Humans ; Microvessels ; Neovascularization, Pathologic ; Neovascularization, Physiologic ; Plaque, Atherosclerotic ; pathology

BACKGROUNDOsteosarcoma is characterized by high neovascularization and a high propensity for metastasis through bloodstream. This study was to examine whether there is evidence for vasculogenic mimicry in osteosarcoma and to illustrate mechanism of tumor blood vessels formation in osteosarcoma.

METHODSOsteosarcoma cell lines (U-2OS) were tested for their ability to form tubular networks in three-dimensional culture containing type I collagen. The structures of the tubular networks were observed with phase contrast microscope and transmission electron microscope (TEM). Morphometric studies using hematoxylin and eosin (HE) stain and CD31 immunohistochemical stain to show tumor-lined channels in human osteosarcoma were also performed.

RESULTSObservation with light microscope and TEM showed that highly aggressive osteosarcoma cell lines (U-2OS) formed networks containing channels when grown in three-dimensional culture containing type I collagen, in the absence of endothelial cells or fibroblasts. Morphometric observation using HE stain and CD31 immunohistochemical stain showed that tumor cell-lined channels were also detected in vivo in osteosarcoma; by comparison, all vascular areas in the pedicle of osteochondroma or outside osteochondroma were endothelial-lined.

CONCLUSIONThese observations strongly suggest that aggressive osteosarcoma cells may generate vascular channels that facilitate tumor perfusion independent of tumor angiogenesis and have the ability of vasculogenic mimicry.

Bone Neoplasms ; pathology ; ultrastructure ; Cell Line, Tumor ; Collagen ; biosynthesis ; Humans ; Immunohistochemistry ; Neovascularization, Pathologic ; pathology ; Osteosarcoma ; pathology

OBJECTIVETo investigate the distribution, phenotype and development of pericytes in infantile hemangioma.

METHODSFifty-two infantile hemangioma samples were included in our study. alpha-SMA was used as the marker antigen to observe the distribution of pericytes. Transmission electron microscope and TUNEL method were used to analyze the apoptosis of pericytes.

RESULTSIn the early and middle proliferating stage, there existed many pericytes in hemangioma; Pericytes together with endothelial cells generated vasculogenesis. In the late proliferating stage, many pericytes became apoptotic. In the early involuting stage, there were only a few of pericytes around the microvessels; After that, the microvessels became obstruction progressively and pericytes disappeared finally.

CONCLUSIONSThe pericyte is one of the major constitutive cells of hemangioma. The vasculogenesis, development and disappearance of microvessels undertaken by pericytes and endothelial cells lead to the pathologic evolution of infantile hemangioma.

Child ; Child, Preschool ; Female ; Hemangioma ; pathology ; Humans ; Infant ; Male ; Microcirculation ; Neovascularization, Pathologic ; pathology ; Pericytes ; pathology

Cancer stem cells (CSCs) and angiogenesis play important roles in generation and development of malignant tumours. The number of researches concerned both of them is increasing rapidly and many impressive conclusions have been achieved based on recent studies. It is indicated that the CSCs have complicated interaction with the adjacent vascular microenvironment and they act on the disease progression together. CSCs may enhance angiogenesis while the vascular microenvironment has effects on maintenance and even induction of stemness, and new illustrations of mechanisms are constantly obtained. In this review, we summarize the current research status of mutual actions between CSCs and the vascular microenvironment, and also overview the latest progresses about relevant targeted therapies, to provide advisable information for future preclinical and clinical explorations.
Humans ; Neoplasms ; blood supply ; pathology ; Neoplastic Stem Cells ; pathology ; physiology ; Neovascularization, Pathologic ; pathology ; physiopathology ; Tumor Microenvironment

Drug Delivery Systems ; Humans ; Neoplasms ; drug therapy ; etiology ; pathology ; Neoplastic Stem Cells ; pathology ; physiology ; Neovascularization, Pathologic

Special emphasis about cancer metastasis was concentrated on tumor cells themselves, and we usually considered the ability of migration and invasion was the final decider. Recently, bewaring of tumor microenvironment is a fundamental determinant in metastasis has become the most outstanding breakthrough. Considerable "microbes" in the microenvironment are closely linked with tumor metastatic behaviors, and the major proportion of them is tumor-associated macrophages (TAMs). Actually, TAMs conserve immediate "cross-talk" with cancer cells throughout tumor development. It is generally accepted that TAMs have mostly pro-tumoral functions and play an important role in several stages of tumor progression. This progression involves a series of events that leads from the primary site to the metastatic site, including tumor cell growth, angiogenesis, migration, invasion, intravasation and finally extravasation at distant site where the process begins again (metastasis). Thereby, TAMs has attracted substantial attentions in recent years and could become a promising therapeutic strategy. In this review, we focus on the multi-functions of TAMs in cancer and certain drugs targeting TAMs for cancer treatment those are under experimental research procedures or have even been entered human clinical tests.
Animals ; Gene Expression Regulation, Neoplastic ; Humans ; Macrophages ; metabolism ; Neoplasms ; pathology ; Neovascularization, Pathologic ; metabolism ; pathology

The occurrence and development of many tumors all relate with abnormal expression of the Notch receptor. The role of different Notch receptors may be different, even contrary in different tissues at different stages of tumor development, as well as in the same system tumors. Notch signaling pathway plays an important role in cell proliferation, differentiation, apoptosis and tumor angiogenesis, and is as a meeting point for many important cell signaling pathway. Angiogenesis is regulated by complex interactions of multiple activators and inhibitors. Vascular endothelial growth factor (VEGF) and Notch signaling pathway are involved in such process. Many studies have confirmed that Notch signaling pathway plays a key role in the embryonic development and tumour angiogenesis. Recent studies have also revealed that Notch signaling pathway has many potential drug targets. Based on study of Notch signaling pathway and its molecular mechanism of leukemia, to design drugs effecting these targets to block and activate Notch signaling pathway for therapy of leukemia and angiogenesis diseases has a broad application prospects. This review summarises the components of Notch signaling pathway and the role of Notch signaling pathway in occurrence of leukemia and angiogenesis.
Animals ; Humans ; Leukemia ; metabolism ; pathology ; Neovascularization, Pathologic ; metabolism ; pathology ; Receptors, Notch ; metabolism ; Signal Transduction

OBJECTIVETo demonstrate that estrogen stimulates the angiogenesis of children' s hemangioma.

METHODSA piece of hemangioma biopsy was embedded in fibrin gel, and a model in vitro of angiogenesis of human hemangioma was then established. The angiogenesis of hemangioma in each group was interfered by the estrogen and tamoxifen. There were four groups divided into the followings: the group with estrogen, the group with tamoxifen, the group with estrogen + tamoxifen and the control. The dimension of newborn tubule area in the 3rd, 6th, 9th day after the culture was calculated to compare statistically differences among the groups.

RESULTSIn the model of angiogenesis of hemangioma, microvessels grew out from the tissue sample in 2 to 3 days after the culture, and in 8 to 9 days a complex network of microvessels had been shown, the tending to inactivity. On the 3rd,6th and 9th day after the culture the dimension of newborn tubule area of the group of estrogen [(2.84 +/- 0.20) mm2 (12.93 +/- 0.85) mm2 (22.47 +/- 1.40) mm2] were larger than those of the control [(1.98 +/- 0.17) mm2, (7.51 +/- 0.48) mm2, (11.26 +/- 0.73) mm2]. Those of the group of estrogen + tamoxifen [(1.08 +/- 0.11) mm2, (3.54 +/- 0.31) mm2, (5.72 +/- 0.40 mm2] and the group of tamoxifen [(1.13 +/- 0.14) mm2 (4.26 +/- 0.29) mm2, (6.08 +/- 0.42) mm2] were smaller than those of the groups of the estrogen and the control (P < 0.05).

CONCLUSIONSThe estrogen may stimulate the angiogenesis of children's hemangioma, and the tamoxifen may reverse the process.

Child ; Estrogens ; adverse effects ; Hemangioma ; pathology ; Humans ; In Vitro Techniques ; Neovascularization, Pathologic ; pathology

OBJECTIVE: To study the expression of vascular endothelial growth factor(VEGF) and microvessel density (MVD), in nasal polyps and its significance. METHOD: The expression of VEGF, in nasal polyps from 50 patients and inferior turbinates from 10 patients were studied with immunohistochemical methods, measuring their grey score, the relations between expression microvessel density were analyzed. RESULT: (1) The differences between the VEGF expression in nasal polyp gland and vascular were significant (P < 0.05). (2) The differences between the microvessel quantities in nasal polyps and inferior turbinates were significant (P < 0.05). (3) The association between VEGF expression in vascular of nasal polyps and microvessel density was significant (r = -0.664 (< 0. 05). CONCLUSION In nasal polyps, VEGF, expression increased. Those results show that the abnormal expression of VEGF and MVD may play an impotent role in the development of nasal polyps. There was an important value for proper treatment and prediction of nasal polyps.
Humans ; Microvessels ; pathology ; Nasal Polyps ; metabolism ; pathology ; Neovascularization, Pathologic ; Vascular Endothelial Growth Factor A ; metabolism

To investigate the state and significance of bone marrow angiogenesis in hematological diseases, bone marrow microvascular density (BM-MVD) in plastic-embedded section was examined using acetone-fixed bone marrow tissues embedded in glycol-methacrylate (GMA) resin and by the method of immunohistochemistry. The results showed that bone marrow MVD increased greatly in newly diagnosed hematological malignancies before treatment. BM-MVD in patients with acute leukemia decreased down to the normal range as the controls at the time of complete remission. In the non-remission group, BM-MVD decreased less, but when relapsed it increased again up to the same range as the newly diagnosed hematological malignancies, significant increase of BM-MVD was found in patients with anemia, but in less degree than that in hematological malignancies. It is concluded that bone marrow angiogenesis plays a key role in the pathogenesis and development of hematological malignancy. Antiangiogenic therapy may be able to constitute a novel strategy for the treatment of hematological malignancies including leukemia.
Acute Disease ; Bone Marrow ; blood supply ; pathology ; Hematologic Diseases ; blood ; pathology ; Humans ; Leukemia ; blood ; pathology ; Microcirculation ; Neovascularization, Pathologic ; blood ; pathology