Characterization of A U‐937 subline which can be induced to differentiate in serum‐free medium

Abstract

We report the selection and characterization of a U-937 subline which is capable of long-term growth in serum-free medium and can be induced to differentiate. The subline (U-937-1SF) can be maintained in standard RPMI-1640 medium supplemented by antibiotics only. As compared to the serum-dependent U-937 parental cell line, U-937-1SF produced lower amounts of lysozyme and elastase and had a decreased surface expression of complement receptor 1 (CD35) and myeloid antigens CDw17 and CD38. Apart from these alterations, the U-937-1SF cells appear to be morphologically, cytogenetically and phenotypically similar to the parental U-937 clone-1 cells. The capacity of U-937 clone-1 cells to undergo phorbol myristic acid (PMA)-, vitamin D3 (VitD3)- and retinoic-acid (RA)-induced differentiation was retained in the U-937-1SF cells as evidenced by the induced growth arrest, development of a monocyte/macrophage morphology and increased expression of differentiation-associated antigens, e.g. CD11b, CD11c, CD14 and CD18. The growth-inhibitory response to cytokines involved in the activation and differentiation of monocytes, IFN-gamma, TNF-alpha, IL-1 beta, IL-6 and GM-CSF, was normal. Our results suggest that the U-937-1SF subline can be used as a serum-free model system for studies on various aspects of monocyte differentiation.

Differential regulation of vitamin D receptor expression in distinct leukemic cell lines upon phorbol ester-induced growth arrest

“…The kinetic properties of HL-60-uninduced cells determined by us are similar to those described by Mehdi et al (37). The potential doubling time of U937 cells resulting from the double label technique confirms previous data obtained by analysis of growth curves (38). However, in K562 cells, the potential doubling time we obtained by bivariate distributions of BrdUrd labeling versus DNA content was lower than that determined before by growth curve experiments (39).…”

Syk and Lyn phosphorylation induced by FcγRI and FγRII crosslinking is determined by the differentiation state of U-937 monocytic cells

“…The maturation-promoting effect of 1␣,25-di-hydroxyVitamin D3 (calcitriol) on monocytic cell lines has been reported by several authors [19][20][21][22][23]. As expected, U-937 cells treated with 100 nM calcitriol for 72 h, showed many differentiation-related changes, such as an increase in CD14 and CR3 expression, lower proliferation rate, and adherence to the plastic surfaces (Fig.…”

“…1). Oberg et al [20] reported an increase in the percentage of U-937 cells expressing CD14, but they did not show the magnitude of the increment in the cell population. We found a ninefold increase in CD14 expression after 72 h of incubation with 100 nM calcitriol.…”