Factor Pathway Inhibitor (TFPI-1) is expressed by a number of different cancer cells.
Methods: Seven human cancer cell lines were studied: three breast, two colorectal and two pancreatic. Cells were maintained in cell culture, and at 90% confluence protein and RNA were extracted. RNA integrity was confirmed using an RNA integrity gel and RNA purity determined by spectrophotometry. Reverse transcription polymerase chain reaction (RT-PCR) was used for TFPI-1 mRNA detection and immunoblotting used for TFPI-1 protein detection.
Results: Six cell lines (two breast, two colorectal, and two pancreatic) expressed the TFPI-1 gene. Gene function was confirmed by detection of TFPI-1 protein expression in these cell lines.
Conclusion: TFPI-1 is expressed by breast cancer and other cancer cell lines maintained in cell culture. This has not been previously reported. Functional expression of TFPI-1 by cancer cells suggests that it has an important role in cancer biology. Further experiments are required to establish its function.