VEGF-A and its isoform VEGF121 mRNA expression measured by quantitative real-time RT-PCR: correlation with F-18 FDG uptake and aggressiveness of lung adenocarcinoma: preliminary study

Abstract

To investigate the correlation of vascular endothelial growth factor (VEGF) A and its isoform VEGF₁₂₁ mRNA expression with F-18 fluorodeoxyglucose (FDG) uptake and aggressiveness in lung adenocarcinoma. Twenty-three patients with lung adenocarcinoma underwent FDG PET before surgery. As semi-quantitative analysis for FDG uptake, partial volume corrected standardized uptake value (PVC-SUV) of the tumor was calculated. Total RNA from lung adenocarcinoma tissue was prepared from the frozen specimens. Using the real-time reverse transcription polymerase chain reaction method, we analyzed the mRNA level of VEGF-A and VEGF-A isoform VEGF₁₂₁ mRNA level. 18S ribosomal RNA was used as an endogenous control. VEGF-A and VEGF₁₂₁ mRNA levels had significantly positive correlation with PVC-SUV in lung adenocarcinoma (r = 0.477, p = 0.021, r = 0.539, p = 0.008, respectively), while they were not correlated with tumor size (≤3 or >3 cm). VEGF-A and VEGF₁₂₁ mRNA levels of the low FDG uptake group were significantly lower than those of the high FDG uptake group (p = 0.005 and p = 0.004, respectively). FDG uptake (PCV-SUV) of aggressive lung adenocarcinoma was higher than that of non-aggressive lung adenocarcinoma (p = 0.01). VEGF-A and VEGF₁₂₁ mRNA levels of aggressive lung adenocarcinoma were higher than those of non-aggressive lung adenocarcinoma (p = 0.0001 and p = 0.0001, respectively). VEGF-A and VEGF₁₂₁ mRNA levels may correlate with FDG uptake and aggressiveness in lung adenocarcinoma. These findings support the hypothesis that VEGF-A and VEGF₁₂₁ may help in predicting the outcome in patients with lung adenocarcinoma.