ABSTRACT
The current classification system of renal tumors is based on morphologic criteria, as supported by genetic findings. We present a group of previously unclassified tumors with similar morphologic and genetic features, suggesting a new entity within renal neoplasms. Seven renal tumors from five patients (ages 31-67 years) were analyzed. All cases were stained with periodic acid-Schiff, Hale's colloidal iron (HCI), and Alcian blue (AB) at pH 2.5/1.0 with and without hyaluronidase (HA) digestion. Immunohistochemical (IHC) stains were performed for CK8, CK18, CK19, vimentin, villin, Tamm-Horsfall protein (THP), renal cell carcinoma marker (RCC), epithelial membrane antigen (EMA), ulex europaeus agglutinin (UEA-1), soy bean agglutinin (SBA), peanut agglutinin (PNA), and MIB-1. Comparative genomic hybridization (CGH) and loss of heterozygosity (LOH) studies were performed on all cases. All tumors showed circumscribed growth, a tubular growth pattern with focal solid areas, no significant nuclear atypia and absence of necrosis, desmoplasia, or inflammation. Abundant extracellular mucin was present. Immunohistochemistry stains support collecting duct origin (EMA+, PNA+, SBA+/-, CK 8/18/19+, vimentin+/-, UEA-1-, RCC-, villin-, THP-). The proliferative rate was low (<1%). CGH showed multiple consistent chromosomal losses (-1,-4, -6, -8, -9, -13, -14, -15, -22). Clinical outcome was favorable, with recurrences but no known distant metastases or death of disease. These findings are distinct from all previously classified renal neoplasms. Our data suggest the presence of a unique tumor entity within tumors of probable collecting duct origin: tubular-mucinous renal tumors of low malignant potential.
Subject(s)
Kidney Neoplasms/pathology , Kidney/pathology , Adult , Aged , Chromosome Aberrations , Female , Humans , Immunohistochemistry , Keratins/analysis , Ki-67 Antigen/analysis , Kidney/chemistry , Kidney/metabolism , Kidney Neoplasms/genetics , Kidney Neoplasms/metabolism , Loss of Heterozygosity , Middle Aged , Mucin-1/analysis , Mucins/metabolism , Nucleic Acid Hybridization/methods , Peanut Agglutinin/analysisABSTRACT
We analyzed the relative expression of Hematopoietic cell phosphatase (HCP) in mononuclear cells (MNC) of peripheral blood (PB), bone marrow (BM) and spleen of patients with juvenile myelomonocytic leukemia (JMML) and normal donors. Two regions of HCP with alternative exon skipping of exon 6 or exon 12 are described. There was no difference in the expression of the amplified HCP cDNA regions in MNC of JMML patients compared to normal donors. The two forms of exon skipping were present in unstimulated MNC of JMML patients or normal donors. In contrast, phytohemagglutinin (PHA) stimulated MNC of normal donors, Epstein-Barr Virus (EBV) transformed B-cells of JMML patients, BFU-E and CFU-GM derived colonies of JMML patients, and the cell lines K562 and HEL did not or only barely express these two forms of exon skipping. These results may indicate that alternative HCP exon skipping may be associated with the proliferative state of the cell.
Subject(s)
Gene Expression Regulation, Leukemic , Leukemia, Myelomonocytic, Chronic/enzymology , Neoplasm Proteins/biosynthesis , Protein Tyrosine Phosphatases/biosynthesis , Bone Marrow Cells/enzymology , Cell Division , Cell Line, Transformed , Cell Transformation, Viral , Child , Child, Preschool , DNA, Complementary/genetics , Enzyme Induction , Exons/genetics , Female , Genes, ras , Herpesvirus 4, Human , Humans , Infant , Intracellular Signaling Peptides and Proteins , K562 Cells/pathology , Leukemia, Myelomonocytic, Chronic/genetics , Leukocytes, Mononuclear/enzymology , Lymphocyte Activation , Male , Neoplasm Proteins/genetics , Neoplastic Stem Cells/enzymology , Phytohemagglutinins/pharmacology , Protein Tyrosine Phosphatase, Non-Receptor Type 6 , Protein Tyrosine Phosphatases/genetics , RNA Splicing , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Neoplasm/genetics , RNA, Neoplasm/metabolism , Spleen/enzymology , Transcription, Genetic , src Homology DomainsABSTRACT
Interferon regulatory factor 1 (IRF-1) is a transcriptional activator in the interferon system and acts as a tumor suppressor. The structurally related IRF-2 represses the effects of IRF-1 by competitive binding to the same DNA sequence elements. Changes in the relative balance between IRF-1 and IRF-2 lead to dysregulation of cell growth and may play a role in the development of neoplasias. The loss of functional IRF-1 has been observed in a number of patients with myelodysplastic syndrome (MDS) and leukemia, suggesting a potentially critical role of IRF-1 in leukemogenesis. We studied the expression of both transcription factors in peripheral blood (PB) and bone marrow (BM) cells of children with juvenile myelomonocytic leukemia (JMML) using RT-PCR and Southern blot hybridization. No significant difference between the expression levels of IRF-1 and IRF-2 could be detected in PB and BM of patients with JMML and normal donors. Although our results are preliminary they suggest that neither the tumor suppressor gene IRF-1 nor the oncogene IRF-2 is involved in the pathogenesis of JMML.
Subject(s)
DNA-Binding Proteins/biosynthesis , Gene Expression Regulation, Leukemic , Hematopoietic Stem Cells/metabolism , Leukemia, Myelomonocytic, Chronic/metabolism , Neoplasm Proteins/biosynthesis , Neoplastic Stem Cells/metabolism , Phosphoproteins/biosynthesis , Repressor Proteins , Transcription Factors , Blotting, Southern , Child , Child, Preschool , DNA-Binding Proteins/genetics , Genes, Tumor Suppressor , Genes, ras , Humans , Interferon Regulatory Factor-1 , Interferon Regulatory Factor-2 , Leukemia, Myelomonocytic, Chronic/genetics , Neoplasm Proteins/genetics , Phosphoproteins/genetics , Proto-Oncogenes , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , RNA, Neoplasm/biosynthesis , RNA, Neoplasm/genetics , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
During 15 days of treatment of K562 cells with sodium phenylacetate, we observed an increase in the cellular hemoglobin concentration with a similar increase in the expression of gamma-globin mRNA. Morphological studies demonstrated characteristic features of erythroid differentiation and maturation. At the same time there was no change in the level of expression of the cell surface antigenes CD33, CD34, CD45, CD71 and glycophorin A. Likewise, the level of expression of the erythroid transcription factors GATA-1, GATA-2, NF-E2, SCL and RBTN2, all expressed in untreated K562 cells, did not increase during sodium phenylacetate induced erythroid differentiation. The expression of the nuclear factors Evi-1 and c-myb, known to inhibit erythroid differentiation, did not decrease. We conclude that sodium phenylacetate treatment of K562 cells increases gamma-globin mRNA and induces cell maturation as judged by morphology without affecting the expression of the erythroid transcription factors, some of which are known to be involved in the regulation of beta-like globin genes.
Subject(s)
Antimetabolites, Antineoplastic/pharmacology , Erythroid Precursor Cells/cytology , Phenylacetates/pharmacology , Transcription Factors/metabolism , Antigens, Surface/metabolism , Cell Differentiation/drug effects , Cell Line , DNA-Binding Proteins/metabolism , Erythroid Precursor Cells/drug effects , Erythroid-Specific DNA-Binding Factors , Flow Cytometry , GATA1 Transcription Factor , Globins/metabolism , Humans , NF-E2 Transcription Factor , NF-E2 Transcription Factor, p45 Subunit , RNA, Messenger/metabolism , Tumor Cells, CulturedABSTRACT
Activation of the Evi-1 gene was first described to be associated with the transformation of murine myeloid leukaemias and has previously been detected in cases of human acute myeloid leukaemia (AML) and chronic myeloid leukaemia (CML) in blast crises and in myelodysplastic syndromes. In this study we determined the frequency and the level of Evi-1 expression in juvenile myelomonocytic leukaemia (JMML) and in normal haemopoiesis. Using RT-PCR and Southern blot hybridization mRNA of Evi-1 could be detected in bone marrow (BM) and peripheral blood (PB) mononuclear cells (MNC) of normal donors. In JMML 12/20 patients examined expressed elevated levels of Evi-1 compared to normal controls. In these samples over-expression of the gene was correlated with a higher percentage of blasts (P = 0.02). Expression levels in BFU-E and CFU-GM derived colonies from BM of JMML patients were lower than those in the corresponding MNC samples. Analysis of CD34+ and CD34- cells demonstrated that Evi-1 is primarily expressed in the CD34+ cell population of both JMML and normal donors. These findings suggest that Evi-1 expression is linked to the early stages of haemopoiesis. Studies on the regulation of Evi-1 expression in CD34+ cells will elucidate its function in progenitor cells and clarify its possible role in the pathogenesis of JMML.
