Microtubule organization in lymphoid malignancies

The abnormal organization of actin-containing microfilaments and vimentin-containing intermediate filaments in neoplastic lymphocytes of T and B cell origin has been described. We investigated microtubules of pathologic cells from 34 lymphoid malignancies, by immunofluorescence microscopy, using monoclonal tubulin antibody. In most cases, apart from two cases of lymphoma, one T cell lymphoma and one B cell lymphoma, interphase leukemia cells, lymphoma cells, and myeloma cells were shown to contain well-organized microtubules which were associated with a microtubule organization center at one end. In the cells of a patient with T cell lymphoma, although microtubules were not visible in the lymphoma cells from lymph nodes, they became visible after 72 hours in culture with concanavalin A (Con A) and interferon alpha. Cap formation was observed with antitubulin monoclonal antibody in the peripheral blood lymphocytes from a chronic lymphocytic leukemia patient, but well-developed microtubules were observed on other occasions in the same patient. There were no obvious structural differences between microtubules in T and B cell lymphoid malignancies, but leukemia cells and lymphoma cells with irregularly shaped nuclei, such as adult T cell leukemia cells and B cell lymphoma cells with cleaved nuclei, had complicated microtubules surrounding their irregular nuclei. In general, after blastogenic stimuli with phytohemagglutinin-P (PHA-P), Con A, and pokeweed mitogen (PWM), the development of the microtubules was proportional to the incorporation of 3H thymidine (3H-TDR). In most cases, after incubation with granulocyte colony-stimulating factor (G-CSF) and interferon alpha, the number of intact cells decreased and the number of degenerated cells increased, but the intact cells had intact microtubules.