No abstract

Herein we describe that in classic Hodgkin lymphomas (cHL, n ‫؍‬ 25) the lymph node (LN) stroma displayed in situ high levels of transcription and expression of the disulfide-isomerase ERp5 and of the disintegrin-metalloproteinase ADAM10, able to shed the ligands for NKG2D (NKG2D-L) from the cell membrane. These enzymes were detected both in LN mesenchymal stromal cells ( IntroductionIt is now accepted that the so-called stress surveillance contributes to the anti-neoplastic immunity, both in solid tumors and hematologic malignancies, through the activation of the NKG2D receptor that recognizes NKG2D ligands (NKG2D-L) on cancer cells, including the MHC class-I related chain-A and -B (MIC-A/B) and the UL16-binding proteins 1-4 (ULBPs). [1][2][3][4][5] These ligands are commonly expressed at very low levels or retained in the cytoplasm, in healthy tissues, but their transcription and surface expression are enhanced on viral infection or tumor transformation. [5][6][7][8][9] Besides natural killer cells and CD8 ϩ T lymphocytes, ␥␦ T cells can recognize these molecules and activate an antitumor response in different cancers. [10][11][12][13][14][15][16][17] In this regard, we have described that ␥␦ T lymphocytes belonging to the V␦1 subset are expanded in patients with chronic lymphocytic leukemia (CLL) and nonHodgkin lymphomas (NHLs), where they proliferate in response to tumor cells, provided they express NKG2D-L, exert cytotoxicity, and produce anti-neoplastic or pro-differentiating cytokines, such as TNF-␣ and IL-4. 15,16 However, NKG2D-L can be shed by tumor cells and, in their soluble form, interact with NKG2D expressed by effector lymphocytes and hinder the recognition of tumor cells. 18,19 Proteolytic cleavage of MIC-A has been shown to depend on the thiol isomerase ERp5 and the disintegrins and metalloproteinases ADAM10 and ADAM17, which are also able to cleave ULBPs. 19,22 Overexpression of these enzymes has been reported in multiple myeloma and other tumors. [19][20][21][22][23] In turn, soluble (s) NKG2D-L and cytokines produced at the tumor site can down-regulate the expression of the NKG2D receptor on effector lymphocytes, contributing to tumor escape from immunosurveillance. [22][23][24][25] Indeed, the TGF-␤ has been shown to reduce the surface density of the NKG2D receptor on CD8 ϩ T and NK cells, impairing their antitumor reactivity in cancer patients. [24][25][26] Moreover, we and others reported that plasma levels of sNKG2D-L correlate with disease progression in multiple myeloma, CLL, NHL, and acute myeloid leukemias; in particular, among sNKG2D-L, both sMIC-A and sULBP2 have been shown as a prognostic marker for multiple myeloma and for the identification of early-stage CLL patients with risk of disease progression. [14][15][16]21,27,28 In this paper, we studied 25 classic HL (cHL) and found that the tumor microenvironment is prone to inhibit the development of an antitumor response. This is mainly because of the release of soluble MIC-A and ULBP3 by lymph node mesenchymal stromal cells (LN MS...

Longitudinal bone growth is determined by the process of endochondral ossification in the cartilaginous growth plate, which is located at both ends of vertebrae and long bones and involves many systemic hormones and local regulators. We report the molecular characterization of a de novo balanced t(2;7)(q37.1;q21.3) translocation in a young female with Marfanoid habitus and skeletal anomalies. The translocation was characterized by fluorescence in situ hybridization (FISH), checked for other abnormalities by array-comparative genomic hybridization (CGH), and finally, the breakpoints were cloned, sequenced, and compared. Biochemical dosage was applied to study the possible mechanisms that may cause the proposita's phenotype. The breakpoint on chromosome 2 disrupts the hypothetical gene MGC42174 (HUGO-approved symbol DIS3L2) and is located in the proximity of the NPPC gene coding for C-type natriuretic peptide (CNP), a molecule that regulates endochondral bone growth. CNP plasma concentration was doubled in the proband compared to five normal controls, while NPPC was substantially overexpressed in her fibroblasts. A transgenic mouse generated to target NPPC overexpression in bone showed a phenotype highly reminiscent of the patient's phenotype. The breakpoint on chromosome 7 is localized proximally at about 75 kb from the COL1A2 gene. The COL1A2 allele on the derivative chromosome was strongly underexpressed in fibroblasts, but total collagen was not significantly different from controls. Several evidences support the conclusion that the proband's abnormal phenotype is associated with C-type natriuretic peptide overexpression.

The role of Hedgehogs (Hh) in murine skeletal development was studied by overexpressing human Sonic Hedgehog (SHH) in chondrocytes of transgenic mice using the collagen II promoter/enhancer. Overexpression caused a lethal craniorachischisis with major alterations in long bones because of defects in chondrocyte differentiation.Introduction: Hedgehogs (Hhs) are a family of secreted polypeptides that play important roles in vertebrate development, controlling many critical steps of cell differentiation and patterning. Skeletal development is affected in many different ways by Hhs. Genetic defects and anomalies of Hhs signaling pathways cause severe abnormalities in the appendicular, axial, and cranial skeleton in man and other vertebrates. Materials and Methods: Genetic manipulation of mouse embryos was used to study in vivo the function of SHH in skeletal development. By DNA microinjection into pronuclei of fertilized oocytes, we have generated transgenic mice that express SHH specifically in chondrocytes using the cartilage-specific collagen II promoter/enhancer. Transgenic skeletal development was studied at different embryonic stages by histology. The expression pattern of specific chondrocyte molecules was studied by immunohistochemistry and in situ hybridization. Results: Transgenic mice died at birth with severe craniorachischisis and other skeletal defects in ribs, sternum, and long bones. Detailed analysis of long bones showed that chondrocyte differentiation was blocked at prehypertrophic stages, hindering endochondral ossification and trabecular bone formation, with specific defects in different limb segments. The growth plate was highly disorganized in the tibia and was completely absent in the femur and humerus, leading to skeletal elements entirely made of cartilage surrounded by a thin layer of bone. In this cartilage, chondrocytes maintained a columnar organization that was perpendicular to the bone longitudinal axis and directed toward its outer surface. The expression of SHH receptor, Patched-1 (Ptc1), was greatly increased in all cartilage, as well as the expression of parathyroid hormone-related protein (PTHrP) at the articular surface; while the expression of Indian Hedgehog (Ihh), another member of Hh family that controls the rate of chondrocyte maturation, was greatly reduced and restricted to the displaced chondrocyte columns. Transgenic mice also revealed the ability of SHH to upregulate the expression of Sox9, a major transcription factor implicated in chondrocyte-specific gene expression, in vivo and in vitro, acting through the proximal 6.8-kb-long Sox9 promoter. Conclusion: Transgenic mice show that continuous expression of SHH in chondrocytes interferes with cell differentiation and growth plate organization and induces high levels and diffuse expression of Sox9 in cartilaginous bones.