TY - JOUR
T1 - Selective cyclooxygenase 2 inhibitor NS-398 induces apoptosis in myeloma cells via a Bcl-2 independent pathway
AU - Zhang, Min
AU - Abe, Yasunobe
AU - Matsushima, Takamitsu
AU - Nishimura, Junji
AU - Nawata, Hajime
AU - Muta, Koichiro
PY - 2005/3
Y1 - 2005/3
N2 - NS-398, a selective inhibitor of cyclooxygenase 2 (COX-2), has been reported to inhibit growth and induce apoptosis in several cancer cell lines that overexpress COX-2. However it has not been extensively studied in multiple myeloma (MM). Here, we studied the effects of COX-2 inhibitors on MM cell lines and primary myeloma patient cells. We investigated the effects of NS-398 on proliferation and apoptosis in three myeloma cell lines (PCM6, U266 and RPMI8226) and isolated CD138-positive cells from MM patients. Furthermore, the combined effects of NS-398 plus dexamethasone (Dex) or thalidomide (Thal) were investigated. All myeloma cell lines express COX-2. NS-398 inhibited growth and induced apoptosis in PCM6, RPMI8226 and CD138-positive MM cells in a time- and dose-dependent manner. At low concentrations (10 μM), NS-398 primarily induced growth arrest without affecting cell viability, but at higher concentrations (over 25 μM), apoptosis was induced. During the process of apoptosis, the number of Fas-positive cells increased. Downstream signals of Fas, such as caspase 8, 3 and 9, were also activated. On the other hand, protein levels of the Bcl-2 family did not change, although mitochondrial transmembrane potential (Δψm) was decreased. Combined incubation with Dex or Thal enhanced NS-398-induced growth inhibition and apoptosis in RPM18226 cells. The combined effect of Dex was more potent than that of Thal. Our findings suggests that COX-2 plays an important role in regulation of apoptosis in myeloma cells, and COX-2 inhibitors might serve as an effective tool for future chemoprevention and/or treatment of myeloma.
AB - NS-398, a selective inhibitor of cyclooxygenase 2 (COX-2), has been reported to inhibit growth and induce apoptosis in several cancer cell lines that overexpress COX-2. However it has not been extensively studied in multiple myeloma (MM). Here, we studied the effects of COX-2 inhibitors on MM cell lines and primary myeloma patient cells. We investigated the effects of NS-398 on proliferation and apoptosis in three myeloma cell lines (PCM6, U266 and RPMI8226) and isolated CD138-positive cells from MM patients. Furthermore, the combined effects of NS-398 plus dexamethasone (Dex) or thalidomide (Thal) were investigated. All myeloma cell lines express COX-2. NS-398 inhibited growth and induced apoptosis in PCM6, RPMI8226 and CD138-positive MM cells in a time- and dose-dependent manner. At low concentrations (10 μM), NS-398 primarily induced growth arrest without affecting cell viability, but at higher concentrations (over 25 μM), apoptosis was induced. During the process of apoptosis, the number of Fas-positive cells increased. Downstream signals of Fas, such as caspase 8, 3 and 9, were also activated. On the other hand, protein levels of the Bcl-2 family did not change, although mitochondrial transmembrane potential (Δψm) was decreased. Combined incubation with Dex or Thal enhanced NS-398-induced growth inhibition and apoptosis in RPM18226 cells. The combined effect of Dex was more potent than that of Thal. Our findings suggests that COX-2 plays an important role in regulation of apoptosis in myeloma cells, and COX-2 inhibitors might serve as an effective tool for future chemoprevention and/or treatment of myeloma.
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U2 - 10.1080/10428190400015691
DO - 10.1080/10428190400015691
M3 - Article
C2 - 15621834
AN - SCOPUS:13544262684
VL - 46
SP - 425
EP - 433
JO - Leukemia and Lymphoma
JF - Leukemia and Lymphoma
SN - 1042-8194
IS - 3
ER -