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At least 1,081 records · Page 60Linked to original sources
PubMed2006

Recruitment of a prostaglandin E receptor subtype, EP3-expressing bone marrow cells is crucial in wound-induced angiogenesis.

E-type prostaglandins have been reported to be proangiogenic in vivo. Thus, we examined prostaglandin receptor signaling relevant to wound-induced angiogenesis. Full-thickness skin wounds were created on the backs of mice, and angiogenesis in wound granulation tissues was estimated. Wound closure and re-epithelization in EP3 receptor knockout mice (EP3-/-) were significantly delayed compared with their wild-type (WT) mice, whereas those in EP1-/-, EP2-/-, and EP4-/- were not delayed. Wound-induced angiogenesis estimated with CD31 immunohistochemistry in EP3-/- mice was significantly inhibited compared with that in WT mice. Immunoreactive vascular endothelial growth factor (VEGF) in wound granulation tissues in EP3-/- mice was markedly less than that in WT mice. Wound closure in WT mice was delayed significantly by VEGF neutralizing antibody compared with control IgG. Wound-induced angiogenesis and wound closure were significantly suppressed in EP3-/- bone marrow transplantation mice compared with those in WT bone marrow transplantation mice. These were accompanied with the reductions in accumulation of VEGF-expressing cells in wound granulation tissues and in mobilization of VEGF receptor 1-expressing leukocytes in peripheral circulation. These results indicate that the recruitment of EP3-expressing cells to wound granulation tissues is critical for surgical wound healing and angiogenesis via up-regulation of VEGF.

Animals↗
PubMed1995

Stimulation of mucosal glutathione and angiogenesis: new mechanisms of gastroprotection and ulcer healing by sucralfate.

BACKGROUND: Among the endogenous mediators (e.g., PG, SH) of gastroprotection, so far only PG was implicated in the mechanism of acute gastroprotection by sucralfate. Angiogenesis, which is stimulated by bFGF, is a recently recognized element in ulcer healing, and sucralfate binds bFGF in vitro and in vivo. METHODS: In fasted rats the gastric mucosal concentration of GSH and protein SH was measured at 30, 60, 120, and 240 min after a single gastroprotective dose of sucralfate. In normally fed rats, angiogenesis was measured in the subcutaneous sponge assay 7 days after the implantation of sponges containing sucralfate and/or bFGF. RESULTS: A gastroprotective dose of sucralfate time-dependently increased GSH concentration in the gastric mucosa. Sucralfate alone accelerated angiogenesis, which was significantly enhanced by combination with an ineffective dose of bFGF in the subcutaneous sponge assay. The same dose of sucralfate combined with an angiogenic dose of bFGF also resulted in synergistic stimulation (e.g., more than fivefold) of angiogenesis. CONCLUSIONS: It appears that elevated mucosal GSH concentration may represent a new factor in the mechanism of acute gastroprotection by sucralfate, and stimulation of angiogenesis is one of the mechanisms of ulcer healing by sucralfate.

Animals↗
PubMed2001

Angiogenesis and mast cells in non-Hodgkin's lymphoma: a strong correlation in angioimmunoblastic T-cell lymphoma.

Mast cells are likely to play a role in angiogenesis under pathological conditions. Solid tumor growth is dependent on angiogenesis, but the influence of mast cells on angiogenesis in non-Hodgkin's lymphoma, (NHL) is not clear. We investigated mast cell number and vessel count in 61 cases of NHL. We also evaluated expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), both important cytokines for angiogenesis. The number of mast cells was greater in T-cell lymphomas than in B-cell lymphomas. Of the T-cell lymphomas, the greatest number of mast cells was observed in the angioimmunoblastic T-cell lymphoma (AIL). In all NHLs, significant correlation was found between vessel count and the number of mast cells (p < 0.0001) and between vessel count and the number of VEGF-expressing cells (p < 0.05) but not between vessel count and bFGF-expressing cells. Strong correlation was detected between the number of mast cells and the number of VEGF-expressing cells (p < 0.0001) in all NHLs. Double fluorescence staining of VEGF mRNA and mast cell tryptase revealed that mast cells expressed VEGF mRNA. Our data suggest that mast cells play a very important role in angiogenesis by expressing VEGF in NHL, especially in AIL.

Cell Count↗
PubMed1995

Angiogenesis in B cell lymphoproliferative diseases. Biological and clinical studies.

Angiogenesis is a necessary step in solid tumor progression (growth, invasion and metastasis) with which it correlates and is indicative of an unfavourable prognosis. We observed bone marrow angiogenesis in patients with active multiple myeloma (MM), though not in patients with non-active MM nor with monoclonal gammopathies of undetermined significance (MGUS). Microvessel density increased in parallel with the labeling index (LI%)--an indicator of plasma cell proliferating activity that correlates with prognosis--and defined a risk of MM progression in much the same way as LI% itself. Consequently, bone marrow angiogenesis could be an indication for unfavourable prognosis in MGUS and MM. Angiogenesis has also been demonstrated in lymph nodes involved by B cell non Hodgkin's lymphoma (B-NHL) belonging to the Working Formulation intermediate-grade (diffuse subtypes), and high-grade categories, but not in the low-grade and intermediate-grade (follicular subtype) categories. It correlated with the B-NHL cell proliferating activity, since large increments in this activity have already been demonstrated in intermediate- and high-grade vs low-grade tumors. Active MM, intermediate-grade, diffuse subtypes, and high-grade B-NHLs correspond to the vascular phases of B cell lymphoproliferative diseases, and could thus be assimilated to locally invasive and metastatic solid tumors. Similarly to solid tumors during these stages of progression, tumor B cells are also capable of inducing angiogenesis, both directly and indirectly by activating the inflammation infiltrate--a possibility that was first demonstrated by means of B-NHL implants onto the chick embryo chorioallantoic membrane. Anti-angiogenic therapy can be envisaged as a possible future development.

Bone Marrow↗
PubMedDate not supplied

Recombinant PAI-1 inhibits angiogenesis and reduces size of LNCaP prostate cancer xenografts in SCID mice.

To understand the fundamental determinants of urokinase plasminogen activator (uPA) driven angiogenesis in cancer we studied how inhibition of uPA activity could reduce neovascularization and consequently reduce tumor size in experimental animals. Proteolytic enzymes are required to mediate tumor cell invasion to adjacent tissues and initiate the metastatic process. Many different human cancers commonly overexpress the urokinase plasminogen activator system, one of the proteolytic enzyme systems. Reduction of urokinase activity in cancer cells is evidently associated with diminished invasion and metastasis. However, it has been shown recently that inhibitors of uPA could reduce tumor size also. The mechanism of action leading to decline in tumor growth rate is not clear. Proteolysis is responsible for degradation of proteins, for invasion or metastasis, but not for the proliferate properties of the cancer cells. It is difficult to envision that diminishing the size of tumor is due to simply blocking of uPA activity of cancer cells. Instead, inhibitors of uPA may be interacting with the elements of the extracellular matrix, such the neovascular bed surrounding tumors that has been reported to contain high amounts of uPA and its receptor. Overall these data strongly suggest that inhibitors of urokinase limit cancer growth by inhibiting angiogenesis. However, it is possible also that uPA inhibitors could act on cancer cells directly or prevent angiogenesis by alternative mechanisms that are not related to uPA inhibition. Therefore, we examined if plasminogen activator inhibitor (PAI-1) could limit angiogenesis. If it does, it will provide definitive evidence of uPA/PAI-1 involvement in reduction of cancer growth. Indeed, our study demonstrates that exogenously applied 14-1b PAI-1 is a powerful inhibitor of angiogenesis in three different in vitro models and is a powerful anti-cancer agent in a SCID mice model inoculated with human LNCaP prostate cancer cells.

Animals↗
PubMed2006

Differential roles of vascular endothelial growth factor receptor-1 and receptor-2 in angiogenesis.

Vascular endothelial growth factor (VEGF)-A, a major regulator for angiogenesis, binds and activates two tyrosine kinase receptors, VEGFR1 (Flt-1) and VEGFR2 (KDR/Flk-1). These receptors regulate physiological as well as pathological angiogenesis. VEGFR2 has strong tyrosine kinase activity, and transduces the major signals for angiogenesis. However, unlike other representative tyrosine kinase receptors which use the Ras pathway, VEGFR2 mostly uses the Phospholipase-Cgamma-Protein kinase-C pathway to activate MAP-kinase and DNA synthesis. VEGFR2 is a direct signal transducer for pathological angiogenesis including cancer and diabetic retinopathy, thus, VEGFR2 itself and the signaling appear to be critical targets for the suppression of these diseases. VEGFR1 plays dual role, a negative role in angiogenesis in the embryo most likely by trapping VEGF-A, and a positive role in adulthood in a tyrosine kinase-dependent manner. VEGFR1 is expressed not only in endothelial cells but also in macrophage-lineage cells, and promotes tumor growth, metastasis, and inflammation. Furthermore, a soluble form of VEGFR1 was found to be present at abnormally high levels in the serum of preeclampsia patients, and induces proteinurea and renal dysfunction. Therefore, VEGFR1 is also an important target in the treatment of human diseases. Recently, the VEGFR2-specific ligand VEGF-E (Orf-VEGF) was extensively characterized. Interestingly, the activation of VEGFR2 via VEGF-E in vivo results in a strong angiogenic response in mice with minor side effects such as inflammation compared with VEGF-A, suggesting VEGF-E to be a novel material for pro-angiogenic therapy.

Animals↗
PubMed1999

The prognostic significance of angiogenesis in epithelial ovarian carcinoma.

The molecular biology underlying the metastatic process in ovarian carcinoma remains poorly understood. For other neoplasms, the induction of angiogenesis by malignant cells has been shown to play a pivotal role in the process of tumor proliferation and metastasis. The purpose of this study was to characterize the degree of angiogenesis in epithelial ovarian malignancies and to determine whether the degree of neovascularization has prognostic significance for survival. Tissue sections obtained from 88 ovarian cancer patients were examined immunohistochemically for angiogenesis after staining with anti-human endothelial cell antibodies to von Willebrand factor and CD31. Light microscopy was performed, and individual microvessel counts were quantified at high power (x400). A chart review was completed, collating data regarding age, stage, grade, status of disease, and survival. Statistical exploratory methods were used to find potentially useful prognostic cutpoints for marker values of angiogenesis. Of the total 88 patients, tissue microvessel counts from 85 were evaluated via antibodies to von Willebrand factor and 87 for CD31. Overall, median survival was 2.7 years in women with cancers containing high microvessel counts versus 7.9 years in those with low microvessel counts (P = 0.03). A low microvessel count was associated with better 5-year survival in both early stage (I and II) and advanced stage (III and IV) disease. Our data suggest that the degree of neovascularization may have prognostic significance in epithelial ovarian carcinoma, especially for women with early-stage disease. In this group of women, the degree of angiogenesis may allow the selection of women at high risk for recurrence who may benefit from aggressive adjuvant therapy.

Adult↗
PubMedDate not supplied

Novel small molecule alpha v integrin antagonists: comparative anti-cancer efficacy with known angiogenesis inhibitors.

Recent evidence supports the involvement of integrins in angiogenesis: blockade of alpha v beta 3 and alpha v beta 5 integrins disrupts angiogenesis leading to decreased blood vessel formation and hence decreased tumor growth. We hypothesized that av antagonists could inhibit tumor growth in tumor cells devoid of alpha v beta 3 integrins. We evaluated SM256 and SD983, novel small molecules that are specific av antagonists in mouse models of angiogenesis and tumorigenesis, and compared them with standards: TNP470, a fumagillin analog in the clinic, and flavopiridol, a cell cycle kinase inhibitor. In vitro SM256 was a selective alpha v beta 3 inhibitor with an IC50 = 4nM, and the affinity of SD983 against the mouse endothelial alpha v beta 3 integrin yielded an IC50 = 2nM and an IC50 = 54nM against alpha v beta 5. In the mouse Matrigel model of angiogenesis SM256 decreased blood vessel formation (hemoglobin content) with an ED50 = 0.055 ug/kg/day, tenfold more potent than TNP470. SG545, an ester of SD983, decreased blood vessel formation with an ED50 = 6 ug/kg/day, while flavopiridol ED50 = 18 ug/kg/day. In the mouse xenograft model, using human colon carcinoma RKO cells that do not express alpha v beta 3 but express alpha v beta 5, tumor growth was inhibited by SG545 (10 mg/kg/day) and flavopiridol (5 mg/kg/every other day) 40% and 70%, respectively (p < 0.05). Although the proliferative index (measured by BrdU incorporation) was not significantly changed with SM256, SG545 or flavopiridol (29-32%), the apoptotic index increased significantly (p < 0.05) in the SM256 and SG545-treated groups (2.3-2.7%) compared with controls (1.1%), suggesting increased cell death contributed to decreased tumor volumes. Neovascularization decreased with SM256 and SG545 treatment. The data demonstrate that potent selective av antagonist can target endothelial cells, tumor cells, inhibit angiogenesis and inhibit tumor growth.

Animals↗
PubMed1999

Tumor angiogenesis.

Tumor angiogenesis is the growth of new blood vessels which is required for tumor growth and progression. Vascularization of the tumor occurs through a series of sequential steps before or during the multistep progression to neoplasia. Several events occur during the formation of new vessels including production of protease enzymes, unregulation of positive regulators of angiogenesis, and down regulation of negative regulators. In addition, tumor associated macrophage also influence angiogenesis by secreting enzymes, enzymes inhibitors and cytokines. Recent knowledge in tumor angiogenesis may have clinical implications in diagnosis and treatment. Quantification of microvessel density in tumor specimen correlates either metastasis or recurrence in many malignancies such as breast cancer and lung cancer. Therefore, assessment of tumor angiogenesis may serve as prognostic factors. Therapeutic applications include the development of new agents with antiangiogenic properties, vascular targeting drugs, antibody-based therapy, and gene therapy. Combination of antiangiogenic therapy with cytotoxic drugs may enhance antitumor activity. Moreover, the role of antiangiogenic therapy in adjuvant setting may provide and alternative approach to better cancer treatment in the near future.

Humans↗
PubMed1999

Protein kinase C lies on the signaling pathway for vascular endothelial growth factor-mediated tumor development and angiogenesis.

The growth of any solid tumor depends on angiogenesis. Among the known angiogenic factors, vascular endothelial growth factor (VEGF) has been shown to play a pivotal role in tumor angiogenesis. However, to date, the signal transduction pathway initiated by VEGF is still not fully understood. It has been suggested that protein kinase C (PKC) plays an important role in the VEGF-induced signal transduction pathway in vitro, although the role of PKC in tumor angiogenesis in vivo still remains to be elucidated. By delivering the VEGF gene within the self-contained tetracycline-regulated retroviral vector (Retro-Tet) into hepatocellular carcinoma (HCC) cells, we manipulated VEGF expression by providing tetracycline in the drinking water to assess the tumor kinetics mediated exclusively by VEGF. In this study, we combined this Retro-tet system and LY333531, an inhibitor of the PKC-beta isoform, to elucidate the role of PKC-beta in tumor development and angiogenesis. Using a syngenic xenograft model, tumor augmentation induced by VEGF overexpression in HCC was markedly suppressed by oral administration of the PKC-beta inhibitor, with an accompanying reduction of neovascularization and p44/42 mitogen-activated protein kinase activation. This inhibitory effect was achieved even after the tumor was fully established. Immunohistochemical analysis revealed that apoptosis increased markedly in the tumor upon PKC-beta inhibitor treatment, whereas tumor cell proliferation itself did not change. Furthermore, with orthotopical transplantation, PKC-beta inhibition suppressed HCC tumor development in the liver. These results suggest that PKC-beta lies on the signal transduction pathway by which VEGF augments development and angiogenesis not only at the initial stage but also after the tumor is fully established.

Animals↗
PubMed1999

Angiogenesis: state of the art.

Considerable progress has been made recently in understanding the molecular mechanisms of angiogenesis, the formation of new blood vessels by a process of sprouting from preexisting vessels. Angiogenesis is fundamental to a number of physiological processes, including embryonic development, the normal menstrual cycle, and tissue or organ regeneration in which growth of new capillaries is tightly controlled by a finely tuned balance between positive and negative mediators of endothelial cell growth. When blood vessels grow unabated or out of control, angiogenesis becomes pathologic and plays a key role in the development of many neoplastic and non-neoplastic diseases. Presently, abundant results from laboratory experiments and clinical trials have greatly improved our understanding of the molecular basis underlying angiogenic events and paved a new way to the diagnosis and treatment of diseases that depend on angiogenesis. This review focuses on the current advances in the regulation and clinical application of angiogenesis.

Animals↗
PubMed2000

Differential expression of VEGF isoforms and VEGF(164)-specific receptor neuropilin-1 in the mouse uterus suggests a role for VEGF(164) in vascular permeability and angiogenesis during implantation.

The mechanism(s) by which localized vascular permeability and angiogenesis occur at the sites of implantation is not clearly understood. Vascular endothelial growth factor (VEGF) is a key regulator of vasculogenesis during embryogenesis and angiogenesis in adult tissues. VEGF is also a vascular permeability factor. VEGF acts via two tyrosine kinase family receptors: VEGFR1 (Flt-1) and VEGFR2 (KDR/Flk-1). Recent evidence suggests that neuropilin-1 (NRP1), a receptor involved in neuronal cell guidance, is expressed in endothelial cells, binds to VEGF(165) and enhances the binding of VEGF(165) to VEGFR2. We examined the spatiotemporal expression of vegf isoforms, nrp1 and vegfr2 as well as their interactions in the periimplantation mouse uterus. We observed that vegf(164) is the predominant isoform in the mouse uterus. vegf(164) mRNA accumulation primarily occurred in epithelial cells on days 1 and 2 of pregnancy. On days 3 and 4, the subepithelial stroma in addition to epithelial cells exhibited accumulation of this mRNA. After the initial attachment reaction on day 5, luminal epithelial and stromal cells immediately surrounding the blastocyst exhibited distinct accumulation of vegf(164) mRNA. On days 6-8, the accumulation of this mRNA occurred in both mesometrial and antimesometrial decidual cells. These results suggest that VEGF(164) is available in mediating vascular changes and angiogenesis in the uterus during implantation and decidualization. This is consistent with coordinate expression of vegfr2, and nrp1, a VEGF(164)-specific receptor, in uterine endothelial cells. Their expression was low during the first 2 days of pregnancy followed by increases thereafter. With the initiation and progression of implantation (days 5-8), these genes were distinctly expressed in endothelial cells of the decidualizing stroma. Expression was more intense on days 6-8 at the mesometrial pole, the presumptive site of heightened angiogenesis and placentation. However, the expression was absent in the avascular primary decidual zone immediately surrounding the implanting embryo. Crosslinking experiments showed that (125)I-VEGF(165) binds to both NRP1 and VEGFR2 present in decidual endothelial cells. These results suggest that VEGF(164), NRP1 and VEGFR2 play a role in VEGF-induced vascular permeability and angiogenesis in the uterus required for implantation. genesis 26:213-224, 2000.

Animals↗
PubMed1999

Angiogenesis and Cancer Control: From Concept to Therapeutic Trial.

BACKGROUND: There is extraordinary interest in developing angiosuppressive agents for cancer treatment. Several new agents appear promising for the treatment of a variety of human cancers. Current concepts and new agents in clinical trials are the focus of this article. In particular, the introduction of a new treatment for human brain tumors is presented in detail, using an antiangiogenic agent, penicillamine, and depletion of an obligatory cofactor of angiogenesis, copper. METHODS: The explosive increase in literature on antiangiogenesis is reviewed using computerized search, findings presented at the recent national cancer and angiogenesis meetings. A specific protocol, NABTT 97-04, "Penicillamine and Copper Reduction for Newly Diagnosed Glioblastoma," is presented as an example of angiotherapeutic drug discovery. RESULTS: A number of promising molecular approaches are being introduced to suppress tumor angiogenesis. Major categories of angiogenesis antagonists include protease inhibitors, direct inhibitors of endothelial cell proliferation and migration, suppression of angiogenic growth factors, inhibition of endothelial-specific integrin/ survival signaling, chelators of copper, and inhibitors with specific other mechanisms. The preliminary results of early trials offer a glimpse into how antiangiogenesis therapy will be integrated into future care of the patient with cancer. CONCLUSIONS: Thirty-five antiangiogenesis therapies are currently being evaluated in clinical trials. As we learn more about the fundamental mechanisms of angiogenesis, eg, the role of copper in growth factor activation, effective methods of cancer control will be implemented.

Journal Article↗
PubMed2000

Angiogenesis and cancer metastasis.

The growth and spread of neoplasms depends on the establishment of an adequate blood supply, that is, angiogenesis. The onset of angiogenesis involves a change in the local equilibrium between proangiogenic and antiangiogenic regulators that are produced by tumor cells, surrounding stromal cells, and infiltrating leukocytes. In most normal tissues, factors that inhibit angiogenesis predominate, whereas in rapidly dividing tissues, the balance of angiogenic molecules favors stimulation of the process. A potent inhibitor of angiogenesis is interferon-alpha or -beta, shown to down-regulate transcription and protein production of basic fibroblast growth factor, collagenase type IV, and interleukin-8. The daily systemic administration of low (but not high) dose of interferon-alpha can produce significant inhibition of angiogenesis and, hence, regression of human tumors implanted orthotopically in nude mice. The recent elucidation of the interaction among proangiogenic molecules during physiological processes and the apparent disruption of this balance in neoplasia should allow the design of potent antiangiogenic therapies against primary cancers and metastases.

Animals↗
PubMed2000

Human endothelial cells express CCR2 and respond to MCP-1: direct role of MCP-1 in angiogenesis and tumor progression.

Although several CXC chemokines have been shown to induce angiogenesis and play roles in tumor growth, to date, no member of the CC chemokine family has been reported to play a direct role in angiogenesis. Here we report that the CC chemokine, monocyte chemotactic protein 1 (MCP-1), induced chemotaxis of human endothelial cells at nanomolar concentrations. This chemotactic response was inhibited by a monoclonal antibody to MCP-1. MCP-1 also induced the formation of blood vessels in vivo as assessed by the chick chorioallantoic membrane and the matrigel plug assays. As expected, the angiogenic response induced by MCP-1 was accompanied by an inflammatory response. With the use of a rat aortic sprouting assay in the absence of leukocytic infiltrates, we ruled out the possibility that the angiogenic effect of MCP-1 depended on leukocyte products. Moreover, the direct effect of MCP-1 on angiogenesis was consistent with the expression of CCR2, the receptor for MCP-1, on endothelial cells. Assessment of supernatant from a human breast carcinoma cell line demonstrated the production of MCP-1. Treatment of immunodeficient mice bearing human breast carcinoma cells with a neutralizing antibody to MCP-1 resulted in significant increases in survival and inhibition of the growth of lung micrometastases. Taken together, our data indicate that MCP-1 can act as a direct mediator of angiogenesis. As a chemokine that is abundantly produced by some tumors, it can also directly contribute to tumor progression. Therefore, therapy employing antagonists of MCP-1 in combination with other inhibitors of angiogenesis may achieve more comprehensive inhibition of tumor growth.

Allantois↗
PubMed2001

Involvement of Flt-1 tyrosine kinase (vascular endothelial growth factor receptor-1) in pathological angiogenesis.

Vascular endothelial growth factor (VEGF) and its two receptors, Fms-like tyrosine kinase 1 (Flt-1) (VEGFR-1) and KDR/Flk-1 (VEGFR-2), have been demonstrated to be an essential regulatory system for blood vessel formation in mammals. KDR is a major positive signal transducer for angiogenesis through its strong tyrosine kinase activity. Flt-1 has a unique biochemical activity, 10-fold higher affinity to VEGF, whereas much weaker tyrosine kinase activity compared with KDR. Recently, we and others have shown that Flt-1 has a negative regulatory function for physiological angiogenesis in the embryo, possibly with its strong VEGF-trapping activity. However, it is still open to question whether the tyrosine kinase of Flt-1 has any positive role in angiogenesis at adult stages. In this study, we examined whether Flt-1+ could be a positive signal transducer under certain pathological conditions, such as angiogenesis with tumors overexpressing a Flt-1-specific, VEGF-related ligand. Our results show clearly that murine Lewis lung carcinoma cells overexpressing placenta growth factor-2, an Flt-1-specific ligand, grew in wild-type mice much faster than in Flt-1 tyrosine kinase domain-deficient mice. Blood vessel formation in tumor tissue was higher in wild-type mice than in Flt-1 tyrosine kinase-deficient mice. On the other hand, the same carcinoma cells overexpressing VEGF showed no clear difference in the tumor growth rate between these two genotypes of mice. These results indicate that Flt-1 is a positive regulator using its tyrosine kinase under pathological conditions when the Flt-1-specific ligand is abnormally highly expressed. Thus, Flt-1 has a dual function in angiogenesis, acting in a positive or negative manner in different biological conditions.

Animals↗
PubMed2001

Tumor angiogenesis is associated with MUC1 overexpression and loss of prostate-specific antigen expression in prostate cancer.

The biological potential of prostate cancer is highly variable and cannot be satisfactorily predicted by histopathological criteria alone. Therefore, additional and more precise information is desirable. Although angiogenesis has been suggested as being of prognostic importance in many human cancers, and MUC1, also known as episialin, was thought to be responsible for the development of metastasis, the role of these parameters in prostate cancer remains unclear. The aim of this study was to investigate whether angiogenesis, assessed as microvessel density (MVD), was correlated with the expression of prostate tumor MUC1 and prostate-specific antigen (PSA) or with histopathological grade at diagnosis, and to determine whether any of these factors might provide additional information with regard to prostate tumor biology. Paraffin-embedded material from 60 patients with prostate carcinoma was examined immunohistochemically, using the monoclonal antibody CD31 to determine MVD, and the monoclonal antibodies CCE831 and ER-PR8 to assess MUC1 and PSA expression, respectively. The tumors were categorized according to the Gleason grading system. MUC1 overexpression was significantly related to a high intratumoral angiogenesis (P = 0.02). By contrast, a high PSA expression by prostate cancer cells was associated with low MVD (P = 0.03). No correlation was found between MUC1 and PSA expression. Usually, high-grade tumors were not PSA-expressive and tended to display increased angiogenesis. These differences, however, were not of statistical significance. Similarly, there was no statistically significant association between histological grade and MUC1 expression or angiogenesis. It is suggested that PSA may have a direct suppressive effect on new blood vessel formation in prostate cancer, whereas the expression of MUC1 in this tumor may be connected with an angiogenic phenotype. Additional studies are obviously needed to clarify the precise role of these proteins in prostate cancer.

Cytoplasm↗
PubMed1999

[The relationship between angiogenesis and p53 overexpression in endometrioid adenocarcinoma].

OBJECTIVE: To determine the relationship between angiogenesis and p53 overexpression and explore the relationship between angiogenesis and clinicopathologic features in endometrioid adenocarcinoma. METHODS: Angiogenesis was evaluated by intratumoral microvessel density (IMD). Eighty-five endometrioid adenocarcinomas' IMD were identified by immunohistochemical staining of endothelial cells for factor VIII-related antigen, and the expression of p53 protein was stained with the same method by it's monoclone antibody. RESULTS: (1) The positive rate of p53 expression in endometrioid adenocarcinoma was 50.6%. The positive rate in stage III-IV (69.2%) was higher than that in stage I-II(42.4%) (P < 0.05). (2) IMD was higher in stage III-IV (13.27 +/- 6.14) than that in stage I-II (8.31 +/- 4.78) (P < 0.01). IMD in G1, G2 and G3 was 8.95 +/- 5.51, 9.28 +/- 4.87 and 14.73 +/- 7.66, respectively (P < 0.05). In groups of non-myoinvasion, < 1/2 myoinvasion and > or = 1/2 myoinvasion, IMD was 8.45 +/- 5.53, 8.95 +/- 4.99 and 11.96 +/- 6.39, respectively (P < 0.05). (3) In negative, weakly positive and strong positive groups of p53 overexpression, IMD was 5.52 +/- 2.11, 11.75 +/- 4.18 and 16.00 +/- 4.63, respectively (P < 0.01). CONCLUSIONS: Angiogenesis tightly correlated with clinicopathologic factors, such as stage, grade and myoinvasion, is promoted by p53 overexpression in endometrioid adenocarcinoma. It can be concluded that angiogenesis may act as a predictor of prognosis of endometrioid adenocarcinoma.

Adult↗