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At least 793 records · Page 44Linked to original sources
PubMed1985

Commitment to differentiation of human promyelocytic leukemia cells (HL60): an all-or-none event preceded by reversible losses of self-renewal potential.

A method for clonal analysis has been developed which allows the characterization of the number and type of progeny cells produced by each single cell arising during clonal evolution. The method is based on a symmetry of self-renewal exhibited by sister cells of the human promyelocytic leukemia cell line -HL60-. This permits the use of one of the sister cells to measure the potential for self renewal of the other. Using a system of sequential daughter cell transfers in semisolid medium, we have analysed self-renewal and differentiation in individual clones exposed to all-trans retinoic acid or dimethylsulfoxide (DMSO). We find that in clones exposed to chemical inducers of differentiation commitment occurs as an all-or-none event which is preceded by coordinated but reversible losses of self-renewal potential. It is concluded that the differentiation pathway of HL60 cells has two distinct portions. These are, first, a predeterministic portion, reflected by coordinated but reversible losses of self-renewal potential, and second, a deterministic portion, reflected by irreversible phenotypic differentiation.

Cell Division↗
PubMed2003

Epithelial carcinogenesis: challenging monoclonality.

How carcinomas begin remains unclear, but experimental data do not entirely exclude the participation of more than one clone of neoplastic cells, even in relatively advanced epithelial tumour growth. Microdissection and new PCR clonality assays exploiting X-linked polymorphisms, some of which (including XIST) are expressed in RNA, create investigational opportunities complementary to other molecular analyses, but a reliable in situ assay of X-inactivation remains desirable. The necessity for stringent controls in clonality analysis is emphasized. While it may be possible to reconcile 'pluriclonal' (oligoclonal or polyclonal) carcinogenesis with widely accepted paradigms of genetic/epigenetic change and clonal selection in epithelial neoplasia, it deserves critical study as novel carcinogenic mechanisms would be implied.

Breast Neoplasms↗
PubMed2003

Composite Hodgkin lymphoma and mantle cell lymphoma: two clonally unrelated tumors.

Association of Hodgkin lymphoma and non-Hodgkin lymphoma is rare and, specifically, the combination of Hodgkin lymphoma and mantle cell lymphoma has not been previously described. Here we describe composite mantle cell lymphoma and Hodgkin lymphoma affecting the spleen in one case and the eyelid and cervical lymph nodes in a second. In both, nodules of classical Hodgkin lymphoma were intermixed with diffuse or nodular areas of typical mantle cell lymphoma. Immunohistochemical and molecular analyses confirmed cyclin D1 overexpression secondary to the translocation t(11;14) in the small mantle cell lymphoma component; with CD30, CD15, and EBV expression in the Hodgkin and Reed-Sternberg cells. Finally, clonal analysis of rearranged immunoglobulin genes performed on microdissected Hodgkin and Reed-Sternberg and mantle cell lymphoma cells provided definite evidence of separate clonal origins of the two tumors in the patients. These EBV-positive, clonally unrelated tumors seem to represent true composite neoplasms, in contrast to cases showing merely clonal progression.

Aged↗
PubMed1996

Allelic deletions on chromosome 11q13 in multiple tumors from individual MEN1 patients.

Familial multiple endocrine neoplasia type 1 is an autosomal dominant hereditary disorder characterized by multiple parathyroid, pancreatic, duodenal, and pituitary tumors. The parathyroid tumors may arise as diffuse areas of hyperplasia, whereas the pancreatic and duodenal tumors usually form as discrete nodules. Except for a single report, tumor loss of heterozygosity (LOH) mapping of the putative MEN1 suppressor gene on chromosome 11q13 in the past has been restricted by analysis of a single tumor from individual patients and somatic cellular contamination. For this reason, it has not been possible to analyze the clonality of the emerging MEN1 neoplasms. Furthermore, it has been previously unknown whether the LOH pattern varies between individual MEN1 tumors in a given patient or among tumors of different histological origins within unrelated patients. To address these previous limitations, the present study introduces a refinement in microdissection in which endothelial cells are stained and selectively excluded. Tissue microdissection was applied to study LOH patterns on chromosome 11q13 using 8 polymorphic DNA markers in 44 different MEN1 tumors from parathyroid, pancreas, and duodenum in nine unrelated patients. In addition, X-chromosome inactivation clonal analysis was applied to 16 individual microdissected regions from seven parathyroid glands in three female patients. The LOH rates of parathyroid lesions (100%) and endocrine tumors of the pancreas (83%) were strikingly different from the LOH rate of gastrinomas (21%), suggesting that the mechanism that drives LOH may be influenced by the tissue context. Moreover, combined LOH and X-chromosome inactivation scoring of the same microdissected region revealed that parathyroid MEN1 neoplasms can consist of more than one clone. In this study, the centromeric boundary of the putative MEN1 gene was PYGM. Analysis of differential LOH patterns in multiple microdissected tumors in the same patient constitutes a novel approach to suppressor gene mapping.

Adult↗
PubMed1975

The structure and properties of a compartment border: the intersegmental boundary in Oncopeltus.

García-Bellido et al. have described how groups of cells in developing Drosophila become subdivided into 'compartments'. Cells within any compartment have rigid prospective fates such that, while their progeny may give rise to variable regions within a compartment, they can never generate cells in any other compartment. Analysis of the position and shapes on clones allows definition of the compartment boundaries. I report studies on a compartment boundary (likewise demonstrated by clonal analysis) in the hemipteran insects Oncopeltus and Rhodnius. The advantage of this border is that it can easily be identified in the light and electron microscopes. There is an abrupt change of cell shape at the border, which has been analysed by means of serial electron microscope sections. The types of cell junctions at the border and elsewhere are compared and shown to have no qualitative differences. The border is an effective barrier to the growth of peripheral sensory axons, although not apparently to dendrites. The intersegmental boundary allows passage of information relating to cuticle deposition, wounding response, tracheolar movement and intercellular coupling. Making wounds across the border leads to greater effects on polarity of epidermal cells than making similar wounds elsewhere on the tergites.

Animals↗
PubMed2002

Cytomegalovirus seropositivity drives the CD8 T cell repertoire toward greater clonality in healthy elderly individuals.

The deterioration in immune function with aging is thought to make a major contribution to the increased morbidity and mortality from infectious disease in old age. One aspect of immune senescence is the reduction in CD8 T cell repertoire as due to the accumulation of oligoclonal, memory T cells and a reduction in the naive T cell pool. CD8 T cell clonal expansions accumulate with age, but their antigenic specificity remains unknown. In this study, we show that in elderly individuals seropositivity for human CMV leads to the development of oligoclonal populations of CMV-specific CTL that can constitute up to one-quarter of the total CD8 T cell population. Furthermore, CMV-specific CTL have a highly polarized membrane phenotype that is typical of effector memory cells (CD28(-), CD57(+), CCR7(-)). TCR analyses show that CMV-specific CTL have highly restricted clonality with greater restriction in the larger expansions. Clonal analysis of the total CD8 T cell repertoire was compared between CMV-seropositive and CMV-seronegative donors. Thirty-three percent more clonal expansions were observed in CMV-seropositive donors in comparison with seronegative individuals. These data implicate CMV as a major factor in driving oligoclonal expansions in old age. Such a dramatic accumulation of virus-specific effector CTL might impair the ability to respond to heterologous infection and may underlie the negative influence of CMV seropositivity on survival in the very elderly.

Aged↗
PubMed1997

Results of a phase I clinical trial of a T-cell receptor peptide vaccine in patients with multiple sclerosis. I. Analysis of T-cell receptor utilization in CSF cell populations.

To identify a panel of multiple sclerosis patients (MS) for a phase I clinical trial of a T-cell receptor (TCR) peptide vaccine we characterized the T-cell populations present in the cerebrospinal fluids (CSF) of a large group of patients with respect to surface phenotype and state of activation, TCR beta chain utilization, features of the CDR3 junctional region, the extent of clonality and persistence of selected clonotypes over time. These CSF cell populations consist of approximately 60% CD4+ T-cells, half of which bear IL-2 receptors, indicating these activated T-cells may be part of the pathogenic process in MS. When these activated CD4+ T-cells were selectively expanded in IL-2/IL-4 supplemented cultures, an over-representation of several TCRV beta families was noted in 39/47 patients, the most frequent being V beta 6.5, V beta 6.7, V beta 2, V beta 5 and V beta 4. Biased expression of various members of the V beta 6 family was seen in 21 of this group of 39 patients. Clonal analysis of TCR beta 6 CDR3 sequences, revealed two notable features: clonal dominance and clonal persistence. CSF cells from two-thirds of MS patients contained a dominant clone comprising 50% or more of sequences and the same patient-specific clone could be shown to persist for up to 18 months. This clonal prevalence and over representation of V beta 6+TCR raises the possibility that immunization with a V beta 6 peptide vaccine may produce a regulatory immune response leading to a clinical benefit.

Adult↗
PubMed1996

Enhanced production of glomerular extracellular matrix in a new mouse strain of high serum IgA ddY mice.

To investigate the relationship between high serum levels of IgA and glomerular lesions, selective mating was performed in high serum IgA ddY mice, a murine model of spontaneously developing mesangioproliferative glomerulonephritis mimicking human IgA nephropathy. The selection and mating of high IgA ddY mice were accomplished when the mice were three to four months old. In the 12th generation of high IgA ddY (HIGA) mice, significantly higher levels of serum IgA from 10 age weeks to 60 weeks (P < 0.0002 to 0.0001) were observed in comparison with BALB/c mice. Relatively high proteinuria was observed at 40 weeks of age, although hematuria was consistently negative. Microscopic observations of renal tissue disclosed a marked glomerular mesangial matrix increase and a reduction of cell proliferation with age by both semiquantitative and morphometric analyses with moderate tubulointerstitial damage. These mesangial matrices were stained markedly by antisera for collagen type IV and by fibronectin, but not by collagen type I. Localization of TGF-beta protein was also detected in the mesangium of the HIGA mice. The positive mesangial IgA deposition was maintained consistently by this mating procedure and became more marked with age. Size analysis of IgA from ten pooled HIGA mice aged 50 to 60 weeks revealed dominant polymeric IgA in sera and dimeric IgA in glomerular eluates. Clonal analysis of serum IgA disclosed heterogeneous spectrotypes in a wide pH range (4.5 to 6.5), in contrast to very limited spectrotypes in the acidic pH range (4.5 to 5.2) of IgA in the glomerular eluates from these mice. The analyses of retroviral gp70 antigen involvement in the HIGA mice disclosed a significant increase of serum levels of gp70 anti-gp70 immune complexes with age, with no relationship to the severity of glomerular gp70 deposition. Northern blot analysis of renal tissue revealed markedly high mRNA expression of collagen type I, IV, fibronectin and TGF-beta even in 10-week-old HIGA mice in comparison with BALB/c mice. The expression became more significant in 60-week-old animals. The genetic background required to induce the expansion of IgA-producing B-cell clones is suggested to be closely related to the increased gene expression of TGF-beta, which induces enhanced glomerular extracellular matrix (especially fibronectin) accumulation in HIGA mice, being possibly mediated by the mesangial deposition of dimeric and highly acidic IgA. This newly established strain may provide a model for investigating the relationship between progressive glomerular sclerotic lesions and the induction of pathogenic IgA in human IgA nephropathy.

Aging↗
PubMed1998

Pattern formation in the cerebellum of murine embryonic stem cell chimeras.

The cerebellar cortex is subdivided into an elaborate, stereotyped array of transverse zones and parasagittal stripes. It has been speculated that (i) all Purkinje cells derive from 10 to 20 precursors allocated early in embryogenesis and (ii) that pattern formation is based on cell lineage restriction in the founder pool. These hypotheses have been tested by clonal analysis of embryonic stem cell chimeras. Neither speculation is supported: the analysis suggests that Purkinje cells derive from a founder population of > 102 precursors, and that neither cerebellar transverse developmental boundaries nor parasagittal stripes have a clonal origin. We conclude that early lineage restriction plays no role in cerebellar pattern formation.

Animals↗
PubMed1997

Evidence for monoclonal expansion of epithelial cells in ovarian endometrial cysts.

Ovarian endometrial cysts, one of the typical manifestations of endometriosis, are generated by the retention of cyclic hemorrhages and are classified as tumor-like lesions rather than neoplasms. Clonality analysis provides important information about the histogenesis and progression of neoplastic diseases. As it is generally accepted that most neoplasms are monoclonal in origin, however, the clonality of endometrial cysts remains uncertain. Using the human androgen receptor gene (HUMARA) as an X-linked polymorphic marker, we examined the clonal status of epithelial cells in endometrial cysts. We separated 21 fresh epithelial cell samples from 11 endometrial cysts and found that all were monoclonal in the methylation pattern of the HUMARA alleles. Moreover, in each of the five cysts from which epithelial cells were sampled from multiple and distant areas, the methylation patterns of all samples from a single cyst were identical. These data indicate that endometrial cysts are monoclonal in origin and suggest their neoplastic potentiality.

Adult↗
PubMed1997

Significance of antigen-specific T cell clones in collagen diseases: analyses with a novel T cell clonality evaluation system.

The involvement of antigen-specific T cells in the pathogenesis of collagen diseases is still controversial. The final stages of collagen diseases are usually characterized by the dominance of inflammation. Therefore, antigen non-specific factors, such as inflammatory cytokines, probably play an important role in this process. On the other hand, the methods available to analyze the antigen-specific aspects of the immune response are still limited. Here we review our novel system of T cell clonality analysis based on the idea that activated antigen-specific T cells should form accumulating clones among the lymphocyte population. Using this method, dynamic changes of clonal accumulation of T cells could be evaluated during antigenic stimulation in vivo and in vitro. The significance of antigen-specific T cell clones in collagen diseases is discussed using data obtained from patients with rheumatoid arthritis and systemic lupus erythematosus.

Arthritis, Rheumatoid↗
PubMed1995

Highly purified primitive hematopoietic stem cells are PML-RARA negative and generate nonclonal progenitors in acute promyelocytic leukemia.

The hierarchical level of stem cell involvement in acute promyelocytic leukemia (APL) characterized by the pathognomonic PML-RARA fusion gene is unknown. To determine if the cells of the primitive hematopoietic stem cell compartment are involved in the leukemic process, we have used molecular and cell sorting techniques in peripheral blood and bone marrow (BM) cells at diagnosis from three patients with APL and t(15; 17). In two of them, clonality analysis was also possible using the BstXI polymorphic site of the PGK gene. The PML-RARA fusion gene was readily identified by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of BM cells obtained at diagnosis in all three patients. These same samples were then used to sort CD34+ cells and their CD38+ and CD38- subsets by fluorescence-activated cell sorting. In both female patients, CD34+/CD38+ and CD34+/CD38- cell fractions were polyclonal using PCR, whereas a monoclonal pattern was identified at the BM sample obtained at diagnosis either by Southern blotting or by PCR. Because of the high sensitivity of the PCR analysis, the polyclonal pattern of these cell populations could mask the presence of a minor clone. To detect this clone, we preformed RT-PCR analysis for t(15; 17). In one female patient, the abnormal PML-RAR fusion gene was found only in the more mature CD34+/CD38+ cell fraction using a nested PCR approach, whereas the polyclonal CD34+/CD38- fraction was PML-RARA negative. These findings were confirmed in a third patient with APL in whom the PML-RARA transcripts were absent in the CD34+/CD38- cell fraction. To study the clonality at the level of clonogenic progenitors, we used in one patient PGK analysis by PCR of individual burst-forming units-erythroid and colony-forming units-granulocyte-macrophage obtained from the CD34+/CD38- and CD34+/CD38+ cell populations at diagnosis and from the BM sample obtained during remission. The two highly purified cell populations gave rise to morphologically normal colonies clonal for both the BstXI site containing (A) and the BstXI site lacking (B) PGK allelles, indicating their polyclonal content, a pattern that was also found in clonogenic progenitors obtained at remission. These findings strongly suggest that the primitive hematopoietic stem cells as defined by the CD34+/CD38- antigens are not involved by the neoplastic process in APL. These results may have important implications for autografting strategies of retinoic acid/chemotherapy-resistant or relapsed patients.

ADP-ribosyl Cyclase↗
PubMed1989

Quantitative analysis of the effect of colony-stimulating factors on human marrow progenitor growth in liquid-suspension cultures: application of limiting dilution assay.

Proliferation of human marrow progenitors in liquid cultures can be quantitated by limiting dilution clonal analysis (LDA) of progenitors in microwells. In this study, we have used LDA to study the effect of purified native or recombinant granulocyte colony-stimulating factors (G-CSFs) and recombinant granulocyte-macrophage CSF (GM-CSF) on progenitor growth. These results were compared to those of simultaneous cultures in methylcellulose. In LDA, single-hit kinetics were obtained with up to 500 U/ml of the recombinant preparation. In LDA with recombinant GM-CSF, progenitor growth conformed to single-hit kinetics from 100 to 2000 U/ml with maximum progenitor frequency at 500 U/ml. In simultaneous methylcellulose cultures with recombinant GM-CSF, colony formation reached a plateau at 100 U/ml. In LDA, purified native G-CSF was shown to support progenitor growth with single-hit kinetics at 100 U/ml, but at greater concentrations (greater than 150 U/ml), it suppressed progenitor growth with almost complete inhibition at a concentration of 200 U/ml. However, this dose-response effect was not observed in either simultaneous methylcellulose culture with G-CSF or in LDA with a purified recombinant preparation of the corresponding G-CSF. In methylcellulose cultures, colony formation reached a maximum at 100 U/ml and maintained a plateau up to 1000 U/ml. Hence, liquid culture allowed detection of contaminating suppressive activity in the G-CSF preparation that was not detected by methylcellulose assay. LDA may be more sensitive than methylcellulose culture for screening factors regulating human hematopoietic cell growth.

Bone Marrow↗
PubMed1996

Epstein-Barr virus-associated gastric adenocarcinomas among Koreans.

Epstein-Barr virus (EBV)-associated gastric carcinomas have been reported from various regions of the world. Epstein-Barr virus appears to be pathogenetically related to some gastric carcinomas. To determine the incidence of EBV association with gastric carcinomas among Koreans, the authors have studied EBV genome expression in 89 consecutive patients with gastric carcinomas diagnosed at the Catholic University Hospitals in Seoul, Korea, using in situ hybridization (ISH) for EBV-encoded small RNAs (EBERs), and immunohistochemistry for EBV latent membrane proteins (LMP) and CD21 antigen on paraffin sections. Thirty-seven gastric specimens with benign ulcer disease were used controls. EBV-encoded small RNAs were expressed in tumor cell nuclei in 12 patients (13.5%). None of the controls or benign portions of the cases were positive. In the positive cases, all tumor cell nuclei were uniformly stained and the staining intensity was strong. Immunohistochemistry for LMP was positive in 3 of 12 EBERs positive patients and none of EBERs negative patients. EBV latent membrane proteins was localized only in the lymphoid cells infiltrating the tumor in two patients, and tumor cells as well as infiltrating lymphoid cells in one patient. These results indicate that the rate of EBV association with gastric carcinomas in Koreans is relatively high and comparable to other Far Eastern Asian regions. The expression pattern in EBV-associated gastric carcinomas is similar to those of nasopharyngeal carcinomas in which clonality analysis using specific probes to the tandem repeat region of EBV yielded single episomal bands suggesting that EBV infection in EBV-associated gastric carcinomas are also clonal and pathogenetically related to the neoplasm. However, the mechanism of tumorigenesis remains to be elucidated.

Adenocarcinoma↗
PubMed1994

Malignant progression of adenomyoepithelial adenosis of the breast.

A case of breast tumor is described, which consisted of dense and uniform proliferation of ducts and lobules composed of both epithelial and myoepithelial cells and in which multiple foci of adenocarcinoma were observed. The tumor surrounding the carcinoma foci was identified as 'adenomyoepithelial adenosis'. Adenomyoepithelial adenosis was not monoclonal by clonal analysis, but revealed a relatively high labeling index for proliferating cell nuclear antigen by immunohistochemistry. Although it was still undetermined whether adenomyoepithelial adenosis is a non-clonal nonneoplastic lesion or a biclonal neoplastic one, the lesion was shown to reveal high proliferative activity in both glandular epithelial and myoepithelial cells and was considered to be prone to progress to obvious carcinoma.

Adenocarcinoma↗
PubMed1975

Mammalian tropism of B77(RBI) virus. Expression of virus genome in the hamster sarcoma cell clones.

In contrast to the B77 virus, its B77(RBI) rat variant continuously produced by the rat RBI sarcoma cells in vivo and in vitro, efficiently induced progressively growing tumors in hamsters and transformed hamster embryo cells in vitro. Both, induced tumors and transformed cell cultures showed production of infectious virus and presence of the avian gs-antigen. Clonal analysis of the established hamster sarcoma cell line RBHtc brought evidence that despite the quantitative differences in the virus production and gs-antigen content among various clonal populations, full expression of the B77(RBI) virus genome does occur in each cell of the virus-induced hamster sarcoma. The permissive relationship of the B77(RBI) virus with rat and hamster cells as well as changed antigenic composititon implies that a genetic change of the virus occured, which is reflected in its increased mammalian tropism and its genetically stable firus-productive interaction with mammalian cells. The possible explanations of these phenomena are discussed.

Animals↗
PubMed1986

Heritable variation in expression of multiple tumor associated epitopes on a high molecular weight mucin-like antigen.

Monoclonal antibodies with specificity for mucin-like antigens have shown great promise for the diagnosis and therapy of human cancer. Heterogeneity in the expression of mucin-like antigens by tumor and normal cells has been noted in several previous studies. An understanding of the nature of this heterogeneity has important implications for the diagnostic and therapeutic usefulness of antibodies to mucin-like antigens. We have studied the mechanism of variability in expression of epitopes on a mucin-like antigen defined by monoclonal antibodies W1, W5, and W9 in the lung carcinoma cell line, Calu-1. Using the fluorescence activated cell sorter and clonal analysis, we have demonstrated that intercellular variability in mucin antigen expression by Calu-1 cells can be explained in part by heritable variation in the tumor cell population. Clonal cell lines were isolated which differ greatly in levels of epitopes for all three mucin directed antibodies. Levels of all three epitopes showed significant variation between different clonal lines but in general were coordinately regulated. Differences in epitope expression between two lines studied in detail could be attributed to a dramatic difference in expression of a high molecular weight mucin-like glycoprotein. In immunoblotting experiments the binding of all three antibodies to this glycoprotein was affected by sodium periodate and/or neuraminidase treatment, suggesting that the antibodies recognize carbohydrate epitopes. Thus, heterogeneity in expression of mucin-like glycoprotein antigens can result from heritable variations which affect expression of multiple carbohydrate epitopes.

Antibodies, Monoclonal↗
PubMed2003

Mitochondrial DNA as a clonal tumor cell marker: gliomatosis cerebri.

The aim of this study was a clonal analysis of gliomatosis cerebri (GC), a rare disease characterized by diffuse, extensively infiltrating glial tumors of the central nervous system. Two females of the series were not informative in assays for X-chromosomal inactivation, and a polycytosine tract of the mitochondrial DNA (mtDNA) was tested as a clonal marker. Following fluorescent PCR, a fraction of human individuals shows several electrophoretic bands in normal tissues, some of which can be lost in corresponding glial tumors. Two male patients of our series fulfilled this prerequisite and were thus informative. In patient 1, four tumor samples from the left temporal and occipital cortex, histologically corresponding to WHO grades III and IV, showed an identical loss of bands, which was not observed in tumor-free brain and in tumors from the left cerebellum, from fornix and corpus callosum, and from the right occipital cortex, corresponding to WHO grades III and IV. Since this patient exhibited a TP53 mutation in exon 7, we sequenced this exon in all tissue samples of this individual. The mutation was found selectively in the tumor samples with a loss of mtDNA bands. In patient 2, all tumors (histologically corresponding to WHO grade II) from putamen, thalamus, midbrain and right parietal cortex exhibited an identical loss of bands in the mtDNA analysis. Taken together, these results support that even distant tumors in a patient with GC can share a common clonal origin. They demonstrate the extraordinary mobility and infiltrative power of these tumor cells.

Biomarkers, Tumor↗