Effects of Celecoxib on Human Acute Promyelocytic Leukemia Cell Line and Its Mechanism.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2851-2851
Author(s):  
Yun Xu ◽  
He Huang ◽  
Yanmin Zhao ◽  
Fenfang Zeng ◽  
Qian Zhou

Abstract Acute promyelocytic leukemia (APL) is a special subtype of acute myelogenous leukemia (AML) which is characterized for a specific translocation between chromosome 15 and 17 [t(15;17)] and the expression of PML/RARα fusion gene. Celecoxib, one of the specific inhibitors of cyclooxygenase-2 (COX-2), has been reported to induce anti-neoplastic activity on many solid human tumor cell lines in recent years. In our study, ATRA resistant APL cell line MR2 cells were used to investigate the effects of celecoxib on hematological malignancy. MR2 cells were treated with celecoxib at different concentration (0, 20, 40, 80, 120 and 160μmol/L). The proliferation of MR2 cells was observed by MTT assay and apoptosis was detected by DNA fragmentation analysis and flow cytometry using Annexin V-FITC/PI staining. Western blot was used to detect the change of caspase-8, -9, -3 and PARP in MR2 cells. The expression of mRNA of fusion gene PML/RARα, COX-2 and survivin, bcl-2/bax, CIAP1 and CIAP2 was assessed by reverse transcription polymerase chain reaction (RT-PCR). Cell cycle analyzed by flow cytometry with PI staining and western blot was used to detect the expression of cell-cycle-regulating proteins. The telomerase activity of MR2 cells was analyzed by PCR-ELISA. The expression of hTERT mRNA and c-myc mRNA was assessed by RT-PCR. MR2 cells viability in presence of celecoxib decreased markedly in a dose- and time- dependent manner. After treated with celecoxib (20-160μmol/L) for 12-48h, the proliferation of MR2 cells were inhibited significantly, in comparison with the control group (P<0.01). 50% growth inhibition (IC50) at 24h and 48h was 80.93μmol/L and 71.72μmol/L, respectively. A DNA ladder pattern of internucleosomal fragmentation was observed. The translocation of phosphatidylserine at the outer surface of the cell plasma membrane could be induced by celecoxib and its level increased following the augmentation of the drug concentration. MR2 cells exposure to 40-160μmol/L celecoxib for 24h caused 9.59%, 24.00%, 36.10% apoptotic cells, which was more than that of the untreated group 2.84% (P<0.01). The expression of survivin mRNA decreased dramatically, while no significant change with PML/RARα and COX-2. Treatment with celecoxib for 24h resulted in the activation of caspase-3 and caspase-9, cleavage of PARP. 40-160μmol/L celecoxib led to cell cycle arrest in G1/S phase, and CyclinD1 and CyclinE decreased, accompanied with up-regulation of P21waf/cip1, P27KIP, P16INK4a. celecoxib could inhibit the telomerase activity of APL cell line, and the inhibition was dose- and time- dependent. The expression of hTERT mRNA and c-myc mRNA were down-regulated by celecoxib in dose- dependent manner. These results indicated that celecoxib could inhibit MR2 cells proliferation by inducing apoptosis, cell cycle arrest and suppression of telomerase activity.

Bionatura ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 1725-1732
Author(s):  
Hamdah Alsaeedi ◽  
Rowaid Qahwaji ◽  
Talal Qadah

Kola nut extracts have recently been reported to contain chemopreventive compounds providing several pharmacological benefits. This study investigated Kola nut extracts' anti-cancer activity on human immortalized myelogenous leukemia cell line K562 through apoptosis and cell cycle arrest. Fresh Kola nuts were prepared as powder and dissolved in DMSO. Different concentrations (50, 100, 150, 200, and 250 μg/ml) of working solutions were prepared. The K562 cells were treated with the different concentrations of Kola nut extract or vehicle control (10% DMSO) followed by incubation at 37°C for 24, 48, and 72 hours, respectively. Treatment activity was investigated in K562 cells; by Resazurin, and FITC/Propidium Iodide and 7-AAD stained cells to evaluate apoptotic cells and the cell cycle's progression. Inhibition of leukemia cell proliferation was observed. The extract effectively induced cell death, early and late apoptosis by approximately 30% after 24 and 48 hours incubation, and an increase in the rate of dead cells by 50% was observed after 72 hours of incubation. Also, cell growth reduction was seen at high dose concentrations (150 and 200 µg/ml), as evident by cell count once treated with Kola nut extract. The total number of apoptotic cells increased from 5.8% of the control group to 27.4% at 250 µg/ml concentration. Moreover, Kola nut extracts' effects on K562 cells increased gradually in a dose and time-dependent manner. It was observed that Kola nut extracts could arrest the cell cycle in the G2/M phase as an increase in the number of cells by 29.8% and 14.6 % were observed from 9.8% and 5.2% after 24 and 48 hours of incubation, respectively. This increase was detected in a dose and time-dependent manner. Kola nut extracts can be used as a novel anti-cancer agent in Leukemia treatment as it has shown significant therapeutic potential and therefore provides new insights in understanding the mechanisms of its action. Keywords: Kola nut extracts, Leukemia, K562 cell line, Apoptosis, Cancer.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4706-4706
Author(s):  
Hongyan Tong ◽  
Jie Jin ◽  
Weilai Xu ◽  
Wenbin Qian ◽  
Maofang Lin

Abstract The telomerase activity can be down regulated by arsenic trioxide (As2O3), which is regarded as an apoptotic induction agent, is confirmed in many kinds of tumor cells. To investigate the mechanisms of telomerase regulation and to explore the correlation of As2O3 inducing apoptosis and telomerase regulation in MUTZ-1 cells, which are established as a high-risk myelodysplasia Cell line that derived from a MDS patient (FAB subtype refractory anemia with excess of blasts), a quantitative assessment of the telomerase activity by TRAP-ELISA and detection of the expression levels of hTERT, TRF1 (TTAGGG repeat binding factor 1), TRF2 (TTAGGG repeat binding factor 2), bcl-2, bax mRNA were performed, together with the assessment of the apoptosis by means of translocation of phosphatidylserine (PS) through flow cytometry assay. The results indicated that a typical apoptotic cell group distribution of DNA content was represented in the MUTZ-1 cells after being exposed to As2O3 at the range of concentration from 1μmol/L to 8μmol/L in a dose-dependent manner (r=0.736, P<0.001) and time-dependent manner (r=0.674, p<0.05), and the telomerase activity was down-regulated in a time-dependent manner (r=−0.976,P=0.024), and the expression level of hTERT mRNA in MUTZ-1 cells was represented in a dose-dependent manner (r=−0.892,P=0.042) and time-dependent manner (r=−1.000,P=0.04), after the cells were treated by As2O3 at the dosage as above. It was showed that a significant correlation between the decreased telomerase activity and the increased percentage of apoptotic cells in the treated cells (r=0.938,P=0.018), and there was a strong relationship between the telomerase activity and the mRNA expression of hTERT gene (r=0.783,P=0.022). However, As2O3 has no obvious effect on the expression level of TRF1 mRNA and TRF2 mRNA, which were regarded as two telomere-binding proteins. Further findings indicated that the inhibition of telomerase activity in MUTZ-1 cells was accompanied with down-regulated mRNA expression of bcl-2 gene (densitometry readings: 0.255±0.017 vs 0.466±0.069, P<0.05) and decreased ration of bcl-2/bax (densitometry reading ratios: 0.890±0.083 vs 0.546±0.014, P<0.05) at the dosage of 4μmol/L for 24 hours. These observations suggest that the apoptosis induced by As2O3 on MUTZ- 1 cells might be mediated through the inhibition of telomerase activity regulated by expression of hTERT gene, which implies that may be one of the mechanisms of As2O3 inducing apoptosis in MUTZ-1 cells.


2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Majid Asadi-Samani ◽  
Mahmoud Rafieian-Kopaei ◽  
Zahra Lorigooini ◽  
Hedayatollah Shirzad

Abstract Some medicinal herbs and compounds are known to target cancer cells, but the success of them as anticancer compounds depends to a large extent on their ability to activate pathways that kill cancer cells by arresting cell cycle and inducing apoptosis. The aim of the present study was to determine the anticancer effects of Euphorbia szovitsii Fisch. & C.A.Mey. on the breast cancer cells to reveal the underlying mechanism of its anti-breast cancer properties. In this experimental study, triple negative breast cancer cell line (MDA-MB-231) was cultivated in RPMI-1640 medium. Hydroalcoholic extract (70:30) of aerial parts of the plant was prepared. The cultured cells were treated with different concentrations (0–1000 μg/ml) of E. szovitsii extract for 24 and 48 h. Toxicity of the extract on MDA-MB-231 cells was examined using MTT (3-[4,5-dimethyl-2-thiazolyl]-2, 5 diphenyl tetrazolium bromide) test. The Annexin V–FITC Apoptosis Detection Kit was used to evaluate apoptosis and necrosis. Flow cytometry technique was employed to differentiate different phases of the cell cycle in the cells. Data were analyzed by GraphPad Prism and SPSS software. After 24 and 48 h, the IC50 values were respectively 76.78 (95% CI = 60.75–97.05; R = 0.8588) and 59.71 (95% CI = 46.25–77.09; R = 0.8543) μg/ml for E. szovitsii. The extract exhibited antiproliferative effects against MDA-MB-231 cells in a dose-dependent manner. Annexin V-FITC/PI assay confirmed that the extract was able to induce apoptosis in MDA-MB-231 cells. Moreover, treatment with the extract resulted in cell cycle arrest at G1 phase. Therefore, E. szovitsii could induce apoptosis and cycle arrest in the MDA-MB-231 cell line. It might be a good resource of natural products for producing anti-breast cancer drugs.


2016 ◽  
Vol 150 (4) ◽  
pp. S439
Author(s):  
Martin G. Martin ◽  
R. Sergio Solorzano-Vargas ◽  
Senta Georgia ◽  
Jiafang Wang ◽  
Shuping S. Wu ◽  
...  

Author(s):  
Hua Zhang ◽  
Xiaojin Zhao ◽  
Fajun Shang ◽  
Huan Sun ◽  
Xu Zheng ◽  
...  

Background: Colorectal cancer (CRC) is the third-ranked malignant tumor in the world that contributes to the death of a major population of the world. Celastrol, a bioactive natural product isolated from the medicinal plant Tripterygium wilfordii Hook F, has been proved to be an effective anti-tumor inhibitor for multiple tumors. Objective: To reveal the therapeutic effect and underlying mechanisms of celastrol on CRC cells. Methods: CCK-8 and clonogenic assay were used to analyze the cell proliferation in CRC cells. Flow cytometry analysis was conducted to assess the cell cycle and cell apoptosis. Wound-healing and cell invasion assay were used to evaluate the migrating and invasion capability of CRC cells. The potential antitumor mechanism of celastrol was investigated by qPCR, western blot, and confocal immunofluorescence analyses. Results: Celastrol effectively inhibited CRC cell proliferation by activating caspase-dependent cell apoptosis and facilitating G1 cell cycle arrest in a dose-dependent manner, as well as cell migration and invasion by downregulating the MMP2 and MMP9. Mechanistic protein expression revealed that celastrol suppressed the expression of COX-2 by inhibiting the phosphorylation of NF-κB p65 and subsequently leading to cytoplasmic retention of p65 protein, thereby inhibiting its nuclear translocation and transcription activities. Conclusion: These findings indicate that celastrol is an effective inhibitor for CRC, regulating the NF-κB/COX-2 pathway, leading to the inhibition of cell proliferation characterized by cell cycle arrest and caspase-dependent apoptosis, providing a potential alternative therapeutic agent for CRC patients.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2493-2493 ◽  
Author(s):  
Victor Y. Yazbeck ◽  
Georgios V. Georgakis ◽  
Yang Li ◽  
Eiji Iwado ◽  
Seiji Kondo ◽  
...  

Abstract Aberrant activation of the PI3-Kinase/Akt/mTOR survival pathway has been implicated in promoting the growth and survival of a variety of cancers, including lymphoma, and is currently being explored for cancer therapy. Importantly, the small molecule mTOR inhibitor temsirolimus (CCI-779) recently demonstrated significant clinical activity in patients with relapsed mantle cell lymphoma (MCL). However, the mechanism of action of temsirolimus in MCL cells is unknown. In this study, we demonstrated that temsirolimus induced cell growth inhibition in three MCL cell lines in a time-dependent and dose-dependent manner. The activity of temsirolimus was determined in 3 mantle cell lymphoma cell lines (Jeko-1, Mino, SP53). Temsirolimus upregulated p27 without altering cyclin D1 levels, resulting in cell cycle arrest in the G0/G1 phase. The Akt/mTOR pathway has been implicated in regulating cellular autophagy in yeasts and in mammalian cells. Thus, we examined whether temsirolimus may also induce autophagy in MCL cells, which is identified by the sequestering of cytoplasmic proteins into the lytic autophagosomes and autolysosome, and the formation of acidic vesicular organelles (AVOs). Temsirolimus induced AVOs formation indicative of autophagy in all MCL cell lines at doses ranging between 1 and 1000 nM in a time-dependent manner, with the highest activity observed between 72 and 96 hours of incubation. LC3 is essential for amino acid starvation-induced autophagy in yeasts. LC3-I is the cytoplasmic form, which is processed into the LC3-II form that is associated with the autophagosome membrane. Incubation of the SP53 cells with temsirolimus (1,000 nM) for 96 hours, resulted in processing LC3-I into LC3-II, indicative of autophagy induction. To further confirm induction of autophagy, SP53 cells expressing LC3-fused green fluorescent protein (GFP-LC3) were treated with temsirolimus and the pattern of LC3 distribution was compared with untreated cells using fluorescence microscopy. Untreated control cells showed a diffuse cytoplasmic distribution of LC3, whereas temsirolimus -treated cells showed a punctate pattern of green fluorescence, indicative of its association with autophagosomes. Furthermore, temsirolimus increased acidic vesicular organelles and microtubule-associated protein 1 light chain 3 (LC3) processing as determined by Western blot, which are characteristic of autophagy. In contrast, temsirolimus had minimal induction of apoptosis. Moreover, temsirolimus inhibited ribosomal S6 phosphorylation, an mTOR downstream target. The histone deacetylase inhibitor vorinostat (suberoylanilide hydroxamic acid, SAHA) demonstrated antiproliferative activity in a dose and time dependent manner in all three MCL cell lines. SAHA enhanced the activity of temsirolimus, which was associated with ERK dephosphorylation and caspase 3 activation. In contrast, temsirolimus did not potentiate the antitumor effects of bortezomib, doxorubicin, or gemcitabine. Our results demonstrate that in short-term culture, temsirolimus is primarily a cytostatic drug, and suggest that SAHA may potentiate the clinical efficacy of temsirolimus patients with MCL.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4590-4590
Author(s):  
Bao-An Chen ◽  
Guo-Hua Xia ◽  
Hui-Xia Lu ◽  
Ze-Ye Shao ◽  
Chong Gao ◽  
...  

Objective: To study the mechanism of proliferation inhibition and apoptosis of MDS-RAEB MUTZ-1 cells by 2-methoxyestradiol(2-ME). Methods: MUTZ-1 cells were treated with different concentrations of 2-ME;cellular proliferation was determined by MTT assay;apoptosis rate was determined with annexinV-FITC/PI double staining and cell cycle was analyzed by flow cytometry (FCM);the changes of morphologic features of MUTZ-1 cells were investigated by cytomorphology with Wright-Giemsa’s staining; lactate dehydrogenises (LD) was determined by Beckman Counter and agarose gel electrophoresis was used to verify whether 2-ME could induce apoptosis in MUTZ-1 cells. Moreover, the activity of telomerase in MUTZ-1 cells was examined by TRAP-ELISA. Results: The results showed that 1∼4μmol/L 2-ME inhibited the proliferation of MUTZ-1 cells in a dose-and time-dependent manner; the typical apoptotic morphological features appeared in MUTZ-1 cells after being treated with 4μmol/L 2-ME for 12hours; the marked DNA ladder pattern of internucleosomal fragmentation was observed after being treated with 4μmol/L 2-ME for 24hours and the up-regulated production of LD was assayed after treatment of 2-ME for 36hours. The number of MUTZ-1 cells of G0/G1 phase and S phase decreased, while the number of G2/M phase increased after MUTZ-1 cells were incubated with 1,2 and 4μmol/L2-ME for 12 hours, respectively(P<0.05). The inhibition effect of telomerase activity was enhanced in a dose- and time- dependent manner. Moreover, telomerase activity was significant negatively correlated with increased apoptosis (r =−0.954, p=0.046) and the number of sustained G2/M phase(r=−0.979, p=0.021) at the corresponding time point, respectively. Conclusions :It is concluded that the mechanism of proliferation inhibition and apoptosis of MUTZ-1 cells induced by 2-ME is probably related with inhibition of telomerase activity and G2/M cell cycle arrest; 2-ME may be a potentially useful, adjunctive anticancer drug in treating myelodysplastic syndrome.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4357-4357
Author(s):  
Bao-An Chen ◽  
Xin Xu ◽  
Ze-Ye Shao ◽  
Jia-Hua Ding ◽  
Guo-Hua Xia ◽  
...  

Abstract The myelodysplastic syndromes (MDS) are characterized by hemopoietic insufficiency associated with cytopenias leading to serious morbidity and the additional risk of leukemic transformation. Vitamin K2(VK2) is reported to induce apoptosis or differentiation of leukemic cell lines in vitro. For investigating the effects and mechanism of VK2 on human MDS cell line MUTZ-1 in vitro,we observed the changes of morphologic features of MUTZ-1 cells by exposing to VK2.The transmission electron microscope was used to observe the apoptosis of MUTZ-1 cells. Cellular proliferation was determined by the MTT assay. The flow cytometry was used to analysis apoptosis rate and the change of cell cycle. The expression of apoposis-related genes bcl-2, survivin and bax were detected by reverse transcriptase polymerase chain reaction(RT-PCR).The activity of caspase-3 was detected by chemiluminescence assay. After exposing to 10μmol L−1 and higher concentration of VK2, it could inhibit MUTZ-1 cells proliferation in a dose-and time-dependent manner(p&lt;0.05). At concentration of 5μmol/l VK2 treatment, it might accelerate cellular proliferation, but there’s no significant difference compared with control group. Apoptosis peak on FCM and positive Annexin-V FITC/PI on cell membrane showed that VK2 induced apoptosis of MUTZ-1 cells in a dose-and-time-dependent manner, G0/G1 cell cycle arrest, significantly dow-regulated the expression of bcl-2 and survivin, but had no effect on the expression of bax.The activities of caspase-3 were significantly increased. Low concentration of VK2 could facilitate cell proliferation. The higher concentration of VK2 could induce apoptosis of MUTZ-1 cells. These results indicate that VK2 induces MUTZ-1 cells apoptosis by activating caspase-3 pathway, the apoptosis related genes bcl-2, survivin down-regulated might play an important role in this process.


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