Expression in childhood primary brain tumors of NY-ESO-1, a cancer/testis antigen: an immunohistochemical study.

Background: NY-ESO-1 is a human gene that codes for antigens that are expressed in malignancies of various histological types, but not in normal tissues, except the testes. The expression of NY-ESO-1 in intracranial brain tumors including astrocytomas (ASTRs) and medulloblastomas (MEDs)/primitive neuroectodermal tumors (PNETs) was examined since the expression of NY-ESO-1 has only previously been explored in depth in neuroblastomas.

Materials And Methods: During our immunohistochemical study, a sensitive, four-step, alkaline phosphatase-conjugated antigen detection technique was employed.

Thymic reticulo-epithelial cells: key cells of neuroendocrine regulation.

The reticulo-epithelial (RE) cellular network of the thymic stromal cellular microenvironment plays a vital role in neuroendocrine regulation and lymphoid cell homing and development. Transmission electronmicroscopic observations have confirmed that there are four functional subtypes of medullar RE cells: undifferentiated; squamous; villous; and cystic. Immunocytochemical observations have shown that the secreted thymic hormones, thymosin alpha1 and thymopoietin (and its short form, thymopentin or TP5), are both produced by RE cells.

Cyclooxygenase-2 (COX-2) overexpression in childhood brain tumors.

The overexpression of COX enzymes has been demonstrated in human neoplasms at various sites, including the colon, gastrointestinal tract, lung, skin and recently in brain tumors. In this study, COX-2 receptor overexpression in primary childhood brain tumors was determined and the distribution pattern of COX-2 receptors was examined. A sensitive, 4-step, alkaline phosphatase conjugated antigen detection technique was used and a specific monoclonal antibody for medulloblastomas/ primitive neuroectodermal tumors (MEDs/PNETs), anaplastic, high-grade astrocytomas (ASTRs) and in glioblastoma multiformes (GMs) was employed.

Up-regulation of VEGF expression and related neo-angiogenesis in childhood high-grade gliomas: implications for anti-angiogenic anti-neoplastic therapy.

Vascular endothelial growth factor (VEGF) is a homodimeric, disulfide-linked glycoprotein which exhibits endothelial cell-specific mitogenic properties. VEGF is also a potent inducer of vascular permeability. There is considerable experimental evidence that VEGF isoforms are strongly involved in provoking neoangiogenesis of neoplastic cells and, consequently, the growth and progression of primary neoplasms (i.

Mechanisms and markers of carcinogenesis and neoplastic progression.

Neoplastic transformation evolves over a period of time involving the progression of the cellular immunophenotype (IP) from normal to hyperplastic to dysplastic, and finally, to fully malignant IPs. Superimposed on these changes is the interaction of the initiated cell with its microenvironment, whereby the neoplastically transformed cells, through the regulation or dysregulation of cytoskeletal, integrin, protease and adhesion molecules, develop a novel manner of relation with their surrounding microenvironment. Studies of the neuroendocrine-immune network revealed that the hormonal and cytokine milieu plays an important role impacting the growth and dedifferentiation capabilities of neoplastic cells.

Epidermal growth factor receptor (EGFR) expression in childhood brain tumors.

Overactivation of epidermal growth factor receptor (EGFR) signaling has been recognized as an important step in the pathogenesis and progression of multiple forms of cancer of epithelial origin. Reports regarding EGFR family members in brain tumors are sparse and, thus, the significance of EGFR expression in childhood brain tumors is unclear. In this study, the expression of the EGFR family members was analyzed in 22 medulloblastomas.

Immunocytochemical detection of members of the caspase cascade of apoptosis in childhood medulloblastomas.

During the process of programmed cell death (PCD), the cell disintegrates into small, membrane-bound apoptotic bodies. Caspase-3 is ubiquitously expressed in normal and neoplastically-transformed human cells and serves as an executioner in the apoptotic or PCD pathway. During our immunocytochemical study, a sensitive, four-step, alkaline phosphatase-conjugated antigen detection technique was employed.

Survivin expression in childhood medulloblastomas: a possible diagnostic and prognostic marker.

Survivin is a member of the inhibitor of apoptosis gene family that is expressed in embryonic tissues during human ontogenesis and most human malignancies, but it is not present in the majority of normal adult tissues. Survivin is also a chromosomal passenger protein required for physiological cell divison. Survivin blocks apoptosis, via its BIR domain, by either directly or indirectly blocking the function of the members of the caspase cascade.

Immunocytochemical detection of members of the caspase cascade of apoptosis in high-grade astrocytomas.

During the physiological process of PCD, the cell initiates a sequence of events culminating in the disintegration of the cell into small, membrane-bound apoptotic bodies. The intrinsic part of the PCD program arises from the mitochondria when it releases cytochrome c from the mitochondrial intermembrane space into the cytosol, forming the caspase-activating complex or apoptosome. The family of caspases is involved in the execution of genetically controlled PCD.

Flat and polypoid adenocarcinomas of the colorectum: A comparative histomorphologic analysis of 47 cases.

"Flat" colorectal adenomas and adenocarcinomas are well documented in the Japanese literature but only sporadically reported in the English literature. The present study involved systematic morphological analysis of a large series of colorectal carcinomas (CRCs) to determine the frequency of these "flat" CRCs (FCRCs) and analyze their pathological characteristics and associated patient survival. The study group comprised 47 patients (19 females and 28 males) with primary CRC who underwent colorectal resection at the H.

Antigen presentation by dendritic cells and their significance in antineoplastic immunotherapy.

Dendritic cells (DCs) are present in essentially every mammalian tissue, where they operate at the interface of innate and acquired immunity by recognizing pathogens and presenting pathogen-derived peptides to T lymphocytes. According to the research group of Shortman, experimental results suggest a "dual" DC differentiation model, demonstrating the existence of both myeloid-derived (with characteristic IF: CD11b+, CD11c+, CD8alpha- and DEC205+) and lymphoid-derived DCs (showing CD11b- CD11c-, CD8alpha+ and DEC205+ IF). DCs, including interdigitating cells (IDCs) and Langerhans cells (LCs), are characterized by dendritic morphology, high migratory mobility and are the most effective, "professional" cells for antigen presentation in primary immune responses.

MAGE-1, a cancer/testis-antigen, expression in childhood astrocytomas as an indicator of tumor progression.

During the last decade, the aberrant expression of normal testicular proteins in neoplastically transformed cells became common knowledge. Cancer/testis-antigens (CTAs) represent a novel family of immunogenic proteins. The MAGE genes were initially analyzed from melanomas and turned out to have an almost exclusively neoplasm-specific expression pattern.

Racial differences in childhood tumors.

The purpose of this brief review is to inform the reader of the appearance of childhood neoplasms along racial and ethnic lines. The Lag time, general aspects and specific tumors, such as astrocytomas, medulloblastomas and those of the skin, including cases affecting the face and mouth, are discussed. Other tumors discussed are melanomas, those of the nasopharynx, liver, bone, Hodgkin's disease and especially leukemias as primary forms.

Cancer-testis antigens: promising targets for antigen directed antineoplastic immunotherapy.

During the last decade, the aberrant expression of normal testicular proteins in neoplastically transformed cells became common knowledge. Cancer-testis antigens (CTAs) represent a novel family of immunogenic proteins. The genes MAGE, BAGE, GAGE, LAGE and NY-ESO-1 code for antigens that are recognised on various neoplastically transformed cells by autologous, cytolytic CD8 ( + ) T lymphocytes.

Spontaneous regression of neoplasms: new possibilities for immunotherapy.

In mammalian cells, neoplastic transformation is directly associated with the expression of oncogenes, loss or simple inactivation of the function of tumour suppressor genes and the production of certain growth factors. Genes for suppression of the development of the neoplastic cellular immunophenotype, as well as inhibitory growth factors, have regulatory functions within the normal processes of cell division and differentiation. Telomerase (a ribonucleoprotein polymerase) activation is frequently detected in various neoplasms.

Restoration of the thymic cellular microenvironment following autologous bone marrow transplantation.

Mammalian thymic histogenesis can be morphologically divided into three consecutive stages: 1) epithelial; 2) lymphopoietic or lympho-epithelial; and 3) differentiated cellular microenvironmental, with formation of Hassall's bodies (HBs). The marked reduction of the thymic cellular microenvironment (TCM) is a well-controlled physiological process and is presumably under both local and global regulation by the cells of the RE meshwork and by the neuroendocrine axis, respectively. In humans, the age-related decline of facteur thymique sérique (FTS) levels in blood begins after 20 years of age and FTS completely disappears between the 5th and 6th decade of life.

The significance of immunohistochemistry in the diagnosis and therapy of neoplasms.

This review article details the diagnostical significance of immunohistochemistry, which has developed during the last quarter of the century. Certainly, the advancement of monoclonal antibody technology has been of great significance in assuring the place of immunohistochemistry in the modern accurate microscopic diagnosis of human neoplasms, as a method of choice in histopathology. The fact still remains that in order to properly assess any immunohistochemical reactivity used for differential diagnostic purposes, the target cells have to be identified as neoplastically transformed cells by routine histopathological techniques.

Neuroendocrine influence on thymic haematopoiesis via the reticulo-epithelial cellular network.

The thymus provides an optimal cellular and humoral microenvironment for a cell line committed differentiation of haematopoietic stem cells. The immigration process requires the secretion of at least one peptide, called thymotaxin, by cells of the reticulo-epithelial (RE) network of the thymic stromal cellular microenvironment. The thymic RE cells are functionally specialised based on their intrathymic location and this differentiation is modulated by various interaction signals of differentiating Thymocytes and other nonlymphatic, haematopoietic stem cells.