Expression of Vasohibin-2 in Pancreatic Ductal Adenocarcinoma Promotes Tumor Progression and is Associated with a Poor Clinical Outcome

This study aimed to assess the expression of vasohibin-2 (VASH2) in pancreatic ductal adenocarcinoma (PDAC) as a marker of tumor aggressiveness and its impact on tumor angiogenesis, proliferation, and clinical outcome. We examined the expression of the VASH2 gene in human pancreatic cell lines PANC-1 and MiaPaCa-2 by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunocytochemistry. Fifty samples from patients with PDAC were immunostained with VASH2, CD34, and Ki-67 antibodies. Further, the immunoreactivity of VASH2 correlated with the pathological features, including microvessel density (MVD), tumor cell proliferation (Ki-67 labeling index), and survival. Forty-seven of the 50 samples from PDAC patients showed immunoreactivity for VASH2 along the tumor cell cytoplasm. Among the VASH2-positive samples, 22 were categorized as high VASH2 expression group, and this group had statistical significance with pN stage (p = 0.006), UICC stage (p = 0.033), tumor proliferation (p < 0.001), and MVD (p = 0.017). Moreover, patients with high VASH2 expression showed worse prognosis compared to those showing low VASH2 expression (overall logrank p = 0.003). Thus, our results suggested that overexpression of VASH2 accelerated the pace of tumor development toward a more serious malignant phenotype and was associated with a poor clinical outcome. VASH2 may be an important novel target for the management of PDAC after surgery.