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Effect of the protein kinase C inhibitor staurosporine on chemosensitivity to daunorubicin of normal and leukemic fresh myeloid cells.
Blood. 1994 Jul 01; 84(1):229-37.Blood

Abstract

The effect of the protein kinase C (PKC) inhibitor staurosporine (ST) on the chemosensitivity of normal (colony-forming unit granulocyte-macrophage [CFU-GM]) and leukemic (acute myeloid leukemia-CFU [AML-CFU]) myeloid progenitors to daunorubicin (DNR) was evaluated. Primary colony inhibition assays allowed us to characterize two distinct groups of AML, a DNR-resistant group (patients no. 1 through 6), which displayed significantly lower DNR sensitivity than normal CFU-GM (D50 = 11.3 +/- 1.4 ng/mL v 1.8 +/- 0.5 ng/mL, after 7 days of exposure, respectively; P < 0.01) and a DNR-sensitive group (patients no. 7 through 12) with D50 = 2.7 +/- 0.4 ng/mL. This classification remained unaltered when assessed by secondary colony inhibition assay (evaluating the self-renewal fraction of AML-CFU) or by viability assay (evaluating the ultimately differentiated blast cell population), suggesting that the DNR sensitivity profile in maintained throughout AML-CFU differentiation. DNR resistance of the differentiated blast cell population was not correlated with the level of P-glycoprotein (P-gp) expression but rather with the ability to extrude rhodamine 123 (Rh123). ST used at subtoxic concentrations induced a twofold to threefold enhancement of DNR cytotoxicity, increased Rh123 accumulation, and decreased Rh123 efflux kinetics in resistant AML cells. These effects were observed for ST concentrations much lower than those required to displace the P-gp-binding probe azidoprazosin, suggesting that ST might act through its PKC inhibitory effect and not through P-gp binding. Finally, this study provides evidence that DNR resistance in AML cells is, at least in part, related to the multidrug-resistance (MDR) phenotype. Because P-gp function can be downregulated by ST, it seems likely that the MDR pheno-type can be functionally regulated by cellular signalization in AML cells.

Authors+Show Affiliations

Laboratoire de Pharmacologie et de Toxicologie Fondamentales, CNRS, Toulouse, France.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

7912555

Citation

Laredo, J, et al. "Effect of the Protein Kinase C Inhibitor Staurosporine On Chemosensitivity to Daunorubicin of Normal and Leukemic Fresh Myeloid Cells." Blood, vol. 84, no. 1, 1994, pp. 229-37.
Laredo J, Huynh A, Muller C, et al. Effect of the protein kinase C inhibitor staurosporine on chemosensitivity to daunorubicin of normal and leukemic fresh myeloid cells. Blood. 1994;84(1):229-37.
Laredo, J., Huynh, A., Muller, C., Jaffrézou, J. P., Bailly, J. D., Cassar, G., Laurent, G., & Demur, C. (1994). Effect of the protein kinase C inhibitor staurosporine on chemosensitivity to daunorubicin of normal and leukemic fresh myeloid cells. Blood, 84(1), 229-37.
Laredo J, et al. Effect of the Protein Kinase C Inhibitor Staurosporine On Chemosensitivity to Daunorubicin of Normal and Leukemic Fresh Myeloid Cells. Blood. 1994 Jul 1;84(1):229-37. PubMed PMID: 7912555.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effect of the protein kinase C inhibitor staurosporine on chemosensitivity to daunorubicin of normal and leukemic fresh myeloid cells. AU - Laredo,J, AU - Huynh,A, AU - Muller,C, AU - Jaffrézou,J P, AU - Bailly,J D, AU - Cassar,G, AU - Laurent,G, AU - Demur,C, PY - 1994/7/1/pubmed PY - 1994/7/1/medline PY - 1994/7/1/entrez SP - 229 EP - 37 JF - Blood JO - Blood VL - 84 IS - 1 N2 - The effect of the protein kinase C (PKC) inhibitor staurosporine (ST) on the chemosensitivity of normal (colony-forming unit granulocyte-macrophage [CFU-GM]) and leukemic (acute myeloid leukemia-CFU [AML-CFU]) myeloid progenitors to daunorubicin (DNR) was evaluated. Primary colony inhibition assays allowed us to characterize two distinct groups of AML, a DNR-resistant group (patients no. 1 through 6), which displayed significantly lower DNR sensitivity than normal CFU-GM (D50 = 11.3 +/- 1.4 ng/mL v 1.8 +/- 0.5 ng/mL, after 7 days of exposure, respectively; P < 0.01) and a DNR-sensitive group (patients no. 7 through 12) with D50 = 2.7 +/- 0.4 ng/mL. This classification remained unaltered when assessed by secondary colony inhibition assay (evaluating the self-renewal fraction of AML-CFU) or by viability assay (evaluating the ultimately differentiated blast cell population), suggesting that the DNR sensitivity profile in maintained throughout AML-CFU differentiation. DNR resistance of the differentiated blast cell population was not correlated with the level of P-glycoprotein (P-gp) expression but rather with the ability to extrude rhodamine 123 (Rh123). ST used at subtoxic concentrations induced a twofold to threefold enhancement of DNR cytotoxicity, increased Rh123 accumulation, and decreased Rh123 efflux kinetics in resistant AML cells. These effects were observed for ST concentrations much lower than those required to displace the P-gp-binding probe azidoprazosin, suggesting that ST might act through its PKC inhibitory effect and not through P-gp binding. Finally, this study provides evidence that DNR resistance in AML cells is, at least in part, related to the multidrug-resistance (MDR) phenotype. Because P-gp function can be downregulated by ST, it seems likely that the MDR pheno-type can be functionally regulated by cellular signalization in AML cells. SN - 0006-4971 UR - https://www.unboundmedicine.com/medline/citation/7912555/Effect_of_the_protein_kinase_C_inhibitor_staurosporine_on_chemosensitivity_to_daunorubicin_of_normal_and_leukemic_fresh_myeloid_cells_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0006-4971(20)78816-6 DB - PRIME DP - Unbound Medicine ER -