Differentiation Of Murine Neuroblastoma Cells Research Articles

Aluminum speciation and morphological differentiation in murine neuroblastoma cells.

Aluminum is known as a neurotoxic metal ion in experimental animals as well as in humans. The present study was carried out to determine whether and how the physicochemical properties of the metal coordination sphere (metal speciation) can influence the differentiation of murine neuroblastoma cells as has been observed previously in this laboratory (1). Results herein reported indicate that while the aluminum lipophilic species--particularly aluminum acetylacetonate (Alacac3) and aluminum maltolate (Almalt3), both hydrolitically stable and differently lipophilic--are both rather cytotoxic, metal hydrophilic species show different neuritogenic properties indicating the ability of Al(III), when diversely coordinated, to produce different biological effects.

Ayurvedic (science of life) agents induce differentiation in murine neuroblastoma cells in culture

Many Indian Ayurvedic (science of life) agents have been introduced into the U.S.A. as food supplements. Two of them, Maharishi Amrit Kalash-Ambrosia (MAK-A) and Maharishi Amrit Kalash-Nectar (MAK-N) are under investigation. This study shows that an ethanol extract of MAK-A induced morphological (neurite formation) and biochemical (increase of activity of tyrosine hydroxylase by about 15-fold) differentiation in murine neuroblastoma (NBP 2) cells in culture, whereas an aqueous extract of MAK-A increased only the activity of tyrosine hydroxylase but to a much lesser extent. The treatment time of 3 days was needed for the expression of maximum differentiation. Ethanol extracts of MAK-A and aqueous extracts of MAK-A increased the intracellular level of adenosine 3',5'-cyclic monophosphate (cAMP) by about 4-fold in 3 days but they did not do so in 15 min. Ethanol extracts of MAK-A also induced neurite formation in neuroblastoma cells grown in serum free medium but the concentration requirement was about a fifth of that needed in serum. The treatment time of 24 hr was sufficient to induce optimal differentiation in neuroblastoma cells grown in serum free medium. The differentiating agents in ethanol-MAK-A were resistant to heat and light and could not be removed by treatment with activated charcoal. Neither ethanol-MAK-N nor aqueous-MAK-N induced differentiation in neuroblastoma cells, suggesting that the differentiating agents were present only in MAK-A.

Effect of cytidine analogs on cell growth and differentiation on a human neuroblastoma line

The cytidine analog 5-AZA-2'-deoxycytidine (5-AZA-CdR) has been demonstrated to induce cellular differentiation; on the other hand, induction of differentiation has been suggested as a possible form of therapy for leukemic cells. We have evaluated the possibility that the neuroblastoma malignant tumor growth could be controlled by treatment that promotes the differentiation of immature tumor cells. We have previously reported on differentiation of murine neuroblastoma cells (41A3) treated with 5-AZA-CdR. In this paper, we describe the effect of 5-AZA-CdR on human neuroblastoma cell line CHP-100. The drug-treated cells show some degree of differentiation, demonstrated by morphological and biochemical markers. A significant DNA hypomethylation and partial inhibition of DNA synthesis and cell proliferation is also observed. This effect is more stable than that caused by another cytidine analog, Cytosine-beta-D-Arabinofuranoside (ARA-C).

A short-term screening test for teratogens using differentiating neuroblastoma cells in vitro.

Thirty-nine teratogenic and 18 nonteratogenic compounds were tested using an assay based on the ability of agents to interfere with normal growth and differentiation of murine neuroblastoma cells (clone N1E-115) in culture. Induction of differentiation in cells under growth-promoting conditions and inhibition of differentiating cells over a period of 7 days was dose-dependent, with the lowest effective dose not being highly toxic. Eighty-six percent of the compounds were correctly identified by the assay. The proportions of both false negatives (10%) and false positives (22%) were of the same order or better than in current, comparable tests. The possibilities offered by the system in rapid screening for teratogenic potential of environmental agents are discussed.

The effects of serine protease inhibitors on morphological differentiation of murine neuroblastoma cells (NB 15)

Morphological differentiation of neuroblastoma cells (NB15) was induced by cAMP effectors in the presence and absence of serine protease inhibitors. In all conditions tested, the percent differentiation was inhibited by protease inhibitors antipain, diisopropylfluorophosphate (DFP), leupeptin, and soybean trypsin inhibitor (SBTI). The level of morphological differentiation obtained in medium containing fetal calf serum was significantly less than the percent differentiation obtained with serum-free medium alone, so serum-free medium was the principal method of induction and comparisons were made to control uninduced cultures or cultures induced with the phosphodiesterase inhibitor R020-1724. Secreted or cell surface caseinolytic protease activity was higher in differentiating cells than in control cultures and was inhibited by the serine protease inhibitors. The effects of the protease inhibitors on growth and differentiation are discussed.

Induction of differentiation in murine neuroblastoma cells by mevinolin, a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase

Mevinolin, a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, stimulated outgrowth of neurites and increased acetylcholinesterase activity in C1300-N2A murine neuroblastoma cells cultured in medium containing 10% fetal calf serum. Changes in cell morphology and enzyme activity were concentration-dependent in the range of 0.25–25 μM mevinolin, and were accompanied by decreased incorporation of [ 3H]thymidine into DNA. The expression of differentiated characteristics induced by 25 μM mevinolin was blocked by simultaneous addition of 100 μM mevalonate to the culture medium. The data suggest that changes in intracellular levels of mevalonate or one of its isoprenoid derivatives may play a role in the regulation of cell differentiation.

Accumulation of histone H1(0) during chemically induced differentiation of murine neuroblastoma cells.

A basic nuclear protein with properties similar to lysine-rich histones accumulates during differentiation in vitro of C1300 murine neuroblastoma cells (clone Neuro-2a) induced by either n-butyrate, dimethyl sulfoxide, hexamethylene bisacetamide or 1,6-dibutyryl-adenosine 3',5'-monophosphate. A protein with the same electrophoretic properties, present in adult mouse brain cell nuclei in amounts similar to those in the induced neuroblastoma cells, has been characterized as histone H1(0). Digestion of the two proteins with Staphylococcus aureus V8 protease gives identical peptide maps (sharing no common peptides with those of histones H1A or H1B), which indicates that the induced protein qualifies as H1. Accumulation of histone H1(0) in neuroblastoma cell nuclei accompanies shutoff of DNA synthesis and transgression of the cells into a G1-phase resting state. Upon removal of n-butyrate the cells resume proliferation and their H1 content decreases, indicating an association of H1 with the resting state during which differentiated cellular functions are expressed.

Morphological differentiation of murine neuroblastoma induced by liposomes lipid specificity and pathway of liposome uptake

A variety of phospholipid vesicles (liposomes) induce morphological differentiation in murine neuroblastoma cells in vitro. This effect is observed when such vesicles are incubated with cells either continuously or for short periods of time in the presence or absence of serum, is not mediated by a specific mode of liposome-cell interaction, and is accompanied by a significant retardation of cell proliferation. Besides phospholipids, fatty acids are also capable of inducing neurite outgrowth in a dose-dependent fashion and thus appear to mediate this effect.

Morphological differentiation of a murine neuroblastoma clone in monolayer culture induced by dexamethasone

Dexamethasone induces morphological differentiation in murine neuroblastoma cells in culture. The percentage of differentiated cells depends on the concentration of dexamethasone in the medium and duration of treatment. After drug removal (with or without replating), many cells maintain their differentiated phenotype. Dexamethasone-treated cells have larger soma and contain more protein. Dexamethasone also produces a concentration-dependent inhibition of population growth. Growth inhibition is complete by 2 days following treatment with dexamethasone 50 μg/ml. Complete growth inhibition is achieved prior to the complete expression of morphological differentiation. Androstenedione, testosterone, and 17-β-estradiol—all steroids without glucocorticoid activity—have no differentiating effect, although they inhibit growth or cause cell death at higher concentrations.

Inhibition of replication and differentiation in malignant mouse neuroblasts

Two specific inhibitors of DNA synthesis, cytosine arabinoside and methotrexate, are shown to induce morphologic differentiation in a malignant murine neuroblastoma line. This differentiation occurs in full serum concentrations and allows the cells to be viably maintained for up to one month. Coincident with differentiation is an arrest in the production of a cytoplasmic virus found in all cells. The relationship of arrest of cell cycling to other means of inducing differentiation in murine neuroblastoma cells is briefly discussed.