Translocation of the p53 gene in t(15;17) in acute promyelocytic leukaemia

p53, cancer and the immune response

The importance of cancer-cell-autonomous functions of the tumour suppressor p53 (encoded by TP53) has been established in many studies, but it is now clear that the p53 status of the cancer cell also has a profound impact on the immune response. Loss or mutation of p53 in cancers can affect the recruitment and activity of myeloid and T cells, allowing immune evasion and promoting cancer progression. p53 can also function in immune cells, resulting in various outcomes that can impede or support tumour development. Understanding the role of p53 in tumour and immune cells will help in the development of therapeutic approaches that can harness the differential p53 status of cancers compared with most normal tissue.

The proportion of cancer-related entries in PubMed has increased considerably; is cancer truly "The Emperor of All Maladies"?

In this work, the public database of biomedical literature PubMed was mined using queries with combinations of keywords and year restrictions. It was found that the proportion of Cancer-related entries per year in PubMed has risen from around 6% in 1950 to more than 16% in 2016. This increase is not shared by other conditions such as AIDS, Malaria, Tuberculosis, Diabetes, Cardiovascular, Stroke and Infection some of which have, on the contrary, decreased as a proportion of the total entries per year. Organ-related queries were performed to analyse the variation of some specific cancers. A series of queries related to incidence, funding, and relationship with DNA, Computing and Mathematics, were performed to test correlation between the keywords, with the hope of elucidating the cause behind the rise of Cancer in PubMed. Interestingly, the proportion of Cancer-related entries that contain “DNA”, “Computational” or “Mathematical” have increased, which suggests that the impact of these scientific advances on Cancer has been stronger than in other conditions. It is important to highlight that the results obtained with the data mining approach here presented are limited to the presence or absence of the keywords on a single, yet extensive, database. Therefore, results should be observed with caution. All the data used for this work is publicly available through PubMed and the UK’s Office for National Statistics. All queries and figures were generated with the software platform Matlab and the files are available as supplementary material.

Nesfatin-1 inhibits proliferation and enhances apoptosis of human adrenocortical H295R cells

NUCB2/nesfatin and its proteolytically cleaved product nesfatin-1 are recently discovered anorexigenic hypothalamic neuroproteins involved in energy homeostasis. It is expressed both centrally and in peripheral tissues, and appears to have potent metabolic actions. NUCB2/nesfatin neurons are activated in response to stress. Central nesfatin-1 administration elevates circulating ACTH and corticosterone levels. Bilateral adrenalectomy increased NUCB2/nesfatin mRNA levels in rat paraventricular nuclei. To date, studies have not assessed the effects of nesfatin-1 stimulation on human adrenocortical cells. Therefore, we investigated the expression and effects of nesfatin-1 in a human adrenocortical cell model (H295R). Our findings demonstrate that NUCB2 and nesfatin-1 are expressed in human adrenal gland and human adrenocortical cells (H295R). Stimulation with nesfatin-1 inhibits the growth of H295R cells and promotes apoptosis, potentially via the involvement of Bax, BCL-XL and BCL-2 genes as well as ERK1/2, p38 and JNK1/2 signalling cascades. This has implications for understanding the role of NUCB2/nesfatin in adrenal zonal development. NUCB2/nesfatin may also be a therapeutic target for adrenal cancer. However, further studies using in vivo models are needed to clarify these concepts.

The p53 family: guardians of maternal reproduction

The p53 family of proteins consists of p53, p63 and p73, which are transcription factors that affect both cancer and development. It is now emerging that these proteins also regulate maternal reproduction. Whereas p63 is important for maturation of the egg, p73 ensures normal mitosis in the developing blastocyst. p53 subsequently regulates implantation of the embryo through transcriptional control of leukaemia inhibitory factor. Elucidating the cell biological basis of how these factors regulate female fertility may lead to new approaches to the control of human maternal reproduction.

Molecular profiling of cancer--the future of personalized cancer medicine: a primer on cancer biology and the tools necessary to bring molecular testing to the clinic

Cancers arise as a result of an accumulation of genetic aberrations that are either acquired or inborn. Virtually every cancer has its unique set of molecular changes. Technologies have been developed to study cancers and derive molecular characteristics that increasingly have implications for clinical care. Indeed, the identification of key genetic aberrations (molecular drivers) may ultimately translate into dramatic benefit for patients through the development of highly targeted therapies. With the increasing availability of newer, more powerful, and cheaper technologies such as multiplex mutational screening, next generation sequencing, array-based approaches that can determine gene copy numbers, methylation, expression, and others, as well as more sophisticated interpretation of high-throughput molecular information using bioinformatics tools like signatures and predictive algorithms, cancers will routinely be characterized in the near future. This review examines the background information and technologies that clinicians and physician-scientists will need to interpret in order to develop better, personalized treatment strategies.

Expression of p53 protein during the cell cycle measured by flow cytometry in human leukemia

The nuclear protein p53 has been reported to be associated with cell transformation and/or proliferation so that the study of p53 expression in human malignancy has potentially important clinical implications. We have analyzed the p53 expression in mitogen-stimulated and nonstimulated human lymphocytes, in several human leukemia cell lines (Molt-4, Raji, Daudi, HL-60, KG-1, K562 and U937) and in fresh bone marrow (BM) cells. Simultaneous differential staining of p53 (identified by a FITC-labeled monoclonal antibody) versus DNA (stained with propidium iodide, PI), followed by bivariate analysis with flow cytometry (FCM) made it possible to evaluate p53 expression with respect to cell position during the cell cycle. The data show that in stimulated lymphocytes p53 is progressively accumulated during the G1, S and G2-phases, while in non-stimulated conditions most cells are remaining in G0/G1 and express p53 to a lesser degree. This suggests that expression of p53 is more correlated with cell growth than with entrance into (or progression through particular phases of) the cell cycle. Cells from acute lymphoblastic leukemia (ALL) and Burkitt's lymphoma cell lines express elevated levels of p53, while all examined human acute myeloid leukemia cell lines synthesize negligible p53 protein. Understanding the variations in p53 expression in different types of human leukemia may provide some insight into the biologic roles of p53 in normal and malignant cells.

ras mutations in human leukemia and related disorders

The clinical association of an increased incidence of acute myelogenous leukemia (AML) with previous chemoradiotherapy, the detection of specific karyotypic changes in these secondary (therapy-induced) cases of AML and the discovery of increasing levels of oncogene-specific RNA in leukemia cells suggest that one potential site of action of environmental agents might be the proto-oncogenes in human hematopoietic stem cells. The location of human proto-oncogenes at the sites of chromosome breaks and/or translocations in cells from some patients with leukemia or lymphoma is a striking observation. These data stimulated research into the mechanism of activation of specific oncogenes that change the biology of human hematopoietic cells. Recent investigations have focused upon several areas that might alter cell biology including: 1) translocation and/or inversion of chromosome fragments containing a proto-oncogene to a location where other gene sequences can stimulate oncogene activation, 2) replication of copy number of proto-oncogenes or increased transcriptional activity and 3) point mutation in proto-oncogenes leading to a structurally altered protein. The third area of research has recently received significant attention with respect to the potential role of three ras genes (c-Harvey-ras, c-Kirsten-ras and N-ras) in human leukemias and myelodysplastic syndromes. Recent studies have proposed a model for leukemogenic transformation of human hematopoietic cells by the product of a mutated ras oncogene. Mutations at codons 12, 13 or 61 of the first exon of its 4.7 Kb of DNA (for c-Ha-ras) have been described. Other data revealing an absence of such mutations in the ras genes of many human leukemias and the absence of detectable transcription of ras genes in many alkylating agent-associated cases of AML, suggest that while ras mutations may be involved in some settings, there are probably multiple genetic pathways to leukemogenic transformation of human hematopoietic cells.

A hypothesis regarding the development of acute myeloid leukemia from preleukemic disorders. The role of protooncogenes

Acute nonlymphocytic leukemia is often preceded by a preleukemic phase that can be characterized by a reduction in hematopoiesis, by ineffective hematopoiesis, or by a myeloproliferative/myelodysplastic state. The time between onset of the preleukemic state and the appearance of leukemia is quite variable, and at times such evolution does not occur. These clinical observations are compatible with the multistep hypothesis of tumor development. In studies underway in our laboratory, chronic myelogenous leukemia (CML) is being used as a model system to study the steps in and possible mechanisms underlying the development of preleukemia and its evolution to acute leukemia. Chronic myelogenous leukemia is particularly suited for this role because the chronic phase of the disease is an easily identifiable myeloproliferative state that invariably evolves into acute leukemia. In the discussion that follows, this clinical entity is used to develop a general model for the preleukemias and their evolution to acute leukemia.

Oncogenes in human leukemias

Eukaryotic cells contain a family of genes termed cellular oncogenes or proto-oncogenes thought to regulate normal cell growth and development. In some abnormal circumstances, such as following transduction by retroviruses, activation of these genes causes leukemias in animals. Possible mechanisms of activation of cellular oncogenes include: point mutation, deletion, or insertion; amplification; activation by internal rearrangement, chromosomal translocation, or promoter insertion; recombinatorial events resulting in the formation of novel chimeric genes; among others. In this review, we consider data implicating activation of cellular oncogenes in the pathogenesis of leukemia in humans. We discuss possible mechanisms whereby oncogene activation may induce leukemias, as well as potential diagnostic and therapeutic implications.

Oncogenes and human leukemias

Eukaryotic cells contain a family of genes termed "cellular oncogenes" or "proto-oncogenes," thought to regulate normal cell growth and development. In some circumstances, such as following transduction by retroviruses, activation of these genes causes tumors and leukemias in animals. Possible mechanisms of cellular oncogene activation include: 1) DNA point mutation, deletion or insertion, 2) gene amplification, 3) gene activation by internal rearrangement, chromosomal translocation or promoter insertion, 4) recombinative events resulting in the formation of novel chimeric genes, and others. In this review, we consider data which implicates cellular oncogene activation in the pathogenesis of leukemia in humans. We discuss possible mechanisms by which oncogene activation may induce leukemias, as well as potential diagnostic and therapeutic implications.

Chromosome marker and enhanced expression of c-Ha-ras in a DMBA-induced erythroleukemia cell line (D5A1)

Oncogene activation induced by chromosomal changes is now regarded as one of the most important phenomena during carcinogenesis. We have reported c-abl activation in a rat leukemia cell line K3D, caused by a secondary chromosomal translocation. Another erythroblastic leukemia cell line D5A1, originally derived from a leukemia induced by 7,12-dimethylbenz(a)anthracene (DMBA) in a Long-Evans rat, is characterized by a marker chromosome 1q+, which also probably occurred as a secondary change. In this cell line, the transcription level of Ha-ras related mRNA increased compared with other cell lines. By the in situ hybridization technique, the c-Ha-ras locus was assigned to 1q43 and the breakpoint 1q+. Because the breakpoint was so near the c-Ha-ras locus on the chromosome, the present system may provide a model of activation of the c-Ha-ras gene brought about by chromosomal translocation.

The molecular genetics of human non-Hodgkin's lymphoma

There is increasing evidence to implicate oncogenes in the etiology of Burkitt's and non-Burkitt's non-Hodgkin's lymphoma. Some of these oncogenes have been identified because of their location at common breakpoints, some because they have been found by transfection assays to be activated, and some because they have been shown to be expressed in non-Hodgkin's lymphomas. So far there is no consistent pattern of involvement between specific oncogenes and specific subtypes of non-Hodgkin's lymphoma. This may be because more than one oncogene is necessary for transformation.

The physical map of Mus musculus chromosome 11 reveals evolutionary relationships with different syntenic groups of genes in Homo sapiens

The physical localization of sequences homologous to three cloned genes was determined by in situ hybridization to metaphase chromosomes. Previous work had assigned the skeletal myosin heavy chain gene cluster (Myh), the functional locus for the cellular tumor antigen p53 (Trp53-1), and the cellular homologue of the viral erb-B oncogene (Erbb) to Mus musculus chromosome 11 (MMU11). Our results provide regional assignments of Myh and Trp53-1 to chromosome bands B2----C, and of Erbb to bands A1----A4. Taken together with in situ mapping of three other loci on MMU 11 (Hox-2 homeobox-containing gene cluster, the Sparc protein, and the Colla-1 collagen gene), which have been reported elsewhere, these data allowed us to construct a physical map of MMU11 and to compare it with the linkage map of this chromosome. The map positions of the homologous genes on human chromosomes suggest evolutionary relationships of distinct regions of MMU11 with six different human chromosome arms: 1p, 5q, 7p, 16p, 17p, and 17q. The delineation of conserved chromosome regions has important implications for the understanding of karyotype evolution in mammalian species and for the development of animal models of human genetic diseases.

Identification of an amplified, highly expressed gene in a human glioma

A gene, termed gli, was identified that is amplified more than 50-fold in a malignant glioma. The gene is expressed at high levels in the original tumor and its derived cell line and is located at chromosome 12 position (q13 to q14.3). The gli gene is a member of a select group of cellular genes that are genetically altered in primary human tumors.

Correlation between acquired pseudo-Pelger-Huet anomaly and involvement of chromosome 17 in chronic myeloid leukemia

Acquired pseudo-Pelger-Huet neutrophils appeared in the peripheral blood of 11 of 83 Philadelphia-positive chronic myeloid leukemia patients during the blastic phase of the disease. Chromosomal analysis performed at the time of pseudo-Pelger appearance showed karyotype evolution with involvement of the short arms of a chromosome #17. In eight cases an i(17q) was present, in two cases an unbalanced translocation, and in one case monosomy. All these rearrangements had in common the loss of the distal end of the short arm. The morphologic and chromosomal study of the remaining 72 chronic myeloid leukemia patients demonstrated neither pseudo-Pelger nor 17p involvement.

Isochromosome 17q in a patient with acute myeloblastic leukemia

This report describes a case of acute myeloblastic leukemia (FAB type M2) with i(17q) as the sole cytogenetic abnormality. This is a rare finding in acute nonlymphocytic leukemia, not previously reported in the M2 subtype of this disorder.

Characterization of the human p53 gene

Cosmid and lambda clones containing the human p53 gene were isolated and characterized in detail. The gene is 20 kilobases (kb) long and has 11 exons, the first and second exons being separated by an intron of 10 kb. Restriction fragments upstream of sequences known to be within the first identified exon were tested for promoter activity by cloning them in front of the chloramphenicol acetyltransferase gene and transfecting the resulting constructs into HeLa cells. A 0.35-kb DNA fragment was identified that had promoter activity. Results of primer extension experiments indicated that the mRNA cap site falls within this fragment, as expected. Analysis of the sequence upstream of the presumptive cap site indicated that the human p53 promoter may be of an unusual type.

Localization of a novel v-erbB-related gene, c-erbB-2, on human chromosome 17 and its amplification in a gastric cancer cell line

The c-erbB-2 gene is a v-erbB-related proto-oncogene which is distinct from the gene encoding the epidermal growth factor receptor. By using two independent methods, hybridization of both sorted chromosomes and metaphase spreads with cloned c-erbB-2 DNA, we mapped the c-erbB-2 locus on human chromosome 17 at q21, a specific breakpoint observed in a translocation associated with acute promyelocytic leukemia. Furthermore, we observed amplification and elevated expression of the c-erbB-2 gene in the MKN-7 gastric cancer cell line. These data suggest possible involvement of the c-erbB-2 gene in human cancer.

Acute promyelocytic transformation of chronic myeloid leukaemia with an isochromosome 17q

Transformation to an acute promyelocytic leukaemia occurred in a patient approximately 2 years after having been diagnosed as suffering from chronic myeloid leukaemia (CML). At this time, in addition to the Ph1 chromosomal aberration, an isochromosome 17q [i(17q)] was noted. The t(15:17) was absent. The implications of this are discussed.

Variant translocation t(8;22) and abnormalities of chromosome 15(q22) and 17(q12-21) in a Burkitt's lymphoma/leukaemia with disseminated intravascular coagulation

Severe disseminated intravascular coagulation was observed in a patient with Burkitt's lymphoma/leukaemia. Immunological studies on leukaemic blasts from relapsed bone marrow revealed a B-cell phenotype (B4+, B1+, HLA-Dr+, J5+) with membrane bound IgM lambda. Cytogenetic investigation revealed a variant Burkitt's translocation t(8;22)(q24;q11) involving the lambda light chain gene region and abnormalities of chromosomes 15 and 17 with breakpoints at q22 and q12 respectively, similar to those observed in the t(15;17) in acute promyelocytic leukaemia. Transmission electron microscopy of the leukaemic blasts showed crystalline cytoplasmic inclusions which may have had a role in precipitating the disseminated intravascular coagulation.

Identification of the p53 protein domain involved in formation of the simian virus 40 large T-antigen-p53 protein complex

An expression vector utilizing the enhancer and promoter region of the simian virus 40 (SV40) DNA regulating a murine p53 cDNA clone was constructed. The vector produced murine p53 protein in monkey cells identified by five different monoclonal antibodies, three of which were specific for the murine form of p53. The murine p53 produced in monkey cells formed an oligomeric protein complex with the SV40 large tumor antigen. A large number of deletion mutations, in-frame linker insertion mutations, and linker insertion mutations resulting in a frameshift mutation were constructed in the cDNA coding portion of the p53 protein expression vector. The wild-type and mutant p53 cDNA vectors were expressed in monkey cells producing the SV40 large T antigen. The conformation and levels of p53 protein and its ability to form protein complexes with the SV40 T antigen were determined by using five different monoclonal antibodies with quite distinct epitope recognition sites. Insertion mutations between amino acid residues 123 and 215 (of a total of 390 amino acids) eliminated the ability of murine p53 to bind to the SV40 large T antigen. Deletion (at amino acids 11 through 33) and insertion mutations (amino acids 222 through 344) located on either side of this T-antigen-binding protein domain produced a murine p53 protein that bound to the SV40 large T antigen. The same five insertion mutations that failed to bind with the SV40 large T antigen also failed to react with a specific monoclonal antibody, PAb246. In contrast, six additional deletion and insertion mutations that produced p53 protein that did bind with T antigen were each recognized by PAb246. The proposed epitope for PAb246 has been mapped adjacent (amino acids 88 through 109) to the T-antigen-binding domain (amino acids 123 through 215) localized by the mutations mapped in this study. Finally, some insertion mutations that produced a protein that failed to bind to the SV40 T antigen appeared to have an enhanced ability to complex with a 68-kilodalton cellular protein in monkey cells.

Monoclonal antibody analysis of p53 expression in normal and transformed cells

The cellular phosphoprotein p53 binds tightly and specifically to simian virus 40 T antigen and the 58,000-molecular-weight adenovirus E1b protein. Many human and murine tumor cell lines contain elevated levels of the p53 protein even in the absence of these associated viral proteins. Recently the cloned p53 gene, linked to strong viral promoters, has been shown to complement activated ras genes in transformation of primary rodent cell cultures. Overexpression of the p53 gene alone rescues some primary rodent cell cultures from senescence. We isolated three new monoclonal antibodies to the p53 protein, designated PAb242, PAb246, and PAb248, and mapped the epitopes they recognized on p53 in comparison with other previously isolated antibodies. At least five sterically separate epitopes were defined on murine p53. One of the antibodies, PAb246, recognizes an epitope on p53 that is unstable in the absence of bound simian virus 40 T antigen. This effect is demonstrable in vivo and in newly developed in vitro assays of T-p53 complex formation. Using the panel of anti-p53 antibodies and sensitive immunocytochemical methods, we found that p53 has a predominantly nuclear location in established but not transformed cells as well as in the vast majority of transformed cell lines. Several monoclonal antibodies to p53 showed cross-reactions with non-p53 components in immunocytochemical staining.

Characterization of the human p53 gene

Cosmid and lambda clones containing the human p53 gene were isolated and characterized in detail. The gene is 20 kilobases (kb) long and has 11 exons, the first and second exons being separated by an intron of 10 kb. Restriction fragments upstream of sequences known to be within the first identified exon were tested for promoter activity by cloning them in front of the chloramphenicol acetyltransferase gene and transfecting the resulting constructs into HeLa cells. A 0.35-kb DNA fragment was identified that had promoter activity. Results of primer extension experiments indicated that the mRNA cap site falls within this fragment, as expected. Analysis of the sequence upstream of the presumptive cap site indicated that the human p53 promoter may be of an unusual type.

Diagnosis of genetic disease using recombinant DNA

Recombinant DNA technology promises to make an important contribution to the analysis and diagnosis of inherited human disease. Direct detection and analysis of various genetic defects at the DNA level are now possible using cloned gene or oligonucleotide probes. In addition, the use of restriction fragment length polymorphisms associated with linked DNA segments should permit not only the diagnosis of hitherto undetectable disease states but also the chromosomal localization of the loci responsible. The eventual isolation of disease loci should lead to a better understanding of the molecular basis of inherited disease.

In vitro models for studying the molecular biology of carcinogenesis

Although carcinogens cause various similar deleterious effects on rodent and human cells, only rodent cells can convert to malignancy in a quantitative, predictable fashion. Therefore, the control mechanisms involving indefinite proliferation and tumorigenicity are different. Human cell lines may exhibit normal or aneuploid chromosome constitutions with numerical or structural alterations frequently involving proto-oncogene loci, but fail to produce progressively growing tumors in nude mice. A new approach for obtaining human cells susceptible to malignant transformation by chemical or physical carcinogens is to use DNA from a cancer associated virus. Transfection of human papilloma virus (HPV) DNA associated with genital cancer can extend life-span of human cells; post-X-irradiated cells grow in agar suspension. Southern blot analysis of extracted DNA indicates that HPV sequences persist. Similar results are obtained with human fibroblast and epithelial cells.

Localization of gene for human p53 tumour antigen to band 17p13

Recently the gene for the cellular tumour antigen p53, a phosphoprotein found in increased concentration in a variety of human cells, had been mapped to region 17q22 by in situ hybridization techniques and has been shown to translocate to the chromosome carrying the translocation [t(15; 17)] associated with acute promyelocytic leukaemia (APL). Based on this finding it has been postulated that this gene has a role in the pathogenesis of APL. Here we present evidence that the gene for p53 is not located on the long arm of chromosome 17, but maps to band 17p13. We therefore suggest that this gene is not directly involved in the chromosome translocation observed in APL.

Localization of a novel v-erbB-related gene, c-erbB-2, on human chromosome 17 and its amplification in a gastric cancer cell line

The c-erbB-2 gene is a v-erbB-related proto-oncogene which is distinct from the gene encoding the epidermal growth factor receptor. By using two independent methods, hybridization of both sorted chromosomes and metaphase spreads with cloned c-erbB-2 DNA, we mapped the c-erbB-2 locus on human chromosome 17 at q21, a specific breakpoint observed in a translocation associated with acute promyelocytic leukemia. Furthermore, we observed amplification and elevated expression of the c-erbB-2 gene in the MKN-7 gastric cancer cell line. These data suggest possible involvement of the c-erbB-2 gene in human cancer.

The nerve growth factor receptor gene is at human chromosome region 17q12-17q22, distal to the chromosome 17 breakpoint in acute leukemias

Genomic and cDNA clones for the human nerve growth factor receptor have been used in conjunction with somatic cell hybrid analysis and in situ hybridization to localize the nerve growth factor receptor locus to human chromosome region 17q12-q22. Additionally, part, if not all, of the nerve growth factor receptor locus is present on the translocated portion of 17q (17q21-qter) from a poorly differentiated acute leukemia in which the chromosome 17 breakpoint was indistinguishable cytogenetically from the 17 breakpoint observed in the t(15;17)(q22;q21) translocation associated with acute promyelocytic leukemia. Thus the nerve growth factor receptor locus may be closely distal to the acute promyelocytic leukemia-associated chromosome 17 breakpoint at 17q21.

Human p53 gene localized to short arm of chromosome 17

The p53 gene codes for a nuclear protein that has an important role in normal cellular replication. The concentration of p53 protein is frequently elevated in transformed cells. Transfection studies show that the p53 gene, in collaboration with the activated ras oncogene, can transform cells. Chromosomal localization may provide a better understanding of the relationship of p53 to other human cellular genes and of its possible role in malignancies associated with specific chromosomal rearrangements. A recent study mapped the human p53 gene to the long arm of chromosome 17 (17q21-q22) using in situ chromosomal hybridization. Here, by Southern filter hybridization of DNAs from human-rodent hybrids, we have localized the p53 gene to the short arm of human chromosome 17.

In situ hybridization--application to gene localization and RNA detection

In situ hybridization offers a direct approach for localization and quantitation of nucleic acid sequences in cellular preparations. Recent improvements in technology and methodology make possible the detection of DNA and RNA of relatively low copy number. For example, development of in situ hybridization methods for detection of single copy DNA sequences on mitotic chromosomes has led to general use of this technique for gene mapping of the human genome. More recently, improvements in methodology for detection of low abundancy RNA make possible a facilitated analysis of gene expression, both from cellular genes and exogenous sequences, such as viral genomes. In situ hybridization is now a powerful method for studying nucleic acid organization and function in normal cells, as well as in malignant cells, which should contribute to better understanding of the cell transformation process.

The technique of premature chromosome condensation to study the leukemic process: review and speculations

The technique of premature chromosome condensation involves the fusion of mitotic cells with interphase cells resulting in the immediate condensation of the interphase chromatin into discrete chromosome units, the prematurely condensed chromosomes (PCC). The ability to visualize the interphase chromosomes of bone marrow and blood cells by this technique has proved useful in the study of human leukemia. This article describes how the PCC technique has been used to predict clinical outcome as well as gain insight into the biology of leukemia.