Uterine tumors in ataxia-telangiectasia

Roughly one-third of patients with ataxia-telangiectasia (AT) develop malignant tumors, usually of lymphoid origin. AT patients also exhibit progeric changes. We describe three patients, between the ages of 27 and 32 years, with uterine tumors: one with a frank leiomyosarcoma and chronic T-cell leukemia, one with a multilobulated leiomyoma of uncertain malignant potential, and one with an unremarkable leiomyoma. Thus, the spectrum of tumors in AT patients beyond adolescence includes nonlymphoid malignancies and precocious, benign leiomyomas.

The germline repertoire of T-cell receptor beta-chain genes in patients with multiple sclerosis

The T-cell receptor (TCR) beta-chain gene repertoire of 40 multiple sclerosis (MS) patients was compared to that of 100 normal individuals. V-beta probes that represent 14 different V-beta subfamilies plus a C-beta probe were used to identify 53 separate beta-chain gene segments. No duplication or deletion of any of these 53 gene segments was found in the MS patients. Restriction fragment length polymorphism (RFLP) alleles detected by V-beta 8, V-beta 11 and C-beta probes defined 8 different beta-chain haplotypes. The distribution of these haplotypes in Caucasian MS patients and normal individuals was significantly different (p = 0.012). Comparison of the DR2+ subset of MS patients (n = 32) to a second group of 43 Caucasian DR2+ normal individuals revealed that the distribution of these beta-chain haplotypes was significantly different in these two populations (p = 0.015). These results suggest that an MS susceptibility gene(s) may be located in the region of the TCR/beta-chain gene complex.

The germline repertoire of T cell receptor beta-chain genes in patients with chronic progressive multiple sclerosis

The T cell receptor (TcR) beta-chain germline gene repertoire of multiple sclerosis (MS) patients was compared to that of 100 normal individuals. No differences in the number of gene segments defined by probes representing 14 different human V beta subfamilies and the constant region genes were found. The distribution of haplotypes defined by restriction fragment length polymorphism (RFLP) alleles detected with V beta 8, V beta 11, and C beta probes in the MS patients was significantly different from that found in normal individuals. Because 84% of the MS patients were DR2+, the findings in these patients were compared to a second group of 43 normals who were DR2+. The distribution of TcR haplotypes in MS patients was also significantly different from that in the DR2+ normals. The data suggest that an MS susceptibility gene(s) may be located in the region of the TcR beta-chain gene complex.

Localization of an ataxia-telangiectasia gene to chromosome 11q22-23

Ataxia-telangiectasia (AT) is a human autosomal recessive disorder of childhood characterized by: (1) progressive cerebellar ataxia with degeneration of Purkinje cells; (2) hypersensitivity of fibroblasts and lymphocytes to ionizing radiation; (3) a 61-fold and 184-fold increased cancer incidence in white and black patients, respectively; (4) non-random chromosomal rearrangements in lymphocytes; (5) thymic hypoplasia with cellular and humoral (IgA and IgG2) immunodeficiencies; (6) elevated serum level of alphafetoprotein; (7) premature ageing; and (8) endocrine disorders, such as insulin-resistant diabetes mellitus. A DNA processing or repair protein is the suspected common denominator in this pathology. Heterozygotes are generally healthy; however, the sensitivity of their cultured cells to ionizing radiation is intermediate between normal individuals and that of affected homozygotes. Furthermore, heterozygous females are at an increased risk of breast cancer. These findings, when coupled with an estimated carrier frequency of 0.5-5.0%, suggest that (1) as many as one in five women with breast cancer may carry the AT gene and that (2) the increased radiation sensitivity of AT heterozygotes may be causing radiation therapists to reduce the doses of radiation used for treating cancer in all patients. To identify the genetic defect responsible for this multifaceted disorder, and to provide effective carrier detection, we performed a genetic linkage analysis of 31 families with AT-affected members. This has allowed us to localize a gene for AT to chromosomal region 11q22-23.

DNA polymorphism in the human Thy-1 gene

Thy-1 is a membrane glycoprotein expressed predominantly in brain tissue and occasionally in lymphoid tissue. The human Thy-1 gene is located on chromosome 11q22.3. Although two allelic forms of Thy-1 exist in mice (Thy-1.1 and Thy-1.2), no allelic forms have been described for the human Thy-1 gene. We describe a polymorphic MspI site within the human Thy-1 gene that distinguishes two alleles, 8 and 9, which are represented in a northern European population at frequencies of 0.7 and 0.3, respectively. Thy-1, therefore, provides a potentially useful marker to identify linkages with human disease genes located near 11q22.

Interferon-induced expression of class II major histocompatibility antigens in the major histocompatibility complex (MHC) class II deficiency syndrome

Class II antigens encoded by genes of the major histocompatibility complex (MHC) are expressed by a variety of cell types and have a vital role in the cellular interactions required for an effective immune response. We have analyzed the regulation of HLA-DR, DP, and DQ class II antigen expression on cells of different lineage from an immunodeficient patient with the MHC class II deficiency syndrome. T and B lymphocytes, monocytes, and fibroblasts, which initially expressed no class II antigens, were treated with inductive stimuli that normally lead to enhanced expression of class II antigens. Monocytes, but not fibroblasts, cultured for 48-96 hr in the presence of recombinant gamma interferon expressed all three types of class II antigens. In contrast, T lymphocytes did not express class II antigens following their exposure to a variety of stimuli, including activation with phytohemagglutinin and culture in the presence of interleukin-2, transformation by the retrovirus HTLV-1 or HTLV-2, or exposure to the demethylating agent 5-azacytidine. Similarly, class II antigens were not induced on B cells by cross-linkage of surface immunoglobulin molecules with anti-mu, exposure to Epstein-Barr virus, or treatment with soluble factors secreted by activated T cells. These results demonstrate that the regulation of class II MHC antigen expression by monocytes and lymphocytes is dissimilar and suggest that different regulatory genes are involved in the control of class II antigen expression by cells of different lineage.

Genetic complementation analysis of ataxia telangiectasia and Nijmegen breakage syndrome: a survey of 50 patients

Cultured cells from patients with ataxia telangiectasia (AT) or Nijmegen breakage syndrome (NBS) are hypersensitive to ionizing radiation. After radiation exposure, the rate of DNA replication is inhibited to a lesser extent than in normal cells, whereas the frequency of chromosomal aberrations is enhanced. Both of these features have been used in genetic complementation studies on a limited series of patients. Here we report the results of extended complementation studies on fibroblast strains from 50 patients from widely different origins, using the radioresistant DNA replication characteristic as a marker. Six different genetic complementation groups were identified. Four of these, called AB, C, D, and E (of which AB is the largest), represent patients with clinical signs of AT. Patients having NBS fall into two groups, V1 and V2. An individual with clinical symptoms of both AT and NBS was found in group V2, indicating that the two disorders are closely related. In AT, any group-specific patterns with respect to clinical characteristics or ethnic origin were not apparent. In addition to the radiosensitive ATs, a separate category of patients exists, characterized by a relatively mild clinical course and weak radiosensitivity. It is concluded that a defect in one of at least six different genes may underlie inherited radiosensitivity in humans. To facilitate research on defined defects, a complete list of genetically characterized fibroblast strains is presented.

Genetic linkage studies of ataxia-telangiectasia: phenotypic blood markers

We have tested thirty-two phenotypic blood markers on sixteen families with with ataxia-telangiectasia (AT) in an attempt to identify the chromosomal location of the AT gene(s). Although at least five complementation groups have been defined, it is not known whether the corresponding AT genes are clustered or dispersed in the genome. Both clustered and dispersed genetic models were considered in linkage analyses. No significant linkages were found. The data exclude approximately 7 per cent of the autosomal genome for a 'clustered' model and 2 per cent of the autosomal genome for a 'dispersed' model. Several genomic areas were identified which warrant further study.

Human ferritin genes: chromosomal assignments and polymorphisms

The ferritins are a family of proteins that function intracellularly to sequester iron that otherwise would be toxic to the cell. The molecules are comprised of 24 heavy and light subunits, the heavy:light ratio varying widely in a tissue-specific manner. We cloned DNA sequences for both the heavy (HL217-1) and light (HL227) subunits from a cDNA library derived from messages that are strongly regulated during in vitro-induced differentiation of a promyelocytic leukemia cell line, HL-60, into either neutrophils or macrophages. The heavy-subunit family (FTH) includes 15-20 genes and/or pseudogenes; the light-subunit family (FTL) includes at least three genes. We have confirmed and extended the chromosomal localization of the heavy-subunit "genes" to chromosomes 1-6, 8, 9, 11, 13, 14, 17, and X. We have also identified and characterized two genetic polymorphisms: FTH/BamHI and FTH/TaqI. FTH/BamHI localizes to chromosome 3, is biallelic, and has a heterozygosity frequency of .39, a minor allele frequency of .33, and a polymorphic information content (PIC) of .34. FTH/TaqI is measured by the presence or absence of a single 6-kb fragment that is absent (i.e., "homozygosity" being presumed) in approximately 63% of Caucasians (PIC = .27). We discuss the possibility that gene-family probes that hybridize to many discrete members of dispersed gene families could be used in conjunction with pulsed- or inverted-field gels to screen a large number of specific genomic regions for microdeletions.

Gamma-actin: unusual mRNA 3'-untranslated sequence conservation and amino acid substitutions that may be cancer related

beta-Actin mutations in chemically transformed human cell lines have been associated with tumorigenicity, an association consistent with other evidence suggesting that altered cytoskeletal proteins may have an important role in cancer initiation or progression. From a human promyelocytic leukemia cell line, we have isolated a gamma-actin cDNA clone with amino acid substitutions in a region highly conserved in the many actins analyzed. To our knowledge, this is the first example of a variant gamma-actin in a human neoplasm. A separate finding from the analysis of this clone is that the gamma-actin 3'-untranslated region is among the most highly conserved of all 3'-untranslated sequences so far reported, but is entirely different from the beta-actin 3'-untranslated region. The high degree of evolutionary conservation suggests that the 3'-untranslated regions of these two mRNAs have important and distinct functional roles that were already fully differentiated more than 100 million years ago. Mutations affecting four major cytoskeletal components have now been identified in human neoplastic cells. These findings suggest that mutated cytoskeletal genes may be members of a class of oncogenes, fundamentally different from both the nuclear-acting (e.g., myc and simian virus 40 large tumor antigen) and growth factor/receptor/protein kinase-related (e.g., sis, erbB, and ras) types of oncogenes.

Human T cell receptor V beta gene polymorphism

Southern blot hybridizations with human T cell receptor V beta gene probes were used to determine the sizes of the various V beta gene subfamilies. An analysis of DNA samples from 100 unrelated individuals identified a single individual who lacked one V beta gene segment. A second individual had an apparently different repertoire of V beta gene segments in one subfamily, as assayed by hybridization, possibly due to a gene conversion event. An analysis with four restriction enzymes of DNA from 30 consanguineous donors detected restriction fragment length polymorphisms associated with 12 of 14 V beta gene segment subfamilies examined. In an analysis of DNAs from a large panel of unrelated individuals, some alleles at these loci were found to be in linkage disequilibrium, indicating a potentially close physical linkage. The segregation of three polymorphisms, two associated with V beta gene segment loci and one associated with the C beta genes, was compatible with Mendelian inheritance, and demonstrated that highly informative haplotypes could be generated. The high degree of polymorphism observed in the human T cell receptor beta chain complex should allow exploration of possible associations between T cell receptor genes and inherited diseases involving the immune system.

mRNA species regulated during the differentiation of HL-60 cells to macrophages and neutrophils

Using cDNA clone banks from differentiated and undifferentiated HL-60 promyelocytic leukemia cells, we have selected clones for genes which are regulated during this differentiation. Regulation of the corresponding mRNAs in HL-60 cells during both monocytic and neutrophilic differentiation was measured for 21 of these clones. The levels of mRNA hybridizing to some of these clones changed by more than 100-fold during differentiation. Unlike erythropoiesis or myogenesis, in which the synthesis of a few new proteins is synchronously regulated, mRNAs in differentiating HL-60 cells are asynchronously regulated, suggesting a complex series of regulatory events. About half of these regulation-selected clones contained repeat sequences, including both Alu and novel repeat families. Most of the regulated genes are members of extensive gene families.

Tissue of origin of elevated alpha-fetoprotein in ataxia-telangiectasia

Although only a single gene exists for alpha-fetoprotein (AFP), differential glycosylation generates several different forms and these are associated with different tissues of origin, namely, liver, gastrointestinal tract, and yolk sac. This microheterogeneity of serum AFP was studied in seven patients with ataxia-telangiectasia (AT) in order to determine the tissue of origin of their elevated AFP levels. Concanavalin A (Con A), Lens culinaris agglutinin A (LCA-A), and erythroagglutinating phytohemagglutinin (E-PHA) affinity electrophoresis and antibody-affinity blotting were used to fractionate AFP. It was found that serum AFP in AT patients was composed mainly of Con-A band 2 (AFP-C2), LCA-A band 1 (AFP-L1), and E-PHA band 2 (AFP-P2). This profile of AFP species in AT patients is similar to those seen in neonates and patients with chronic hepatitis, but clearly different from AFP originating in hepatocellular carcinoma, gastric carcinoma, and yolk sac tumour cells. These data are compatible with a hepatic origin for the elevated AFP in AT patients. Since no evidence exists for ongoing liver damage in these patients, we suggest that the AFP gene in the AT liver may be under aberrant transcriptional control, perhaps secondary to a defect of DNA regulatory proteins which are necessary for hepatic maturation.

Inverted duplication of JH associated with chromosome 14 translocation and T-cell leukemia in ataxia-telangiectasia

A specific 14q32 breakpoint is observed in a homologous chromosome 14 translocation [t(14;14)q12q32] occurring in the T-cells of about 10% of patients with ataxia-telangiectasia (AT). To investigate whether the 14q32 breakpoint in AT occurs within the immunoglobulin gene cluster as is frequently detected in B-cell lymphoma, immunoglobulin clones were hybridized to Southern blots of DNA isolated from the T-cells of two AT patients with this chromosome 14 translocation. The 14q32 translocation breakpoints in these patients are apparently not within JH, S mu, C mu, S alpha-1 or -2, or C alpha-1 or -2, but one of the patients has an inverted duplication of at least 26 kilobases (kb) of the C mu region, with an associated 5' flanking deletion. The point of origin of the inverted duplication is within JH near the recombination signal for the J4 gene. This suggests that normal JH recombination mechanisms may have played a role in the development of this 14q32 chromosomal aberration. The presence of AT chromosomal breakpoints near other rearranging genes suggests a role for exaggerated recombination in the pathogenesis of chromosomal instability in AT.

Structure and expression of ferritin genes in a human promyelocytic cell line that differentiates in vitro

HL-60 is a human promyelocytic cell line with the capability of differentiating in vitro to give neutrophils, macrophages, or eosinophils. We screened libraries of HL-60 cDNA clones representing different time points during these differentiation processes to isolate clones corresponding to mRNAs whose expression is regulated during terminal differentiation. Upon sequencing this group of regulated clones, one clone encoding the heavy subunit and two clones encoding the light subunit of human ferritin were identified by reference to published amino acid sequences. Southern blot analyses showed that these clones are encoded by distinct multigene families. These clones identify two mRNAs whose ratios vary in a complex manner during both neutrophil and macrophage differentiation.

Genetic linkage analysis in a high-risk cancer family: HLA and 24 other markers

Family Pi is a high-risk cancer family in which more than 40% of the members of two generations have had cancer, mostly breast, endometrial, and gastrointestinal. An analysis of over 30 polymorphic genetic markers for possible genetic linkage to a gene increasing susceptibility to cancer revealed positive LOD scores to markers within or near the major histocompatibility complex [HLA-A,B (0.639), properdin B (Bf) (0.162), glyoxylase-1 (GLO-1) (0.166)] as well as to acid phosphatas (0.566) and MNSs (0.449). While no LOD score is statistically significant in the linkage analyses of this family alone, the data are compatible with the hypothesis that a cancer-susceptibility gene(s) (CSG) may be located on chromosome 6p, 2p, or 4q. Analyses of additional families with a similar cancer syndrome are warranted to resolve this ambiquity.

Measurement of nanogram concentrations of IgG by mixed hemadsorption

We have modified the mixed hemadsorption technique so as to minimize the non-specific adsorption of indicator cells. This is accomplished by: (1) introducing fetal calf serum at several crucial steps in the procedure, and (2) standardizing the selection of high-power fields to be counted so as to avoid erratic adherence patterns which occur around the well rim. Using these adjustments, IgG concentrations in the 12.5--400 ng/ml range can be measured accurately.

SAMPLE SIZE

2 microliter. Test time: 4 h. No radioisotope is required.

A clinicopathologic analysis of chronic lymphocytic leukemia

Sixty consecutive patients with chronic lymphocytic leukemia (CLL) were studied from both a clinical and laboratory standpoint. Hypoimmunoglobulinemia was found in 45% of patients; many of these patients suffered from severe bacterial infections. Second primary malignancies were diagnosed in 20% of patient's; most of these predated the diagnosis of CLL. HLA-B17 typing was found in unexpectedly high frequency in a small group of Coombs'-positive patients. The Rai-staging system was found to be generally useful for determining prognosis of groups of patients, although less useful in any individual patient. Findings relating to surface membrane immunoglobulin-positive (B) and E-rosetting (T) lymphocytes are described. A patient with null-cell CLL is described. All patients with proliferation of gamma heavy-chain-bearing cells were diagnosed in early Rai stages suggesting that this marker may identify a subset of patients who present early and have a good prognosis. These data suggest that lymphocyte marker studies augment the Rai criteria in evaluating prognosis and may eventually be of value to the clinician in evaluating stage of disease and response to treatment.

HLA--D typing with lymphoblastoid cell lines. VIII. Cut points and gene frequency estimates by multiple testing analysis

One-way mixed leukocyte culture (MLC) data were analyzed using multiple testing analysis, a new procedure for separating HLA--D typing and non-typing responses. Using the cut points derived by this analysis, HLA--Dw phenotype frequency estimates were computed from a data base which included testing of over 400 Caucasian donors. From these, gene frequency estimates were computed and compared with those of other investigators.

Use of long-term leukapheresis in the treatment of chronic lymphocytic leukemia

We used repeated leukapheresis in the long-term management of chronic lymphocytic leukemia. Twelve patients with far-advanced disease that was refractory to standard forms of therapy, were studied. Six patients completed a predefined course of therapy. Although a single patient responded favorably for a period of time, no other patient was benefited by this treatment. While circulating lymphocyte counts in these patients always could be reduced, generally, this was not associated with improvements in pancytopenia, hypogammagobulinemia, adenopathy, organomegaly, or constitutional symptoms of lethargy, fevers and night sweats. Mean survival was only ten months from onset of therapy. We conclude that long-term leukapheresis is ineffective in the management of far-advanced chronic lymphocytic leukemia.

Ataxia-telangiectasia and xeroderma pigmentosum: no evidence of linkage to HLA

Nine HLA-typed multiplex nuclear families segregating ataxia-telangiectasia (A-T), an autosomal recessive disorder, were studied. Linkage analysis performed by lod scores and by a previously published sib pair method revealed no evidence for linkage between A-T and HLA. An alternative method of linkage detection, previously applied to xeroderma pigmentosum (XP) and HLA, was reexamined and found to contain an error. As a consequence, neither of these "DNA repair disorders" appears to be linked to HLA.