Cancer stem cells contribute to angiogenesis and lymphangiogenesis in serous adenocarcinoma of the ovary.

The origin of blood and lymphatic vessels in high-grade serous adenocarcinoma of ovary (HGSOC) is uncertain. We evaluated the potential of cancer stem cells (CSCs) in HGSOC to contribute to their formation. Using spheroids as an in vitro model for CSCs, we have evaluated their role in primary malignant cells (PMCs) in ascites from previously untreated patients with HGSOC and cell lines. Spheroids from PMCs grown under specific conditions showed significantly higher expression of endothelial, pericyte and lymphatic endothelial markers. These endothelial and lymphatic cells formed tube-like structures, showed uptake of Dil-ac-LDL and expressed endothelial nitric oxide synthase confirming their endothelial phenotype. Electron microscopy demonstrated classical Weibel-Palade bodies in differentiated cells. Genetically, CSCs and the differentiated cells had a similar identity. Lineage tracking using green fluorescent protein transfected cancer cells in nude mice confirmed that spheroids grown in stem cell conditions can give rise to all three cells. Bevacizumab, a monoclonal antibody that targets vascular endothelial growth factor inhibited the differentiation of spheroids to endothelial cells in vitro. These results suggest that CSCs contribute to angiogenesis and lymphangiogenesis in serous adenocarcinoma of the ovary, which can be inhibited.

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.

Expression of Nestin and CD133 in serous ovarian carcinoma.

Pupose: Nestin and CD133 are regarded as putative markers of cancer stem cells (CSCs) and related to poor prognosis in various cancer sites. Since few studies have focused on their role in ovarian cancer, we aimed to investigate their predictive value and association with neoangiogenesis. METHODS: Immunohistochemical analysis for nestin and CD133 was performed on 85 serous ovarian carcinoma tumor samples using tissue microarray technique. Nestin immunoreactivity was detected in both tumor and endothelial cells, whilst CD133 was only identified in tumor cells. CD34 endothelial expression was used to assess intratumor microvessel density (MVD). RESULTS: Of the tissue samples 49.4% were nestin-positive and 24.7% were positive for CD133. In both univariate and multivariate analysis nestin or CD133 expressions in tumor cells were not significantly associated with clinicopathological parameters (age, serum CA125, peritoneal carcinomatosis, malignant ascites, tumor grade). However, in multivariate analysis nestin expression in tumor cells proved to be an independent prognostic factor, associated with poorer survival and time to progression (p=0.025 and p=0.05, respectively). This has not been achieved for CD133. Furthermore, a significant concordance between nestin endothelial expression (nestin-determined MVD) and CD34-determined MVD was achieved. CONCLUSION: In addition to the well-known clinicopathological characteristics, tumor expression of nestin might be a valuable prognostic factor for survival in patients with advanced ovarian cancer. With regard to its endothelial expression, nestin might be as reliable as CD34 for quantifying tumor angiogenesis. Further investigation is justified in order to better clarify the role of these biomarkers.

Hypervascular solid-appearing serous cystic neoplasms of the pancreas: Differential diagnosis with neuroendocrine tumours.

PURPOSE: To describe imaging findings of arterial hypervascular solid-appearing serous cystic neoplasms (SCNs) of the pancreas on CT and MR and determine imaging features differentiating them from neuroendocrine tumours (NETs). MATERIALS AND METHODS: We retrospectively identified 15 arterial hypervascular solid-appearing SCNs and randomly chose 30 size-matched pancreatic NETs. On CT, two radiologists in consensus assessed the size, morphology, and CT attenuation. On MR, predominant signal intensity and the amount of the cystic component on T2-weighted images and ADC maps were evaluated and compared using Fisher's exact and Student's t-test. RESULTS: The mean SCN size was 2.6 cm (range, 0.8-8.3). The CT findings were similar between the two tumours: location, shape, margin, and enhancement pattern. SCNs were significantly more hypodense on non-enhanced CT images than NETs (P = .03). They differed significantly on MR: bright signal intensity (P = .01) and more than a 10% cystic component on T2-weighted images (P = .01) were more common in SCNs than in NETs. All SCNs showed a non-restrictive pattern on the ADC map, while NETs showed diffusion restriction (P < .01). CONCLUSION: Arterial hypervascular solid-appearing SCNs and NETs share similar imaging features. Non-enhanced CT and MR images with T2-weighted images and ADC maps can facilitate the differentiation. KEY POINTS: • Frequency of hypervascular solid-appearing SCNs was 7.3% among surgically confirmed SCNs. • Hypervascular solid-appearing SCN of the pancreas can mimic pancreatic NETs. • Unenhanced CT and MR features help to differentiate the two tumours.

Serous neoplasms of the pancreas share many, but not all aspects of their microvascular and angiogenic profile with low-grade clear cell renal cell carcinomas.

Similarly to clear cell renal cell carcinomas (CCRCC), serous neoplasms (SN) of the pancreas frequently show inactivation of VHL gene, clear cell histology and abundant microvasculature. Data on the microvascular and angiogenic profile of SN are scarce. Aiming to examine further the striking resemblance of clear cell epithelial neoplasia in pancreas and kidney, we compared the microvascular profile and expression of pro-angiogenic factors in SN and in CCRCC using immunohistochemical stains. SN and CCRCC shared a predominance of differentiated blood vessels, scarcity of lymphatic vessels, presence of CD105 and claudin-5 in tumoral vessels, expression of vascular endothelial growth factor (VEGF)-A, cyclooxygenase-2 (COX-2), carbonic anhydrase IX in tumoral cells, and lack of VEGF-C in tumoral cells. In contrast to CCRCC, SN showed lower pericyte coverage of vessels, lower blood vessel endothelial cell proliferaction fraction, more pronounced VEGF receptor (VEGFR)-2 and glucose transporter-1 expression, higher inducible (iNOS) but lower endothelial nitric oxide synthase (eNOS) expression, as well as presence of VEGFR-3 and D2-40 expression in epithelial cells. In conclusion, we found a significant similarity but not equality of microvascular biology of SN and CCRCC. We recognized VEGFR-2, VEGFR-3, COX-2, iNOS, eNOS and D2-40 as new markers of epithelial cells of SN of the pancreas.

A novel angiomatoid epithelioid sarcoma cell line, Asra-EPS, forming tumors with large cysts containing hemorrhagic fluid in vivo.

BACKGROUND: Whereas we can use several human epithelioid sarcoma (ES) cell lines for basic and preclinical research, an angiomatoid ES cell line has not been reported to date. We have treated a case of an angiomatoid ES developing in the right upper extremity of a 67-year-old man. METHODS: An angiomatoid ES cell line, Asra-EPS was newly established and characterized for its morphology, growth rate and chromosomal analysis. Tumorigenicity of Asra-EPS cells was also analyzed in athymic nude mice. RESULTS: Asra-EPS cells were round, polygonal or spindle-shaped with an abundant cytoplasm and have been maintained continuously in vitro for over 150 passages during more than 15 months. These cells secreted cancer antigen 125 (CA 125), interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) into the culture medium. Asra-EPS cells were tumorigenic when implanted in nude mice with tumors reaching a volume of 1000 mm3 at around 50 days. Histological features of tumors formed in mice were essentially the same as those of the original tumor, exhibiting a multinodular proliferation of eosinophilic epithelioid and spindle-shaped cells with prominent areas of hemorrhage and blood-filled cystic spaces strikingly corresponding to the potential of hemorrhagic cyst formation in the original tumor. They showed immunopositive staining for cytokeratins (AE1/AE3 and CAM5.2), epithelial membrane antigen (EMA), vimentin, CD31, CD34 and CA 125, but negative for integrase interactor 1 (INI-1) and factor VIII-related antigen. CONCLUSIONS: The established cell line represents a biologically relevant new tool to investigate the molecular pathology of human angiomatoid ES and to evaluate the efficacy of novel therapeutics both in vitro and in vivo.

Modified model of VX2 tumor overexpressing vascular endothelial growth factor.

PURPOSE: To determine whether upregulated expression of vascular endothelial growth factor (VEGF) in VX2 cells can increase vessel density (VD) and reduce tumor necrosis. MATERIALS AND METHODS: The VX2 cell line was transfected with expression vectors containing cDNA for rabbit VEGF. Stable clones producing rabbit VEGF (VEGF-VX2) were selected. VEGF-VX2 cells (n = 5 rabbits) or nontransfected VX2 cells (controls; n = 5 rabbits) were implanted into leg muscle of 10 rabbits. The animals were sacrificed at day 21. Tumor volume, percentage of necrosis, VD, and VEGF concentration in tumor protein extract were quantified. RESULTS: Overexpression of VEGF by VX2 cells augmented tumor implantation efficiency 100% and favored cyst formation. The tumor volume was significantly larger for VEGF-VX2 transfected tumors versus controls (P = .0143). Overexpression of VEGF in VX2 cells significantly increased the VD of the tumors (P = .0138). The percentage of necrosis was reduced in VEGF-VX2 tumors versus controls (19.5% vs 38.5 %; P = .002). VEGF concentration in VEGF-VX2 tumors was significantly higher than in control tumors (P = .041) and was correlated with tumor volume (ρ = .883, P = .012). CONCLUSIONS: The overexpression of VEGF increased tumor growth and vascularization, favored cyst formation, and reduced tumor necrosis. This new phenotype of the VX2 tumor may offer some advantages over classic models of VX2 tumor for evaluating anticancer therapies.

Angiogenesis index CD105 (endoglin)/CD31 (PECAM-1) as a predictive factor for invasion and proliferation in intraductal papillary mucinous neoplasm (IPMN) of the pancreas.

BACKGROUND: Intraductal papillary-mucinous neoplasm (IPMN) of the pancreas is an increasingly diagnosed entity since its definition by the World Health Organization in 1996. It has a broad clinical spectrum ranging from benign to malignant tumors. Optimum treatment is controversial and a better understanding of the development of IPMN of the pancreas and identification of potential prognostic factors will help to address this. Angiogenesis plays an elementary role in the development of malignant tumors and may well also be important in the development of IPMN of the pancreas. Therefore we investigated endothelial cell marker CD31 (PECAM-1) and angiogenesis associated marker CD105 (endoglin) by immunohistochemistry. METHODS: Thirty-two cases of surgically resected IPMN were chosen retrospectively and clinical data were obtained. Specimens were stained for proliferation marker (Ki-67), CD31 and CD105 by immunohistochemistry. A CD105/CD31 Angiogenesis ratio (AR) was established to determine the proliferating fraction of endothelial cells. RESULTS: The AR is significantly elevated in invasive IPMN of the pancreas (Mann-Whitney-U Test, p<0.05) and is associated with the Ki-67-labelling-index, demonstrating synergy between tumor-growth and neovascularisation. Invasive IPMN of the pancreas is associated with significantly lower recurrence-free and overall survival. CONCLUSIONS: Neovascularisation plays an important role in the tumorigenesis of invasive IPMN of the pancreas, and therefore angiogenesis-associated molecules like CD105 and CD31 might be useful tools as prognostic markers. Furthermore, the results indicate a potential role for adjuvant anti-angiogenic therapies in selected patients with recurring and/or invasive IPMN of the pancreas.