Proliferation and maturation of intratumoral blood vessels in women with malignant ovarian tumors assessed with cancer stem cells marker nestin and platelet derived growth factor PDGF-B

Objectives: Platelet-derived growth factor B (PDGF-B) and nestin have been suggested to be useful in the assessment of neoangiogenesis in malignant ovarian masses. We aimed to investigate a possible association of these markers with newly formed microcapillaries and perivascular cells in ovarian tumors. Material and methods: Microvessel density (MVD) and pericytes were studied in 82 women with ovarian neoplasms, including 7 benign cysts, 7 borderline masses, 64 epithelial ovarian cancers and 4 other malignant ovarian tumors. Immunohistochemical staining included antibodies to CD34, PDGF-B and nestin. Results: Median values of CD34-positive and nestin-positive MVD were: 24,5 (range:17-32) and 21 (range: 12–31), respectively. No significant correlation between intratumoral CD-34 positive MVD and nestin-positive MVD was found. Benign and borderline lesions more frequently than malignant tumors displayed low or medium values of nestin-positive MVD (p = 0.01). Histological grading of malignant tumors was associated with nestin-positive MVD (p = 0.01). Nestin expression in tumor cells was not correlated with tumor grade or histological subtype. PDGF-B expression was found in tumor microves­sels in 72% of cases (59/82). High expression of PDGF in pericapillary cells was strongly associated with high expression of this marker in cancer cells (p = 0.007). Significant correlations between PDGF-B and nestin expression in malignant tumor microvessels were also found (p = 0.04). Nestin and PDGF-B expressions were strongly associated with high grade tumors when compared to low grade or benign masses. Conclusions: We conclude that the assessment of PDGF-B and nestin-positive MVD could be used to identify only highly active, angiogenic malignant ovarian masses, where tumor vasculature is formed

Mig-7 expression and vasculogenic mimicry in malignant ovarian tumors

Objectives: To investigate the possible association of vasculogenic mimicry (VM), VE-cadherin and MIG-7 expression with clinicopathological features of women with malignant ovarian masses. Material and methods: VM was studied with the PAS reaction and VE-cadherin was assessed with immunohistochemistry in 108 women with malignant ovarian tumors. Additionally, quantitative expression of MIG-7 mRNA was performed in 52 ovarian cancers with qRT-PCR. Results: VM was found in 48/108 cases (44%), more often in higher FIGO stage tumors (83% cases; 40 vs. 8; p = 0.01). High expression of VE-cadherin was present in 37% of all ovarian masses. Ovarian tumors without VM more often expressed low levels of VE-cadherin than tumors where VM was found (37.6% vs.14.6%). No expression or very low expression of MIG-7 mRNA was found in all normal ovarian tissues and in 32 cancer samples. Median RQ of MIG-7 mRNA in tumor samples was higher than in normal ovarian tissue (RQ = 0.29 vs. RQ = 0.05, respectively; p < 0.005) and higher than in non-malignant ovarian masses (0.98 vs. 0.05 respectively; p = 0.03). Expression of MIG-7 mRNA was significantly correlated with VM (p = 0.039). In tumors with PAS-positive structures median RQ MIG-7 mRNA was higher than in tumors with PAS-negative findings (1.89 vs. 0.13 respectively). VE-cadherin expression was more frequently found in tumors where MIG-7 mRNA was present (p = 0.004). Conclusions: Vasculogenic mimicry exists in malignant ovarian tumors and advanced clinical stages of malignancy are accompanied by a high incidence of VM formation. MIG-7 mRNA and VE-cadherin expression may serve as additional molecular markers of VM in ovarian malignancies

Prognostic significance of TEM7 and nestin expression in women with advanced high grade serous ovarian cancer

Objectives: Tumor endothelial marker 7 (TEM7) and nestin have been proposed to be new candidates for neoangiogenesis assessment. Nestin is also cancer stem cells marker in various malignant tumors. AIMS. To investigate the expression of TEM7, nestin and nestin-related microvessel density (MVD) in high-grade serous ovarian cancer samples and to study their correlation with overall survival (OS) and disease-free survival (DFS) times. Material and methods: Tumor samples obtained from 70 women with FIGO IIIc/IV ovarian serous cancer were studied with immunohistochemistry. Results: Patients median age was 54 yrs (range: 29–72 years), 86% died of the disease with median OS = 28.5 months and median DFS = 10 months (3 years DFS = 19%; 5 years. DFS = 13.8%). High nestin expression was found in 16 (23%) patients with 3 years and 5 years OS of 14% and 0%. In low-nestin expression group OS and DFS were 42% and 25%, respectively. Median nestin-MVD (16, range:12–23) was not correlated with cancer cells nestin expression and with both DFS and OS. High TEM7 expression was found in 29 women (41%) of whom 21 (72%) died of the disease. A 5-year OS in these women was 27% as compared to 8% in low TEM7 expression group, but TEM7 presence had no association with nestin, nestin-MVD and both OS and DFS. Conclusions: Nestin as a marker of cancer stem cells may assist in the prediction of OS and DFS in women with high grade serous ovarian cancer. Nestin may also be considered a novel therapeutic target for antiangiogenic agents