Sources/Clones
Becton Dickinson (4C12.8), Biogenesis (2D8-39, 2D8-30, 2D8-33), Biogenex (LAM1), Dako (polyclonal, 4C7), EY Labs (polyclonal), Eurodiagnostics (polyclonal), Immunotech (4C12) and Monosan (polyclonal).
Fixation/Preparation
Most available antibodies are immunoreactive in cryostat sections and fixed, embedded tissues but require antigen retrieval in the form of HIER or proteolytic digestion or both.
Background
Laminin, a glycoprotein of about 900 kD, is secreted by fibroblasts, epithelial, myoepithelial, endothelial and smooth muscle cells and, together with type IV collagen, forms the principal component of basal lamina. There are three genetically distinct chains of laminin,a-, b-, and g-chains, which are held together by disulfide bonds and by a triple-stranded coiled structure. Ultrastructurally, the basal lamina is composed of a lamina lucida of low electron density, adjacent to the parenchymal cells, and a basal lamina densa of high electron density, adjacent to the connective tissue matrix. By rotary shadowing, laminin has a cruciform shape, consisting of three short arms of 200 kD and one long arm of 400 kD. Laminin is exclusively localized to the basal lamina, predominantly to the lamina lucida, and is invariably present in basal lamina surrounding muscle, nerve, fat and decidua cells and separating epithelial and endothelial cells from adjacent connective tissues. Laminins are potent modulators of numerous biological processes in development, including cell proliferation, migration and differentiation. In adult tissues, laminins influence the maintenance of specific gene expression and are involved in various pathological situations, including fibrosis, carcinogenesis and metastasis. Clone 4D7 reacts with the terminal globular domain of the A-chain of laminin, whereas polyclonal antibodies were generated to laminin isolated from rat yolk sac tumor cell line.
Applications
Laminin has been shown to play a role in cell adhesion and attachment to the basal lamina, bothin vivo and in vitro. The basal lamina is generally extremely stable but in certain pathological states may undergo local dissolution. This process is likely to play a crucial role in the invasiveness and progression of malignant tumors (Liotta, 1984). Loss or defective organization of the basal lamina matrix in malignant neoplasms may be the result of increased breakdown by tumor-derived degradative enzymes, decreased synthesis or decreased or abnormal assembly of the secreted basal lamina components (Pujuguet et al, 1994). In human breast carcinoma, there is suggestion that overexpression of the nm23-H1 gene, a putative metastasis suppressor gene, leads to the formation of basal lamina and growth arrest (Howlett et al, 1994). Antisera to type IV collagen and laminin, the major components of basal lamina allow the study of the organization of the basal lamina in various benign and malignant tumors (Autio-Harmainen et al, 1988; Havenith et al, 1989, Nair et al, 1997, Kuwano et al, 1997). Laminin immunostaining with the immunogold-silver technique in resin-embedded sections allows exquisite demonstration of the basal lamina in a variety of tissues (Leong, 1993). The majority of invasive carcinomas are recognized to synthesize varying amounts of basal lamina material, but the basal lamina surrounding the tumor nests are generally fragmented and, in many cases, completely absent. Benign and in situ lesions appear to be circumscribed by intact basal lamina.
Diagnostic applications of collagen type IV immunostaining have mostly centered around the demonstration of basal lamina in invasive tumors, particularly epithelial tumors, and their changes with tumor invasion and metastasis. In particular, the demonstration of an intact basal lamina has been used to distinguish benign glandular proliferations such as microglandular adenosis and sclerosing adenosis from well-differentiated carcinoma like tubular carcinoma of the breast (Raymond & Leong, 1991; Tavassoli & Bratthauer, 1993). Distinctive patterns of basal distribution were recently demonstrated in various types of soft tissue tumors, adding to the diagnostic armamentarium for this group of neoplasms which are often difficult to separate histologically and with existing immunological markers (Leong et al, 1997). While the presence of basal lamina cannot be used as an absolute discriminant for blood vessels and lymphatic spaces, the latter do not display the reduplication of the basal lamina characteristic of blood vessels and generally show thin and discontinuous staining of basal lamina (Suthipintawong et al, 1995). The distinctive staining observed around blood vessels has been employed as a marker when performing capillary density measurements (Madsen & Holmskov, 1995).
A recent study suggests that the presence of basal lamina as demonstrated with laminin immunostaining may be a clue to the identification of hepatocellular carcinoma as non-malignant hepatocytes lack basal lamina (Yoshida et al, 1996).
Comments
The use of proteolytic digestion following HIER further enhances immunoreactivity. With the polyclonal antibodies we employ protease at 0.25 mg/ml for 2 min (Leong et al 1996).
References
•Autio-Harmainen H, Karttunen T, Apaja-Sarkkinen M et al 1988. Laminin and type IV collagen in different histological stages of Kaposi's sarcoma and other vascular lesions of blood vessels or lymphatic vessel origin. American Journal of Surgical Pathology 12: 469-476.
•Tavenith MG, Van Zandvoort EHM, Cleutjens JPM, Bosman FT 1989. Basement membrane deposition in benign and malignant naevomelanocytic lesions: an immunohistochemical study with antibodies to type IV collagen and laminin. Histopathology 15: 137-146.
•Howlett AR, Petersen OW, Steeg PS, Bissell MJ 1994. A novel function for the nm23-H1 gene: overexpression in human breast carcinoma leads to the formation of basement membrane and growth arrest. Journal of the National Cancer Institutes 86: 1838-1844.
•Kuwano H, Sonoda K, Yasuda M et al 1997. Tumor invasion and angiogenesis in early esophageal squamous cell carcinoma. Journal of Surgical Oncology 65:188-193.
•Leong AS-Y 1993. Immunohistochemistry theoretical and practical aspects. In: Leong AS-Y (ed) Applied immunohistochemistry for surgical pathologists. London: Edward Arnold, pp 1-22.
•Leong AS-Y, Milios J, Leong FJ 1996. Epitope retrieval with microwaves. A comparison of citrate buffer and EDTA with three commercial retrieval solutions. Applied Immunohistochemistry 4: 201-207.
•Leong AS-Y, Vinyuvat S, Suthipintawong C, Leong FJ 1997. Patterns of basal lamina immunostaining in soft-tissue and bony tumors. Applied Immunohistochemistry 5:1-7.
•Liotta LA 1984 Tumor invasion and metastases: role of the basement membrane. Warner-Lambert Parke-Davis Award Lecture. American Journal of Pathology 117:339-348.
•Madsen K, Holmskov U 1995. Capillary density measurements in skeletal muscle using immunohistochemical staining with anti-collagen type IV antibodies. European Journal of Applied Physiology 71: 472-474. immunohistochemical staining with anti-collagen type IV antibodies. European Journal of Applied Physiology 71: 472-474.
•Nair SA, Nair MB, Jayaprakash PG et al 1997. The basement membrane and tumor progression in the uterine cervix. General Diagnostic Pathology 142:297-303.
•Pujuguet P, Hammann A, Martin F, Martin M 1994. abnormal basement membrane in tumors induced by rat colon cancer cells. Gastroenterology 107:701-711.
•Raymond WA, Leong AS-Y 1991. Assessment of invasion in breast lesions using antibodies to basement membrane components and myoepithelial cells. Pathology 23:291-297.
•Suthipintawong C, Leong, AS-Y, Vinyuvat S 1995. A comparative study of immunomarkers for lymphangiomas and hemangiomas. Applied Immunohistochemistry 3: 239-244.
•Tavassoli FA, Bratthauer GL 1993. Immunohistochemical profile and differential diagnosis of microglandular adenosis. Modern Pathology 6:318-322.
•Yoshida K, Ta aska Y, Manabe T 1996. Expression of laminin in hepatocellular carcinoma: an adjunct for its histological diagnosis. Japanese Journal of Clinical Oncology 26:70-76.
Bibliografia
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
Becton Dickinson (4C12.8), Biogenesis (2D8-39, 2D8-30, 2D8-33), Biogenex (LAM1), Dako (polyclonal, 4C7), EY Labs (polyclonal), Eurodiagnostics (polyclonal), Immunotech (4C12) and Monosan (polyclonal).
Fixation/Preparation
Most available antibodies are immunoreactive in cryostat sections and fixed, embedded tissues but require antigen retrieval in the form of HIER or proteolytic digestion or both.
Background
Laminin, a glycoprotein of about 900 kD, is secreted by fibroblasts, epithelial, myoepithelial, endothelial and smooth muscle cells and, together with type IV collagen, forms the principal component of basal lamina. There are three genetically distinct chains of laminin,a-, b-, and g-chains, which are held together by disulfide bonds and by a triple-stranded coiled structure. Ultrastructurally, the basal lamina is composed of a lamina lucida of low electron density, adjacent to the parenchymal cells, and a basal lamina densa of high electron density, adjacent to the connective tissue matrix. By rotary shadowing, laminin has a cruciform shape, consisting of three short arms of 200 kD and one long arm of 400 kD. Laminin is exclusively localized to the basal lamina, predominantly to the lamina lucida, and is invariably present in basal lamina surrounding muscle, nerve, fat and decidua cells and separating epithelial and endothelial cells from adjacent connective tissues. Laminins are potent modulators of numerous biological processes in development, including cell proliferation, migration and differentiation. In adult tissues, laminins influence the maintenance of specific gene expression and are involved in various pathological situations, including fibrosis, carcinogenesis and metastasis. Clone 4D7 reacts with the terminal globular domain of the A-chain of laminin, whereas polyclonal antibodies were generated to laminin isolated from rat yolk sac tumor cell line.
Applications
Laminin has been shown to play a role in cell adhesion and attachment to the basal lamina, bothin vivo and in vitro. The basal lamina is generally extremely stable but in certain pathological states may undergo local dissolution. This process is likely to play a crucial role in the invasiveness and progression of malignant tumors (Liotta, 1984). Loss or defective organization of the basal lamina matrix in malignant neoplasms may be the result of increased breakdown by tumor-derived degradative enzymes, decreased synthesis or decreased or abnormal assembly of the secreted basal lamina components (Pujuguet et al, 1994). In human breast carcinoma, there is suggestion that overexpression of the nm23-H1 gene, a putative metastasis suppressor gene, leads to the formation of basal lamina and growth arrest (Howlett et al, 1994). Antisera to type IV collagen and laminin, the major components of basal lamina allow the study of the organization of the basal lamina in various benign and malignant tumors (Autio-Harmainen et al, 1988; Havenith et al, 1989, Nair et al, 1997, Kuwano et al, 1997). Laminin immunostaining with the immunogold-silver technique in resin-embedded sections allows exquisite demonstration of the basal lamina in a variety of tissues (Leong, 1993). The majority of invasive carcinomas are recognized to synthesize varying amounts of basal lamina material, but the basal lamina surrounding the tumor nests are generally fragmented and, in many cases, completely absent. Benign and in situ lesions appear to be circumscribed by intact basal lamina.
Diagnostic applications of collagen type IV immunostaining have mostly centered around the demonstration of basal lamina in invasive tumors, particularly epithelial tumors, and their changes with tumor invasion and metastasis. In particular, the demonstration of an intact basal lamina has been used to distinguish benign glandular proliferations such as microglandular adenosis and sclerosing adenosis from well-differentiated carcinoma like tubular carcinoma of the breast (Raymond & Leong, 1991; Tavassoli & Bratthauer, 1993). Distinctive patterns of basal distribution were recently demonstrated in various types of soft tissue tumors, adding to the diagnostic armamentarium for this group of neoplasms which are often difficult to separate histologically and with existing immunological markers (Leong et al, 1997). While the presence of basal lamina cannot be used as an absolute discriminant for blood vessels and lymphatic spaces, the latter do not display the reduplication of the basal lamina characteristic of blood vessels and generally show thin and discontinuous staining of basal lamina (Suthipintawong et al, 1995). The distinctive staining observed around blood vessels has been employed as a marker when performing capillary density measurements (Madsen & Holmskov, 1995).
A recent study suggests that the presence of basal lamina as demonstrated with laminin immunostaining may be a clue to the identification of hepatocellular carcinoma as non-malignant hepatocytes lack basal lamina (Yoshida et al, 1996).
Comments
The use of proteolytic digestion following HIER further enhances immunoreactivity. With the polyclonal antibodies we employ protease at 0.25 mg/ml for 2 min (Leong et al 1996).
References
•Autio-Harmainen H, Karttunen T, Apaja-Sarkkinen M et al 1988. Laminin and type IV collagen in different histological stages of Kaposi's sarcoma and other vascular lesions of blood vessels or lymphatic vessel origin. American Journal of Surgical Pathology 12: 469-476.
•Tavenith MG, Van Zandvoort EHM, Cleutjens JPM, Bosman FT 1989. Basement membrane deposition in benign and malignant naevomelanocytic lesions: an immunohistochemical study with antibodies to type IV collagen and laminin. Histopathology 15: 137-146.
•Howlett AR, Petersen OW, Steeg PS, Bissell MJ 1994. A novel function for the nm23-H1 gene: overexpression in human breast carcinoma leads to the formation of basement membrane and growth arrest. Journal of the National Cancer Institutes 86: 1838-1844.
•Kuwano H, Sonoda K, Yasuda M et al 1997. Tumor invasion and angiogenesis in early esophageal squamous cell carcinoma. Journal of Surgical Oncology 65:188-193.
•Leong AS-Y 1993. Immunohistochemistry theoretical and practical aspects. In: Leong AS-Y (ed) Applied immunohistochemistry for surgical pathologists. London: Edward Arnold, pp 1-22.
•Leong AS-Y, Milios J, Leong FJ 1996. Epitope retrieval with microwaves. A comparison of citrate buffer and EDTA with three commercial retrieval solutions. Applied Immunohistochemistry 4: 201-207.
•Leong AS-Y, Vinyuvat S, Suthipintawong C, Leong FJ 1997. Patterns of basal lamina immunostaining in soft-tissue and bony tumors. Applied Immunohistochemistry 5:1-7.
•Liotta LA 1984 Tumor invasion and metastases: role of the basement membrane. Warner-Lambert Parke-Davis Award Lecture. American Journal of Pathology 117:339-348.
•Madsen K, Holmskov U 1995. Capillary density measurements in skeletal muscle using immunohistochemical staining with anti-collagen type IV antibodies. European Journal of Applied Physiology 71: 472-474. immunohistochemical staining with anti-collagen type IV antibodies. European Journal of Applied Physiology 71: 472-474.
•Nair SA, Nair MB, Jayaprakash PG et al 1997. The basement membrane and tumor progression in the uterine cervix. General Diagnostic Pathology 142:297-303.
•Pujuguet P, Hammann A, Martin F, Martin M 1994. abnormal basement membrane in tumors induced by rat colon cancer cells. Gastroenterology 107:701-711.
•Raymond WA, Leong AS-Y 1991. Assessment of invasion in breast lesions using antibodies to basement membrane components and myoepithelial cells. Pathology 23:291-297.
•Suthipintawong C, Leong, AS-Y, Vinyuvat S 1995. A comparative study of immunomarkers for lymphangiomas and hemangiomas. Applied Immunohistochemistry 3: 239-244.
•Tavassoli FA, Bratthauer GL 1993. Immunohistochemical profile and differential diagnosis of microglandular adenosis. Modern Pathology 6:318-322.
•Yoshida K, Ta aska Y, Manabe T 1996. Expression of laminin in hepatocellular carcinoma: an adjunct for its histological diagnosis. Japanese Journal of Clinical Oncology 26:70-76.
Bibliografia
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
