Sirolimus-Induced Thrombotic Microangiopathy is Associated with Decreased Expression of Vascular Endothelial Growth Factor in Kidneys

The aim of this study was to examine the clinical characteristics, the histological features and the renal expression of vascular endothelial growth factor (VEGF) of five patients with sirolimus-associated thrombotic microangiopathy (TMA). Sirolimus-induced TMA occurs preferentially in kidneys with concomitant endothelial injury: it was observed in three patients with acute cellular rejection on calcineurin inhibitor-free regimen, in one patient with chronic graft rejection on a calcineurin inhibitor-free protocol and in one patient with chronic calcineurin inhibitor nephrotoxicity. We found that renal VEGF expression during sirolimus-induced TMA was significantly lower than VEGF expression in normal transplanted kidneys (p < 0.01). Decreased expression of VEGF seems to be a consequence of sirolimus treatment since (i) analysis of two biopsies performed after the switch of sirolimus to calcineurin inhibitor showed reappearance of VEGF expression, (ii) no decreased expression of VEGF was found in five kidneys with classical TMA and, (iii) an increased expression of VEGF was observed in seven kidneys with acute cellular rejection on a sirolimus-free immunosuppressive regimen (p < 0.01). The potential role of sirolimus-induced downregulation of VEGF as a predisposing factor to the development of TMA is discussed.     

结直肠腺瘤及腺癌中P73表达与VEGF的关系

目的:探讨结直肠腺瘤和腺癌组织中P73的表达及其与血管内皮生长因子(vascular endothelial growth factor,VEGF)的关系.方法:采用免疫组化(SP法),检测P73抗体与VEGF蛋白的表达.结果:结直肠腺瘤中18例P73表达有17例(94.4%)阳性反应,与结直肠腺癌组间无显著性差异(P＞0.05),而与癌旁正常组织间存显著性差异(P＜0.01);同一标本中,癌组织中P73的染色强度均大于其癌旁组织(P＜0.01).腺癌各组VEGF阳性表达率高于腺瘤(P＜0.01), 整个腺癌组VEGF阳性表达率显著高于腺瘤组(84.1%∶33.3%,χ2=3.911,P＜0.05).结论:结直肠腺瘤及腺癌中P73与VEGF有显著的相关性, 加强术前检测P73,对高表达的患者有助于结直肠腺瘤癌变或腺癌早期诊断,及指导术后治疗.     

Vascular Endothelial Growth Factor and Soft Tissue Sarcomas: Tumor Expression Correlates With Grade

Introduction: Vascular endothelial growth factor (VEGF), an endothelial–specific mitogen overexpressed in various epithelial malignancies is thought to be a potent regulator of angiogenesis. We hypothesized that some soft tissue sarcomas, due to their high propensity for hematogenous metastases (1) would overexpress VEGF, (2) that the degree of expression may represent a significant biologic predictor for disease-specific survival, and (3) that recurrent tumor would express as high or higher VEGF compared with the primary tumor.Methods: Selected paraffin-embedded tissue of surgical specimens from 79 patients with soft tissue sarcomas, treated between 1989 and 1995 were stained with a rabbit polyclonal anti-VEGF antibody at a concentration of 2 g/ml. Slides were assessed for VEGF expression as high or low by two investigators blinded to the clinicopathologic data. Twelve patients had VEGF expression of their primary tumors, and their recurrent tumors were compared. The Fishers exact test assessed for differences in VEGF expression; survival analyses were performed according to the methods of Kaplan and Meier.Results: Seventy-eight percent (29 of 37) of patients who died of disease had high VEGF expression. However, VEGF expression was not an independent predictor of either overall or disease-free survival. Tumor grade correlated with VEGF expression significantly. For the low-grade tumors, 7 of 13 expressed low VEGF, whereas for high-grade tumors, 53 of 66 expressed high VEGF (P = .016). Seven of the 12 paired tumor samples expressed identical VEGF immunostaining.Conclusions: The majority of high-grade soft tissue sarcomas in this study have high intensity VEGF expression. This finding may provide useful information on individual soft tissue sarcomas and offer the basis for therapeutic and biologic targeting in high-risk patients using anti-angiogenesis strategies. However, in our analysis, after accounting for tumor grade, VEGF does not seem to be an independent predictor of clinical outcome.Presented at the 53rd Annual Cancer Symposium of the Society of Surgical Oncology Poster Session, New Orleans, Louisiana, March 16-19, 2010434_2001_Article_260.     

Vascular Endothelial Growth Factor Expression in Stage I Non-Small Cell Lung Cancer Correlates With Neoangiogenesis and a Poor Prognosis

Background: Vascular endothelial growth factor (VEGF) plays an important role in tumor growth and metastasis. We investigated the prognostic significance of VEGF overexpression, intratumoral microvessel density (MVD), and angiolymphatic invasion in stage Ia-b non-small cell lung cancer (NSCLC).Methods: Eighty-five patients undergoing complete surgical resection of pathologic stage Ia-b NSCLC were evaluated. The mean and median clinical follow-up were 37.1 and 39.0 months (range, 30–44 months), respectively. Paraffin-embedded tumor specimens were stained with VEGF and CD31 (a specific endothelial marker) using immunohistochemical methods. VEGF staining was evaluated, by combining both percentage of positive tumor cells and staining intensity, as low (negative and < 20% of tumor cells showing weak positivity), or high (>20% of tumor cells showing strong positivity). CD31 staining was expressed as MVD per high power field at 400× magnification. Angiolymphatic invasion was expressed as either presence or absence.Results: Low VEGF expression was seen in 25 (29%) patients, and high VEGF expression was seen in 60 (71%) patients. The survival rate in patients with low VEGF expression was significantly higher (80%) than that in those with high VEGF expression (48%, P = .018). The mean MVD in the low VEGF group was 23.7 ± 5.7 vs. 34.4 ± 9.3 in the high VEGF group (P = .001). Patients with high MVD also had a significantly lower survival rate than did those with low MVD count (46% vs. 73%, P = .0053). Age, sex, tumor type, and tumor differentiation were not found to be associated with overall survival. The presence of angiolymphatic invasion and T2 stage (i.e., tumor size > 3 cm) were associated with decreased survival. High VEGF expression, tumor size, and angiolymphatic invasion emerged as three independent factors predicting worsening prognosis using multivariate analysis.Conclusion: High VEGF expression within stage I NSCLC is closely associated with high intratumoral angiogenesis and poor prognosis. Immunohistochemical evaluation of T stage and VEGF expression along with examination of angiolymphatic invasion perioperatively may aid in predicting prognosis. Adjuvant therapies aimed at retarding tumor angiogenesis may be considered for stage I NSCLC patients with high VEGF levels.Presented at the 53rd Annual Meeting of the Society of Surgical Oncology, New Orleans, Louisiana, March 16-19, 2000.     

大肠癌组织VEGF-C表达与血管生成和细胞增殖关系的研究

目的：研究大肠癌组织血管内皮生长因子C（VEGF—C）表达与肿瘤血管生成及肿瘤细胞增殖的关系。方法：采用SP免疫组织化学方法，检测81例大肠癌VEGF-C、CD34和Ki-67的表达，并分析VEGF-C与微血管密度（MVD）、Ki-67增殖指数（Ki-67PI）的相关性。结果：81例大肠癌中，VEGF-C表达阳性45例（55．56％）；VEGFC表达阳性的肿瘤其MVD和Ki-67PI高于VEGF-C者（P〈0.05）。VEGF-C表达与MVD、Ki-67PI呈正相关（P〈0.05）。有转移组（包括淋巴结转移和远处转移）的VEGF-C表达明显高于无转移组，表达随肿瘤分期的升高而增强。结论：VEGF-C通过诱导新生血管形成，促进肿瘤细胞的增殖生长，影响着大肠癌的浸润和转移。