Regulation of the Proliferation of the Established Human Monoblast Cell Line, U937, at the Single Cell Level1
نویسندگان
چکیده
U937 cells, an established monoblast or early monocyte cell line, were assessed as a model in vitro for the regulation of cell growth at the single cell level. Colony formation by 500 U937 cells, preinduced to a state of responsiveness to lactoferrin (LF) by incubation with human y Interferon was suppressed by LF. LF-suppressed colony formation was restored by partially purified growth activity derived from U937 cells. The release of growth factor(s) into conditioned medium required concentrations of >51III U937 cells/ml and this release was dependent on the length of time that the cells conditioned the culture medium. This release was suppressed by LF. U937 cells were induced to a state of responsiveness to LF by incubation with human 7 Interferon, washed, and plated as a single cell per well. Individual cells formed colonies with a cloning efficiency of -50% which equalled the cloning efficiency detected when 500 U937 cells/ml were plated, suggesting that U937 colony forming cells might contain endogenous growth activity. Detection of these endogenous growth activities required the use of LF. The cloning efficiency of individually isolated U937 cells was suppressed by -50% with LF, similar to the LF suppression of colony formation when 500 cells/ml were plated. That the LF-suppressed U937 colony forming cells required growth activity was suggested as the cloning efficiency of LF-suppressed individually isolated U937 colony forming cells was restored by partially purified U937 growth activity. Partially purified U937 growth activity did not stimulate, enhance, or inhibit colony formation by normal human bone marrow granulocyte-macrophage progenitors. U937 cells can thus serve as a useful model for the study of growth regulation at the level of a single cell.
منابع مشابه
CYTOTOXIC ACTIVITY OF THYMUS VULGARIS, ACHILLEA MILLEFOLIUM AND THUJA ORIENTALIS ON DIFFERENT GROWING CELL LINES
The cytotoxic activity of ethanolic extracts of Thymus vulgaris, Thuja orientalis and Achillea millefolium was investigated on various growing tumor cell lines. MTT colorimetric assay was used for measuring the inhibition of cell proliferation. All of the three extracts showed a relatively dose-dependent inhibition of proliferation of human breast cancer (SK-Br-3, MDA-MB-435) and leukemia ...
متن کاملStudy of Cytotoxic Activity of Daphne Mucronata Royle Grown in Iran
Background: Plants are a proven source of anti-tumor compounds and it is reasonable to assume that many such substances remain to be discovered. In Iranian folk medicine, ethanolic extract of the aerial parts of Daphne mucronata Royle is used against various skin disorders.Objective: In order to evaluate anti-neoplastic plants, we initiated a cytotoxic study using Daphne mucronata that is indig...
متن کاملTHE EFFECT OF HYPERTHERMIA ON THE DIFFERENTIATION OF LEUKEMIC CELL LINES
Treatment of human promonocytic leukemic cell line U937 with mild hyperthermia in the temperature range of 40-43°C resulted in differentiation of these cells into monocyte/macrophage-like cells in a heat dose and time dependent manner. This process was accompanied by marked morphological, functional and proliferational changes. U937 cells which normally grow in supension in the logarithmic...
متن کاملProfiles of MMP-2 Expression in Jurkat, Molt-4 and U937 Cells
Background: Leukemia is a malignant proliferative disorder of the hematopoietic cells. The important role of angiogenesis in leukemia has been reported by several studies. Matrix metalloproteinases (MMPs) are a large group of endopeptidases which degredate the extracellular matrix and play an important role in angiogenesis. Objective: The present study was conducted to evaluate the patterns of ...
متن کاملDevelopment and Cytogenetic Characterization of a Continuous Bovine Kidney Cell Line (IRKHBK) and Evaluation its Susceptibility to some Viruses
In this syudy a continuous bovine kidney cell line derived from a primary bovine kidney cells was established for the first time in Iran. The cells were originating from two-day-old normal male calf of Holstein breed. The cell cultures were continuously passaged following complete proliferation of primary cells. The specific properties or characteristics of the cell were defined using cytogenet...
متن کامل