title: Correlation between decreased sensitivity of the Daudi lymphoma cells to VP-16-induced apoptosis and deficiency in DNAS1L3 expression.
abstract: A functional relationship between the apoptotic endonuclease DNAS1L3 and the chemotherapeutic drug VP-16 was established. The lymphoma cell line, Daudi, exhibited a significant resistance to VP-16 treatment in comparison to the lymphoma/leukemia cell line, U-937. While U-937 cells degraded their DNA into internucleosomal fragments, Daudi cells failed to undergo such fragmentation in response to the drug. Activation of both caspase-3 and DNA fragmentation factor was not sufficient to trigger internucleosomal DNA fragmentation in Daudi cells. No correlation was found between expression levels of topoisomerase-II, Pgp, Bcl-2, Bax, or Bad and decreased sensitivity of Daudi cells to VP-16. Daudi cells failed to express DNAS1L3 and ectopic expression of this protein significantly sensitized the cells to VP-16. An enhancement of caspase-3 activity and collapse of mitochondrial membrane potential underlie DNAS1L3-mediated sensitization of Daudi cells to VP-16, which may be a direct result of DNAS1L3-mediated increase in PARP-1-activating DNA breaks after VP-16 treatment. Our results suggest that DNAS1L3 plays an active role in lymphoma cell sensitization to VP-16 and that its deficiency may constitute a novel mechanism of drug resistance in these cells.
authors.affiliation: Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA. hboulr@lsuhsc.edu
authors.forename: Hamid
authors.initials: H
authors.lastname: Boulares
authors.forename: Anna
authors.initials: A
authors.lastname: Zoltoski
authors.forename: Sangeetha
authors.initials: S
authors.lastname: Kandan
authors.forename: Talha
authors.initials: T
authors.lastname: Akbulut
authors.forename: Alexander
authors.initials: A
authors.lastname: Yakovlev
authors.forename: Mustapha
authors.initials: M
authors.lastname: Oumouna
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D002118:Calcium / Q000378:metabolism; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D004247:DNA / Q000378:metabolism; D004249:DNA Damage; D053938:DNA Fragmentation; D004250:DNA Topoisomerases, Type II / Q000378:metabolism; D003851:Deoxyribonucleases / Q000737:chemistry / Q000378:metabolism; D019008:Drug Resistance, Neoplasm; D004706:Endodeoxyribonucleases / Q000096:biosynthesis*; D004789:Enzyme Activation; D005047:Etoposide / Q000494:pharmacology*; D017353:Gene Deletion; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015151:Immunoblotting; D020287:In Situ Nick-End Labeling; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008223:Lymphoma / Q000188:drug therapy*; D008274:Magnesium / Q000378:metabolism; D008564:Membrane Potentials; D009707:Nucleosomes / Q000378:metabolism; D000075223:Poly-ADP-Ribose Binding Proteins; D011506:Proteins / Q000737:chemistry; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D014162:Transfection; D020298:U937 Cells; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D051025:bcl-Associated Death Protein / Q000378:metabolism
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D000972:Antineoplastic Agents, Phytogenic; D051017:Apoptosis Regulatory Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009707:Nucleosomes; D000075223:Poly-ADP-Ribose Binding Proteins; D011506:Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D051025:bcl-Associated Death Protein; C109664:caspase-activated DNase inhibitor; D005047:Etoposide; D004247:DNA; C113696:DFFB protein, human; C485421:DNASE1L3 protein, human; D003851:Deoxyribonucleases; D004706:Endodeoxyribonucleases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D004250:DNA Topoisomerases, Type II; D008274:Magnesium; D002118:Calcium