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S J Collins

Publications and source records attributed to S J Collins.

87 records · Page 5Linked to original sources
PubMed1986

Breakpoints on chromosomes 9 and 22 in Philadelphia chromosome-positive chronic myelogenous leukemia (CML). Amplification of rearranged c-abl oncogenes in CML blast crisis.

We surveyed 20 Philadelphia chromosome (Ph1) positive chronic myelogenous leukemia (CML) samples by Southern blot hybridization to determine the location of the breakpoints that occur on chromosomes 9 and 22 in the Ph1 translocation. Only 3 of 20 samples exhibited breakpoints on chromosome 9 within 18 kilobases (kb) of the v-abl homologous sequences. Mapping of these three chromosome 9 breakpoints indicates that each is at a separate location within this 18-kb region, indicating that there are no breakpoint "hot spots" in this area. In contrast, all 20 CML samples exhibited breaks on chromosome 22 within a 5.0-kb Bgl II fragment that lies within the previously described breakpoint cluster region (bcr). Several patients with CML blast crisis exhibiting multiple Ph1 chromosomes/metaphase exhibited amplified and rearranged c-abl-related fragments. These additional Ph1 chromosomes in blast crisis cells do not arise from a second, independent 9:22 translocation but rather result from a duplication of the preexisting Ph1 chromosome.

Cell Line↗
PubMed1985

Cell lines and clinical isolates derived from Ph1-positive chronic myelogenous leukemia patients express c-abl proteins with a common structural alteration.

The Philadelphia chromosome (Ph1), observed in greater than 90% of chronic myelogenous leukemia (CML) patients, results from a specific chromosomal translocation involving the c-abl gene. The translocation breakpoint occurs near c-abl and correlates with the production of an altered c-abl mRNA. In the CML-derived cell line K562, Ph1 is accompanied by a structurally altered c-abl protein (P210c-abl) with in vitro tyrosine kinase activity not detected with the normal c-abl protein (P145c-abl). We have examined c-abl proteins in other Ph1-positive CML cell lines and found that they all express P210c-abl. P210c-abl was also detected in bone marrow cells from CML patients with Ph1 in the accelerated and blast crisis phases of the disease. Comparison of the [35S]methionine-labeled tryptic peptides generated from the normal P145c-abl and P210c-abl showed that they have closely related structures, but additional polypeptide sequences are present in P210c-abl. Based on these results we propose that translocation of c-abl in Ph1-positive CML results in the creation of a chimeric gene leading to the production of a structurally altered c-abl protein with activated tyrosine kinase activity. The altered P210 c-abl protein is strongly implicated in the pathogenesis of CML.

Cell Line↗
PubMed1984

Altered transcription of the c-abl oncogene in K-562 and other chronic myelogenous leukemia cells.

Expression of the cellular abl (c- abl ) oncogene was studied in K-562 and other chronic myelogenous leukemia (CML) cells and cell lines by means of Northern blot hybridization. In contrast to non-CML cells, which contained 7.4- and 6.8-kilobase abl -related transcripts, the CML cells contained a predominant and novel 8.2-kilobase abl -related RNA. In addition, the levels of abl -related message were up to eight times higher in CML cell lines from patients at the blast crisis stage of the disease compared with CML cells obtained during the chronic phase and with non-CML cells.

Animals↗
PubMed1983

Rearrangement and amplification of c-abl sequences in the human chronic myelogenous leukemia cell line K-562.

Structural rearrangements of specific cellular sequences (c-onc genes) homologous to acute transforming retrovirus oncogenes (v-onc genes) have been recently described in various malignancies. Here we show that human cellular sequences (c-abl) homologous to the transforming sequences of the mouse Abelson leukemia virus (v-abl) are amplified some 4- to 8-fold in K-562, a Philadelphia chromosome-positive cell line derived from a patient with chronic myelogenous leukemia in blast crisis. Restriction analysis of K-562 and other human DNA samples reveals a significant rearrangements of the c-abl sequences in this cell line. In addition, investigation of v-abl-related cytoplasmic RNA reveals relatively high levels of these sequences in K-562 compared to other normal and leukemia cells. We have also observed that lambda light chain constant region immunoglobulin genes are amplified in K-562, whereas kappa light chain sequences exhibit no amplification. These results are discussed within the context of the possibility that these Philadelphia chromosome-positive cells exhibit a reciprocal translocation involving chromosome 9 (containing c-abl) and chromosome 22 (containing the lambda light chain genes).

Cell Line↗
PubMed1983

Clonal nature of mink cell focus-inducing virus-induced AKR leukemia: studies with X-chromosome inactivation cellular mosaicism.

The number of cells from which murine thymic leukemias (thymomas) develop after neonatal injection with a mink cell focus-inducing recombinant virus was studied in AKR mice heterozygous at the X-linked phosphoglycerate kinase (PGK) locus. Because only one of the two X-chromosomes is active in XX somatic cells, thymic leukemias that are clonal should display either type A or type B PGK but not both, whereas those with a multicellular origin may exhibit both enzymes. In 23 of 25 animals studied, thymomas expressed exclusively (11 animals) or predominantly (12 animals) a single enzyme in contrast to normal tissue which expressed both enzyme types in approximately equal ratios. In the 12 thymomas expressing a minor enzyme component, the predominant enzyme in the original tumor always predominated in the thymomas arising in animals transplanted with the original tumors, indicating that this minor PGK component was not contributed by malignant cells. The results indicate that the great majority of recombinant virus-induced AKR leukemias are clonal.

Animals↗
PubMed1982

Clonal nature of spontaneous AKR leukemia: studies utilizing the X-linked enzyme phosphoglycerate kinase.

AKR mice heterozygous at the X-linked phosphoglycerate kinase (PGK) locus were used in experiments to determine the number of cells from which spontaneous thymic leukemias (thymomas) develop. Because only one of the two X-chromosomes is active in XX somatic cells, thymic leukemias that are clonal should display either type A or type B PGK, but not both, while those that are multicellular in origin may exhibit both enzymes. Spontaneous thymomas from 19 PGK heterozygous animals expressed exclusively (11 tumors) or predominantly (8 tumors) a single enzyme in contrast to non-malignant tissue from these animals which expressed both enzyme types in approximately equal ratios. When primary tumors expressing a single or predominant enzyme type were transplanted, the transplanted tumors invariably displayed the PGK phenotype that predominated in the initial tumor indicating that the minor PGK component was not contributed by malignant cells. These results indicate that spontaneous AKR leukemias are clonal.

Animals↗
PubMed1981

Terminal differentiation of human promyelocytic leukemic cells in primary culture in response to retinoic acid.

The recent finding that retinoic acid induces terminal granulocytic differentiation of the human promyelocytic leukemia cell line, HL-60, prompted an investigation of the sensitivity to this inducer of human myelocytic leukemia cells in primary suspension culture. Of the 21 leukemic specimens, only cells from the two patients with acute promyelocytic leukemia differentiated in response to retinoic acid. After an incubation period of 5--7 days in 1 microM retinoic acid, the cells from these two patients showed extensive morphological and functional maturation. Thus, because it appears that retinoic acid specifically induces granulocytic differentiation of leukemic promyelocytes, this compound may have therapeutic utility in the treatment of acute promyelocytic leukemia.

Adolescent↗
PubMed1981

Clonal analysis of the response of human myeloid leukemic cell lines to colony-stimulating activity.

The recent development of two continuously proliferating human myeloid leukemic cell lines (HL-60 and KG-1) that response to CSA provides an opportunity for a detailed study of the interaction of CSA with leukemic myeloid cells. Here we report on the colony-forming ability of HL-60 and KG-1 over an extended culture life of the cells. Several different sources of human CSA of different stages of purity enhanced colony formation of these cells. CSA, obtained from conditioned media from an SV-40 transformed human trophoblast, was partially purified, and its activity for normal bone marrow copurified with the activity that stimulated HL-60 colony formation. Over 100 clones of HL-60 were developed and tested for their response to CSA. All responded to CSA by showing an increase in colony size and number. However, none of the colonies formed from any of the 100 clones differentiated in response to CSA despite the fact that many chemical can induce differentiation of HL-60. since HL-60 forms spontaneous colonies without the addition of any exogenous stimulating factors, HL-60 conditioned media and cell extracts were tested for the production by these cells of their own endogenous growth-promoting activity (such as a CSA-like molecule). No growth-promoting endogenous activity was found that stimulated normal bone marrow or HL-60 colony formation even after concentration and fractionation methods were employed. These experiments suggest that: (1) the effect of CSA markedly favors proliferation over differentiation in these cell lines; (2) CSA is unlikely to suppress growth of the age of the type of leukemic myeloid cells that HL-60 and KG-1 represent; and (3) if HL-60 cells produce their own growth-promoting factor it is not detectable in the media.

Cell Line↗
PubMed1980

Induction of morphological and functional differentiation of human promyelocytic leukemia cells (HL-60) by componuds which induce differentiation of murine leukemia cells.

Various compounds active in promoting in vitro differentiation of certain murine leukemia cell lines (Friend erythroleukemia cells and mouse myeloid leukemia cells) were tested for their capacity to induce differentiation of HL-60 cells, a human promyelocytic leukemia cell line capable of terminally differentiating in vitro to functionally mature granulocytes. Polar planar compounds including hexamethylene bisacetamide (HMBA), certain purines (particularly hypoxanthine), and actinomycin-D induced morphological and functional (as assessed by the capacity to reduce NBT dye) differentiation of HL-60. In contrast, hemin, ouabain, prostaglandin E1, X-irradiation, dexamethasone and some other anti-leukemic chemotherapeutic agents induced little if any significant differentiation of HL-60 cells. These results, together with previous observations with murine leukemia cells, suggest that the human HL-60 cells share common cellular target sites for the inducing action of polar planar compounds, hypoxanthine and actinomycin-D with some murine leukemic cells. In contrast, hemin, ouabain and prostaglandin E1 may be specific for mouse erythroleukemia cells, while X-irradiation and chemotherapeutic agents induce differentiation of both types (erythroid and myeloid) of mouse leukemic cells, but have little effect on HL-60 cells.

Animals↗
PubMed1980

Induction of differentiation of the human promyelocytic leukemia cell line (HL-60) by retinoic acid.

The HL-60 cell line, derived from a patient with acute promyelocytic leukemia, proliferates continuously in suspension culture and consists predominantly (greater than 90%) of promyelocytes. These cells can be induced to differentiate to morphologically and functionally mature granulocytes by incubation with a wide variety of compounds, including butyrate and hypoxanthine and polar planar compounds such as dimethyl sulfoxide and hexamethylene bisacetamide. We have now found that retinoic acid (all-trans-retinoic acid) induces differentiation (as measured morphologically and by the ability to reduce nitroblue tetrazolium) of HL-60 at concentrations as low as 1 nM. Maximal differentiation (approximately 90%) occurs at 1 micro M, a concentration 1/500th to 1/160,000th the concentrations of butyrate (0.5 mM) and dimethyl sulfoxide (160 mM) that promote a similar increase in differentiation. Continuous exposure to retinoic acid is necessary for optimal differentiation, with the percentage of mature cells in the culture directly related to the length of time of exposure to retinoic acid. Retinoic acid and 13-cis-retinoic acid are equally effective in inducing differentiation of HL-60. Retinol (vitamin A), retinal, and retinyl acetate are approximately 1/1000th less potent. This study suggests that retinoids could provide a therapeutic tool in the treatment of acute myeloid leukemia, a disease that has been looked upon as primarily involving a block in myeloid differentiation, and indicates that retinoids, in addition to their well-characterized involvement in epithelial cell differentiation, may also be involved in the differentiation of certain hematopoietic cells.

Cell Differentiation↗
PubMed1979

Normal functional characteristics of cultured human promyelocytic leukemia cells (HL-60) after induction of differentiation by dimethylsulfoxide.

The HL-60 human promyelocytic leukemia cell line can be induced to terminally differentiate to mature myeloid cells sharing a number of functional characteristics with normal granulocytes including response to chemoattractants, development of complement receptors, phagocytosis, superoxide production, and nitroblue tetrazolium dye reduction. Hence the Me2SO-induced HL-60 cells provide a unique in vitro model for studying various important aspects of human myeloid cell differentiation.

Binding Sites↗
PubMed1978

Terminal differentiation of human promyelocytic leukemia cells induced by dimethyl sulfoxide and other polar compounds.

A human leukemic cell line (designated HL-60) has recently been established from the peripheral blood leukocytes of a patient with acute promyelocytic leukemia. This cell line displays distinct morphological and histochemical commitment towards myeloid differentiation. The cultured cells are predominantly promyelocytes, but the addition of dimethyl sulfoxide to the culture induces them to differentiate into myelocytes, metamyelocytes, and banded and segmented neutrophils. All 150 clones developed from the HL-60 culture show similar morphological differentiation in the presence of dimethyl sulfoxide. Unlike the morphologically immature promyelocytes, the dimethyl sulfoxide-induced mature cells exhibit functional maturity as exemplified by phagocytic activity. A number of other compounds previously shown to induce erythroid differentiation of mouse erythroleukemia (Friend) cells can induce analogous maturation of the myeloid HL-60 cells. The marked similarity in behavior of HL-60 cells and Friend cells in the presence of these inducing agents suggests that similar molecular mechanisms are involved in the induction of differentiation of these human myeloid and murine erythroid leukemic cells.

Butyrates↗