Enhancement of tumorigenicity of human breast adenocarcinoma cells in nude mice by matrigel and fibroblasts.

The failure of MCF7 cells to induce the formation of tumours after sub-cutaneous inoculation into athymic nude mice can be obviated by the simultaneous injection of an extract of basement membrane proteins (matrigel). Tumour growth is promoted and the latency period is low (2 to 4 weeks). In the absence of matrigel, the simultaneous inoculation of fibroblasts and MCF7 cells also resulted in the development of tumours, but with a longer latency period (about 2 months). The tumorigenic synergy between matrigel and fibroblasts was evidenced by co-inoculating MCF7 cells MDA-MB 231 cells with fibroblasts and matrigel. This co-inoculation decreased the delay of appearance of the tumours and/or accelerated the tumour growth, depending upon the number of fibroblasts injected. Repeated injections of fibroblasts conditioned medium, at the site of inoculum of tumour cells also enhanced tumour growth, suggesting the involvement of soluble factors secreted by fibroblasts. Histologically, tumours induced by co-inoculation of tumour cells and fibroblasts contained more stromal structures including vimentin-positive cells, fibronectin and interstitial collagens. These data suggest that human tumours may be reconstituted and grown in athymic nude mice using basement membrane components and fibroblasts as inductors

A Newly Identified 105-kD Lower Lamina Lucida Autoantigen Is an Acidic Protein Distinct from the 105-kD γ2 Chain of Laminin-5

A 105-kD lower lamina lucida antigen (p105) has been detected by autoantibodies (anti-p105) from patients with a novel immunobullous disease. To distinguish p105 from other known lamina lucida components, we performed comparative irnmunoblotting on purified human amniotic laminin-5 (kalinin), 804G matrix (enriched in laminin-5), and keratinocyte and fibroblast proteins using anti-804G matrix antibody 0-18) and anti-p105. J-18 labeled the truncated laminin-5 γ2 chain in amniotic laminin-5, 804G matrix, and keratinocyte conditioned medium, but did not label fibroblast cytosol. Conversely, anti-p105 did not label amniotic laminin-5 or 804G matrix, but did label p105 in both keratinocyte conditioned medium and fibroblast cytosol. J-18 labeled the 105-kD laminin-5 γ2 chain in reduced keratinocyte proteins and a 400-kD laminin-5 complex under non-reducing conditions. In contrast, anti-p105 labeled p105 under both reducing and non-reducing conditions but did not label a 400-kD protein complex. Similarly, comparative immunoblotting on keratinocyte proteins using anti-p105 and anti-laminin-1 revealed no commonly labeled protein bands. Electrophoretic fractionations by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting of these fractions revealed that the peak fractions of keratinocyte proteins reactive with anti-p105 are different from those reactive with J-18. Furthermore, keratinocyte proteins fractionated by Mono Q anionexchange chromatography revealed fractions immunoreactive with anti-p105, whereas J-18 showed no reactivity with these fractions. Two-dimensional gel electrophoresis and immunoblotting with anti-p105 revealed p105 to be an acidic protein with isoelectric points between 5.7 and 6.3, distinct from the isoelectric points of laminin-5 γ2 chain. We conclude that p105 is an acidic protein located in the lamina lucida and distinct from the truncated laminin-5 γ2 chain and the laminin-1 family

TIMP-2 and PAI-1 mRNA levels are lower in aneurysmal as compared to athero-occlusive abdominal aortas.

peer reviewedOBJECTIVE: Significant alterations of the vascular wall occurs in abdominal aortic aneurysm (AAA) and atherosclerotic occlusive disease (AOD) that ultimately may lead to either vascular rupture or obstruction. These modifications have been ascribed to one or a group of proteases, their inhibitors or to the matrix macromolecules involved in the repair process without considering the extent of the observed variations. METHODS: The mRNA steady-state level of a large spectrum of proteolytic enzymes (matrix metalloproteinases: MMP-1, -2, -3, -8, -9, -11, -12, -13, -14; urokinase plasminogen activator: u-PA), their physiological inhibitors (tissue inhibitors of MMPs: TIMP-1, -2, -3; plasminogen activator inhibitor: PAI-1) and that of structural matrix proteins (collagens type I and III, decorin, elastin, fibrillins 1 and 2) was determined by RT-PCR made quantitative by using a synthetic RNA as internal standard in each reaction mixture. The profile of expression was evaluated in AAA (n=7) and AOD (n=5) and compared to non-diseased abdominal (CAA, n=7) and thoracic aorta (CTA, n=5). RESULTS: The MMPs -8, -9, -12 and -13 mostly associated with inflammatory cells were not or barely detected in CAA and CTA while they were largely and similarly expressed in AAA and AOD. Expression of protease inhibitors or structural proteins were only slightly increased in both pathological conditions with the exception of elastin which was reduced. The main significant difference between AAA and AOD was a lower expression of TIMP-2 and PAI-1 in the aneurysmal lesions. CONCLUSIONS: The remodeling of the aortic wall in AAA and AOD involves gene activation of a large and similar spectrum of proteolytic enzymes while the expression of two physiological inhibitors, TIMP-2 and PAI-1, is significantly lower in AAA compared to AOD. The repair process in the aneurysmal disease seems similar to that of the occlusive disease

Thinking about politics

There are distinctive modes of thinking about politics, three of which are discussed here. A mode consists of a characteristic domain of relevance, filing system, and grammar of beliefs. A person relying on Mode A treats politics as an extension of interpersonal experience. A person relying on Mode B organizes political thinking around a set of salient group identifications. A person relying on Mode C views public objects in terms of their consequences for collective goods. The three modes are illustrated by applying them to concrete issues in a hypothetical manner: Vietnam, bussing, and attitudes toward presidential candidates. The concept of surrogate attitudes is developed and various implications of the theoretical argument are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45481/1/11109_2004_Article_BF00988519.pd

The Classic: Bone Morphogenetic Protein

This Classic Article is a reprint of the original work by Marshall R. Urist and Basil S. Strates, Bone Morphogenetic Protein. An accompanying biographical sketch of Marshall R. Urist, MD is available at DOI 10.1007/s11999-009-1067-4; a second Classic Article is available at DOI 10.1007/s11999-009-1069-2; and a third Classic Article is available at DOI 10.1007/s11999-009-1070-9. The Classic Article is © 1971 by Sage Publications Inc. Journals and is reprinted with permission from Urist MR, Strates BS. Bone morphogenetic protein. J Dent Res. 1971;50:1392–1406

Ossification of the femur in thyroxine-treated tadpoles of Rana pipiens

Tadpoles of Rana pipiens at Taylor-Kollros stage IX were treated by immersion in a thyroxine solution at a concentration of 6.25 x 10-8 M. Hindlimbs developed precociously, and alizarin-stained specimens showed that treatment with thyroxine induced accelerated ossification of limb bones.Light microscopy of thick Epon sections showed that cartilage and perichondrium were beginning to organize in the femur of normal animals at stage IX and had become separated by a narrow zone of osteoid matrix by stage XI. After 4 days of exposure to thyroxine, inner perichondrial cells had enlarged to become osteoblasts bordering a prominent zone of osteoid matrix. By 9 days of treatment some inner osteoblasts were entirely surrounded by bone matrix and thus had become osteocytes.Electron microscopy revealed that rough endoplasmic reticulum began to accumulate in osteoblasts by the second day of treatment. Fusion of collagen fibrils was observed in the osteoid matrix of a specimen treated for 5 days. Deposition of hydroxyapatite crystals along collagen protofibrils in scattered mineralization sites began after 6 days of treatment. Mineralized sites grew and became confluent, so that by 9 days the lower two-thirds of the bone matrix was almost completely mineralized. Enlarged mineralization sites at 9 days usually were organized with collagen protofibrils in the interior and hydroxyapatite crystals clustered around the periphery of the mineralizing mass.Thyroxine appears to stimulate differentiation of osteoblasts from perichondrial cells. The hormone may stimulate osteoblasts to secrete depolymerases which prepare osteoid matrix for mineralization along collagen fibrils.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32873/1/0000251.pd