Upregulation of vascular endothelial growth factor mRNA level is significantly related to progression and prognosis of oral squamous cell carcinomas.

Abstract

Vascular endothelial growth factor (VEGF) is a potent angiogenic factor. This study evaluated whether the VEGF mRNA level in oral squamous cell carcinoma (OSCC) tissue could be a biomarker to predict the progression and prognosis of OSCCs in Taiwan. This study used quantitative real-time reverse transcription-polymerase chain reaction (quantitative RT-PCR) to detect the VEGF mRNA levels in 60 OSCC specimens. Threshold cycle (CT) was defined as the PCR cycle number needed to generate a predetermined amount of DNA (threshold). The relative amount of tissue VEGF mRNA, standardized against the amount of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA, was expressed as ΔCT = (VEGF CT - GAPDH CT). For a chosen threshold, a smaller starting copy number of mRNA results in a higher CT value. Thus, the lower the ΔCT, the greater the copy number of VEGF mRNA in tissues. The lower mean VEGF mRNA ΔCT value was significantly associated with OSCCs with larger tumor size (p=0.040), positive lymph node metastasis (p=0.023), and more advanced clinical stages (p=0.008). VEGF mRNA ΔCT value < 4.2 (p=0.026) was identified as an independent unfavorable prognosis factor using multivariate regression analyses. Moreover, Kaplan-Meier curve showed that OSCC patients with a VEGF mRNA ΔCT value < 4.2 had a significantly poorer overall survival than those with a VEGF mRNA ΔCT value ≥4.2 (log-rank test, p=0.0427). The OSCC tissue VEGF mRNA level can be used to predict the progression and prognosis of OSCCs in Taiwan.