Biochimica et Biophysica Acta (BBA) - Molecular Cell Research
Regular paperHydroxyurea induces apoptosis and regular DNA fragmentation in a Burkitt's lymphoma cell line
Abstract
Hydroxyurea (HU) is an S-phase-specific cytotoxic drug used in the clinical treatment of haematological malignancies. HU treatment has been shown to lead to accumulation of short DNA fragments which show direct correlation with cytotoxicity. Specific regular DNA fragmentation is a biochemical feature of apoptosis (programmed cell death) in some systems. We investigated the effect of HU on a neoplastic (Burkitt's lymphoma) cell line (BM13674) in vitro to determine the role of apoptosis in HU action. HU produced growth inhibition and cell death by apoptosis in BM13674 cells. Low dose HU (66 and 131 μmol/l) gave a growth inhibition effect only with no apoptosis being induced. Higher doses (0.66–13 mmol/l) induced apoptosis in a dose-dependent manner. Regular DNA fragmentation was detected by agarose gel electrophoresis of DNA and this correlated in time with the onset of apoptosis detected by light and electron microscopy. The results do not exclude the possibility that HU directly induces DNA strand breaks, which then initiate apoptosis and accompanying regular fragmentation of DNA in the apoptotic cells.
References (21)
- I.R. Radford et al.
Biochim. Biophys. Acta
(1982) - I.R. Radford et al.
Biochim. Biophys. Acta
(1982) - D.A. Carson et al.
Exp. Cell Res.
(1986) - E. Farber et al.
Cancer Res.
(1969) - D.J. Allan
Int. J. Radiat. Biol.
(1992) - N.I. Walker et al.
Meth. Achiev. Exp. Path.
(1988) - A.I. Aruin et al.
Biul. Exsp. Biol. Med.
(1987) - L.I. Aruin et al.
Biul. Exsp. Biol. Med.
(1989) - K. Ijiri et al.
Br. J. Cancer
(1983) - V.N. Afanas'ev et al.
FEBS Lett.
(1986)
Cited by (27)
Apoptosis may be either suppressed or enhanced with strategic combinations of antineoplastic drugs or anti-IgM
1998, Experimental Cell ResearchA variety of drugs have been used to treat B-lymphocyte neoplasms, including both cell cycle-specific (CCS) and non-cell-cycle-specific drugs. Although the therapy for such cancers is complex and can include both types of drugs, the efficacy of these drugs in inducing cell death remains unclear. In this paper we have concentrated on specific CCS drugs and have examined their ability to induce programmed cell death (apoptosis) in Burkitt's lymphoma cell lines derived from patients. The CCS drugs chosen were hydroxyurea and aphidicolin (active in late G1, early S phase), the topoisomerase poisons camptothecin and etoposide (S, early G2phase) and vincristine and Taxol (late G2, M phase). These choices allow comparison of two drugs with differing modes of action for each of the various phases of the cell cycle. Our results indicate that the variation in apoptosis between drugs that act at the same phase of the cell cycle is negligible. Both S/G2and G2/M blockers are very potent at inducing apoptosis whereas G1/S blockers are ineffective in the induction of apoptosis. In addition, marked kinetic variations in the rate of apoptosis induction were observed, etoposide and camptothecin being more rapid in their action than the other agents. The order of effectiveness in inducing apoptosis on a kinetic basis was S/G2agents ⪢ G2/M agents ⪢ G1/S agents. In this study we have also found that growth inhibition was induced by all the CCS agents chosen and by anti-IgM in various Burkitt's lymphoma lines. Furthermore c-mycwas down-regulated under similar conditions. Since apoptosis was only selectively induced by some of the CCS agents, it implies c-mycexpression is associated with growth regulation and c-myc down-regulation is an insufficient condition for the induction of apoptosis. In addition, cotreatments using the CCS and other agents revealed the following: Cotreatment using two CCS drugs which act at the same stage in the cell cycle showed either no change or only additivity to the effects seen with either agent alone. However, cotreatment with CCS drugs showed that an inhibitory effect is found between G1/S and G2/M drugs or S/G2and G2/M drugs. No effect was found between G1/S and S/G2drugs. Anti-IgM, which by itself was capable of inducing apoptosis, was observed to augment apoptosis induced by very low concentrations of G2/M-acting drugs but it has little effect on G1/S or the S/G2drugs. The inhibitory effect of anti-CD40 or TNF-α on anti-IgM-induced apoptosis did not carry over to an effect on apoptosis induction by the CCS agents. Thus specific combinations of agents may lead to either enhancement, inhibition, or no interactive effect on apoptosis.
TPA induces apoptosis in MPC-11 mouse plasmacytoma cells grown in serum-free medium
1997, Biology of the CellApoptotic-like events could be rapidly induced by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) in cells of the mouse plasmacytoma cell line MPC-11 grown in serum-free medium. Indicators for apoptosis were morphological changes visualized by light and electron microscopy, such as chromatin condensation and the formation of cellular buds and fragments, as well as biochemical indices like the appearance of the so-called ‘DNA ladder’. Additionally, in these cells which are usually devoid of significant amounts of cytoplasmic intermediate filament (cIF) proteins, synthesis and accumulation of the cIF protein vimentin was rapidly induced by TPA treatment and almost all cells became vimentin-positive. Later on, substantial amounts of vimentin and lamin B degradation products appeared, and an increasing fraction of cells displayed low or even undetectable quantities of intact vimentin. This subpopulation was characterized via microscopy to be in the late stages of apoptosis. We suggest that in MPC-11 cells undergoing apoptosis in response to TPA treatment vimentin as well as lamin B are degraded, leading to a rearrangement and eventual loss of their respective filament networks.
Chemotherapy-Induced Apoptosis
1997, Advances in PharmacologyThis chapter focuses on the current state of knowledge regarding the mechanisms by which programmed cell death (PCD) is triggered by cancer chemotherapeutic agents and discusses a series of outstanding questions that require further investigation if the recent observations are to be translated into more successful cancer chemotherapy. PCD generally affects individual cells responding to identifiable physiological or pharmacological signals. It is now clear that many physiologically normal cell deaths, in addition to those associated with development; occur as a result of similar biochemical changes. These biochemical changes are usually associated with a series of stereotypic morphological changes that have been given the name apoptosis. Apoptosis typically begins with cellular shrinkage and condensation of the chromatin. This process of compaction is quickly followed by the disaggregation of the cell into a number of membrane-enclosed “apoptotic bodies,” many of which contain nuclear fragments. When apoptosis occurs in vivo, these apoptotic bodies are efficiently ingested by neighboring cells, an observation that might explain why PCD typically occurs without provoking an inflammatory reaction. To understand and eventually exploit the ability of chemotherapeutic agents to induce PCD, it is essential to have the ability to accurately recognize this mode of cell death. Based on certain criteria, a wide variety of cancer chemotherapeutic agents have been shown to induce PCD in various tumor cell lines in vitro. In vivo observation of chemotherapy-induced Apoptosis establish that cancer chemotherapeutic agents can induce PCD in tissue culture, much less attention has been paid to the question of whether cells die by a similar process when neoplasms undergo chemotherapy-induced regression in animals or people.
Ribonucleotide reductase inhibitors: New strategies for cancer chemotherapy
1996, Critical Reviews in Oncology/HematologyApoptosis in the developing CNS
1995, Progress in NeurobiologyIn this review, apoptosis during normal development of the CNS and abnormal apoptosis inducing hydrocephaly and arhinencephaly will be discussed. As the prominent sites of apoptosis during normal development of the CNS, we focused on the area of fusion of the neural plate to form the neural tube, the developing rhombomeres, and neuronal loss in the CNS during embryogenesis and postnatal development. As examples of abnormal apoptosis inducing abnormal brain morphogenesis, we will discuss genetically induced arhinencephaly and hydrocephaly. It was suggested that apoptosis of the precursor mitral cells in the anlage of the olfactory bulb was induced by non-innervation of olfactory neurons, and apoptosis of the precursor neurons in the pyriform cortex was induced by the non-innervation caused by the death of mitral cells in the mutant arhinencephalic mouse brain (Pdn/Pdn). Thus, sequential apoptosis of the precursor neurons and sequential manifestation of the brain abnormalities were proposed in arhinencephalic mutant mouse embryos and also in the arhinencephalic brains induced experimentally by fetal laser surgery exo utero. Meanwhile, it was speculated that the Gli3 gene, mutation of which is responsible for the arhinencephaly in Pdn/Pdn mice, might play a role in mesenchymal programmed cell death during development.
Apoptosis and programmed cell death in health and disease
1994, Advances in Clinical Chemistry