Mechanism of ELL-associated factor 2 and vasohibin 1 regulating invasion, migration, and angiogenesis in colorectal cancer

BACKGROUND

As a novel endogenous anti-angiogenic molecule, vasohibin 1 (VASH1) is not only expressed in tumor stroma, but also in tumor tissue. Moreover, studies have shown that VASH1 may be a prognostic marker in colorectal cancer (CRC). Knockdown of VASH1 enhanced transforming growth factor-β1 (TGF-β1)/Smad3 pathway activity and type I/III collagen production. Our previous findings suggest that ELL-associated factor 2 (EAF2) may play a tumor suppressor and protective role in the development and progression of CRC by regulating signal transducer and activator of transcription 3 (STAT3)/TGF-β1 signaling pathway. However, the functional role and mechanism of VASH1-mediated TGF-β1 related pathway in CRC has not been elucidated.

AIM

To investigate the expression of VASH1 in CRC and its correlation with the expression of EAF2. Furthermore, we studied the functional role and mechanism of VASH1 involved in the regulation and protection of EAF2 in CRC cells in vitro.

METHODS

We collected colorectal adenocarcinoma and corresponding adjacent tissues to investigate the clinical expression of EAF2 protein and VASH1 protein in patients with advanced CRC. Following, we investigated the effect and mechanism of EAF2 and VASH1 on the invasion, migration and angiogenesis of CRC cells in vitro using plasmid transfection.

RESULTS

Our findings indicated that EAF2 was down-regulated and VASH1 was up-regulated in advanced CRC tissue compared to normal colorectal tissue. Kaplan-Meier survival analysis showed that the higher EAF2 Level group and the lower VASH1 Level group had a higher survival rate. Overexpression of EAF2 might inhibit the activity of STAT3/TGF-β1 pathway by up-regulating the expression of VASH1, and then weaken the invasion, migration and angiogenesis of CRC cells.

CONCLUSION

This study suggests that EAF2 and VASH1 may serve as new diagnostic and prognostic markers for CRC, and provide a clinical basis for exploring new biomarkers for CRC. This study complements the mechanism of EAF2 in CRC cells, enriches the role and mechanism of CRC cell-derived VASH1, and provides a new possible subtype of CRC as a therapeutic target of STAT3/TGF-β1 pathway.

The prognostic significance of vasohibin 1-associated angiogenesis in patients with hepatocellular carcinoma

Vasohibin 1, an endothelium-derived negative feedback regulator of angiogenesis, is induced by fibroblast growth factor 2 (FGF-2) and vascular endothelial growth factor A (VEGF-A). In this study, we retrospectively evaluated immunoreactivity of FGF-2 and VEGF-A as well as microvessel density (MVD) determined by expression of vasohibin 1 and CD34 (MVD-CD34) and correlated the findings with clinical outcomes of 181 patients with hepatocellular carcinoma (HCC). Double immunostaining of an endothelial marker CD34 and vasohibin 1 with Ki-67 was also performed to assess angiogenic activity of endothelial cells in HCC. The ratio of Ki-67-positive endothelial cells in vasohibin 1-positive vessels (22%) was significantly higher than that of CD34-positive vessels (9%, P < .001), suggesting the correlation between vasohibin 1 and neovascularization in endothelial cells of HCC. MVD-CD34 decreased, but the ratio of MVD determined by expression of vasohibin 1 to MVD-CD34 (vasohibin 1/CD34) increased significantly according to histologic grade. Vasohibin 1 was significantly correlated with the status of FGF-2 (P = .007) but not with that of VEGF-A (P = .055). The 10-year overall survival and the 2-year disease-free survival rates of the low vasohibin 1/CD34 group (vasohibin 1/CD34 ≤0.459) were significantly higher than those of the high vasohibin 1/CD34 group (vasohibin 1/CD34 >0.459) (survival, 48% versus 38% and 52% versus 35%; P < .001 and P < .05, respectively). In addition, vasohibin 1/CD34 in HCC patients was an independent marker of poor prognosis, as determined by multivariate analysis (risk ratio, 1.973; 95% confidence interval, 1.049-3.711; P = .035). Vasohibin 1/CD34 could identify the proliferative vessels and could be a useful biomarker for predicting the clinical outcome of HCC patients.