Cytokinetically quiescent (G0/G1) human multiple myeloma cells are susceptible to simultaneous inhibition of Chk1 and MEK1/2
| Autor: | Paul Dent, Yukie Takabatake, Lora Kramer, Jorge A. Almenara, Xin-Yan Pei, Leena E. Youssefian, Steven Grant, Yun Dai, Wesley W. Bodie, Jessica Felthousen, Shuang Chen |
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| Rok vydání: | 2011 |
| Předmět: |
Programmed cell death
MAP Kinase Kinase 2 Immunology Population MAP Kinase Kinase 1 CD34 Apoptosis Thiophenes Biology Resting Phase Cell Cycle environment and public health Biochemistry Small hairpin RNA Cell Line Tumor Humans Urea CHEK1 education Protein Kinase Inhibitors education.field_of_study Lymphoid Neoplasia Interleukin-6 G1 Phase Cell Biology Hematology Cell cycle Cell culture embryonic structures Checkpoint Kinase 1 Cancer research Benzimidazoles Syndecan-1 biological phenomena cell phenomena and immunity Multiple Myeloma Protein Kinases DNA Damage |
| Zdroj: | Blood. 118:5189-5200 |
| ISSN: | 1528-0020 0006-4971 |
| DOI: | 10.1182/blood-2011-02-339432 |
| Popis: | Effects of Chk1 and MEK1/2 inhibition were investigated in cytokinetically quiescent multiple myeloma (MM) and primary CD138+ cells. Coexposure to the Chk1 and MEK1/2 inhibitors AZD7762 and selumetinib (AZD6244) robustly induced apoptosis in various MM cells and CD138+ primary samples, but spared normal CD138− and CD34+ cells. Furthermore, Chk1/MEK1/2 inhibitor treatment of asynchronized cells induced G0/G1 arrest and increased apoptosis in all cell-cycle phases, including G0/G1. To determine whether this regimen is active against quiescent G0/G1 MM cells, cells were cultured in low-serum medium to enrich the G0/G1 population. G0/G1–enriched cells exhibited diminished sensitivity to conventional agents (eg, Taxol and VP-16) but significantly increased susceptibility to Chk1 ± MEK1/2 inhibitors or Chk1 shRNA knock-down. These events were associated with increased γH2A.X expression/foci formation and Bim up-regulation, whereas Bim shRNA knock-down markedly attenuated lethality. Immunofluorescent analysis of G0/G1–enriched or primary MM cells demonstrated colocalization of activated caspase-3 and the quiescent (G0) marker statin, a nuclear envelope protein. Finally, Chk1/MEK1/2 inhibition increased cell death in the Hoechst-positive (Hst+), low pyronin Y (PY)–staining (2N Hst+/PY−) G0 population and in sorted small side-population (SSP) MM cells. These findings provide evidence that cytokinetically quiescent MM cells are highly susceptible to simultaneous Chk1 and MEK1/2 inhibition. |
| Databáze: | OpenAIRE |
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