[The relationship between vimentin protein expression in endothelial cells and contrast-enhanced ultrasound characters in VETC (+ ) hepatocellular carcinoma].

Objective: To detect the possible molecular mechanisms of the formation of vessels that encapsulated tumor clusters (VETC) and identify the relationship between vimentin protein expression in endothelial cells and contrast-enhanced ultrasound characters in VETC (+ ) hepatocellular carcinoma (HCC). Methods: A total of 64 paraffin embedded HCC tissue samples were collected, all of which the tumor diameters were between 2 cm and 5 cm measured by the preoperative ultrasound. Immunohistochemistry staining for CD34 was used to detect the formation of VETC and the expressions of angiopoietin-2 (Ang-2) and vimentin were also determined. Human umbilical vein endothelial cells (HUVECs) were treated with 150 ng/ml recombinant human Ang-2 protein (rhAng-2) at various times and the protein expression of vimentin was detected by western blot assay. The contrast-enhanced ultrasound characters were also analyzed in both VETC (+ ) and VETC (-) HCC. Results: Tumor clusters encapsulated by vessels to form cobweb-like networks, which were identified as VETC phenotype, were observed in 27 HCC tissues (42.18%). In VETC (+ ) HCC tissues, Ang-2 was overexpressed in tumor cells and endothelial cells while vimentin was only upregulated in endothelial cells. With the treatment of 150 ng/ml rhAng-2 protein, the expression of vimentin in HUVECs was 0.878±0.102 and 0.918±0.092 at 12 h and 36 h, significantly upregulated when compared to the 0.322±0.061 at 6 h (P<0.01). In contrast-enhanced ultrasound, a crack and tendon-like filling character was observed in VETC (+ ) HCC during the arterial-phase, while the large scale and diffuse-like filling character was observed in VETC (-) HCC. The filling time of unit diameter in VETC (+ ) HCC was (3.95±0.22)s, significantly longer than (2.28±0.27)s of VETC (-) HCC (P<0.01). Conclusions: The overexpressions of Ang-2 and vimentin are positively correlated with the formation of VETC and considered as potential therapeutic targets of VETC (+ ) HCC. The crack and tendon-like filling characters in arterial-phase of contrast-enhanced ultrasound indicates the VETC (+ ) HCC.目的： 探讨VETC(vessels that encapsulated tumor clusters)的形成机制，明确VETC(＋)肝癌内皮细胞中蛋白表达的特点及其与超声造影表现的关系。 方法： 收集术前超声肿瘤直径在2～5 cm之间的肝癌石蜡标本64例，通过免疫组化染色，判断肝癌组织中VETC(＋)的形成，观察血管生成素2(Ang-2)和波形蛋白(vimentin)的表达。以150 ng/ml重组人Ang-2(rhAng-2)处理HUVECs细胞不同时间，体外观察Ang-2对内皮细胞vimentin蛋白表达的调控。分析肝癌患者的超声造影资料，比较VETC(＋)和VETC(－)肝癌的超声造影表现特点。 结果： 免疫组化染色结果显示，64例肝癌标本中，VETC(＋)27例(42.18%)，典型表现为球状血管内皮细胞包绕的肿瘤细胞团；Ang-2在VETC(＋)肝癌的癌细胞、癌组织内皮细胞中高表达；vimentin在VETC(＋)肝癌的癌组织内皮细胞中高表达。Western blot检测结果显示，150 ng/ml rhAng-2蛋白处理12、36 h的HUVECs细胞中，vimentin蛋白相对表达量分别为0.878±0.102、0.918±0.092，显著高于处理6 h的HUVECs细胞(0.322 ±0.061，均P<0.01)。超声造影显示，与VETC(－)肝癌的大片状、弥漫性充盈比较，VETC(＋)肝癌在动脉充盈期多表现为裂隙状、条索状的向心性充盈。VETC(＋)肝癌和VETC(－)肝癌单位直径(cm)所需充盈时间分别为(3.95±0.22)s和(2.28±0.27)s，VETC(＋)肝癌的单位直径充盈时间长于VETC(－)肝癌(P<0.01)。 结论： Ang-2和vimentin的高表达与肝癌的VETC形成有关，是VETC(＋)肝癌的潜在治疗靶点。超声造影中裂隙状、条索状充盈的动脉相提示肿瘤为VETC(＋)肝癌。.