The role of candidate-gene CNTNAP2 in childhood apraxia of speech and specific language impairment.

Childhood apraxia of speech (CAS) is a debilitating pediatric speech disorder characterized by varying symptom profiles, comorbid deficits, and limited response to intervention. Specific Language Impairment (SLI) is an inherited pediatric language disorder characterized by delayed and/or disordered oral language skills including impaired semantics, syntax, and discourse. To date, the genes associated with CAS and SLI are not fully characterized. In the current study, we evaluated behavioral and genetic profiles of seven children with CAS and eight children with SLI, while ensuring all children were free of comorbid impairments. Deletions within CNTNAP2 were found in two children with CAS but not in any of the children with SLI. These children exhibited average to high performance on language and word reading assessments in spite of poor articulation scores. These findings suggest that genetic variation within CNTNAP2 may be related to speech production deficits.

Producing primate embryonic stem cells by somatic cell nuclear transfer.

Derivation of embryonic stem (ES) cells genetically identical to a patient by somatic cell nuclear transfer (SCNT) holds the potential to cure or alleviate the symptoms of many degenerative diseases while circumventing concerns regarding rejection by the host immune system. However, the concept has only been achieved in the mouse, whereas inefficient reprogramming and poor embryonic development characterizes the results obtained in primates. Here, we used a modified SCNT approach to produce rhesus macaque blastocysts from adult skin fibroblasts, and successfully isolated two ES cell lines from these embryos. DNA analysis confirmed that nuclear DNA was identical to donor somatic cells and that mitochondrial DNA originated from oocytes. Both cell lines exhibited normal ES cell morphology, expressed key stem-cell markers, were transcriptionally similar to control ES cells and differentiated into multiple cell types in vitro and in vivo. Our results represent successful nuclear reprogramming of adult somatic cells into pluripotent ES cells and demonstrate proof-of-concept for therapeutic cloning in primates.

Inactivating mutations and overexpression of BCL10, a caspase recruitment domain-containing gene, in MALT lymphoma with t(1;14)(p22;q32).

Mucosa-associated lymphoid tissue (MALT) lymphomas most frequently involve the gastrointestinal tract and are the most common subset of extranodal non-Hodgkin lymphoma (NHL). Here we describe overexpression of BCL10, a novel apoptotic signalling gene that encodes an amino-terminal caspase recruitment domain (CARD), in MALT lymphomas due to the recurrent t(1;14)(p22;q32). BCL10 cDNAs from t(1;14)-positive MALT tumours contained a variety of mutations, most resulting in truncations either in or carboxy terminal to the CARD. Wild-type BCL10 activated NF-kappaB but induced apoptosis of MCF7 and 293 cells. CARD-truncation mutants were unable to induce cell death or activate NF-kappaB, whereas mutants with C-terminal truncations retained NF-kappaB activation but did not induce apoptosis. Mutant BCL10 overexpression might have a twofold lymphomagenic effect: loss of BCL10 pro-apoptosis may confer a survival advantage to MALT B-cells, and constitutive NF-kappaB activation may provide both anti-apoptotic and proliferative signals mediated via its transcriptional targets.

Rapid aneuploidy screening with fluorescence in-situ hybridisation: is it a sufficiently robust stand-alone test for prenatal diagnosis?

OBJECTIVES: To assess the clinical utility of fluorescence in-situ hybridisation with chromosomes 13, 18, 21, X and Y as a stand-alone test in detecting chromosomal abnormalities, and the types of chromosomal abnormalities missed. DESIGN: Retrospective analysis. SETTING: A restructured Government hospital in Singapore and an academic hospital in the United States. PARTICIPANTS: Cytogenetic data of prenatal specimens and results of fluorescence in-situ hybridisation of 5883 patients performed between January 2000 and August 2007 were reviewed. RESULTS: Fluorescence in-situ hybridisation detected 558 (9.5%) patients with chromosomal abnormalities. Abnormal ultrasounds (70%) and maternal serum screens (21%) were the most indicative of chromosomal abnormalities. When comparing fluorescence in-situ hybridisation data with karyotype results for the five chromosomes of interest, the sensitivity and specificity were 99.3% and 99.9%, respectively. When comparing fluorescence in-situ hybridisation data with karyotype results for all chromosomes, the sensitivity decreased to 86.8%, whereas the specificity remained at 99.9%. Of 643 cases with karyotype abnormalities, 85 were fluorescence in-situ hybridisation-negative (false negative rate, 13.2%), which included structural rearrangements, chromosome mosaicism, and other trisomies. Despite abnormal ultrasound indications, fluorescence in-situ hybridisation missed 32 cases which included structural rearrangements, mosaicisms, and other trisomies. CONCLUSION: This study does not support fluorescence in-situ hybridisation as a stand-alone test. Institutions supporting fluorescence in-situ hybridisation as a stand-alone test must seriously consider the risks of a missed diagnosis.

Distinctive patterns of BCL6 molecular alterations and their functional consequences in different subgroups of diffuse large B-cell lymphoma.

Gene expression profiling of diffuse large B-cell lymphoma (DLBCL) has revealed biologically and prognostically distinct subgroups: germinal center B-cell-like (GCB), activated B-cell-like (ABC) and primary mediastinal (PM) DLBCL. The BCL6 gene is often translocated and/or mutated in DLBCL. Therefore, we examined the BCL6 molecular alterations in these DLBCL subgroups, and their impact on BCL6 expression and BCL6 target gene repression. BCL6 translocations at the major breakpoint region (MBR) were detected in 25 (18.8%) of 133 DLBCL cases, with a higher frequency in the PM (33%) and ABC (24%) subgroups than in the GCB (10%) subgroup. Translocations at the alternative breakpoint region (ABR) were detected in five (6.4%) of 78 DLBCL cases, with three cases in ABC and one case each in the GCB and the unclassifiable subgroups. The translocated cases involved IgH and non-IgH partners in about equal frequency and were not associated with different levels of BCL6 mRNA and protein expression. BCL6 mutations were detected in 61% of DLBCL cases, with a significantly higher frequency in the GCB and PM subgroups (>70%) than in the ABC subgroup (44%). Exon-1 mutations were mostly observed in the GCB subgroup. The repression of known BCL6 target genes correlated with the level of BCL6 mRNA and protein expression in GCB and ABC subgroups but not with BCL6 translocation and intronic mutations. No clear inverse correlation between BCL6 expression and p53 expression was observed. Patients with higher BCL6 mRNA or protein expression had a significantly better overall survival. The biological role of BCL6 in translocated cases where repression of known target genes is not demonstrated is intriguing and warrants further investigation.

Familial multiple myeloma: a family study and review of the literature.

BACKGROUND: The etiology of multiple myeloma (MM) remains obscure, although reports of familial clustering have implicated both a host susceptibility factor and environmental effects. Here we describe the medical histories of members of a family prone to MM. METHODS: We developed a pedigree for an MM-prone family by using information obtained from a questionnaire. Protein immunoelectrophoresis of serum and urine from the proband and from 19 family members was performed to detect monoclonal immunoproteins. Peripheral blood obtained from the proband and from five relatives was subjected to standard cytogenetic studies to detect constitutional chromosomal abnormalities. Multifluor-fluorescence in situ hybridization (M-FISH) and standard FISH studies were performed on peripheral blood from the proband and from two other affected living relatives to determine their karyotypes and to detect clonal chromosomal abnormalities frequently seen in patients with MM. RESULTS: Within this family, a sibship of seven included three individuals (including the proband) with histologically verified MM and two individuals with a monoclonal gammopathy of unknown significance (MGUS), as determined by immunoelectrophoresis of serum and urine. This family also had members with acute lymphocytic leukemia, malignant melanoma, and prostate cancer. In the family members tested, we detected no constitutional chromosomal abnormality. None of the three individuals analyzed by FISH had a deletion of the retinoblastoma (Rb-1) locus, which is frequently deleted in patients with MM, and only one (the proband) had a translocation involving chromosomes 11 and 14, a clonal abnormality commonly seen in MM. CONCLUSION: The study of familial MM may provide insights into the pathogenesis and, ultimately, the control and prevention of MM and related disorders.

Correlation of secondary cytogenetic abnormalities with histologic appearance in non-Hodgkin's lymphomas bearing t(14;18)(q32;q21).

Successful cytogenetic studies were performed on 69 biopsies from 64 patients with non-Hodgkin's lymphoma bearing a t(14;18)(q32;q21) translocation. This translocation appears to be a primary abnormality associated with the development of certain B-cell non-Hodgkin's lymphomas. We correlated the occurrence of secondary abnormalities, in addition to the t(14;18)(q32;q21), with histologic subtype to test the hypothesis that secondary abnormalities correlate with more aggressive histologic appearance. A large number of secondary abnormalities were identified, the most frequent being additional copies of chromosomes 7 (30%), 12 (22%), 18 (22%), 20 (16%), or 21 (14%), deletion of a portion of the long arm of chromosome 6 (17%), and either an additional chromosome 17 or an isochromosome for the long arm of chromosome 17 (13%). An extra chromosome 7 was highly associated with a diffuse histologic pattern; it was present in 52% of patients with a diffuse pattern and in only 15% of those with a follicular pattern (P = .002). A weaker association with a diffuse growth pattern was found for the addition of chromosome 17 or an i(17q); it was found in 24% of patients with a diffuse pattern and only 5% of those with a follicular pattern (P = .05). No other significant correlations between secondary chromosome abnormalities and histologic subtype were identified. Although the explanation for this association is not clear, it appears that patients with B-cell non-Hodgkin's lymphomas bearing the t(14;18)(q32;q21) translocation which also have an additional chromosome 7 are likely to exhibit a diffuse growth pattern.

Association of DNA content and proliferative activity with clinical outcome in patients with diffuse mixed cell and large cell non-Hodgkin's lymphoma.

Formalin-fixed and paraffin-embedded lymph node biopsy specimens from 52 untreated patients with newly diagnosed diffuse large cell (n = 48) or mixed cell (n = 4) non-Hodgkin's lymphoma (NHL) were analyzed for DNA content and proliferative activity (PA) by flow cytometry. The results obtained by flow cytometry were compared with the results of cytogenetic studies performed on 28 of the specimens. The median age of the patients was 65 years (range, 15-84 years) and the male to female ratio was 3 to 2. All patients were uniformly staged and uniformly treated with cyclophosphamide, doxorubicin, procarbazine, bleomycin, vincristine, and prednisone. The flow cytometric results were compared statistically by univariate analysis with the rate and duration of complete remission and survival. Tumors with low PA (greater than or equal to 80% of cells in G0/G1 phase) were found in 65% of the patients; 74% of those with low PA versus only 44% of those with high PA achieved an initial complete remission (P less than 0.02). DNA aneuploidy was detected in tumors of 56% of the patients and was associated with a significantly longer duration of complete remission (P less than 0.01). Both low PA and aneuploidy independently predicted longer survival. The predicted 2-year actuarial survival for patients with tumors with low PA was 68% versus 10% for those with high PA (P less than 0.01). Similarly, the 2-year survival of patients with aneuploid tumors was 60% versus 36% for those with diploid tumors (P less than 0.01). The combination of PA and DNA content categorized the patients into four groups with decreasing 2-year survivals: low PA/aneuploid (n = 20), 77%; low PA/diploid (n = 14), 57%; high PA/aneuploid (n = 9), 32%; high PA/diploid (n = 9), 0%. The flow cytometric results correlated well with those of the cytogenetic studies. We conclude that low PA and DNA aneuploidy, both separately and in combination, predict a favorable clinical outcome for patients with diffuse mixed cell and large cell NHL.

Results of semen cryopreservation in young men with testicular carcinoma and lymphoma.

Sixty-two young men with testicular carcinoma (31 patients) or lymphoma (31 patients) were referred for semen analysis and possible cryopreservation before systemic therapy. Seventy-seven percent of the patients, 24 patients with testicular carcinoma and 24 patients with lymphoma, had semen with a decreased chance for fertility (ie, sperm density less than 20 X 10(6)/mL and/or less than 40% motile sperm and/or decreased sperm motility). A decreased number of motile sperm as well as a poor grade of motility appeared in the majority of semen specimens from both patient groups. However, 14 patients had semen that met our criteria for fertility with sperm density greater than or equal 20 X 10(6)/mL, greater than or equal 40% motile sperm, and motility grade greater than 2. Semen quality appeared to be better in patients referred immediately after diagnosis than in patients in whom there was a delay between diagnosis and referral for semen cryopreservation. Twelve patients with semen meeting our criteria for possible fertility and 42 patients failing our criteria elected to cryopreserve semen. A median of three collections per patient were stored. To date, seven patients have withdrawn semen for artificial insemination by husband attempts, and two of these attempts have resulted in pregnancies. Both attempts involved patients with semen that meet our criteria for potential fertility. In the minority of young men with lymphoma or testicular carcinoma who have good-quality semen, semen cryopreservation can preserve reproductive potential after therapy that might otherwise cause sterility.

Clinical features and prognosis of follicular large-cell lymphoma: a report from the Nebraska Lymphoma Study Group.

PURPOSE: Our purpose was to describe the treatment outcome of patients with follicular large-cell lymphoma (FLCL) and to identify prognostic factors that affect the treatment outcome. PATIENTS AND METHODS: Between 1980 and 1991, 107 newly diagnosed, previously untreated patients with FLCL were prospectively treated using treatment plans of the Nebraska Lymphoma Study Group (NLSG). Most stage I/II patients received two to three cycles of one of four closely related six-drug combination chemotherapy regimens (cyclophosphamide, doxorubicin or mitoxantrone, and procarbazine, plus bleomycin, vincristine, and prednisone or dexamethasone [CAP/BOP I-IV]) plus involved-field radiotherapy; 10 patients received involved-field irradiation only. Stage III/IV patients received six to eight cycles of CAP/BOP. RESULTS: Forty-four percent of patients had stage I/II disease. Stage I/II patients were older and more often female than stage III/IV patients. Cytogenetic studies were available on 35 patients: seven were normal; the most common abnormality was a translocation involving 14q32. Abnormalities of 1p or 1q were also common, often secondary to a 14q32 abnormality. The median follow-up of surviving patients is 2 years. The complete response rates observed were stage I/II, 88%; stage III/IV, 49%. Complete response rates were affected by both age and tumor bulk. Failure-free survival (FFS; time to first occurrence of progression, relapse after response, or death from any cause) at 3 years was estimated to be 61% for stage I/II patients and 34% for stage III/IV patients. Survival at 3 years was estimated to be 76% and 61%, respectively. FFS of stage III/IV patients was poorer for stage IV patients and those with composite lymphomas. Significantly poorer survival was only seen in patients older than 70 years of age. CONCLUSION: A proportion of stage I/II FLCL patients may obtain long-term disease control with combination chemotherapy plus radiotherapy. Results for patients with stage III/IV FLCL are similar to those seen for other follicular lymphomas.

Incidence and characterization of secondary myelodysplastic syndrome and acute myelogenous leukemia following high-dose chemoradiotherapy and autologous stem-cell transplantation for lymphoid malignancies.

PURPOSE: To analyze the risk of developing myelodysplastic syndrome (MDS) or acute myelogenous leukemia (AML) following autologous bone marrow transplantation (ABMT) or peripheral stem-cell transplantation (PSCT) and to determine the impact on failure-free survival (FFS). PATIENTS AND METHODS: Patients underwent ABMT or PSCT for the treatment of Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) at the University of Nebraska Medical Center. For those patients who went on to develop MDS/AML, controls were selected and a case-control-within-a-cohort study undertaken. RESULTS: Twelve patients developed MDS or AML a median of 44 months following ABMT/PSCT. The cumulative incidence (P = .42) and the conditional probability (P = .32) of MDS/AML were not statistically different between HD and NHL patients. Age greater than 40 years at the time of transplant (P = .05) and receipt of a total-body irradiation (TBI)-containing regimen (P = .06) were predictive for developing MDS/AML in patients with NHL. CONCLUSION: There is an increased risk of MDS/AML following ABMT/PSCT for lymphoid malignancies. NHL patients age > or = 40 years at the time of transplant and who received TBI are at greatest risk.

Inactivation of the E3/LAPTm5 gene by chromosomal rearrangement and DNA methylation in human multiple myeloma.

Chromosomal band 1p34-36 is a commonly rearranged locus in many types of cancers. We cloned the breakpoint region of a chromosomal translocation, t(1;14)(p34;q32), found in the human multiple myeloma (MM) cell line, ODA. This rearrangement occurred between the nearby switch region of the immunoglobulin heavy chain (IgH) gene (Sgamma3) at 14q32 and the first intron of the human retinoic acid-inducible E3 protein (E3)/lysosome-associated protein, transmembrane-5 (LAPTm5) gene at the 1p34 locus. Consequently, the E3 gene, which is a hematopoietic cell-specific transcript induced by retinoic acid and located at the rearranged allele, was interrupted within its coding region and was not expressed in the ODA cell line in spite of the other allele still being intact. The expression derived from the remaining intact allele in ODA cells was silenced by DNA methylation at sequences within the first intron around a GC-rich EagI site. Interestingly, the silenced expression of E3 mRNA due to DNA methylation of intron 1 sequences was frequently encountered in MM cells [6/10 (60%) of MM cell lines tested], while E3 is expressed in normal plasma cells and in most other hematopoietic cell lines including those of B-cell lineage. Thus, as the E3 protein has been suggested to be involved in cellular differentiation and apoptotic pathways in certain cell types, our results suggest that loss of E3 gene expression might be a crucial event during the progression of human MM.

Acute leukemia expressing the normal human hematopoietic stem cell membrane glycoprotein CD34 (MY10).

Thirty-one cases of acute leukemia with blast cells greater than or equal to 70% positive for the hematopoietic stem cell Ag, CD34 (MY10, HPCA-1), were identified from the University of Nebraska Medical Center and The Johns Hopkins Oncology Center over an 18-month period. Fourteen of the cases were classified as early B-lineage ALL, 3 cases were other ALL subtypes, and 14 of the cases were ANLL. Five of the 17 cases of ALL expressed one or more myeloid-associated surface Ags, 3 ANLL cases expressed CD10 (CALLA, J5), and T-lymphoid Ags were present in 12 of 31 cases (1 T-cell ALL, 3 of 16 B-lineage ALL cases, and 8 of 14 ANLL cases). Eleven of 12 CD34+ ALL cases studied had abnormal karyotypes; only 7 of 12 CD34+ ANLL cases studied had abnormal karyotypes, and 3 of these were CD10+ ANLL. Six cases were Ph1 positive, including the one mature B cell ALL, 4 early B-lineage ALL, and 1 CD10+ ANLL case. Good and poor prognosis subgroups of high frequency of expression of CD34 leukemias could be identified, generally, as would have been predicted by previously defined criteria. Thus, of the 10 Ph1-negative early B-lineage ALL patients, 9 achieved CR (90%). At the other extreme, the CR rate of CD10- ANLL was 4 of 11 (36%). The leukemias characterized by greater than or equal to 70% of cells positive for CD34 form a relatively undifferentiated subset of the leukemias which may show features associated with more than one lineage, and if CD10- and myeloid morphology, may respond poorly to therapy.

Rearrangements of chromosome band 1p36 in non-Hodgkin's lymphoma.

We studied 850 consecutive cases of histologically ascertained pretreatment non-Hodgkin's lymphoma with cytogenetically abnormal clones. The diagnostic karyotypes revealed that 12% of these cases exhibited structural rearrangements involving chromosome band 1p36. Here, we describe the karyotypes of 53 cases containing a 1p36 rearrangement [often involving translocations of unknown material and presented as add(1)(p36)]. We used fluorescence in situ hybridization to determine the origin of the translocation partners. We report three different recurrent translocations involving 1p36. These include der(1)t(1;1)(p36;q21) (three cases), der(1)t(1;1)(p36;q25) (three cases), and der(1)t(1;9)(p36;q13) (four cases). Using cytogenetic and fluorescence in situ hybridization analyses, we have resolved the translocation partners in 31 cases. Rearrangements of band 1p36 were found among different histopathological subtypes. Alterations of 1p36 never occurred as a sole abnormality, and in 42 of 53 cases, alterations of the band 14q32 were observed. The t(14;18)(q32;q21) translocation was present in 35 cases. The significantly high occurrence of 1p36 breakpoint in structural rearrangements and its involvement in recurrent translocations suggest that the region is bearing gene(s) that are important in lymphomagenesis. Our study also showed that cytogenetically evident deletions were frequent in chromosome 1p, almost always involving the p36 region, whereas duplications were rare and never encompassed the p36 region. Chromosome band 1p36 harbors many candidate tumor suppressor genes, and we propose that one or more of these genes might be deleted or functionally disrupted as a molecular consequence of the rearrangements, thus contributing to lymphomagenesis.

Interleukin-1beta upregulates MMP-9 expression in stromal cells of human giant cell tumor of bone.

Giant cell tumor (GCT) of bone is a progressive, potentially malignant process that destroys skeletal tissue. It consists of multinucleated giant cells, which are hypothesized to be derived from a monocyte/macrophage lineage and mononuclear stromal cells, and the precise relationship of these cells is not fully understood. Recently, we demonstrated that the production of matrix metalloproteinase-9 (MMP-9) in GCT stromal cells is regulated by certain factor(s) secreted by the multinucleated giant cells. In the present study, we evaluated for the presence of interleukin-1beta (IL-1beta) and attempted to establish its possible role for the induction of MMP-9 in GCT stromal cells. Using enzyme-linked immunosorbent assay (ELISA), we have demonstrated that the primary GCT cultures secrete both IL-1beta and MMP-9. The addition of monoclonal antibody (mAb) against IL-1beta partially abrogated, but did not abolish, MMP-9 expression. Our results on gelatin zymography, reverse transcriptase-polymerase chain reaction (RT-PCR), and immunofluorescence showed that GCT stromal cells did not express MMP-9, although treatment with IL-1beta induced MMP-9 expression in a dose-dependent manner, and the secretion peaked 24 h after stimulation and then plateaued. Studies with cycloheximide, a protein synthesis inhibitor, demonstrated that de novo protein synthesis is required for IL-1beta induced MMP-9 expression. Moreover, nuclear run-on analysis has revealed that IL-1beta significantly increased MMP-9 gene transcription in GCT stromal cells. The data suggest that IL-1beta secreted by the multinucleated giant cells in GCT may be one of the factors responsible for the induction of MMP-9 at the transcriptional level in GCT stromal cells in vivo. We conclude that GCT has a self-stimulatory system for the production of MMP-9, and the ability of stromal cells to produce MMP-9 with appropriate stimuli, such as IL-1beta, and possibly in concert with other cytokines may contribute to the aggressive and potentially malignant behavior of GCT.

Regulation of MMP-9 (92 kDa type IV collagenase/gelatinase B) expression in stromal cells of human giant cell tumor of bone.

Matrix metalloproteinases (MMPs) play an important regulatory role in tissue morphogenesis, cell differentiation, tumor invasion and metastasis. Several authors have reported a direct correlation between the production of 72 kDa (MMP-2) and 92 kDa (MMP-9) type IV collagenases/gelatinases and the metastatic potential of cancer cells. Recently, we have identified the expression of both MMP-2 and MMP-9 in primary cultures of human giant cell tumor (GCT) of bone in vitro, and in tissue extracts in vivo. Interestingly, MMP-9 is not secreted by late-passaged GCT cells. It is possible that the production of MMP-9 is regulated by certain factor(s) secreted by the multinucleated giant cells in the primary culture. In order to test this hypothesis, the effect of primary-culture-conditioned medium on the expression of MMP-9 by late-passaged mononuclear stromal cells was examined. Adding conditioned medium from the primary GCT culture to the late-passaged stromal cells induced MMP-9, as evidenced by the presence of lytic bands at M(r) 92,000 and 72,000 on a gelatin zymogram. These enzyme activities were inhibited by EDTA, a well-known inhibitor of the MMPs. We confirmed these results by Western blotting using specific antibodies and RT-PCR for MMP-2 and MMP-9. Immunofluorescence studies with specific antibodies to MMP-9 further confirmed its expression by the passaged stromal cells cultured in the primary-culture-conditioned medium. The data indicate that MMP-2 and MMP-9 are produced by the mononuclear stromal cells when cultured in GCT primary-culture-conditioned medium. This suggests that multinucleated giant cells in primary cultures secrete a factor(s) that stimulates stromal cells to produce MMP-9, which, in turn, may contribute to the aggressive behavior of GCT.

Sister chromatid exchange in aged human lymphocytes. A brief note.

A study of the sister chromatid exchange (SCE) frequency in peripheral lymphocytes from 26 human subjects, with in vivo age of the cells as the variable, demonstrated a significant increase in SCE frequency with increasing age of the subject (analysis of variance: p less than 0.01). The cells were cultured in Eagles' basal medium with 5-bromodeoxyuridine added to a final concentration of 10 microM. These results are contradictive to the brunt of the literature which indicates that background SCE frequency does not change with age.

Chromosomal abnormalities in patients with non-cutaneous T-cell non-Hodgkin's lymphoma. The Nebraska Lymphoma Study Group.

In contrast to non-Hodgkin's lymphomas (NHL) with a B-cell phenotype, almost no data have been reported dealing with correlations between chromosomal abnormalities and characteristics of the disease in patients with T-cell NHL. In a retrospective analysis we studied all patients with a non-cutaneous T-cell NHL and chromosomal abnormalities that were evaluated at our institution; 20 patients could be identified. Numerical abnormalities involving chromosomes 3, 4, 5, 22 and X were observed most frequently. Structural abnormalities involved mainly the breakpoints 1q22-25, 6q23 and 11q13. There appeared to be an association between +7, breakpoints 2p23-24, 4p14-15, 8q21 and the presence of extranodal disease. All patients with +7 had a diffuse mixed histology. Patients with +2, +3, +11, +17, +18, +20 or breakpoint 1q22-25 had an immunoblastic lymphoma and patients with breakpoints 9q32-34 or 14q12 had a lymphoblastic lymphoma. No correlations were observed between chromosomal abnormalities and response to therapy, survival or phenotypic markers. Abnormalities involving the chromosomes containing the T-cell receptor genes and T-cell markers were infrequent. Several breakpoints were identified that correlate with already described oncogenes.

Preferential in-vitro growth and expansion of leukemic T lymphoblasts.

An in-vitro culture system was used to selectively grow malignant cells from the bone marrow of a patient with acute T-lymphoblastic leukemia. Molecular analysis of DNA extracted from the bone marrow cells before culture showed the presence of both rearranged and germ line patterns for the T-cell beta receptor (CTB) gene, and chromosomal analysis revealed the presence of a major and a minor abnormal clone. The cells were cultured in RPMI medium supplemented with 20% fetal calf serum, 2% lymphocyte conditioned medium, L-glutamine and antibiotics. The presence of malignant cells in the cultured population was confirmed by morphologic, molecular probing and cytogenetic analysis. After four weeks in culture, DNA extracted from the cultured cells showed only the rearranged pattern for the CTB gene. Chromosomal analysis of the same cultured sample revealed only the presence of the initially predominant abnormal clone. Shortly thereafter, analysis of fresh uncultured bone marrow cells from the patient in relapse revealed that the same chromosomally abnormal clone also predominated in vivo. Thus, our results demonstrate the selective nature of this culture system and its ability to amplify leukemic T-lymphoblasts. This culture system is also useful for detecting occult malignant cells in histologically normal bone marrow.

Partial deletion of 14q and partial duplication of 14q in sibs: testicular mosaicism for t(14q;14q) as a common mechanism.

The propositus and a subsequently born sister presented with multiple congenital anomalies. Chromosome analyses were performed initially on peripheral blood lymphocytes from the propositus and his parents: the propositus was found to have a deletion of chromosome 14 (q32.11- greater than qter); the parents' chromosomes were normal. When the sister of the propositus was born, she was determined to have a duplication of an equivalent segment of 14qter. Chromosome studies on the parents' fibroblasts demonstrated no structural abnormality or mosaicism. The parents have an older, phenotypically normal, healthy daughter, which supports mosaicism for intragonadal t(14;14)(q32.11;q32.33) in one parent. Chromosome polymorphism comparisons show that the normal number 14 chromosome in the propositus and his sister was inherited from the mother, thus indicating paternal testicular mosaicism. Clinical findings are compared to those of other reported cases of deletion 14q and duplication 14q.