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J D Rowley

Publications and source records attributed to J D Rowley.

At least 145 records · Page 8Linked to original sources
PubMed1992

Hyperdiploidy arising from near-haploidy in childhood acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) of childhood is frequently characterized by a hyperdiploid karyotype. Typically, most of the affected chromosomes in the abnormal clone are present in three copies. We have studied two patients with hyperdiploid ALL whose leukemic cells were atypical in that all or most of the chromosomes were present in either two or four copies, raising a suspicion that the observed karyotype arose through duplication of chromosomes in a precursor cell with a near-haploid chromosome number. Analysis of restriction fragment length polymorphisms confirmed that both cases arose from a near-haploid cell; all informative disomic chromosomes tested had loss of heterozygosity. Furthermore, the hyperdiploid karyotypes did not arise via a perfect haploid cell with exactly 23 chromosomes, because tetrasomic chromosomes remained heterozygous. These two patients probably are classified best as near-haploid cases, which often are observed to have a co-existing hyperdiploid clone with a duplicated chromosome set. The distinction between typical hyperdiploidy and hyperdiploidy arising via a near-haploid cell may be clinically important, because the prognosis for patients with a hyperdiploid karyotype is favorable in comparison to that of patients with a near-haploid karyotype.

Adolescent↗
PubMed1992

The der(11) chromosome contains the critical breakpoint junction in the 4;11, 9;11, and 11;19 translocations in acute leukemia.

Translocations involving 11q23 are recurring abnormalities in human acute leukemia cells of either lymphoid or myeloid lineage. Analysis of 13 variant translocations associated with four of these [t(4;11), t(6;11), t(9;11) and t(11;19)] reveals that the der(11) chromosome is conserved in all of them and therefore contains the critical genetic rearrangement. The MLL gene (myeloid/lymphoid leukemia) is involved in each of these translocations. It is transcribed from centromere to telomere. The present analysis indicates that the 5' region of MLL on the der(11) is juxtaposed to the coding sequences of genes on each of the other translocation partners.

Acute Disease↗
PubMed1992

A method for the rapid sequence-independent amplification of microdissected chromosomal material.

We have developed a simple, efficient method by which microdissected material can be amplified directly in the collection container in a few hours. The procedure involves two initial rounds of DNA synthesis with T7 DNA polymerase, using a primer that contains a random pentanucleotide sequence at its 3' end and a defined sequence at its 5' end, followed by PCR amplification with the defined sequence as the primer. The resulting products can be biotinylated and used for fluorescence in situ hybridization (FISH) to confirm their chromosomal location. As few as 17 dissected chromosomal regions provide sufficient material for a specific FISH signal on the appropriate band of metaphase chromosomes. We have obtained a chromosome 6q25-qter-specific painting probe in this way.

Base Sequence↗
PubMed1992

Therapy-related acute myeloid leukemia secondary to inhibitors of topoisomerase II: from the bedside to the target genes.

In the past five years, several groups have reported acute myeloid leukemia (AML) often monoblastic, as a complication of chemotherapy regimens including the epipodophyllotoxins, etoposide and teniposide. This syndrome is distinct clinically, pathologically and cytogenetically from classical therapy-related myelodysplasia and AML. There is also evidence that other topoisomerase II inhibitors, such as the intercalating agents (including doxorubicin, mitoxantrone, and actinomycin D) may be leukemogenic. Furthermore, there may be further interactions from concomitant topoisomerase II inhibitors and alkylating agents. Topoisomerase II inhibitors induce DNA cleavage and other chromosomal aberrations, including sister chromatid exchanges. These clastogenic abnormalities are not fully understood, and may be specific for each cytotoxic agent. Work is in progress to clone breakpoints such as the t(9;11) and t(8;21) and the use of the resultant DNA probes will enhance our understanding of the leukemogenic process. Given the potential diversity in patients with secondary leukemia, cytogenetic studies should be mandatory for both enhancing our knowledge base and guiding treatment in individual patients. Clinicians must also be wary of the leukemogenic potential of 'dose-intense' regimens including agents such as etoposide and doxorubicin.

Acute Disease↗
PubMed1991

Identification of a gene, MLL, that spans the breakpoint in 11q23 translocations associated with human leukemias.

Recurring chromosomal translocations involving chromosome 11, band q23, have been observed in acute lymphoid leukemias and especially in acute myeloid leukemias. We recently showed that breakpoints in four 11q23 translocations, t(4;11)(q21;q23), t(6;11)(q27;q23), t(9;11)(p22;q23), and t(11;19)(q23;p13.3), were contained within a yeast artificial chromosome clone bearing the CD3D and CD3G gene loci. We have identified within the CD3 yeast artificial chromosome a transcription unit that spans the breakpoint junctions of the 4;11, 9;11, and 11;19 translocations, and we describe two other, related transcripts that are upregulated in the RS4;11 cell line. We have named this gene MLL (myeloid/lymphoid, or mixed-lineage, leukemia.

Adult↗
PubMed1991

Therapy-related myelodysplastic syndrome and acute myeloid leukemia in children: correlation between chromosomal abnormalities and prior therapy.

We have studied 20 children with therapy-related myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) who were 3 months to 16 years old at diagnosis of their primary neoplasm and 1 to 24 years old at diagnosis of their secondary neoplasm. The median interval from initial treatment for the first malignancy to diagnosis of therapy-related MDS or AML was 46 months (range, 12 to 116 months). Twelve patients had chromosomal abnormalities resulting in loss of material from the long arm of chromosomes 5 and/or 7, three patients had abnormalities of chromosome 11 band q23, one patient had both classes of abnormalities, three patients had other abnormalities, and one patient had a normal karyotype. Ten of 12 patients with chromosome 5 and/or 7 abnormalities had been exposed to an alkylating agent, and two of three patients with 11q23 abnormalities had been exposed to an epipodophyllotoxin. The patient with both classes of abnormalities had been exposed to both types of therapy. We conclude that abnormalities of chromosomes 5 and/or 7 are common in children with therapy-related MDS or AML. The proposed relationships between exposure to alkylating agents and abnormalities of chromosomes 5 and/or 7 and between exposure to epipodophyllotoxins and abnormalities of 11q23 are supported in this pediatric series.

Adolescent↗
PubMed1991

Isolation of a yeast artificial chromosome spanning the 8;21 translocation breakpoint t(8;21)(q22;q22.3) in acute myelogenous leukemia.

The 8;21 translocation is one of the most common specific rearrangements in acute myelogenous leukemia. We have identified markers (D21S65 and a Not I boundary clone, Not-42, referred to as probe B) flanking the chromosome 21 translocation breakpoint (21q22.3) that demonstrate physical linkage in normal genomic DNA, by using at least three restriction endonucleases (Not I, Sac II, and BssHII), and that are located not more than 250-280 kilobases apart. Pulsed-field gel analysis of DNA from somatic cell hybrids containing the 8;21 translocation chromosomes demonstrates rearrangement of these markers. A 470-kilobase yeast artificial chromosome, YAC-Not-42, has been isolated that contains both probes. Mapping of lambda subclones constructed from YAC-Not-42 suggests that greater than 95% (25/26 probes tested) of the yeast artificial chromosome DNA is located on the proximal (D21S65) side of the breakpoint. In situ hybridization studies using metaphase chromosomes from five acute myelogenous leukemia patients with the 8;21 translocation confirmed these results and demonstrated the translocation of probe B to the derivative chromosome 8. A chromosome walk of approximately 39 kilobases from probe B has allowed identification of the breakpoint in DNA from a somatic cell hybrid containing the derivative chromosome 8. Since probe B contains conserved DNA sequences and is in close proximity to the translocation breakpoint, it may represent a portion of the involved gene on chromosome 21.

Blotting, Southern↗
PubMed1991

The LCK gene is involved in the t(1;7)(p34;q34) in the T-cell acute lymphoblastic leukemia derived cell line, HSB-2.

HSB-2 is a cell line derived from a patient who had T-cell acute lymphoblastic leukemia (T-cell ALL) with a t(1;7)(p34;q34). We used a genomic probe from the T-cell receptor beta (TCR beta) locus (7q34) to identify DNA rearrangements in HSB-2. Two rearranged BglII DNA fragments were cloned, and one of these clones was shown to contain the translocation breakpoint on the derivative chromosome I [der(I)]. We used a probe derived from this clone to isolate an unrearranged phage clone encompassing the breakpoint at Ip34. The restriction map of this clone was compared to the published maps of known protooncogenes located at Ip32-34. By restriction mapping, Southern blot analysis, and DNA sequencing we showed that the translocation breakpoint on chromosome I is located within the first intron of the LCK gene. The LCK gene codes for p56lck, a member of the SRC family of cytoplasmic tyrosine protein kinases. There are two classes of LCK transcripts (type I and type II), each expressed from a distinct promoter, and each having a unique 5' untranslated region (UTR); the protein coding regions of the two classes are identical. The breakpoint in the t(1;7) separates the two LCK promoters and juxtaposes the constant region of the TCR beta locus with the proximal promoter and with the protein-coding region of the LCK gene on the der(I) chromosome.

Base Sequence↗
PubMed1991

The proportion of abnormal karyotypes in acute leukemia samples related to method of preparation.

Bone marrow and peripheral blood were studied from 200 patients with acute leukemia [109 with acute myeloid leukemia (AML), 91 with acute lymphoblastic leukemia (ALL)] who had samples cultured for varying times and who had a mixture of chromosomally abnormal and normal cells. The mean percentage of abnormal metaphase cells increased with culture time. The peak was reached at 48 hours and declined slightly after 72 hours in culture for ALL patients. The mean percentage of abnormal cells increased up to 72 hours in culture for AML patients. In 68 patients (31 AML and 37 ALL), cytogenetic data were available from samples processed with both direct preparations and culture methods. The percentage of abnormal cells increased after culture in 49 patients (23 AML and 26 ALL), while it decreased or remained at the same level in 19 patients. For AML patients, the mean percentage of abnormal cells was significantly different between direct (38%) and cultured preparations (63%), (p less than 0.001). Seven of 9 patients with AML who showed a greater than 50% increase in abnormal cells after culture had either a t(8;21), t(15;17), or abnormalities involving 11q23. The two patients who showed a significant decrease in abnormal cells both had a translocation involving 11q13. Compared with ALL, more AML patients showed greater than 80% abnormal bone marrow metaphase cells at diagnosis or at relapse.

Acute Disease↗
PubMed1990

t(3;21)(q26;q22): a recurring chromosomal abnormality in therapy-related myelodysplastic syndrome and acute myeloid leukemia.

We have identified an identical reciprocal translocation between the long arms of chromosomes 3 and 21 with breakpoints at bands 3q26 and 21q22, [t(3;21)(q26;q22)], in the malignant cells from five adult patients with therapy-related myelodysplastic syndrome (t-MDS) or acute myeloid leukemia (t-AML). Primary diagnoses were Hodgkin's disease in two patients and ovarian carcinoma, breast cancer, and polycythemia vera in one patient each. Patients had been treated with chemotherapy including an alkylating agent for their primary disease 1 to 18 years before the development of t-MDS or t-AML. We have not observed the t(3;21) in over 1,500 patients with a myelodysplastic syndrome or acute myeloid leukemia arising de novo or in over 1,000 patients with lymphoid malignancies. We have previously reported that the t(3;21) occurs in Philadelphia chromosome-positive chronic myelogenous leukemia (CML). Thus, the t(3;21) appears to be limited to t-MDS/t-AML and CML, both of which represent malignant disorders of an early hematopoietic precursor cell. These results provide a new focus for the study of therapy-related leukemia at the molecular level.

Acute Disease↗
PubMed1990

Deletions of interferon genes in acute lymphoblastic leukemia.

Structural rearrangements involving the short arm of chromosome 9, including bands 9p21 and 22, are found in the leukemia cells of 7 to 13 percent of patients with acute lymphoblastic leukemia. The interferon-alpha gene cluster and the interferon-beta 1 gene have been localized to this chromosomal region. We have previously demonstrated deletions of these genes in several cell lines established in vitro from patients with lymphoblastic leukemia. We report here homozygous or hemizygous deletions of the interferon-alpha and interferon-beta 1 genes in samples of leukemia cells from patients with lymphoblastic leukemia. Of 62 patients examined, 18 (29 percent) had such deletions. Four patients (7 percent) had homozygous deletions of the interferon-alpha gene cluster; of these, one also had a homozygous deletion and three had hemizygous deletions of the interferon-beta 1 gene. Fourteen patients (23 percent) had hemizygous deletions of both the interferon-alpha gene cluster and the interferon-beta 1 gene. In 8 of the 18 patients with deletions, the deletions of interferon genes were submicroscopic; in the 11 other patients, chromosomal rearrangements of 9p, including translocations or deletions, were visible on light microscopy. These chromosomal and molecular deletions are likely to be related to the loss of a tumor-suppressor gene (or genes) located on 9p, which may be an interferon gene or an unrelated but closely linked gene.

Adolescent↗
PubMed1990

Clinical, morphologic, and cytogenetic characteristics of patients with lymphoid malignancies characterized by both t(14;18)(q32;q21) and t(8;14)(q24;q32) or t(8;22)(q24;q11).

Six patients with an aggressive leukemia/lymphoma disorder had a t(14;18) as well as either a t(8;14) (three patients) or a t(8;22) (three patients). Leukemia cells from all three patients with the t(8;22) had a mature B cell phenotype (Smlg + and TdT-), whereas two of three patients with the t(8;14) had a pre-B phenotype and were Smlg-. None of the patients with the t(8;22) had a prior history of follicular lymphoma, whereas two of the three patients with the t(8;14) had had a follicular lymphoma. The clinical, cytogenetic, and morphologic characteristics of these six patients along with eight previously reported cases with both the t(14;18) and the t(8;14), the t(8;22) or the t(2;8) are discussed.

Adult↗
PubMed1990

Mapping chromosome band 11q23 in human acute leukemia with biotinylated probes: identification of 11q23 translocation breakpoints with a yeast artificial chromosome.

Translocations involving chromosome 11, band q23, are frequent recurring abnormalities in human acute lymphoblastic and acute myeloid leukemia. We used 19 biotin-labeled probes derived from genes and anonymous cosmids for hybridization to metaphase chromosomes from leukemia cells that contained four translocations involving band 11q23: t(4;11)(q21;q23), t(6;11)(q27;q23), t(9;11)(p22;q23), and t(11;19)(q23;p13). The location of the cosmid probes relative to the breakpoint in 11q23 was the same in all translocations. Of the cosmid clones containing known genes, CD3D was proximal and PBGD, THY1, SRPR, and ETS1 were distal to the breakpoint on 11q23. Hybridization of genomic DNA from a yeast clone containing yeast artificial chromosomes (YACs), that carry 320 kilobases (kb) of human DNA including CD3D and CD3G genes, showed that the YACs were split in all four translocations. These results indicate that the breakpoint at 11q23 in each of these translocations occurs within the 320 kb encompassed by these YACs; whether the breakpoint within the YACs is precisely the same in the different translocations is presently unknown.

Adult↗
PubMed1990

Cytogenetic analysis of 51 patients with chronic myeloid leukemia.

The Ph1 translocations were observed in 43 of the 51 patients with chronic myeloid leukemia (CML). Of the 43 patients with Ph1 chromosome, 19 (45%) had other structural abnormalities. Complex translocations were observed in 5 patients (12%). Twenty-eight patients with Ph1-positive CML have been followed up genetically.

Humans↗