Sustained effect of continuous treatment with bevacizumab following bevacizumab in combination with chemotherapy in a human ovarian clear cell carcinoma xenograft model.

Although bevacizumab maintenance following bevacizumab in combination with chemotherapy has demonstrated significant prolongation of progression-free survival in clinical studies in patients with ovarian cancer, the majority of the cancer cases in the study were of the serous histotype; therefore, data regarding clear cell carcinoma is limited. Furthermore, the efficacy of bevacizumab beyond progression has not yet been demonstrated in ovarian cancer. A xenograft model using the human ovarian clear cell carcinoma cell line RMG-I was used to investigate the antitumor effects and the mechanisms of bevacizumab in maintenance treatment and bevacizumab when administered beyond disease progression. In the RMG-I model, bevacizumab maintenance following bevacizumab in combination with paclitaxel exhibited increased tumor suppression, compared with its absence, and inhibited the increase of microvessel density (MVD) in tumors. Following disease progression during bevacizumab maintenance, continued bevacizumab treatment in combination with PEGylated liposomal doxorubicin as a secondary chemotherapeutic agent had increased efficacy, compared with PEGylated liposomal doxorubicin alone, and resulted in lower MVD accompanied with lower levels of insulin-like growth factor binding protein-3, which is reported to have angiogenic activity. Continuous suppression of angiogenesis by bevacizumab may contribute to the superior efficacy of bevacizumab maintenance and bevacizumab beyond progression in ovarian cancer.

A phase II evaluation of sunitinib in the treatment of persistent or recurrent clear cell ovarian carcinoma: An NRG Oncology/Gynecologic Oncology Group Study (GOG-254).

OBJECTIVES: To determine the efficacy and tolerability of sunitinib in recurrent or persistent clear cell ovarian cancer patients. METHODS: All patients had one or two prior regimens with measurable disease. Tumors were at least 50% clear cell histomorphology and negative for WT-1 antigen and estrogen receptor expression by immunohistochemistry. Sunitinib 50 mg per day for 4 weeks was administered in repeated 6-week cycles until disease progression or prohibitive toxicity. Primary end points were progression-free survival (PFS) at 6 months and clinical response. The study was designed to determine if the drug had a response rate of at least 20% or 6-month PFS of at least 25%. RESULTS: Of 35 patients enrolled, 30 were treated and eligible (median age: 51, range: 27-73). Twenty-five (83%) were White, 4 (13%) Asian, and 1 (3%) unknown. The majority 28 (83%) patients, underwent ≤3 but 2 (7%) had 16 courses of study therapy. Five (16.7%) patients had PFS ≥6 months (90% CI: 6.8%-31.9%). Two (6.7%) patients had a partial or complete response (90% CI: 1.2%-19.5%). The median PFS was 2.7 months. The median overall survival was 12.8 months. The most common grade 3 adverse events were fatigue (4), hypertension (4), neutropenia (4), anemia (3), abdominal pain (3), and leukopenia (3). Grade 4-5 adverse events included: thrombocytopenia (5), anemia (2), acute kidney Injury (1), stroke (1), and allergic reaction (1). CONCLUSION: Sunitinib demonstrated minimal activity in the second- and third-line treatment of persistent or recurrent clear cell ovarian carcinoma. ClinicalTrials.gov number, NCT00979992.

Age-Related Renal Microvascular Changes: Evaluation by Three-Dimensional Digital Imaging of the Human Renal Microcirculation Using Virtual Microscopy.

The renal microvasculature is targeted during aging, sometimes producing chronic kidney disease (CKD). Overdiagnosis of CKD in older persons is concerning. To prevent it, a new concept of "healthy aging" is arising from a healthy renal donor study. We investigated the renal microcirculatory changes of three older persons and compared them with that of one patient with nephrosclerosis using a three-dimensional (3D) reconstruction technique that we previously developed. This method uses a virtual slide system and paraffin-embedded serial sections of surgical material that was double-immunostained by anti-CD34 and anti-α smooth muscle actin (SMA) antibodies for detecting endothelial cells and medial smooth muscle cells, respectively. In all cases, the 3D images proved that arteriosclerotic changes in large proximal interlobular arteries did not directly induce distal arterial change or glomerulosclerosis. The nephrosclerotic patient showed severe hyalinosis with luminal narrowing of small arteries directly inducing glomerulosclerosis. We also visualized an atubular glomerulus and intraglomerular dilatation of an afferent arteriole during healthy aging on the 3D image and showed that microcirculatory changes were responsible for them. Thus, we successfully visualized healthy aged kidneys on 3D images and confirmed the underlying pathology. This method has the ability to investigate renal microcirculatory damage during healthy aging.

Differential vascular expression and regulation of oncofetal tenascin-C and fibronectin variants in renal cell carcinoma (RCC): implications for an individualized angiogenesis-related targeted drug delivery.

The study was aimed at determining the vascular expression of oncofetal fibronectin (oncfFn) and tenascin-C (oncfTn-C) isoforms in renal cell carcinoma (RCC) and its metastases which are well-known targets for antibody-based pharmacodelivery. Furthermore, the influence of tumour cells on endothelial mRNA expression of these molecules was investigated. Evaluation of vascular ED-A(+) and ED-B(+) Fn as well as A1(+) and C(+) Tn-C was performed after immunofluorescence double and triple staining using human recombinant antibodies on clear cell, papillary and chromophobe primary RCC and metastases. The influence of hypoxic RCC-conditioned medium on oncfFn and oncfTn-C mRNA expression was examined in human umbilical vein endothelial cells (HUVEC) by real time RT-PCR. There are RCC subtype specific expression profiles of vascular oncfFn and oncfTn-C and corresponding patterns when comparing primary tumours and metastases. Within one tumour, there are different vessel populations with regard to the incorporation of oncfTn-C and oncfFn into the vessel wall. In vitro tumour-derived soluble mediators induce an up regulation of oncfTn-C and oncfFn mRNA in HUVEC which can be blocked by Avastin(®). Vascular expression of oncFn and oncTn-C variants depends on RCC subtype and may reflect an individual tumour stroma interaction or different stages of vessel development. Therefore, oncFn or oncTn-C variants can be suggested as molecular targets for individualized antibody based therapy strategies in RCC. Tumour-derived VEGF could be shown to regulate target expression.

Metastatic renal cell carcinoma to the oral cavity and clear cell mucoepidermoid carcinoma: comparative clinicopathologic and immunohistochemical study.

BACKGROUND: Metastatic clear cell renal cell carcinoma (CCRCC) should be considered in differential diagnosis of intraoral clear cell tumors, including mucoepidermoid carcinoma (MEC). OBJECTIVE AND STUDY DESIGN: We compared the clinical, histologic, histochemical, and immunohistochemical characteristics of 9 oral metastatic CCRCCs and 8 intraoral clear cell MECs. RESULTS: Oral metastatic CCRCC affected salivary-gland containing tissues in 7 cases (78%). Microscopically, oral metastasis revealed a proliferation of neoplastic clear cells arranged in an alveolar pattern with central blood vessels, features that were not seen in any intraoral clear cell MEC. Mucicarmine staining was positive only in clear cell MEC. Immunohistochemistry showed similarities in cytokeratin expression; vimentin and CD10 were expressed in all oral metastatic CCRCCs but in only 1 clear cell MEC each. CONCLUSIONS: Besides clinical history, the alveolar pattern, vessel distribution, absence of mucicarmine staining, and vimentin and CD10 immunoexpression are useful in histologic differential diagnosis of CCRCC and clear cell MEC.

Adnexal mass vascularity assessed by 3-dimensional power Doppler: does it add to the risk of malignancy index in prediction of ovarian malignancy?: four hundred-case study.

The Risk of Malignancy Index (RMI) is used for the prediction of ovarian malignancy. It includes menopausal status, carbohydrate antigen 125 serum levels, and ultrasound criteria. Three-dimensional power Doppler (3-DPD) is a reproducible investigation for assessment of tumor vascularity, classifying vascularity to avascular, parallel, and chaotic patterns. In this study; 3-DPD was added to RMI for prediction of malignancy in 400 cases of ovarian masses. Sensitivity of RMI for prediction of malignancy was 88%, with a cutoff value of 202.5 at 95% confidence interval. Sensitivity of 3-DPD for prediction of malignancy was 75%, adding 3-DPD to RMI increased its sensitivity to 99%. Considering the pilot nature of the study, further studies are needed to corroborate such findings.

The reduction in pigment epithelium-derived factor is a sign of malignancy in ovarian cancer expressing low-level of vascular endothelial growth factor.

BACKGROUND: Angiogenesis is a critical factor in the progression of solid tumors and metastasis. The aim of this study was to characterise the roles of angiogenic and anti-angiogenic factors on ovarian cancer. METHODS: The expression levels of vascular endothelial growth factor (VEGF, angiogenic factor) and pigment epithelial growth factor (PEDF, anti-angiogenic factor) were measured by real-time polymerase chain reaction and Western blotting in ovarian tumors. Microvessel density (MVD) was evaluated by the total microvessel length in high-power field of tumor tissue preparations. RESULTS: MVD correlated with tumor malignancy. The tissues with the highest expression levels of VEGF (VEGF-H) were malignant tumors. The VEGF expression levels in some malignant tumors (VEGF-L) were as low as that in benign tumors. Therefore, the expression of PEDF was examined. The PEDF expression levels in VEGF-L malignant tumors were significantly lower than those in benign tumors. On the other hand, the PEDF expression levels in VEGF-H malignant tumor tissues were not significantly different from those in benign tumors. CONCLUSION: The reduction in PEDF expression levels may be, in part, responsible for tumor malignancy in VEGF-L ovarian tumors. Furthermore, PEDF may be a useful marker of malignancy in VEGF-L ovarian tumors.

[Prognostic value of microvessel density and angiogenesis-related molecules in epithelial ovarian cancer].

OBJECTIVE: To evaluate the correlations of microvessel density (MVD), vascular endothelial growth factor (VEGF), thrombospodin1 (TSP1) and p53 protein with prognosis in epithelial ovarian cancer. METHODS: Samples from 57 patients with primary epithelial ovarian cancer were examined by immunohistochemical staining using anti-VEGF, anti-TSP1, anti-p53 and anti-CD34 antibodies. The correlation of MVD, expression of VEGF, TSP1 and p53 protein with postoperative recurrence and overall survival were analyzed retrospectively. RESULTS: VEGF, TSP1 and p53 protein was positively detected in 40 (70.2%), 27 (47.4%) and 35 (61.4%) of those patients, respectively. The mean MVD in this series was 30.3 +/- 8.5. High MVD, positive VEGF expression and negative TSP1 expression were positively correlated with postoperative recurrence. Univariate analysis showed that patients with high MVD, positive expression of VEGF and p53 had shorter median overall survival time than those with lower MVD, negative expression of VEGF and p53 (P = 0.0187, P = 0.010 and P = 0.005, respectively), while TSP1 expression was revealed as a protective factor for prognosis. Patients with positive expression of TSP1 had longer median overall survival time than those with negative TSP1 expression (P = 0.042). Multivariate analysis showed that MVD and p53 expression were two independent prognostic factors in epithelial ovarian cancer (P = 0.018 and P = 0.009, respectively). CONCLUSION: VEGF, TSP1 and p53 protein may play an important role in the angiogenesis of epithelial ovarian cancer. High MVD level and p53 protein expression are two independent poor prognostic factors.

Targeted therapies for kidney cancer in urologic practice.

Renal cell carcinoma (RCC) is the most lethal of all genitourinary malignancies with nearly half of all patients presenting with locally advanced or metastatic disease. Systemic treatments such as chemo- or immunotherapy have historically been associated with overall response rates of 5-15% with very few durable responses. The basis of newly approved, more effective targeted therapies for metastatic RCC are based on a fundamental knowledge of the molecular mechanisms that give rise to RCC. We review the clinical data for targeted therapies in RCC and discuss the pertinent biology, side effects, and targets important to the practicing clinician.

Sorafenib (BAY 43-9006) inhibits tumor growth and vascularization and induces tumor apoptosis and hypoxia in RCC xenograft models.

PURPOSE: New research findings have revealed a key role for vascular endothelial growth factor (VEGF) in the stimulation of angiogenesis in clear cell renal carcinoma (RCC) which is a highly vascularized and treatment-resistant tumor. Sorafenib (BAY 43-9006, Nexavar) is a multi-kinase inhibitor which targets receptor tyrosine and serine/threonine kinases involved in tumor progression and tumor angiogenesis. The effect of sorafenib on tumor growth and tumor histology was assessed in both ectopic and orthotopic mouse models of RCC. METHODS: Sorafenib was administered orally to mice bearing subcutaneous (SC, ectopic) or sub-renal capsule (SRC, orthotopic) tumors of murine (Renca) or human (786-O) RCC. Treatment efficacy was determined by measurements of tumor volume and tumor growth delay. In mechanism of action studies, using the 786-O and Renca RCC tumor models, the effect of sorafenib was assessed after dosing for 3 or 5 days in the SC models and 21 days in the SRC models. Inhibition of tumor angiogenesis was assessed by measuring level of CD31 and alpha-smooth muscle actin (alphaSMA) staining by immunohistochemistry (IHC). The effect of sorafenib on MAPK signaling, cell cycle progression and cell proliferation was also assessed by IHC by measuring levels of phospho-ERK, phospho-histone H3 and Ki-67 staining, respectively. The extent of tumor apoptosis was measured by terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) assays. Finally, the effects of sorafenib on tumor hypoxia was assessed in 786-O SC model by injecting mice intravenously with pimonidazole hydrochloride 1 h before tumor collection and tumor sections were stained with a FITC-conjugated Hypoxyprobe antibody. RESULTS: Sorafenib produced significant tumor growth inhibition (TGI) and a reduction in tumor vasculature of both ectopic and orthotopic Renca and 786-O tumors, at a dose as low as 15 mg/kg when administered daily. Inhibition of tumor vasculature was observed as early as 3 days post-treatment, and this inhibition of angiogenesis correlated with increased level of tumor apoptosis (TUNEL-positive) and central necrosis. Consistent with these results, a significant increase in tumor hypoxia was also observed 3 days post-treatment in 786-O SC model. However, no significant effect of sorafenib on phospho-ERK, phospho-histone H3 or Ki-67 levels in either RCC tumor model was observed. CONCLUSION: Our results show the ability of sorafenib to potently inhibit the growth of both ectopically- and orthotopically-implanted Renca and 786-O tumors. The observed tumor growth inhibition and tumor stasis or stabilization correlated strongly with decreased tumor angiogenesis, which was due, at least in part, to inhibition of VEGF and PDGF-mediated endothelial cell and pericyte survival. Finally, sorafenib-mediated inhibition of tumor growth and angiogenesis occurred at concentrations equivalent to those achieved in patients in the clinic.

Recombinant semaphorin 6A-1 ectodomain inhibits in vivo growth factor and tumor cell line-induced angiogenesis.

The Semaphorins are a large family of transmembrane, GPI-anchored and secreted proteins that play an important role in neuronal and endothelial cell guidance. A human gene related to the class 6 Semaphorin family, Semaphorin 6A-1 (Sema 6A-1) was identified by homology-based genomic mining. Recent implication of Sema 3 family members in tumor angiogenesis and our expression analysis of Sema 6A-1 suggested that class 6 Semaphorin might effect tumor neovascularization. The mRNA expression of Sema 6A-1 was elevated in several renal tumor tissue samples relative to adjacent nontumor tissue samples from the same patient. Sema 6A-1 transcript was also expressed in the majority of renal clear cell carcinoma (RCC) cell lines and to a lesser extent in endothelial cells. To test the role of Sema 6A-1 in tumor angiogenesis, we engineered, expressed and purified the Sema 6A-1 soluble extracellular domain (Sema-ECD). The purified Sema-ECD was screened in a variety of endothelial cell-based assays both in vitro and in vivo. In vitro, Sema-ECD blocked VEGF-mediated endothelial cell migration. These effects were explained in part by our observation in endothelial cells that Sema-ECD inhibited VEGF-mediated Src, FAK and ERK phosphorylation. In vivo, mouse Matrigel assays demonstrated that the intraperitoneal administration of recombinant Sema-ECD inhibited both bFGF/VEGF and tumor cell line-induced neovascularization. These findings reveal a novel therapeutic utility for Sema 6A-1 (Sema-ECD) as an inhibitor of growth factor as well as tumor-induced angiogenesis.

[Mutation of von Hippel-Lindau gene and expression of vascular endothelial growth factor in sporadic clear cell renal cell carcinoma and their relationships to angiogenesis].

OBJECTIVE: To evaluate the relationship between the mutation of the von Hippel-Lindau (VHL) gene and expression of vascular endothelial growth factor (VEGF) in sporadic clear cell renal cell carcinoma (CCRCC) and angiogenesis. METHODS: Polymerase chain reaction (PCR) was used to detect the mutation of VHL gene in the specimens of cancerous tissue and normal tissues away from tumor from 77 patients with CCRCC. Immunohistochemistry was used to examine the expression of VEGF. CD34 staining was used to measure the microvascular density (MVD). RESULTS: VHL gene mutations were detected in 40 cases (51.9%). The expression rate of VEGF was 79.2% (61 cases). The positive rate of VEGF in the cases with VHL mutation was 92.5%, significantly higher than that in the cases without VHL mutation (64.9%, P = 0.003). The levels of MVD was higher in the cases with VHL mutation and those with VEGF expression were 760.80/mm2 and 715.95/mm2 respectively, both significantly higher than those in the cases without VHL-mutation and those without VEGF expression (547.03/mm2 and 437.44/mm2 respectively, all P = 0.001). The cases with expression of VEGF were divided into two groups according the presence or absence of VHL gene mutations or not. The MVD of the cases with VEGF expression and VHL mutation was 760.80 mm2, significantly higher than that of the cases with VEGF expression and without VHL mutation (547.03 mm2, P = 0.011). CONCLUSION: The mutation rate of VHL gene is high among the Chinese with sporadic CCRCC. VHL gene mutation increases significantly the VEGF expression, thus, and perhaps via other mechanism too, promoting the angiogenesis in tumor. The high level of MVD of the cases with VHL gene mutation may be related to the high malignant potential of CCRCC.

Immature tumor angiogenesis in high-grade and high-stage renal cell carcinoma.

OBJECTIVES: To investigate the correlation between pathologic findings and maturation of the tumor neovasculature of renal cell carcinoma by immunohistochemical studies. METHODS: Formalin-fixed and paraffin-embedded specimens from 25 randomly selected patients with renal cell carcinoma were stained with mouse monoclonal antibodies, anti-human CD31, anti-alpha smooth muscle actin (alphaSMA), and anti-human calponin by the indirect immunoperoxidase method. The microvessels were counted in six areas with the higher number of microvessels in each patient at 200x magnification (0.255 mm2 per area). RESULTS: The number of CD31-positive microvessels in grade 3 tumors was significantly lower than those in grade 1 or 2 tumors (P = 0.003222 and P = 0.043217, respectively). The CD31-positive microvessel counts of those of higher stage, tumor size greater than 4.5 cm, or non-clear cell type were significantly lower than tumors of lower stage, size less than 4.6 cm, or clear cell type. In the grade 3 tumors, the expression ratio of the number of alphaSMA-positive microvessels to the number of CD31-positive microvessels was significantly decreased compared with grade 1 or 2 tumors (P = 0.000011 and P = 0.000000, respectively). The expression of calponin in the tumor neovasculature was not observed. The expression ratios of the number of alphaSMA-positive microvessels to the number of CD31-positive microvessels in higher stages, larger tumor sizes, or non-clear cell types were significantly decreased. CONCLUSIONS: The tumor neovasculature of high-grade and high-stage tumors was immature. These results imply that high-grade tumors of renal cell carcinomas may be susceptible to antiangiogenesis therapy inducing apoptosis of immature tumor vessels.

Increased in situ gelatinolytic activity in renal cell tumor tissues correlates with tumor size, grade and vessel invasion.

Degradation of collagen, or gelatinolysis, by tumor cells is one of the most important events in tumorigenesis. We investigate the possible relationship between the in situ gelatinolytic activities exerted by matrix metalloproteinases (MMPs) and clinico-pathological factors in renal cell tumor (RCT) patients. Using the film in situ zymography (FIZ) method, we determined in situ localization of MMP-like gelatinolytic activities in cancerous and normal tissues in the kidney (n = 51). To clarify the MMP(s) responsible for the gelatinolytic activity in RCTs, we examined the expressions of MMP-2 and MMP-9 in the kidney tissues by means of gelatin zymography (GZG). MMP expression was also detected by RT-PCR and Western blotting analysis. We then investigated the associations of MMP expression, as detected by GZG, with the intensity of gelatinolytic activity, as determined by FIZ. We analyzed the possible relationship of FIZ findings to several clinico-pathological factors such as tumor size, grade, vessel invasion, histologic type, stage and metastasis. FIZ demonstrated that all tumor and normal kidney tissues showed in situ gelatinase activities, and that gelatinolytic activities in RCTs were much stronger than those of normal kidney tissues. There was a statistically significant correlation between the intensity of MMP-like gelatinolytic activity and tumor size, tumor grade and vessel invasion (p < 0.05), but not between it and histological type, tumor stage or metastatic status. FIZ showed that tumor tissues in 5 of the 6 patients with fatal outcome exhibited the intense gelatinolytic pattern. Stronger in situ gelatinolytic patterns were documented in cases with higher MMP-2 expression. The molecular species of MMPs detected by GZG were confirmed by RT-PCR and Western blotting analysis. The FIZ technique enables a direct assessment of in situ gelatinolytic activity in RCT tissues. The intensity of the activity seems to affect the biology of RCT tissues. Our results also indicate a major role for MMP-2 in in situ gelatinolysis in RCT tissues.

Thymidine phosphorylase-mediated angiogenesis regulated by thymidine phosphorylase inhibitor in human ovarian cancer cells in vivo.

Metastasis or progression of ovarian cancer cells is known to be due to the action of various angiogenic factors. We determined the expression of thymidine phosphorylase/platelet-derived endothelial cell growth factor (TP/PD-ECGF) and vascular endothelial growth factor (VEGF) in cell lines established from 3 serous adenocarcinomas, 3 clear cell carcinomas and 2 mucinous carcinomas of the human ovary. TP activity and the TP mRNA level were much higher in the serous adenocarcinoma cells than in the clear cells and mucinous carcinoma cells, and TP expression was extremely low in the clear cell carcinoma cells. Expression of VEGF mRNA was variable, but not significantly different between the 3 histological types of ovarian cancer. In vivo angiogenesis in the ovarian cancer cells was evaluated by the dorsal air sac assay and revealed that SHIN-3 and HRA serous adenocarcinoma cells, which have high levels of TP expression, induced angiogenesis, while KK clear cell carcinoma cells with low TP expression, did not. The degree of ovarian-cancer-induced angiogenesis seemed to be independent of expression of VEGF in the cells. To confirm that the serous adenocarcinoma-induced angiogenesis is dependent on TP levels, a potent and specific inhibitor of TP was administered orally to mice implanted with a chamber containing SHIN-3 or HRA cells. The TP inhibitor significantly inhibited the angiogenesis induced by the serous adenocarcinoma cells. These results suggest that the angiogenic potency of ovarian cancer cells differs with the histological type and is controlled by expression of TP/PD-ECGF, not by VEGF, and that TP-mediated angiogenesis may be the main factor responsible for progression or metastasis of ovarian serous adenocarcinomas.

Expression of hypoxia-inducible factors in human renal cancer: relationship to angiogenesis and to the von Hippel-Lindau gene mutation.

The von Hippel-Lindau tumor suppressor protein acts as the substrate recognition component of a ubiquitin E3 ligase that targets hypoxia-inducible factor (HIF)-alpha subunits for proteolysis. Stabilization of HIF-alpha subunits has been described in VHL-defective cell lines, leading to HIF activation and up-regulation of hypoxia-inducible mRNAs. Mutations of the von Hippel-Lindau tumor suppressor protein are found in most clear cell renal cell carcinomas (CC-RCCs) but not other renal tumors, raising a question about the importance of activation of the HIF pathway in CC-RCC development. To address this question, we have examined the expression of HIF-alpha subunits in 45 primary renal tumors and related this to tumor subtype, the presence of VHL mutations, and measures of angiogenesis. We show that HIF-alpha is up-regulated in the majority of CC-RCCs, and that the pattern of expression is biased toward the HIF-2alpha isoform. Expression of HIF-alpha proteins was associated significantly with up-regulation of VEGF mRNA and protein and increased microvessel density. Up-regulation of HIF-alpha in CC-RCC was found to involve increased mRNA as well as protein expression, suggesting that both VHL-dependent and VHL-independent mechanisms are involved. These results suggest that activation of the HIF pathway is functionally important in CC-RCC development and might provide a new therapeutic target.

Prognostic significance of microvessel density, vascular cuffing and vascular endothelial growth factor expression in ovarian carcinoma: a special review for clear cell adenocarcinoma.

Our purpose is to demonstrate the relationship between microvessel density (MVD), vascular cuffing (VC), vascular endothelial growth factor (VEGF) expression and clinicopathological parameters in ovarian cancer. Surgical specimens from 105 primary ovarian cancers were examined for vascularization and VEGF expression by immunohistochemical staining. The higher MVD group (MVD> or =70) and the positive VEGF group were associated with better progression-free survival only in early stages. The significant association of the MVD with better progression-free survival was recognized only in the patients with clear cell adenocarcinomas. The complete VC group showed a similar trend as MVD though there was no statistical difference. A multivariate analysis revealed MVD to correlate independently with progression-free survival. In ovarian carcinoma, MVD was found to be an independent prognostic factor. In addition, the higher MVD with clear cell adenocarcinoma had the better prognosis. The clinicopathological role of angiogenesis should be analyzed taking account of histologic type.

Metastatic renal cell carcinoma neovasculature expresses prostate-specific membrane antigen.

OBJECTIVES: To determine whether the tumor-associated neovasculature of metastatic prostate and metastatic conventional (clear cell) renal carcinoma express prostate-specific membrane antigen (PSMA). PSMA is a type II integral membrane glycoprotein highly expressed in prostate cancer cells and also recently discovered to be expressed in the neovasculature of non-prostatic primary malignancies. METHODS: We examined metastatic prostate carcinoma (22 patients) and metastatic conventional (clear cell) renal carcinoma (20 patients) in various anatomic sites, including bone, lymph nodes, liver, lung, and soft tissue. Using the biotin-streptavidin method, we performed immunohistochemical reactions with the anti-PSMA monoclonal antibodies (mAbs) 7E11 and PM2J004.5 and with the anti-endothelial cell mAb CD34. RESULTS: Metastatic conventional (clear cell) renal carcinoma consistently expressed PSMA. The PM2J004.5 mAb was positive in 20 of 20 specimens, and the 7E11 mAb was positive in 15 of 20. The anti-PSMA immunoreactions with the neovasculature were confirmed by similar staining by the anti-CD34 mAb (20 of 20). Although the metastatic prostatic cancer cells expressed PSMA in all the specimens, only 2 of 22 had neovasculature PSMA expression. CONCLUSIONS: As in primary prostatic adenocarcinomas, the neovasculature of metastatic prostate cancer, regardless of site, rarely express PSMA. The neovascular endothelial cells of metastatic clear cell renal carcinoma, however, express PSMA. This expression may make PSMA an effective target for mAb-based antineovasculature therapy in metastatic renal carcinoma.