Tissue Factor Expression in Non-small Cell Lung Cancer: Relationship with Vascular Endothelial Growth Factor Expression, Microvascular Density, and K-ras Mutation

K-RAS mutation in the screening, prognosis and treatment of cancer

The potential use of K-RAS mutation as a cancer screening biomarker has been investigated for many years. Numerous associations between K-RAS mutation and various cancers have been established, but these associations have not been translated into effective, cost-efficient cancer screening strategies. This lack of progress may be due to the existence of K-RAS mutation in nontumor tissues and/or using detection, rather than quantitation, of K-RAS mutation as the endpoint for cancer risk categorization. K-RAS mutation appears to be a useful prognostic biomarker for colon cancer. Recent progress toward sensitive and quantitative mutation characterization and the successful use of K-RAS mutation in a personalized medicine approach to targeted biological therapy selection are likely to re-direct and expand the use of K-RAS mutation as a cancer biomarker in the near future.

Thiazolidinediones enhance vascular endothelial growth factor expression and induce cell growth inhibition in non-small-cell lung cancer cells

Background

It is known that thiazolidinediones are involved in regulating the expression of various genes, including the vascular endothelial growth factor (VEGF) gene via peroxisome proliferator-activated receptor γ (PPARγ); VEGF is a prognostic biomarker for non-small-cell lung cancer (NSCLC).

Methods

In this study, we investigated the effects of troglitazone and ciglitazone on the mRNA expression of VEGF and its receptors in human NSCLC cell lines, RERF-LC-AI, SK-MES-1, PC-14, and A549. These mRNA expressions were evaluated by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis. We also studied the effect of Je-11, a VEGF inhibitor, on the growth of these cells.

Results

In NSCLC cells, thiazolidinediones increased the mRNA expression of VEGF and neuropilin-1, but not that of other receptors such as fms-like tyrosine kinase and kinase insert domain receptor-1. Furthermore, the PPARγ antagonist GW9662 completely reversed this thiazolidinedione-induced increase in VEGF expression. Furthermore, the addition of VEGF inhibitors into the culture medium resulted in the reversal of thiazolidinedione-induced growth inhibition.

Conclusions

Our results indicated that thiazolidinediones enhance VEGF and neuropilin-1 expression and induce the inhibition of cell growth. We propose the existence of a pathway for arresting cell growth that involves the interaction of thiazolidinedione-induced VEGF and neuropilin-1 in NSCLC.

Molecular diversity of VEGF-A as a regulator of its biological activity

The vascular endothelial growth factor (VEGF) family of proteins regulates blood flow, growth, and function in both normal physiology and disease processes. VEGF-A is alternatively spliced to form multiple isoforms, in two subfamilies, that have specific, novel functions. Alternative splicing of exons 5-7 of the VEGF gene generates forms with differing bioavailability and activities, whereas alternative splice-site selection in exon 8 generates proangiogenic, termed VEGF(xxx), or antiangiogenic proteins, termed VEGF(xxx)b. Despite its name, emerging roles for VEGF isoforms on cell types other than endothelium have now been identified. Although VEGF-A has conventionally been considered to be a family of proangiogenic, propermeability vasodilators, the identification of effects on nonendothelial cells, and the discovery of the antiangiogenic subfamily of splice isoforms, has added further complexity to their regulation of microvascular function. The distally spliced antiangiogenic isoforms are expressed in normal human tissue, but downregulated in angiogenic diseases, such as cancer and proliferative retinopathy, and in developmental pathologies, such as Denys Drash syndrome and preeclampsia. Here, we examine the molecular diversity of VEGF-A as a regulator of its biological activity and compare the role of the pro- and antiangiogenic VEGF-A splice isoforms in both normal and pathophysiological processes.

Increased tissue factor expression is associated with reduced survival in non-small cell lung cancer and with mutations of TP53 and PTEN

BACKGROUND

Tissue factor (TF), the main initiator of blood coagulation, is also a signaling protein that regulates cancer progression. TF synthesis was recently shown to be affected by tumor suppressor genes (TSGs) in tumor cell lines. We therefore studied TF gene (F3) expression and the status of genes coding for tumor protein p53 (TP53), phosphatase and tensin homolog (PTEN), and serine/threonine kinase 11 (STK11) in non-small cell lung cancer (NSCLC). Heparanase (HPSE) gene expression was also measured because this endo-beta-D-glucuronidase was recently shown to enhance TF gene expression.

METHODS

TF and heparanase mRNA expression was measured by real-time PCR in 53 NSCLC tumors. Exons 5-8 of TP53 were sequenced from genomic DNA. Mutations of PTEN and STK11 were screened by multiplex ligation-dependent probe amplification.

RESULTS

TF mRNA levels were significantly higher in T(3)-T(4) tumors (P = 0.04) and in stages III-IV of NSCLC (P = 0.03). Mutations of TP53, STK11, and PTEN were identified in 20 (37.7%), 21 (39%), and 20 (37.7%) of tumors, respectively. TF expression was higher in mutated TP53 (TP53(Mut)) (P = 0.02) and PTEN(Mut) (P = 0.03) samples. Moreover, TF mRNA increased from 2700 copies (no mutation) to 11 6415 when 3 TSG were mutated. Heparanase gene expression did not differ according to TF gene (F3) expression or TSG mutation. The median survival time was shorter in patients with tumor TF mRNA levels above median values (relative risk 2.2; P = 0.03, multivariate analysis) and when TP53 was mutated (relative risk 1.8; P = 0.02).

CONCLUSIONS

These results provide clear evidence that combined oncogene events affecting TSG dramatically increase TF gene expression in lung tumors. Moreover, this study suggests that TF gene expression could be used as a prognostic marker in NSCLC.

Microparticles, thrombosis and cancer

Microvesicles comprised of exosomes and microparticles are shed from both normal and malignant cells upon cell activation or apoptosis. Microvesicles promote clot formation, mediate pro-inflammatory processes, facilitate cell-to-cell interactions, transfer proteins and mRNA to cells, and induce cell signalling. Microparticles bearing tissue factor play a central role in coagulation initiation and thrombus formation. This chapter will review earlier studies which focus on the role of procoagulant microvesicles in cancer thrombogenicity, and discuss the effects of microvesicles on vascular cell dysfunction and angiogenesis. In addition, this chapter will present new findings which characterize the haemostatic balance of microparticles, and suggest a method that may potentially serve to predict a state of hypercoagulability in cancer patients. This chapter highlights the interplay between microvesicles, coagulation factors and cancer.