Expression of angiogenic genes in resectable non-small cell lung cancer (NSCLC)

Abstract

e22207 Background: NSCLC is a major cause of cancer-related death worldwide. The prognosis for lung cancer patients is poor with 5-years survival rates being less than 15%. It is known that angiogenesis is an essential event for solid tumour growth. Vascular endothelial growth factor (VEGF) family of ligand and receptors (VEGFR) are described as powerful angiogenic factors. VEGF belongs to a protein family, within which Placental growth factor (PlGF) is a member, they bound to their receptors at the membrane levels, gathering a cascade of intracellular events. In this study, we examine the expression of angiogenic genes in NSCLC samples correlating the expression of these genes between them and with clinicopathological variables. Methods: We performed real-time quantitative polymerase chain reaction (RT-qPCR) to assess the expression of VEGF, PlGF, VEGFR1 and VEGFR2 in frozen lung cancer specimens from untreated NSCLC patients who had undergone surgical resection (n=21). For this purpose, RNA was extracted and RTqPCR was performed using TaqMan® probes. Relative quantification was calculated by Pfaffl formulae, using an endogenous gene for normalization. We correlate the expression of the angiogenic genes between them and with other biologic variables. Statistical analysis were done using the SPSS 13.0 software. Results: Our results show that tumor samples have higher expression of PlGF than normal tissue. The expression of PlGF and VEGF correlates with the expression of their receptors in the group of samples analyzed. The expression of VEGFR1 and VEGFR2 was also significant correlated. We found a significant correlation between the levels of expression of PlGF and the tumor size (p= 0.023, Spearman's test), whereas no relation was found between the expression of the genes and the histology or stage of disease. Conclusions: Our results reveal that, in NSCLC, PlGF mRNA is higher in tumor than in normal tissue and is positively correlated with the tumor size and with the expression of angiogenic receptors. Theses finding could indicate that PlGF have some role in lung cancer progression and may be a promising new biomarker in NSCLC, but still more investigations are necessary with a larger number of samples. Supported by Instituto de Salud Carlos III (Fondo de Investigación Sanitario Grant). No significant financial relationships to disclose.