Non-small cell lung cancer (NSCLC) comprises of 75% of all lung cancers. Human full length tissue factor (flHTF), the physiological initiator of blood coagulation, is aberrantly expressed in certain solid tumors. FlHTF and its soluble isoform, alternatively spliced human tissue factor (asHTF), have been shown to contribute to thrombogenicity of the blood of healthy individuals. The aim of this study was to quantify flHTF and asHTF on mRNA and protein levels (using immunohistochemistry, immunoblotting, and ELISA) on a panel of human NSCLC tissue and plasma specimens. The tissue factor (TF) expression of 21 pulmonary adenomatous (AC) and 12 normal healthy tissues was assessed by real-time qRT-PCR. The TF protein concentration was quantified by ELISA in a subset of 11 AC and 9 normal tissue specimens as well as in the plasma of 13 lung cancer patients and 15 healthy controls. We found a significant increase in the ratio of flHTF/HGAPDH mRNA in AC (0.24±0.06 vs. 0.07±0.01; p=0.02 vs. controls) and in asHTF/HGAPDH mRNA (0.027±0.01 vs. 0.004±0.001; p=0.03 AC vs. controls). AsHTF mRNA expression was significantly lower in patients with stage IA disease compared to patients with higher grade stages, pointing to TF as being a marker of malignancy and metastases. TF protein of lung tumors was significantly increased in AC (p=0.004 vs. controls). TF in plasma was up-regulated in lung cancer patients (334.9±95.4 vs. 124.1±14.8 pg/ml; p=0.02 vs. controls). Immunohistochemical and immunoblotting data are in line with the increased TF expression, showing elevated blood thrombogenicity of NSCLC patients. The upregulation of flHTF and, especially, asHTF in AC suggests not only a raised risk of thrombosis, but also of tumor progression, thereby, indicating a poor prognosis in these patients.

Antioxidative treatment inhibited apoptosis and shedding of microparticles, thereby reducing thrombogenicity. Thus, antioxidants may help to prevent late thrombosis after antiproliferative treatment when used in combination with anticoagulants.

The signals which initiate proliferation of endothelial cells after injury are important for selective blood vessel growth during wound healing or tumour growth. Upon mechanically wounding quiescent cells, a transient [Ca2+]i increase was induced in cells at the wound edge. These same cells proliferated 18-24 h post wounding, as measured by bromodeoxyuridine incorporation. The localized Ca2+ signal was required specifically during wounding since blocking Ca2+ influx reduced proliferation by 40-50%. Proliferation also required serum since starvation reduced proliferation by 80%. Serum-starved cells proliferated if briefly primed with serum prior to wounding. The signals derived from serum and [Ca2+]i combined at least additively to induce proliferation. Therefore, serum priming followed by a single, transient Ca2+ signal induced by mechanical injury must occur in a temporally and spatially regulated manner for normal proliferation. Co-ordination between signalling cascades induced by growth factors and release from contact inhibition might be obligatory for localized re-endothelialization after injury.

The signals which initiate proliferation of endothelial cells after injury are important for selective blood vessel growth during wound healing or tumour growth. Upon mechanically wounding quiescent cells, a transient [Ca2+]i increase was induced in cells at the wound edge. These same cells proliferated 18-24 h post wounding, as measured by bromodeoxyuridine incorporation. The localized Ca2+ signal was required specifically during wounding since blocking Ca2+ influx reduced proliferation by 40-50%. Proliferation also required serum since starvation reduced proliferation by 80%. Serum-starved cells proliferated if briefly primed with serum prior to wounding. The signals derived from serum and [Ca2+]i combined at least additively to induce proliferation. Therefore, serum priming followed by a single, transient Ca2+ signal induced by mechanical injury must occur in a temporally and spatially regulated manner for normal proliferation. Co-ordination between signalling cascades induced by growth factors and release from contact inhibition might be obligatory for localized re-endothelialization after injury.

No abstract