Browsing by Subject "Hemangiosarcoma"

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    Activation of matrix metalloproteinase (MMP)-2 by membrane type 1-MMP and abnormal immunolocalization of the basement membrane components laminin and type IV collagen in canine spontaneous hemangiosarcomas
    (Murcia : F. Hernández, 2009) Murakami, M.; Sakai, Hidetaka; Kodama, A.; Mori, T.; Yanai, T.; Maruo, K.; Masegi, T.
    We performed immunohistochemical investigation of the basement membrane (BM) components, namely, type IV collagen and laminin, in 83 canine hemangiosarcomas (HSAs), 22 hemangiomas, and some granulation tissues (GTs). Additionally, we analyzed the expression and activities of matrix metalloproteinase (MMP)-2, MMP-9, and membrane type 1-MMP (MT1-MMP) using the same samples by immunohistochemistry and gelatin zymography to investigate whether MMPs were associated with the BM degradation. In immunohistochemistry for the BM components, many HSAs showed discontinuous linear/negative immunoreactivity in the BM (type IV collagen: 49.4%/14.5%, laminin: 60.3%/10.8%, respectively). In contrast, almost all hemangiomas showed continuous staining in the BM (type IV collagen: 90.9%, laminin: 95.5%, respectively). Interestingly, positive cytoplasmic immunoreactivity for type IV collagen and laminin was observed in 97.6% and 91.6% HSA, respectively. Although MMP-9 immunoreactivity wasn’t detected in neoplastic and active angiogenic endothelial cells (ECs), MMP-2 was detected in all ECs of GTs and in neoplastic cells of both vascular tumors. A strong immunoreactivity for MT1- MMP was observed in active angiogenic ECs in GTs and in neoplastic ECs in HSAs. However, almost all hemangiomas showed weak/negative immunoreactivity. In gelatin zymography, significantly strong activity of active MMP-2 was observed in HSAs, similar to that in active angiogenesis in GTs; however, weak/no activity of active MMP-2 was detected in hemangiomas. In canine HSA, neoplastic cells had active MMP-2, possibly activated by MT1-MMP, and discontinuous status of BM might be associated with activity of active MMP-2.
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    Expression of platelet-derived growth factor and its receptors in spontaneous canine hemangiosarcoma and cutaneous hemangioma
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2012) Abou Asa, S.; Murai, A.; Murakami, M.; Hoshino, Y.; Mori, T.; Maruo, K.; Khater, A.; El-sawak, A.; Abd el-Aziz, E.; Yanai, T.; Sakai, H.
    Hemangiosarcoma (HSA) is a malignant neoplasia of vascular endothelial cells (ECs). Our previous report on the expression of vascular endothelial growth factor, basic fibroblast growth factor, and their receptors in canine HSA suggested an autocrine/paracrine mechanism of tumor growth. However, the influence of other angiogenic growth factors in canine HSA was not elucidated; therefore, the expression of platelet-derived growth factor (PDGF) and its receptors was investigated by immunohistochemical analysis. Forty-six canine HSAs and 21 canine cutaneous hemangiomas (HAs) were analyzed. For immunohisto-chemistry, anti-PDGF-BB, anti-PDGFR-α, and anti-PDGFR-ß antibodies were utilized as primary antibodies. Immunoreactivities were scored as strongly positive (>25% positive neoplastic cells), weakly positive (1-25% positive neoplastic cells), and negative if not staining at all. In cutaneous HA, 33.3% and 57.1% of cases were strongly and weakly positive, respectively, and 43.5% and 13.0% of HSAs were strongly and weakly positive for PDGF-BB, respectively. Moreover, 38.1% and 28.6% of cutaneous HAs cases were strongly and weakly positive, respectively, and 23.9% and 4.3% of HSAs cases were strongly and weakly positive, respectively, for PDGFR-α. Thirty-five HSAs cases (76.1%) were strongly positive, and the remaining 11 (23.9%) were weakly positive for PDGFR-ß. In contrast, 18 (72.0%) cutaneous HAs were negative, and only 3 cases (12.0%) were weakly positive, for PDGFR-ß. The proportion of strongly positive cases of HSAs was significantly higher than that of cutaneous HA for PDGFR-ß (P<0.01), while PDGFR-α was highly expressed in cutaneous HA and may be related to pathogenesis of cutaneous HA. Therefore, PDGFR-ß may be associated with the malignant nature of canine HSA