Clinical research on the expression of three vascular regulatory factors in different morphological regions of Marjolin ulcer and their relationship with angiogenesis

Abstract

Objective: To investigate the expressions of vascular endothelial growth factor (VEGF), hypoxia inducible factor-1 alpha (HIF-1α), and epidermal growth factor receptor (EGFR) in different morphological regions of Marjolin ulcer and their clinical relationship with angiogenesis. Methods: From January 2012 to December 2017, the patients admitted to our hospital who met the inclusion criteria were selected, including 92 patients with Marjolin ulcer [56 males and 36 females, aged (55±15) years], 100 patients with chronic non-cancerous skin ulcer [59 males and 41 females, aged (51±16) years], and 100 patients performed with other skin-related surgery [58 males and 42 females, aged (52±15) years], and they were enrolled into Marjolin ulcer group (MU), chronic non-cancerous ulcer group (CNU), and other skin surgery group (OSS) respectively. The etiology, pathogenic site, ulcer diameter, and course of patients in group MU were retrospectively analyzed. Ulcer tissue specimens from patients of group MU and group CNU and specimens of normal skin tissue attached to the tissue resected during operation from patients of group OSS were collected. The expressions of VEGF, HIF-1α, EGFR, and CD34 in the above-mentioned tissue and the surrounding normal skin, ulcer, epitheliomatous hyperplasia, and canceration areas in Marjolin ulcer tissue were detected by immunohistochemical method, and the positive expression rate and protein expression level were calculated. Data were processed with Pearson chi-square test, Mann-Whitney U test, Bonferroni method, and Bonferroni correction, and Spearman correlation analysis was used to analyze the relationship among the total protein expression levels. Results: In group MU, burns accounted for 91.3% (84/92) of the causes of patients, 44.6% (41/92) of the patients had tumors in the lower extremities, 62.0% (57/92) of the patients had skin ulcer diameter of 2.1-5.0 cm, and 75.0% (69/92) of the patients had a course of disease of more than 20 years. The positive rates of VEGF, HIF-1α, and EGFR in ulcer tissue of patients in group CNU were 41.0% (41/100), 77.0% (77/100), and 83.0% (83/100), respectively, significantly higher than those of normal skin tissue of patients in group OSS [12.0% (12/100), 45.0% (45/100), and 67.0% (67/100), χ(2)=21.589, 21.522, 6.827, P<0.01]. The positive rates of VEGF, HIF-1α, and EGFR in ulcer tissue of patients in group MU were 91.3% (84/92), 100.0% (92/92), and 100.0% (92/92), respectively, which were significantly higher than those in corresponding tissue of patients in group CNU and group OSS (χ(2)=53.372, 24.772, 17.159; 120.543, 72.777, 36.661, P<0.01). In ulcer tissue of patients in group MU, the positive expression rates of VEGF in ulcer, epitheliomatous hyperplasia, and canceration areas were significantly higher than the rate in surrounding normal skin area (χ(2)=87.120, 42.368, 89.624, P<0.01); the positive expression rates of VEGF in canceration and ulcer areas were significantly higher than the rate in epitheliomatous hyperplasia area (χ(2)=22.586, 16.060, P<0.01). In ulcer tissue of patients in group MU, the positive expression rates of EGFR in ulcer, epitheliomatous hyperplasia, and canceration areas were significantly higher than the rate in surrounding normal skin area (χ(2)=21.679, 27.600, 27.600, P<0.01), but the positive expression rates of HIF-1α in four morphological areas were similar (χ(2)=3.008, P>0.05). In ulcer tissue of patients in group MU, the protein expression levels of VEGF and CD34 in ulcer, epitheliomatous hyperplasia, and canceration areas were significantly higher than those in surrounding normal skin area (Z=-6.765, -6.819; -6.765, -6.640; -6.765, -6.819, P<0.01), the protein expression levels of VEGF and CD34 in epitheliomatous hyperplasia area were significantly lower than those in ulcer area (Z=-4.484, -5.266, P<0.01), and the protein expression levels of VEGF and CD34 in canceration area were significantly higher than those in ulcer area (Z=-6.427, -6.723, P<0.01) and epitheliomatous hyperplasia area (Z=-6.427, -6.462, P<0.01). In ulcer tissue of patients in group MU, the protein expression levels of HIF-1α and EGFR in ulcer, epitheliomatous hyperplasia, and canceration areas were significantly higher than those in surrounding normal skin area (Z=-6.819, -6.393; -6.819, -6.393; -6.819, -6.393, P<0.01), the protein expression levels of HIF-1α and EGFR in ulcer area were significantly lower than those in epitheliomatous hyperplasia and canceration areas (Z=-6.118, -5.638; -6.640, -6.393, P<0.01), and the protein expression levels of HIF-1α and EGFR in canceration area were significantly higher than those in epitheliomatous hyperplasia area (Z=-6.558, -6.819, P<0.01). In ulcer tissue of patients in group MU, the total protein expression levels of VEGF, HIF-1α, and EGFR were significantly positively correlated with the total protein expression level of CD34 (r=0.772, 0.415, 0.502, P<0.01) respectively; the total protein expression level of EGFR was significantly positively correlated with that of HIF-1α (r=0.839, P<0.01), both of which were significantly positively correlated with the total protein expression level of VEGF (r=0.531, 0.440, P<0.01) respectively. Conclusions: The expressions of VEGF, HIF-1α, and EGFR are the highest in Marjolin ulcer canceration area, and EGFR may promote angiogenesis through HIF-1α or directly increasing the expression of VEGF.