Relationships of high mobility protein group 1 with vascular endothelial growth factor and microvessel density in colorectal cancer

Objective To observe the expressions of high mobility protein group 1 (HMGB1), vascular endothelial growth factor (VEGF) and microvessel density (MVD) in colorectal cancer tissues, and the correlations of HMGB1 with VEGF and MVD.

Methods A total of 89 patients with colorectal cancer were divided into metastasis group (n=32) and non-metastasis group (n=57) according to whether lymph node metastasis occurred or not. The expressions of HMGB1, VEGF and MVD in cancer tissues of the two groups were detected. The best cut-off values of three indexes for the diagnosis of lymph node metastasis in patients with colorectal cancer were obtained by receiver operating characteristic (ROC) curve. The correlations of HMGB1 with VEGF and MVD were analyzed, and the linear regression equation was established.

Results The positive scores of HMGB1 and VEGF and MVD in cancer tissues and adjacent tissues in the metastasis group were higher than those in the non-metastasis group, and the positive scores of HMGB1 and VEGF and the number of MVD in cancer tissues in the two groups were higher than those in adjacent tissues (P < 0.05). ROC curve results showed that the best cut-off values of HMGB1 and VEGF for diagnosis of lymph node metastasis in cancer tissues were 4.5 points and 3.5 points, respectively, and the best cut-off value of MVD was 32.5 per 200 times field of vision. The proportions of patients with lymph node metastasis and HMGB1 overexpression in the VEGF high expression group and MVD high expression group were higher than those in low expression groups for VEGF and MVD(P < 0.05). In cancer tissues, the positive score of HMGB1 was positively correlated with positive score of VEGF and MVD. The linear regression equation was established, y_VEGF=2.459+0.516x_HMGB1 and y_MVD=-17.365+13.502x_HMGB1.

Conclusion HMGB1, VEGF and MVD are overexpressed in the cancer tissues of patients with colorectal cancer, and the expression of HMGB1 is significantly correlated with VEGF and MVD. The angiogenesis of tumor can be detected by HMGB1 and effective preventive measures for lymph node metastasis should be made in time.