No abstract

Development of allograft rejection continues to be the major determinant of morbidity and mortality post-lung transplantation. We have recently demonstrated that a population of donor-derived mesenchymal stem cells are present in human lung allografts and can be isolated and expanded ex vivo. In this study, we investigated the impact of lung resident mesenchymal stem cells (LR-MSCs), derived from allografts of human lung transplant recipients, on T cell activation in vitro. Similar to bone marrow derived MSCs, LR-MSCs did not express MHC II nor the co-stimulatory molecules CD80 or CD86. In vitro, LR-MSCs profoundly suppressed the proliferative capacity of T cells in response to a mitogenic or an allogeneic stimulus. The immunosuppressive function of LR-MSCs was also noted in absence of direct cell contact, indicating that LR-MSCs mediated their effect predominantly via a soluble mediator. LR-MSCs isolated from lung transplant recipients demonstrated PGE2 secretion at baseline (385 ± 375 pg/ml) which increased in response to IL-1β (1149 ± 1081 pg/ml). Addition of prostaglandin synthesis inhibitors (indomethacin and NS-398) substantially abrogated LR-MSC-mediated immunosuppression, indicating that PGE2 may be one of the major soluble mediators impacting T cell activity. This is the first report to demonstrate that human tissue-derived MSCs isolated from an allogeneic environment, have the potential to mediate immunological responses in vitro.

Lipiodol marking is a useful, safe, and inexpensive procedure for localizing ground-glass opacity lesions, small pulmonary nodules, or both for thoracoscopic resection.

A disintegrin and metalloproteinases (ADAMs) are involved in various biological events including cell adhesion, cell fusion, membrane protein shedding, and proteolysis. In the present study, our reverse transcription-PCR analysis showed that among the 12 different ADAM species with a putative metalloproteinase motif, prototype membrane-anchored ADAM28m and secreted-type ADAM28s are selectively expressed in human breast carcinoma tissues. By real-time quantitative PCR, their expression levels were significantly higher in carcinomas than in nonneoplastic breast tissues. In situ hybridization, immunohistochemistry, and immunoblotting analyses indicated that ADAM28 is predominantly expressed in an active form by carcinoma cells within carcinoma tissues. A direct correlation was observed between mRNA expression levels and proliferative activity of the carcinoma cells. Treatment of ADAM28-expressing breast carcinoma cells (MDA-MB231) with insulin-like growth factor-I (IGF-I) increased cell proliferation, cleavage of IGF binding protein (IGFBP)-3, as well as IGF-I cell signaling; these processes were all significantly inhibited by treatment with ADAM inhibitor or anti-ADAM28 antibody. Down-regulation of ADAM28 expression in MDA-MB231 cells with small interfering RNA significantly reduced cell proliferation, IGFBP-3 cleavage, and growth of xenografts in mice. In addition, cleavage of IGFBP-3 in breast carcinoma tissues was correlated with ADAM28 expression levels and inhibited by treatment with ADAM inhibitor or anti-ADAM28 antibody. These results show that ADAM28 is overexpressed in an activated form in human breast carcinoma cells and suggest that ADAM28 is involved in cell proliferation through enhanced bioavailability of IGF-I released from the IGF-I/ IGFBP-3 complex by selective IGFBP-3 cleavage in human breast carcinomas.

Cancer-associated fibroblasts (CAFs) drive tumour progression, but the emergence of this cell state is poorly understood. A broad spectrum of metalloproteinases, controlled by the Timp gene family, influence the tumour microenvironment in human cancers. Here, we generate quadruple TIMP knockout (TIMPless) fibroblasts to unleash metalloproteinase activity within the tumour-stromal compartment and show that complete Timp loss is sufficient for the acquisition of hallmark CAF functions. Exosomes produced by TIMPless fibroblasts induce cancer cell motility and cancer stem cell markers. The proteome of these exosomes is enriched in extracellular matrix proteins and the metalloproteinase ADAM10. Exosomal ADAM10 increases aldehyde dehydrogenase expression in breast cancer cells through Notch receptor activation and enhances motility through the GTPase RhoA. Moreover, ADAM10 knockdown in TIMPless fibroblasts abrogates their CAF function. Importantly, human CAFs secrete ADAM10-rich exosomes that promote cell motility and activate RhoA and Notch signalling in cancer cells. Thus, Timps suppress cancer stroma where activated-fibroblast-secreted exosomes impact tumour progression.

ADAMs (a disintegrin and metalloproteinases) are multifunctional molecules involved in cell-cell fusion, cell adhesion, membrane protein shedding, and proteolysis. In the present study, we examined the mRNA expression of 13 different ADAM species with putative metalloproteinase activity in human astrocytic tumors, nonneoplastic brain tissues, and other intracranial tumors by reverse transcriptase-polymerase chain reaction, and found that prototype membrane-anchored ADAM12 (ADAM12m) is predominantly expressed in glioblastomas. Real-time quantitative polymerase chain reaction indicated that the expression level of ADAM12m is remarkably at least 5.7-fold higher in glioblastomas (n ‫؍‬ 16) than in nonneoplastic brain tissues (n ‫؍‬ 6), low grade (n ‫؍‬ 7) and anaplastic astrocytic tumors (n ‫؍‬ 9) (P < 0.05 for each group), and intracranial neurinomas (n ‫؍‬ 5) (P < 0.01). In situ hybridization showed that glioblastoma cells are responsible for the gene expression. ADAMs (a disintegrin and metalloproteinases) are a gene family of multidomain membrane-anchored proteins comprising of more than 30 members in various animal species (see http://www.people.virginia.edu/ϳjw7g/Tableof theADAMs.html) and are implicated in pathophysiological conditions, which include neuronal development, 1 cancer development and progression, 2,3 and inflammatory responses 4 through proteolysis, cell adhesion, cell fusion, and cell-matrix interaction. 5,6 They contain several distinct domains with structural homology to the reprolysin/adamalysin family of snake venom metalloproteinases.7 A typical ADAM protein includes an N-terminal signal peptide, and propeptide, metalloproteinase, disintegrin, cysteine-rich, epidermal growth factor-like, transmembrane, and cytoplasmic domains. The metalloproteinase domains of several ADAMs have a catalytic site with the conventional zinc-dependent metalloproteinase sequence (HEXGHXXGXXHD), which is highly homologous to that of the matrix metalloproteinases (MMPs).

No abstract

ADAM (a disintegrin and metalloproteinases) are a recently discovered gene family of proteins with sequence similarity to the reprolysin family of snake venom metalloproteinases, and about one-third of the family members have the catalytic site consensus sequence in their metalloproteinase domains. We screened the mRNA expression of 11 different ADAM species with putative metalloproteinase activity in human non-small cell lung carcinomas by RT-PCR, and found that prototype membrane-anchored ADAM28 (ADAM28m) and secreted ADAM28 (ADAM28s) are predominantly expressed in the carcinoma tissues. Real-time quantitative PCR demonstrated that the expression levels of ADAM28m and ADAM28s are significantly 16.8-fold and 9.0-fold higher in the carcinomas than in the non-carcinoma tissues, respectively. In addition, the expression levels of ADAM28m and ADAM28s were significantly higher in the carcinomas with >30 mm in diameter than in those 530 mm. The expression levels were also significantly higher in the carcinomas with lymph node metastasis than in those without metastasis. MIB1-positive cell index of the carcinomas had a direct correlation with the expression levels of ADAM28m and ADAM28s (r 5 0.667, p < 0.001 and r 5 0.535, p < 0.01, respectively). In situ hybridization and immunohistochemistry demonstrated that ADAM28 is expressed predominantly in the carcinoma cells. Immunoblot analysis showed the activated form of ADAM28 in the carcinoma tissues. These data demonstrate for the first time that ADAM28 is overexpressed and activated in human non-small cell lung carcinomas, and suggest the possibility that ADAM28 plays a role in cell proliferation and progression of the human lung carcinomas. ' 2005 Wiley-Liss, Inc.Key words: ADAM; MMP; lung cancer; proliferation; metastasis ADAM (a disintegrin and metalloproteinases) are a gene family that have significant sequence similarity to the reprolysin/adamalysin family of snake venom metalloproteinases.1 ADAM are composed of several domains including propeptide, metalloproteinase, disintegrin, cysteine-rich, epidermal growth factor (EGF)-like, transmembrane and cytoplasmic tail domains. More than 30 members of the ADAM gene family have been identified in a variety of animal species (see http://www.people.virginia.edu/ jw7g/ Table_of_the_ADAMs.html). Although the specific biological functions of ADAM are not clear, they may be involved in shedding of various membrane-anchored receptors and proteins, degradation of extracellular matrix (ECM), and cell adhesion and migration.2,3 About one-third of the ADAM members have the catalytic consensus sequence (HEXGHXXGXXHD) in their metalloproteinase domains, and are predicted to have catalytic activity. ADAM10 is reported to digest myelin basic protein 4 and type IV collagen.5 ADAM9 degrades insulin B chain, 6 and ADAM28 cleaves myelin basic protein 7 and insulin-like growth factor binding protein-3 (IGFBP-3). 8 In addition, the precursor of tumor necrosis factor-a (proTNF-a) is processed to the mature form by ADAM10 and ADAM17. 9 CD23 ...