Endoglin Staining Research Articles

Endoglin (CD105) expression in non-seminomatous germ cell tumors.

e16036 Background: Nonseminomatous germ cell tumors are known for hematogenous spread and new therapeutics are needed. Endoglin (CD105) is a cell-surface protein that is overexpressed on endothelial cells and a potential target for anti-angiogenic therapy. Preclinical studies demonstrate overexpression of CD105 in tumor vasculature and targeting CD105 in murine models have resulted in tumor regression. We examine CD105 expression in tumor cells and tumor vasculature of patients with non-seminomatous germ cell tumor. Methods: Slides of NSGCT were incubated with rabbit anti-human CD105 followed by horseradish peroxidase-labeled anti-rabbit IgG and then with substrate chromogen followed by hematoxylin counterstaining. Human kidney served as positive internal control. Endoglin positivity was assessed in tumor cells and vasculature and graded (0-3+). Results: 37 total samples were obtained, 4 were excluded (3 seminoma, 1 pure teratoma) All 37 specimens had positive endoglin staining in tumor vasculature. Of 33 specimens, 79% (26/33) had positive staining for endgolin, whereas 21% did not (7/33). (Table 1)Of patients with relapsed or refractory disease, 83% (5/6) stained positively for CD105. While this is a small sample size, 3+ staining was seen in 50% of patients (n=6) with relapsed or refractory disease, but vs 18.5% of patients (n=27) in 1stremission (Fisher’s exact test p =0.14). Conclusions: Endoglin was highly expressed in tumor and tumor vasculature of NSGCT. This small pilot study suggests high (>50%) expression correlating with relapsed or refractory disease. Further samples from patients with relapsed or refractory disease are being collected and analyzed. Endoglin is a potential target for study in non-seminomatous germ cell tumors. [Table: see text]

High expression of endoglin in primary breast cancer may predict response to neoadjuvant chemotherapy

Neoadjuvant chemotherapy (NAC) is a widely-used treatment for breast cancer, as it may render unresectable breast tumors to become resectable. In addition, NAC provides the unique opportunity to assess response to treatments within months rather than years of follow-up. However, predictive markers of tumor response to NAC are lacking. Therefore, the present study aimed to investigate the expression of endoglin, a marker of angiogenesis, and its association with pathologic responses to NAC. Samples from 34 breast cancer patients were obtained prior to and following NAC treatment. Immunohistochemical staining for endoglin and the mechanistic target of rapamycin (mTOR) was performed, and the correlation between the expression of these markers and pathologic response was examined. The overall response rate to NAC of these 34 patients was 67.6%. A mean microvascular density value of 14 served as a threshold score for the increased expression of endoglin. Increased expression of endoglin in primary tumors prior to NAC correlated with improved response in primary tumors (P=0.019) or in primary tumors and regional lymph nodes (P=0.014), when compared with reduced expression of endoglin. Increased expression of mTOR following NAC was additionally correlated with improved response to NAC. The results of the present study demonstrated that the expression of endoglin in breast tumor samples prior to NAC may be a predictor of treatment response. Long-term follow-up of clinical outcome is required to explain the elevation of mTOR expression levels following NAC treatment in responsive tumors.

Correlation between selected angiogenic markers and prognosis in pediatric adrenocortical tumors: Angiogenic markers and prognosis in pediatric ACTs

Pediatric adrenocortical tumor (ACT) remains a challenging disease. Tumor weight and disease stage are still the most used indicators to prognosis and guidance of clinical decisions. Histology has not added meaningful data for risk stratification and management. ACT is metabolically active, highly vascularized, locally invasive and has the propensity to produce distant metastasis. Our objective was to correlate the expression of vascular endothelial growth factor (VEGF) and intratumoral microvessel density (MVD) with clinical and prognostic aspects in pediatric ACT. In 27 tumors, immunohistochemical expression of VEGF, CD105 (endoglin) and CD34 was analyzed. MVD was determined by CD34 and CD105 antibodies. MVD and VEGF expression was correlated with clinical characteristics and outcome. Normal pediatric glands were used as controls. Endoglin MVD was significantly higher and CD34 MVD was significantly lower in ACT than control. The VEGF expression did not differ between groups. Cytoplasmic staining for endoglin was correlated with hypertension in ACT. Endoglin MVD greater than 1 mv/field, CD34 MVD less than 32 mv/field and VEGF expression levels above 4.8% were associated with clinical and biological indicators of poor prognosis. Endoglin and CD34 MVD values are potential histological markers to refine the histologic classification of pediatric ACT.

High Immunohistochemical Expression of TGF-β1 Predicts a Poor Prognosis in Cervical Cancer Patients who Harbor Enriched Endoglin Microvessel Density

Endoglin, a coreceptor for transforming growth factor β1 (TGF-β1) in vascular endothelial cells, is highly upregulated in tumor vessels and therefore is a specific biomarker for angiogenesis. Some studies have suggested that assessment of tumor angiogenesis may predict cancer response to chemotherapy and radiotherapy. In this study, we attempted to analyze the immunohistochemical expression of endoglin and TGF-β1 from 80 patients with different International Federation of Gynecology and Obstetrics (FIGO) stages of cervical cancer before they received concurrent chemoradiation and to investigate their prognostic significance. The median follow-up period was 86 months (range, 2-144 months). Endoglin staining was assessed by microvessel density (MVD), whereas TGF-β1 expression was semiquantified as negative, weakly, or strongly staining. A receiver operating characteristic curve was established for endoglin MVD in predicting survival; the optimal cutoff value was 11.125. With a Cox regression analysis, we found that an advanced FIGO stage (hazard ratio 4.66; 95% confidence interval 2.10-10.32, P<0.001) and endoglin MVD more than 11.125 (hazard ratio 12.21; 95% confidence interval 3.62-41.16, P=<0.001) were independent factors to predict survival. Interestingly, a strong TGF-β1 expression was significantly associated with poor survival only when the endoglin MVD value was higher than 10. Our study shows that evaluation of endoglin MVD by immunochemistry can be used as an independent prognostic marker for cervical cancer patients receiving concurrent chemoradiation. TGF-β1 also had an impact on survival only when endoglin MVD was enriched, suggesting its involvement in tumor progression in the later stage of angiogenesis.

Endoglin (CD105) expression in ovarian serous carcinoma effusions is related to chemotherapy status

Endoglin (CD105), a cell surface co-receptor for transforming growth factor-β, is expressed in proliferating endothelial cells, as well as in cancer cells. We studied endoglin expression and its clinical relevance in effusions, primary tumors, and solid metastatic lesions from women with advanced-stage ovarian serous carcinoma. Endoglin expression was analyzed by immunohistochemistry in effusions (n = 211; 174 peritoneal, 37 pleural). Cellular endoglin staining was analyzed for association with the concentration of soluble endoglin (previously determined by ELISA) in 95 corresponding effusions and analyzed for correlation with clinicopathologic parameters, including survival. Endoglin expression was additionally studied in 34 patient-matched primary tumors and solid metastases. Carcinoma and mesothelial cells expressed endoglin in 95/211 (45%) and 133/211 (63%) effusions, respectively. Carcinoma cell endoglin expression was more frequent in effusions from patients aged ≤60 years (p = 0.048) and in post- compared to prechemotherapy effusions (p = 0.014), whereas mesothelial cell endoglin expression was higher in prechemotherapy effusions (p = 0.021). No association was found between cellular endoglin expression and its soluble effusion concentration. Endoglin was expressed in 17/34 (50%) primary tumors and 19/34 (56%) metastases, with significantly higher percentage of immunostained cells in solid metastases compared to effusions (p = 0.036). Endoglin expression did not correlate with survival. Tumor cell endoglin expression is higher in post- vs. prechemotherapy effusions, whereas the opposite is seen in mesothelial cells. Together with its upregulation in solid metastases, this suggests that the expression and biological role of endoglin may differ between cell populations and change along tumor progression in ovarian carcinoma.

Papillary capillary activation in Terson syndrome

We report the immunopathology and histopathology of a patient with Terson syndrome. The design was an observational case-report. Histopathology and immunohistochemical staining for endoglin (CD105) of an eye from a patient with subarachnoid haemorrhage and Terson syndrome was performed. Immunohistology revealed high papillary endoglin expression. Up-regulation of endoglin indicates activation of endothelial cells. This may suggest a regeneration process after the acute insult.

Macroscopic portal vein tumor thrombi of liver metastasis from colorectal cancer

We present a case of multiple colorectal liver metastases with macroscopic portal vein thrombi. A 55-year-old woman presented to us with rectosigmoid cancer and presented with two liver metastases. The tumor in the posterior sector was associated with invasion of first order branches of the portal vein. We performed low anterior resection, hepatic posterior sectorectomy and partial left anterior sectorectomy. Both the colorectal cancer and liver tumors exhibited histological characteristics of moderately differentiated adenocarcinoma with a substantial amount of mucin production. The liver metastases were associated with prominent tumor thrombi in many branches of the portal vein. Stronger staining for endoglin (CD 105) than for Fas ligand (Fas L) and matrix metalloproteinase (MMP-2) was observed in both the colorectal cancer and metastatic liver tumor cells. Expression of the vascular endothelial growth factor within the tumor cells was seen in both the colorectal cancer as well as the metastatic liver tumor cells. Six months after the operation, she was diagnosed to have multiple, more than about 20 liver metastases, and in 9 months after the operation, the patient died. The colorectal cancer with liver metastases associated with portal vein tumor thrombosis was poor prognosis, found neoplastic microvessel formation.

Endoglin (CD105) immuno-expression in human foetal and neonatal lungs.

Endoglin is a 180 KDa glycoprotein mainly expressed on endothelial cells of newly formed vessels. Its expression is increased by the hypoxia inducible factor 1 (HIF-1), a potent stimulator of VEGF expression. The relative hypoxic environment in which foetal lung develops favours HIF-1 dependent gene expression, including the endoglin and VEGF ones. Herein, we analysed endoglin immunoexpression in the human neonatal and foetal lung throughout gestation. Lungs from 18 foetuses (9-41 weeks), 7 preterm and 2 term infants were submitted to the immunohistochemical study. A slight immunostaining was found in some mesenchymal aggregates in the lungs of foetuses at the first trimester of pregnancy. At mid gestation, endoglin was evidenced in peri-tubular mesenchymal stem cells or in peri-canalicular vessels and in the endothelia of peri-bronchial vessels; by contrast, no immunoreaction was observed in case of Down syndrome or in a foetus with cardiac malformations. At late gestation and in preterm infants, endoglin antibody labelled endothelia of the alveolar capillaries and of peri-bronchial vessels. In case of alveolar capillary dysplasia (ACD) or macrosomy associated with maternal diabetes, endoglin expression was restricted to peri-bronchial vessels; no immunoreaction was encountered in foetuses with IUGR (intra-uterine growth restriction) or massive pulmonary haemorrhage. Lungs of term infants both displayed atelectasis; there was no evidence of endoglin immunoexpression in one case, whereby only the endothelia of peri-bronchial vessels were stained in the other. Our study suggests that lung vasculogenesis endures throughout gestation. Absence of endoglin staining in some pathologic conditions may reflect lung vasculogenesis disorders; nonetheless, since each pathologic state is represented by a single case in our cohort, further studies are required to clarify this issue.

Endoglin (CD105) expression in human renal cell carcinoma

To evaluate the prognostic potential of endoglin (CD105) expression in human renal cell carcinoma (RCC), as endoglin is a cell membrane glycoprotein expressed in tumour-associated vascular endothelium and a marker of angiogenesis; intratumoral microvessel density assessed by endoglin staining has prognostic significance in some neoplasms. Tumour samples from 210 patients with RCC (168 conventional), diagnosed between 1982 and 1997, were assessed using the tissue microarray technique with immunohistochemical staining for endoglin. The expression of endoglin was related to clinical variables and survival. Of the tumours, 75% expressed endoglin, and in conventional RCC the expression was inversely correlated to the Tumour-Node-Metastasis (TNM) stage (P = 0.008) and nuclear grade (P = 0.01). There was no correlation between endoglin expression and gender, age, tumour size or cell type. Patients with conventional RCC and high endoglin expression had a more favourable prognosis than those with tumours with lower expression (P = 0.04). A multivariate analysis of prognostic factors showed that TNM stage and nuclear grade were independent predictors of prognosis. Endoglin expression did not add further prognostic information. These results indicate that endoglin expression is inversely related to stage and grade in RCC, and that it is associated with prognosis.

Endoglin (CD105) and vascular endothelial growth factor as prognostic markers in esophageal adenocarcinoma

Endoglin (CD105), a member of transforming growth factor beta1 receptor complex, has been shown to be a more useful marker to identify tumor angiogenesis than panendothelial markers such as CD31. We investigated endoglin and vascular endothelial growth factor (VEGF) expression as possible prognostic markers in esophageal adenocarcinoma. Surgical specimens from 75 patients with esophageal adenocarcinoma treated with esophagectomy were immunostained for endoglin, CD31, and VEGF. We also included 10 cases of Barrett's esophagus with high-grade dysplasia and 10 cases with Barrett's esophagus low-grade dysplasia. Positively stained microvessels (MVs) were counted in hot spots at magnification of x400. Results were expressed as the highest number of MV identified. For VEGF, intensity of staining was scored on 3-tiered scale. Endoglin demonstrated significantly more vessels than the CD31 (mean, 28.9 +/- 13.2 versus 19.0 +/- 9.4, P < .001). Both endoglin and CD31 MV counts showed significant correlation with stage of the disease (r = 0.59, P < .001; r = 0.52, P < .001, respectively) and patient survival (log rank P < .01). Only endoglin MV count was significantly correlated with the presence of angiolymphatic invasion (r = 0.34, P < .05) and lymph node (LN) metastases (r = 0.48, P < .001). Univariate analysis showed that endoglin MV count is an independent prognostic factor. Endoglin showed a significant increase in MV count in Barrett's esophagus with high-grade dysplasia when compared with Barrett's esophagus low-grade dysplasia (P < .01), whereas CD31 did not show any significant difference. VEGF was expressed in 48 (64%) of 75 cases of adenocarcinoma and was significantly correlated with angiolymphatic invasion, LN metastases, and survival. In conclusion, endoglin is a specific and sensitive marker for tumor angiogenesis. Endoglin staining also showed prognostic significance with positive correlation with the presence of angiolymphatic invasion, LN metastases, tumor stage, and survival.

Angiogenic factors in squamous cell carcinoma of the oral cavity: do they have prognostic relevance?

Angiogenesis is a cascade-like mechanism which is essential for tumour growth and metastasis. Therefore the existence of angiogenic molecules and the density of activated endothelial cells in individual tumours is of major interest. MATERIAL/PATIENTS: In order to evaluate the prognostic significance of these molecules, the distribution pattern was studied of vascular endothelial growth factor (VEGF) and activated endothelial cells in tumours and normal, healthy oral mucosal specimens from 51 consecutive patients with primary oral squamous cell carcinoma. Frozen sections (vascular endothelial growth factor) and paraffin-embedded sections (endoglin, CD105) were investigated quantitatively by immunohistochemistry. The Pearson correlation, the non-parametric Mann-Whitney test, the non-parametric Wilcoxon rank sum test with multiple comparisons and the non-parametric Kruskal-Wallis test with multiple comparisons were used for statistical analyses. Endoglin expression in tumour tissue was significantly higher than in normal healthy mucosa (P<0.001). T1 tumours showed a significantly lower staining for endoglin compared with T2, T3 and T4 tumours but there was no increase with each T stage. No statistical correlation was found between VEGF expression and endoglin staining. Even though there is controversy about the prognostic relevance of VEGF, our results suggest that the factor is not suitable to decide prognosis in oral cancer. Endoglin may have a significant role in the development of squamous cell carcinoma of the oral cavity and might be relatively more specific than commonly used endothelial markers.

Endoglin (CD105) and vascular endothelial growth factor as prognostic markers in colorectal cancer

Endoglin (CD105) has been shown to be a more useful marker to identify proliferating endothelium involved in tumor angiogenesis than panendothelial markers such as CD31. We investigated endoglin and vascular endothelial growth factor expression as possible prognostic markers in colorectal cancer. Surgical specimens from 150 patients with resected colorectal carcinomas were immunostained for endoglin, CD31 and vascular endothelial growth factor. Colorectal carcinoma cases consisted of 50 cases without lymph node metastases, 50 cases with only lymph node metastases and 50 cases with liver metastases (38 cases also had positive lymph nodes). Positively stained microvessels were counted in densely vascular foci (hot spots) at x 400 fields in each specimen. For vascular endothelial growth factor, intensity of staining was scored on a three-tiered scale. Results were correlated with other prognostic parameters. Endoglin demonstrated significantly more proliferating neoplastic microvessels than CD31 (31+/-10 vs 19+/-8/0.15 mm2 field, P<0.001). Low vascular endothelial growth factor expression within tumor cells was seen in 49 (33%) and high expression in 101 cases (67%). There was a positive correlation of endoglin, CD31 counts and vascular endothelial growth factor overexpression with the presence of angiolymphatic invasion and lymph node metastases (P<0.05). Only endoglin counts correlated significantly with liver metastases and positive vascular pedicle lymph nodes (P<0.05), while vascular endothelial growth factor showed significant correlation with the depth of invasion (P<0.01). Endoglin, by staining higher numbers of the proliferating vessels in colon carcinoma, is a more specific and sensitive marker for tumor angiogenesis than the commonly used panendothelial markers. Endoglin staining also showed prognostic significance with positive correlation with angiolymphatic invasion and metastases to lymph nodes and liver.

Endoglin (CD105) and vascular endothelial growth factor as prognostic markers in colorectal cancer

Endoglin (CD105) has been shown to be a more useful marker to identify proliferating endothelium involved in tumor angiogenesis than panendothelial markers such as CD31. We investigated endoglin and vascular endothelial growth factor expression as possible prognostic markers in colorectal cancer. Surgical specimens from 150 patients with resected colorectal carcinomas were immunostained for endoglin, CD31 and vascular endothelial growth factor. Colorectal carcinoma cases consisted of 50 cases without lymph node metastases, 50 cases with only lymph node metastases and 50 cases with liver metastases (38 cases also had positive lymph nodes). Positively stained microvessels were counted in densely vascular foci (hot spots) at × 400 fields in each specimen. For vascular endothelial growth factor, intensity of staining was scored on a three-tiered scale. Results were correlated with other prognostic parameters. Endoglin demonstrated significantly more proliferating neoplastic microvessels than CD31 (31±10 vs 19±8/0.15 mm2 field, P<0.001). Low vascular endothelial growth factor expression within tumor cells was seen in 49 (33%) and high expression in 101 cases (67%). There was a positive correlation of endoglin, CD31 counts and vascular endothelial growth factor overexpression with the presence of angiolymphatic invasion and lymph node metastases (P<0.05). Only endoglin counts correlated significantly with liver metastases and positive vascular pedicle lymph nodes (P<0.05), while vascular endothelial growth factor showed significant correlation with the depth of invasion (P<0.01). Endoglin, by staining higher numbers of the proliferating vessels in colon carcinoma, is a more specific and sensitive marker for tumor angiogenesis than the commonly used panendothelial markers. Endoglin staining also showed prognostic significance with positive correlation with angiolymphatic invasion and metastases to lymph nodes and liver.

Endoglin (CD105) expression in endometrial carcinoma.

Tumor angiogenesis plays an important role in tumor growth and metastasis. We evaluated endoglin (CD105) as an endothelial marker of angiogenesis in endometrial carcinoma (EC) and its prognostic significance. Fifty-five cases of EC, 10 cases of complex endometrial hyperplasia with atypia (CHA), and 10 cases of simple hyperplasia (SH) were immunohistochemically stained for endoglin, CD31, and vascular endothelial growth factor (VEGF). Positively stained microvessels (MV) were counted in densely vascular foci (hot spots) in a 400x field in each specimen. For VEGF, intensity of staining was scored on three-tiered scale. Results were correlated with other prognostic parameters using appropriate statistics. Endoglin staining demonstrated significantly more MV than did CD31 (mean 30.8 +/- 10.95 vs. 13.38 +/- 7.53, p < 0.001). There was a positive correlation of both endoglin and CD31 MV counts with tumor differentiation (p < 0.05) and the depth of invasion (p < 0.01). However, only endoglin counts correlated significantly with the presence of angiolymphatic invasion (p < 0.01), lymph nodes metastases (p < 0.01), and tumor stage (p < 0.001). VEGF expression in EC had a significant correlation with angiolymphatic invasion (p < 0.01) and lymph node status (p < 0.05) but not with other prognostic parameters. Endoglin and VEGF showed significant differences between CHA and SH (p < 0.001). Our study showed that endoglin, by staining the proliferating MV in EC, is a more specific and sensitive marker for tumor angiogenesis than is the commonly used pan-endothelial marker, CD31. Endoglin staining also had prognostic significance, with positive correlation with angiolymphatic invasion, lymph node metastases, and tumor stage.

Up-regulation of endoglin, a TGF-beta-binding protein, in rats with experimental renal fibrosis induced by renal mass reduction.

The central process in chronic renal failure is the progressive accumulation of extracellular matrix in the glomeruli and in the tubulo-interstitial space, resulting in renal fibrosis. Transforming growth factor-beta1 (TGF-beta1) up-regulation plays a major role in the genesis of renal fibrosis. Endoglin is a membrane glycoprotein that binds TGF-beta1 and TGF-beta3 with high affinity. An increased level of endoglin immunostaining has been demonstrated previously in biopsies from patients with chronic progressive renal disease. We have assessed the expression of endoglin in the rat 5/6th renal mass reduction (RMR) model. One, 3 and 5 months after RMR, mean arterial pressure and renal function were measured, animals were sacrificed, renal fibrosis was evaluated quantitatively and the expression of endoglin was assessed by western blot, northern blot and immunohistochemistry. RMR induced a progressive increase in mean arterial pressure and urinary protein excretion. Renal corpuscular area, and mesangial and interstitial fibrosis increased with time after RMR. Immunohistochemical staining for endoglin demonstrated its expression mainly on the endothelial surface of major vessels. In kidneys 1 and 3 months after RMR, the expression of endoglin in renal corpuscles was limited to Bowman's parietal epithelium. In rats 5 months after RMR, the immunoexpression in glomerular endothelium was more marked. Northern blot analysis revealed that rats with RMR showed an increase in the expression of mRNA for endoglin, only at 5 months after RMR. Western blot analysis gave a different time course: a marked increase in the first month, a decrease in the 3rd month and a further increase in the 5th month after RMR. The present study demonstrates increased endoglin expression in rats with severe hypertension and renal damage. This increased endoglin expression coincides with the period of higher renal damage and renal dysfunction.