Sensitivity of camptothecin-resistant human leukemia cells and tumors to anticancer drugs with diverse mechanisms of action

Pantazis, Panayotis; Vardeman, Dana; Mendoza, John; Early, Janet; Kozielski, Anthony J.; DeJesus, Albert; Giovanella, Beppino C.

doi:10.1016/0145-2126(94)00060-n

Cited by 10 publications

(13 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1,2 The effect of these two drugs has been widely studied on cell lines stemmed from solid tumors (e.g. osteoblastoma, 3 hepatoblastoma, 4 colon carcinoma 5 neuroblastoma 6 or glioma 7 ), or hematopoietic cell lines such as promyelocytic, 8 monocytic 9 or lymphoid (CEM 10 and Jurkat 11,12 ) leukemia cell lines. Topoisomerase inhibitors can induce either inhibition of proliferation or apoptosis, depending on the cell line tested.…”

Section: Introductionmentioning

confidence: 99%

The topoisomerase inhibitors camptothecin and etoposide induce a CD95-independent apoptosis of activated peripheral lymphocytes

et al. 2000

View full text Add to dashboard Cite

The effect of etoposide and camptothecin, two topoisomerase inhibitors directed against topoisomerases II and I, respectively, was evaluated on human peripheral blood lymphocytes. Etoposide and camptothecin induced apoptosis of mitogen-activated but not resting CD4 + and CD8 + T lymphocytes. Cell sensitivity to these agents required G 1 to S-phase transition of the cell cycle. Conversely, daunorubicin, an intercalating agent and topoisomerase II inhibitor, induced apoptosis of both resting and activated lymphocytes. Although etoposide and camptothecin induced CD95-ligand mRNA expression, drug-induced apoptosis of activated human lymphocytes was not inhibited by CD95 antagonists. Drug-induced cell death was also not inhibited by p55 TNFR-Ig fusion protein. Activation of the caspases cascade was suggested by the partial inhibitory effect of the tripeptide zVAD-fmk and documented by activation of caspase 3. Finally etoposide and camptothecin induced a rapid production of ceramide in activated but not resting peripheral blood lymphocytes, suggesting that ceramide might initiate the signaling apoptotic cascade in sensitive cells. Cell Death and Differentiation (2000) 7, 197 ± 206.

show abstract

Section: Introductionmentioning

confidence: 99%

The topoisomerase inhibitors camptothecin and etoposide induce a CD95-independent apoptosis of activated peripheral lymphocytes

et al. 2000

View full text Add to dashboard Cite

show abstract

“…Regardless of the mechanistic hypothesis, however, the increased sensitivity of U-937/RE cells to the human cytokines TNF and LT provides another possibility of treatment of etoposide-resistant cells. Because development of 9NC resistance in U-937 cells is accompanied by increased sensitivity to etoposide (40), we had predicted that the inverse correlation would exist in the etoposide-resistant U-937 cells. Indeed, this hypothesis was confirmed by exposing the cells to various 9NC concentrations and monitoring cell proliferation and perturbations in the cell cycle.…”

Section: Discussionmentioning

confidence: 99%

“…A suspension of chicken erythrocyte nuclei was provided by Coulter and served as a reference. In general, flow cytometry was applied to study cell cycle perturbations, and apoptosis was induced in cultured cells by chemotherapeutic agents, including 9NC, etoposide, and doxorubicin (38)(39)(40).…”

Section: Cellsmentioning

confidence: 99%

“…In this context, we have shown recently that development of U-937 cell sublines resistant to 9NC is accompanied by decreased levels of topo I and increased levels of topo II (34) and concomitant increased sensitivity to etoposide (35). On the other hand, etoposide-resistant U-937 cells exhibit lower topo II activity than U-937 cells because of decreased synthesis of the topo Ha isoform, whereas the topo I synthesis or activity is upregulated.…”

Section: Sensitivity To 9ncmentioning

confidence: 99%

“…On the other hand, noncytotoxic concentrations of TNF result in increased response of cells to the cytotoxic activity of several anticancer drugs (27)(28)(29)(30)(31)(32). Further, U-937 cells have been studied for sensitivity and development of resistance to the anticancer drugs 9-nitrocamptothecin (9NC) (33)(34)(35), doxorubicin (36), and vincristine (37).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Altered Sensitivities to Anticancer and Differentiation Agents in Etoposide-Resistant Human Myeloid Leukemia U-937 Cells

Pantazis

DeJesus²,

Early³

et al. 1998

Journal of Hematotherapy

Self Cite

View full text Add to dashboard Cite

We previously have exposed U-937 human leukemia cells to stepwise increased concentrations of the anticancer drug etoposide, and this treatment has resulted in stable sublines (termed U-937/RE) exhibiting various extents of resistance to the drug and constitutively expressing c-fms mRNA, a specific marker of monocytic differentiation. In this report, we pursued studies to show that the P-glycoprotein blocker, verapamil, partially restores sensitivity to etoposide in U-937/RE cells. Further, the U-937/RE cells exhibit differential sensitivities to compounds that induce maturation of U-937 cells, as judged by the ability to reduce nitroblue tetrazolium and by morphologic changes, and increased sensitivities to apoptosis induction by the cytokines tumor necrosis factor (TNF) and lymphotoxin (LT) and the anticancer drugs 9-nitrocamptothecin and doxorubicin. In addition, the U-937/RE cells, xenografted in immunodeficient mice, demonstrate decreased or no ability to induce tumors. Taken together, these findings indicate that U-937/RE cells differ from the parental U-937 cells in several functional properties and can serve as models to develop protocols for treatment of human leukemia.

show abstract

The water-insoluble camptothecin analogues: Promising drugs for the effective treatment of haematological malignancies

Pantazis

1995

Leukemia Research

View full text Add to dashboard Cite

Sensitivity of camptothecin-resistant human leukemia cells and tumors to anticancer drugs with diverse mechanisms of action

Cited by 10 publications

References 24 publications

The topoisomerase inhibitors camptothecin and etoposide induce a CD95-independent apoptosis of activated peripheral lymphocytes

The topoisomerase inhibitors camptothecin and etoposide induce a CD95-independent apoptosis of activated peripheral lymphocytes

Altered Sensitivities to Anticancer and Differentiation Agents in Etoposide-Resistant Human Myeloid Leukemia U-937 Cells

The water-insoluble camptothecin analogues: Promising drugs for the effective treatment of haematological malignancies

Contact Info

Product

Resources

About