Role of Bcl-2 family proteins and caspase-3 in sanguinarine-induced bimodal cell death.

Sanguinarine, a benzophenanthridine alkaloid, has anticancer potential through induction of cell death. We previously demonstrated that sanguinarine treatment at a low level induced apoptosis or programmed cell death (PCD) in the Bcl-2 low-expressing K562 human erythroleukemia cells, and that a high level induced blister cell death (BCD); whereas Bcl-2 overexpressing, sanguinarine-treated JM1 pre-B lymphoblastic cells displayed neither apoptosis nor BCD morphologies. Here, we report that sanguinarine-treated K562 cells, when analyzed by western blot, showed significant increase in expression of the pro-apoptotic Bax protein in apoptosis, but not in BCD. cDNA expression array of PCD in K562 cells failed to reveal the presence of Bax at the gene transcript level, which suggests that this cell death process does not require de novo protein synthesis. Treated JM1 cells, on the other hand, showed an increase in the expression of Bcl-2 protein in both forms of cell death, but failed to show Bax expression. The role of other members of the Bcl-2 family remained negligible. Caspase-3 activation was observed in apoptosis of K562 cells but not in BCD or in sanguinarine-treated JM1 cells. These results suggest that sanguinarine in K562 cells induces apoptosis through increasing Bax and activating caspase-3, whereas sanguinarine-induced BCD involves neither. These results also suggest that in JM1 cells, Bcl-2 may play a role in susceptibility of cells to induction of apoptosis and BCD.

[The nucleolar apparatus of the lymphoid cells in AKR mice at different stages of leukemogenesis]. / Nukleoliarnyi apparat limfoidnykh kletok myshei linii AKR na razlichnykh étapakh leikozogeneza.

Morphological features of nuclear apparatus in mice leukemic cells of the peripheral blood, lymph nodes, thymus, bone marrow and spleen were studied. These cells were taken from 12-months-old AKR mice. Enlarged percentage of cells with nucleolar lipid component in thymus characterizes preleukemic state for 6-months-old AKR line mice.

Platelet aggregation and electron microscopic studies of platelets in preleukemia.

Platelet aggregation and electron microscopic studies of platelets were carried out at the time of diagnosis in 11 patients thought to have preleukemia. The clinical course confirmed the diagnosis of preleukemia in seven, of whom platelet aggregation had been performed in six and the results were abnormal in all. Electron microscopic studies were performed in six of the seven, and showed abnormal morphologic structure in five. One patient was unavailable for follow-up, and aplastic anemia developed in another. In time, two patients were seen to have nonmalignant blood disorders. Results of platelet aggregation studies were normal in both of these, but electron microscopy showed morphologic abnormalities. Platelet aggregation is useful in confirming the diagnosis of preleukemia. Electron microscopy of platelets is not so clearly helpful.

Diagnostic and prognostic significance of chromosome abnormalities in marrow and mitogen response of lymphocytes of acute nonlymphocytic leukemia.

Chromosomes of bone marrow from 28 patients with acute nonlymphocytic leukemia (ANLL) (26 with AML, 2 with AMMoL), 19 of whom had chromosome abnormalities, were studied; 11 cases exhibited previously unreported karyotypic abnormalities. The marrows of two cases had 8-21 translocations associated with an iso-X chromosome in the female patient and with 9q13- and a missing Y in the male patient. Usually, AML patients with a 8-21 translocation have been considered to have a good prognosis; however, our cases had rather short survival times. Therefore, the prognosis of AML with an 8-21 translocation but associated with other abnormalities is still not clear. Centromere spreading (CS), which was originally reported in marrow cells of megaloblastic anemia (B12 and folic acid deficiency), was detected in leukemic cells, disappeared during remission, and reappeared on relapse. These findings suggest that CS may be a new type of abnormality in AML. In two patients with atypical hypoplastic anemia and hemolytic anemia, chromosome abnormalities were detected at the anemic stage. One case with CS was associated with atypical hypoplastic anemia and developed AML after 1 year; the other with 48,XY,+i(1q),+3,/12 and -14 had hemolytic anemia and developed AMMoL 3 weeks later. Interestingly, identical clones were detected both before and after the clinical diagnosis of leukemia. These cases strongly support the concept that some chromosome abnormalities precede the clinical manifestations of leukemia. The present study also revealed that lymphocytes in ANLL respond poorly to PHA in the presence of high numbers of blasts but do respond well to mitogens during remission. Therefore, the response of lymphocytes to PHA may serve as one criterion for determining remission.

Ultrastructural diagnosis of large cell 'undifferentiated' neoplasia.

Large cell undifferentiated neoplasia' provides a generic designation for a heterogeneous group of neoplasms which by histological study, are devoid of discriminate architecture and appear under the light microscope as patternless sheets of large cytoplasmic cells. The interpretation of such a tumour will routinely present significant problems in differential diagnosis. By conventional light microscopy the neoplasm may subjectively be judged to represent a certain form of carcinoma or large cell lymphoma, but often identification is relegated to a label of "consistent with', or "undifferentiated malignant neoplasm'. Such interpretations are not acceptable and preclude rational management decisions. This paper has analysed tumour cell ultrastructure derived from a spectrum of clinicopathological situations involving the diagnostic problem of the large cell undifferentiated neoplasm. The fine structural morphologies of these enigmatic tumours are often sufficiently specific to allow resolution of the differential diagnosis and assignment of cell type. Diagnostic electron microscopy, in coordination with histopathology and clinical information, will often play a significant role in solving complex problems involving the differential diagnosis of large cell undifferentiated neoplasms.

Aberrant megakaryocytopoiesis preceding radiation-induced leukemia in the dog.

Six of nine decedent beagles exposed continuously to 2.5 R*/22 hour day of whole-body 60Co gamma-radiation died with myeloproliferative diseases: three cases of myelogenous leukemia and one each of monocytic leukemia, erythroleukemia, and erythremic myelosis. The three dogs that died with myelogenous leukemia had micromegakaryocytes and megakaryoblasts in the peripheral blood during the preleukemic phase when myeloblasts were not observed in the peripheral blood or in increased numbers in the bone marrow. In this study we have examined the megakaryocytes during the preleukemic period by a combination of light, transmission, and scanning electron microscopy. Morphologic abnormalities seen by light microscopy included mononucleated and binucleated forms, many with cytoplasmic blebs. The small mononuclear forms in the bone marrow tended to form clusters. Ultrastructural features included a paucity of both specific alpha granules and dense granules. The micromegakaryocytes showed dysgenesis of the demarcation membrane system. This membrane system appeared disorganized with a few dilated round, oval, or rarely, elongated vesicles and showed no evidence of platelet formation. The cells also had a paucity of endoplasmic reticulum, few mitochrondria, and sparse glycogen accumulations. The scarcity of cytoplasmic organelles gave a pale immature appearance to the cytoplasm. By scanning electron microscopy, the sponge-like surface of large mature megakaryocytes from unirradiated marrow contrasted with the characteristically smooth, topographically featureless surfaces of the micromegakaryocytes from preleukemic dogs.

Preleukemias.

A chromosomally abnormal clone is demonstrable in the bone marrow of a significant number of patients with hemic disorders that carry an increased risk for the subsequent development of leukemia. These "preleukemia" states include a variety of cytopenias, myeloproliferative disorders, and childhood syndromes. The cytogenetic alterations that occur nonrandomly in these dyscrasias are often similar to those observed in acute nonlymphocytic leukemia and in the accelerated phase of chronic granulocytic leukemia: monosomy for chromosome 7; trisomy for 8,9,21, and the long arm of 1(1q); deletions of 5 and 20 (5q-, 20q-); and an isochromosome derived from 17 (iso 17q). These findings support the view that despite clinical differences, these various preleukemic disorders are all characterized by the presence in the hematopoietic tissues of a clone of cells derived from an altered hemic stem cell. Furthermore, the data suggest that preleukemia, chronic leukemia, and acute leukemia may be fundamentally similar diseases, differing primarily in the rate at which the aberrant clone is expanding. Chromosome studies may be of prognostic value in the cytopenic preleukemias. Patients with abnormalities show a decreased survival and are at increased risk for progression to acute nonlymphocytic leukemia. In the myeloproliferative disorders and the preleukemic childhood disorders, cytogenetic alterations are not clearly predictive, and aberrant clones may persist for years without clinical progression.

Intracellular "labyrinths" in acute leukaemia. Do they indicate the maturational ability of leukaemic cells?

The occurrence and ultrastructure of the so-called "labyrinths" were investigated in the bone marrow cells from 13 patients with preleukaemia and acute leukaemia. Except for one patient, labyrinths were found in the myeloid cells from patients with preleukaemia and acute myelogenous leukaemia. Labyrinths could not be detected in lymphoblasts from patients suffering from acute lymphoblastic leukaemia or in plasma cells from a patient with plasma cell leukaemia. In patients with preleukaemia and smoldering leukaemia, labyrinths could be detected in all differentiation forms, from myeloblasts to mature polymorphonuclear granulocytes. Since it is improbable that labyrinths develop in consequence of exogenous effects, their presence in the mature granulocytes points to the in vivo maturational ability of leukaemic precursors in certain cases of acute myelogenous leukaemia and preleukaemia.

Atypical leukemia--relation to chronic myelomonocytic leukemia.

An autopsy case of a 71-year-old man with atypical leukemia was reported. The interesting points in this case were the followings: (1) three clonal proliferations; granulocytic, monocytic, megakaryocytic; (2) abnormality of several kinds of blood cells; (3) phagocytosis of granular leucocytes within megakaryocytes; (4) elevation of anti-EB virus antibody, and (5) detection of herpes-type virus-like particle in the nucleus of monocytoid cell in peripheral blood. Relationship between atypical leukemia and chronic myelomonocytic leukemia was also discussed.

A combined assay for the rapid preliminary detection of structural retroviruses.

This report describes the use of equilibrium gradients, RNA dependent DNA polymerase assays and electron microscopy (EM) in a combined assay for the rapid preliminary detection of intact retroviruses in crude preparations. Positive combined assays of platelets from preleukemic patients corresponded with karyotypic abnormalities found in these patients. Reconstruction experiments with Rauscher Leukemia Virus added to buffer or disrupted mouse spleen demonstrated the ease of detecting 10(9) or greater particles/g crude tissue, and the effects of buffer or added protein.