Capsaicin induces G1/S cell cycle arrest leading to apoptosis of multiple myeloma cells through suppression of STAT3 activation and STAT3-regulated gene products

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 20039-20039
Author(s):  
M. Bhutani ◽  
A. K. Pathak ◽  
G. Sethi ◽  
B. B. Aggarwal
Keyword(s):  
Cell Cycle ◽  
Multiple Myeloma ◽  
Cyclin D1 ◽  
Cell Cycle Arrest ◽  
Hot Pepper ◽  
Dependent Manner ◽  
Antiapoptotic Proteins ◽  
Cycle Arrest ◽  
Stat3 Phosphorylation ◽  
Synergistic Cytotoxicity

20039 Background: Agents that can block activated STAT3, a central player for proliferation, cell survival and chemoresistance, have a potential as therapeutic agents for the treatment of Multiple Myeloma (MM). Capsaicin, a spicy component of hot pepper, is a homovanillic acid derivative that preferentially induces certain cancer cells to undergo apoptosis. We have previously shown that Capsaicin blocked activation of NF-kappa B in human myeloid ML-1a cells. In this study we evaluated the effect of Capsaicin on STAT3 in MM cells. Methods: We used U266, a well-characterized MM cell line, which constitutively expresses activated STAT3. MM cells treated with Capsaicin were subjected to western blot analysis with specific antibodies to STAT3, tyrosyl phosphorylated STAT3 and STAT5. The effect of Capsaicin on nuclear-cytoplasmic compartment of STAT3 was studied by immunocytochemistry. The antiproliferative effect of Capsaicin was determined by the MTT assay and the effect on the cell cycle was determined by flowcytometry. Apoptosis of cells was measured using the Live and Dead assay. To determine the downstream targets like antiapoptotic proteins (Bcl-xL, Bcl-2, and Survivin), and cell cycle-regulators (cyclin D1) immunoblot analysis of Capsaicin treated cells was performed. Results: Capsaicin suppressed the constitutive activation of STAT3 in human MM cells in a dose- and time-dependent manner, prior to cell death. Capsaicin’s effect on STAT3 was specific as STAT5 was unaffected. Capsaicin depleted nuclear pool of STAT3 in U266 cells. Abrogation of constitutive STAT3 phosphorylation in MM cells induced G1 cell cycle arrest. The antiapoptotic proteins BCl-xl, suvivin, cyclin D1, and Bcl-2, which are encoded in target genes of STAT3, were down regulated by Capsaicin, followed by induction of apoptosis through activation of caspase-3. We further demonstrated that low dose combined Capsaicin and thalidomide/ bortezomib treatment triggered synergistic cytotoxicity. Conclusions: These findings suggest that the antitumor activity of Capsaicin is at least partially due to inhibition of STAT3 pathway and provide a basis for potential application of Capsaicin for treatment of relapsed and refractory MM. No significant financial relationships to disclose.

PI3K a Selective Inhibitor Induces Growth Inhibition In Mantle Cell Lymphoma

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1812-1812
Author(s):  
Yixin Zhou ◽  
Linhua Jin ◽  
Stefania Pittaluga ◽  
Mark Raffeld ◽  
Takashi Miida ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Growth Inhibition ◽  
Cyclin D1 ◽  
Cell Cycle Arrest ◽  
Cell Lines ◽  
Pi3k Inhibitor ◽  
Dependent Manner ◽  
Pi3k Inhibitor Ly294002 ◽  
Pi3k Inhibitors ◽  
Cycle Arrest

Abstract Abstract 1812 Deregulation of the phosphatidylinositol 3-kinase (PI3K)-mediated signaling plays an important role in the development of cell proliferation of mantle cell lymphoma (MCL). The PI3K pathway activation in MCL has been shown to result from constitutive B cell receptor (BCR) activation which is directly mediated by the Class IA PI3K p110 isoforms (a, β, and d). However, their relative contribution in MCL is not fully understood. In this study, the activity and molecular mechanisms of isoform-selective PI3K inhibitors which target different isoforms of the p110-kDa subunit has been investigated. We utilized the isoform-selective PI3K inhibitors; PI3-Ka inhibitor IV (p110a), TGX115 (p110b), IC87114 (p110d) and the non-specific PI3K inhibitor LY294002 (all inhibitors were purchased commercially). The p110a and p110d but not p110b isoform protein expression was detected in all tested MCL cell lines (Granta 519, JVM-2, Z138, Jeko-1, MINO). PI3-Ka inhibitor IV as well as non-specific PI3K inhibitor LY294002 induced cell growth inhibition with dose-dependent manner (IC50 at 48 hrs; PI3-Ka inhibitor IV: 17.5 μM for Granta 519, 14.3 μM for Jeko-1, 16.5 μM for Z138, LY294002: 14.8 μM for Granta 519, 19.4 μM for Jeko-1, 15.0 μM for Z138, MTT test). However, neither IC87114 nor TGX115 showed significant cell growth inhibition up to 40mM. Low dose of PI3-Ka inhibitor IV (5 μM) or LY294002 (5 μM) induced G0/G1 cell cycle arrest (increase of G0/G1 phase: PI3-Ka inhibitor IV 17.9 % for Granta 519, 28.2 % for Jeko-1, LY294002 19.3 % for Granta 519, 14.5 % for Jeko-1), and the higher dose (10 μM) increased apoptosis(specific apoptosis: PI3-Ka inhibitor IV 10.8 % for Granta 519, 15.3 % for Jeko-1, LY294002 13.6 % for Granta 519, 19.6 % for Jeko-1). No induction of cell cycle arrest/apoptosis by IC87114 or TGX115 treatment was observed. We then tried to assess the inhibition of PI3K/Akt signaling activation by p110a and p110d inhibitors. PI3-Ka inhibitor IV (10 μM) completely diminished phosphorylated (p-) Akt in all cell lines analyzed. Further investigation with 1–10 μM PI3-Ka inhibitor IV or IC87114 in Granta 519 and Jeko-1 cells declared that 1 μM PI3-Ka inhibitor IV almost diminished p-Akt and p-S6rp in both cells. The phosphorylation level of other PI3K/Akt signaling downstream substrates, GSK3-b and 4E-BP1, were down-regulated in dose dependent manner. Recently, GSK3-b kinase has been shown to negatively regulate cell cycle progression through Cyclin D1 repression in MCL. We observed that PI3-Ka inhibitor IV decreased Cyclin D1 expression and active pRb which are responsible for G0/G1 cell cycle arrest. The treatment with IC87114 (10 μM) performed moderate decrease of p-Akt, p-S6rp, and p-4E-BP, while no change in the levels of p-GSK3-b, Cyclin D1, or p-pRb was observed in both Granta 519 and Jeko-1 cells. We also tested whether the combination of PI3-Ka inhibitor IV or IC87114 with the proteasome inhibitor bortezomib induces synergistic cytotoxicity in MCL. No synergistic anti-proliferative effect was observed in any of the MCL cell lines analyzed. These findings demonstrate that p110a may be the responsible Class IA PI3K isoform for the development of MCL cell proliferation, and p110a isoform-selective PI3K inhibitor but not p110d or p110b inhibitors may provide a better therapeutic index relative to pan-PI3K inhibitors. Disclosures: No relevant conflicts of interest to declare.

Resveratrol induces cell cycle arrest and apoptosis in epithelioid malignant pleural mesothelioma cells

2017 ◽  
Vol 43 (2) ◽  
pp. 197-204
Author(s):  
Saime Batirel ◽  
Ergul Mutlu Altundag ◽  
Selina Toplayici ◽  
Ceyda Corek ◽  
Hasan Fevzi Batirel
Keyword(s):  
Cell Cycle ◽  
Cell Viability ◽  
Cyclin D1 ◽  
Cell Cycle Arrest ◽  
Malignant Pleural Mesothelioma ◽  
Cell Cycle Distribution ◽  
Pleural Mesothelioma ◽  
Dependent Manner ◽  
P53 Expression ◽  
Cycle Arrest

Abstract Background: Resveratrol is a natural anti-carcinogenic polyphenol. Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor prognosis. In this study, we investigated the effects of resveratrol on epithelioid MPM. Material and methods: Human epithelioid MPM cell line (NCI-H2452) was exposed to resveratrol (5–200 μM) for 24 or 48 h. Cell viability was assessed by WST-1 assay. Flow cytometry analyses were performed to evaluate the effects of resveratrol on cell cycle distribution and apoptosis. Western blot analysis was used to determine protein expression levels of antioxidant enzymes, cyclin D1 and p53. Reactive oxygen species (ROS) were measured using H2DCFDA. Results: Resveratrol reduced cell viability of the cells in a concentration and time dependent manner. After treatment, the cells accumulated in G0/G1 phase and the percentage of cells in G2/M phase was reduced. Resveratrol decreased cyclin D1 and increased p53 expression in cell lysates. Treated cells exhibited increased apoptotic activity. ROS were elevated with resveratrol treatment, but there was no change in the expression of superoxide dismutase (SOD)-1, SOD-2 and glutathione peroxidase. Conclusion: Our results revealed that resveratrol exhibits anti-cell viability effect on epithelioid MPM cells by inducing cell cycle arrest and apoptosis. Resveratrol may become a potential therapeutic agent for epithelioid MPM.

β1 Integrin Adhesion Enhances IL-6 Mediated STAT3 Signaling in Multiple Myeloma Cells: Implications for Microenvironment Influence on Tumor Cell Survival and Proliferation.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1706-1706
Author(s):  
Kenneth H Shain ◽  
Danielle Yarde ◽  
Mark Mead ◽  
Lori Hazlehurst ◽  
William S Dalton
Keyword(s):  
Cell Cycle ◽  
Multiple Myeloma ◽  
Cell Cycle Arrest ◽  
Cell Lines ◽  
Genetic Alterations ◽  
Β1 Integrin ◽  
Cycle Arrest ◽  
Stat3 Signaling ◽  
Stat3 Phosphorylation ◽  
In Cells

Abstract Multiple Myeloma (MM) is a B cell malignancy characterized by the monoclonal expansion of plasma cells. Although numerous genetic alterations have been implicated in MM pathogenesis, it is widely hypothesized that the bone marrow (BM) microenvironment contributes to MM cell pathogenesis. The BM microenvironmental components, interleukin (IL)-6 and fibronectin (FN), have individually been shown to influence the proliferation and survival of MM cells; however, in vivo these effectors most likely work together. We examined signaling events, cell cycle progression, and levels of drug response in MM cells either adhered to FN via β1 integrins, stimulated with IL-6, or with the two combined. IL-6 and FN adhesion have been demonstrated to protect cells from a host of cytotoxic stimuli suggesting co-stimulation of MM cell lines with IL-6 and FN-adhesion may confer a greater protection against chemotherapeutics than either effector alone. However, MTT cytotoxicity assays demonstrate that although adhesion to FN provides significant protection against treatment with mitoxantrone or doxorubicin (p=0.0002 and p=<0.0001 respectively), the addition of IL-6 provides no further protection. These findings were corroborated by analysis of drug-mediated apoptosis using FCM by Annexin-V/7-AAD. In regards to cell cycle kinetics, our laboratory has previously demonstrated that adhesion of the 8226 MM cell line to FN mediated a p27Kip1 dependent G0/G1 cell cycle arrest. As predicted, BrdU/PI analysis of 8226 cells adhered to FN for 24 hours results in an increased number of cells in G0/G1 relative to cells maintained in suspension (p=0.0028). In contrast, when cells were adhered to FN in the presence of IL-6 no accumulation of cells in G0/G1 was observed, with levels similar to that observed in cells maintained in suspension with or without stimulation by IL-6. Our studies demonstrated that the G1/S cell cycle arrest associated with FN adhesion of MM cell lines was overcome when IL-6 was added; however, the cell adhesion mediated drug resistance (CAM-DR) was maintained in the presence of IL-6. Investigation of the biochemical signaling following concomitant exposure of MM cells to IL-6 and FN adhesion revealed a synergistic increase in STAT3 phosphorylation, nuclear translocation and DNA-binding as compared to either IL-6 or FN-adhesion alone in four MM cell lines. STAT3 phosphorylation was increased in cells adhered to FN in an IL-6 dose dependent manner. Electrophoretic mobility shift assay demonstrated a parallel 3-fold increase in STAT3/DNA complexes in cells adhered to FN relative to cells in suspension. To further characterize the receptor proximal affects of FN adhesion on IL-6 signaling we immunoprecipitated the IL-6R complex with antisera to gp130. Immunoprecipitation of gp130 revealed enhanced tyrosine phosphorylation of the gp130/Jak family complexes following stimulation FN-adhered RPMI 8226 MM cells with IL-6. Consistent with increased phosphorylation of the receptor complex, increased levels of phospho-STAT3 were identified associated with gp130 under co-stimulatory conditions relative to IL-6 or FN adhesion alone. Interestingly, immunoprecipitation with gp130 antibodies also revealed an association between STAT3 (non-phosphorylated) and gp130 in the absence of IL-6 stimulation in cells adhered to FN. These results suggest that adhesion to FN facilitates an IL-6-independent association between gp130 and STAT3, resulting in enhanced STAT3 signaling. Taken together, these data demonstrate a novel mechanism by which collaborative signaling by β1 integrin and gp130 confer an increased survival advantage to MM cells.

scholarly journals Cell Cycle Arrest and Repression of Cyclin D1 Transcription by INI1/hSNF5

2002 ◽  
Vol 22 (16) ◽  
pp. 5975-5988 ◽  
Author(s):  
Zhi-Kai Zhang ◽  
Kelvin P. Davies ◽  
Jeffrey Allen ◽  
Liang Zhu ◽  
Richard G. Pestell ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Tumor Suppressor ◽  
Cyclin D1 ◽  
Cell Cycle Arrest ◽  
Cell Formation ◽  
Dependent Manner ◽  
Tumor Suppressor Function ◽  
Suppressor Function ◽  
Cycle Arrest ◽  
Flat Cell

ABSTRACT INI1/hSNF5 is a component of the ATP-dependent chromatin remodeling hSWI/SNF complex and a tumor suppressor gene of aggressive pediatric atypical teratoid and malignant rhabdoid tumors (AT/RT). To understand the molecular mechanisms underlying its tumor suppressor function, we studied the effect of reintroduction of INI1/hSNF5 into AT/RT-derived cell lines such as MON that carry biallelic deletions of the INI1/hSNF5 locus. We demonstrate that expression of INI1/hSNF5 causes G0-G1 arrest and flat cell formation in these cells. In addition, INI1/hSNF5 repressed transcription of cyclin D1 gene in MON, in a histone deacetylase (HDAC)-dependent manner. Chromatin immunoprecipitation studies revealed that INI1/hSNF5 was directly recruited to the cyclin D1 promoter and that its binding correlated with recruitment of HDAC1 and deacetylation of histones at the promoter. Analysis of INI1/hSNF5 truncations indicated that cyclin D1 repression and flat cell formation are tightly correlated. Coexpression of cyclin D1 from a heterologous promoter in MON was sufficient to eliminate the INI1-mediated flat cell formation and cell cycle arrest. Furthermore, cyclin D1 was overexpressed in AT/RT tumors. Our data suggest that one of the mechanisms by which INI1/hSNF5 exerts its tumor suppressor function is by mediating the cell cycle arrest due to the direct recruitment of HDAC activity to the cyclin D1 promoter thereby causing its repression and G0-G1 arrest. Repression of cyclin D1 gene expression may serve as a useful strategy to treat AT/RT.

scholarly journals Rafoxanide, an Organohalogen Drug, Triggers Apoptosis and Cell Cycle Arrest in Multiple Myeloma By Enhancing DNA Damage Responses and Suppressing the p38 MAPK Pathway

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5628-5628
Author(s):  
Jumei Shi ◽  
Wenqin Xiao ◽  
Zhijian Xu ◽  
Shuaikang Chang ◽  
Lu Gao ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Multiple Myeloma ◽  
Dna Damage ◽  
Cell Cycle Arrest ◽  
P38 Mapk ◽  
Mapk Pathway ◽  
Cycle Arrest ◽  
P38 Mapk Pathway ◽  
Mouse Xenograft Model ◽  
Synergistic Cytotoxicity

Abstract Rafoxanide is used in veterinary medicine for the treatment of fascioliasis. We previously repositioned the drug as the inhibitor of B-Raf V600E, but its anti-tumor effect in human cancer has never been reported. In this study, we investigated the effects of rafoxanide in multiple myeloma (MM) in vitro and in vivo. We found that rafoxanide inhibited cell proliferation and overcame the protective effect of the bone marrow (BM) microenvironment on MM cells. Rafoxanide induced cell apoptosis by reducing mitochondrial membrane potential (MMP) and regulating the caspase pathway, while having no apparent toxic effect on normal cells. Rafoxanide also inhibited DNA synthesis and caused cell cycle arrest by regulating the cdc25A-degradation pathway. In addition, rafoxanide enhanced the DNA damage response by up-regulating the expression of γ-H2AX. Importantly, as a potent B-Raf V600E inhibitor, rafoxanide could suppress activation of the p38 MAPK pathway. Rafoxanide treatment inhibited tumor growth, with no significant side effects, in an MM mouse xenograft model. Finally, combination of rafoxanide with bortezomib or lenalidomide significantly induced synergistic cytotoxicity in MM cells. Collectively, our results may provide a rationale for use of this drug in MM treatment. This study was supported by grants from the National Natural Science Foundation of China (Nos. 81570190; 81670194 and 81529001). Figure. Figure. Disclosures No relevant conflicts of interest to declare.

The Novel NFkB Inhibitor V1810 Induces Apoptosis and Cell Cycle Arrest in Multiple Myeloma Cells and Overcomes NFkB Mediated Drug Resistance.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1715-1715 ◽  
Author(s):  
Felix Meinel ◽  
Sonja Mandl-Weber ◽  
Philipp Baumann ◽  
Johann Leban ◽  
Ralf Schmidmaier
Keyword(s):  
Cell Cycle ◽  
Multiple Myeloma ◽  
Drug Resistance ◽  
Cell Death ◽  
Cyclin D1 ◽  
Cell Cycle Arrest ◽  
Cyclin D3 ◽  
Cycle Arrest ◽  
Rpmi 8226

Abstract Multiple Myeloma (MM) is a fatal malignancy characterised by the accumulation and expansion of antibody producing plasma cells in the bone marrow. Evidence is increasing that nuclear factor kappa B (NFκB) is a promising target for new anti-myeloma therapies. In this study, we assessed the in vitro activity of V1810, a novel NFκB inhibitor. V1810 potently induces cell death in all tested MM cell lines (OPM-2, U266, NCI-H929, RPMI-8226) with an IC50 ranging between 5μM to 10μM as well as in primary MM cells from patients. Cell death induced by V1810 clearly shows biological features of apoptosis such as DNA fragmentation and caspase 3 cleavage. In OPM2, U266 and RPMI-8226 cells induction of apoptosis is accompanied by cell cycle arrest. Western blots revealed downregulation of cyclin D1 (U266) or cyclin D2 (OPM2, NCI-H929, RPMI-8226) respectively, but not cyclin D3. Consistent with the downregulation of cyclin D1/2, retinoblastoma protein was found to be hypophosphorylated. Considering that cyclin D1 and D2 are known to be NFκB target genes, this is in line with our finding that V1810 inhibits baseline NFκB activity in MM cells (36% relative reduction). Importantly, V1810 also abrogates NFκB activation induced by genotoxic drugs like melphalan and doxorubicin. Accordingly, V1810 and melphalan synergistically decrease MM cell viability. Taken together, V1810 induces apoptosis and cell cycle arrest in MM cells by inhibition of NFκB and overcomes NFκB mediated drug resistance to melphalan. The maximum tolerable dose (MTD) of V1810 in BalbC mice was 10mg/kg i.v. and plasma concentrations of 9.5μM are achievable in NRMI mice after 5mg/kg V1810 i.v., which corresponds well to the used in vitro concentrations. This study strongly supports the further development of NFkB inhibitors in MM, especially in combination with genotoxic drugs.

scholarly journals SOX7 is involved in polyphyllin D-induced G0/G1 cell cycle arrest through down-regulation of cyclin D1

2020 ◽  
Vol 70 (2) ◽  
pp. 191-200 ◽  
Author(s):  
Bin Zheng ◽  
Gang Wang ◽  
Wenbo Gao ◽  
Qiquan Wu ◽  
Weizhi Zhu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cyclin D1 ◽  
Cell Cycle Arrest ◽  
Complete Medium ◽  
Dependent Manner ◽  
Cyclin Dependent Kinase ◽  
Down Regulation ◽  
Cycle Arrest ◽  
G1 Cell Cycle Arrest ◽  
Polyphyllin D

AbstractThe incidence of mortality of prostate cancer (PCa) has been an uptrend in recent years. Our previous study showed that the sex-determining region Y-box 7 (SOX7) was low-expressed and served as a tumor suppressor in PCa cells. Here, we describe the effects of polyphyllin D (PD) on proliferation and cell cycle modifications of PCa cells, and whether SOX7 participates in this process. PC-3 cells were cultured in complete medium containing PD for 12, 24, and 48 h. MTT assay was used to investigate the cytotoxic effects of PD. Cell cycle progression was analyzed using propidium iodide (PI) staining, and protein levels were assayed by Western blot analysis. Our results showed low expression of SOX7 in PCa tissues/cells compared to their non-tumorous counterparts/RWPE-1 cells. Moreover, PD inhibited the proliferation of PC-3 cells in a dose- and time-dependent manner. PD induced G0/G1 cell cycle arrest, while co-treatment with short interfering RNA targeting SOX7 (siSOX7) had reversed this effect. PD downregulated SOX7, cyclin D1, cyclin-dependent kinase 4 (CDK4), and cyclin-dependent kinase 6 (CDK6) expressions in a dose-dependent manner, whereas co-treatment of siSOX7 and PD rescued the PD-inhibited cyclin D1 expression. However, no obvious changes were observed in CDK4 or CDK6 expression. These results indicate that SOX7 is involved in PD-induced PC-3 cell cycle arrest through down-regulation of cyclin D1.

scholarly journals Inhibition of TFII-I-Dependent Cell Cycle Regulation by p53

2005 ◽  
Vol 25 (24) ◽  
pp. 10940-10952 ◽  
Author(s):  
Zana P. Desgranges ◽  
Jinwoo Ahn ◽  
Maria B. Lazebnik ◽  
Todd Ashworth ◽  
Caleb Lee ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cyclin D1 ◽  
Cell Cycle Arrest ◽  
Cell Cycle Regulation ◽  
Cellular Proliferation ◽  
Cell Cycle Control ◽  
Genotoxic Stress ◽  
Dependent Manner ◽  
Cycle Arrest ◽  
Cycle Regulation

ABSTRACT The multifunctional transcription factor TFII-I is tyrosine phosphorylated in response to extracellular growth signals and transcriptionally activates growth-promoting genes. However, whether activation of TFII-I also directly affects the cell cycle profile is unknown. Here we show that under normal growth conditions, TFII-I is recruited to the cyclin D1 promoter and transcriptionally activates this gene. Most strikingly, upon cell cycle arrest resulting from genotoxic stress and p53 activation, TFII-I is ubiquitinated and targeted for proteasomal degradation in a p53- and ATM (ataxia telangiectasia mutated)-dependent manner. Consistent with a direct role of TFII-I in cell cycle regulation and cellular proliferation, stable and ectopic expression of wild-type TFII-I increases cyclin D1 levels, resulting in accelerated entry to and exit from S phase, and overcomes p53-mediated cell cycle arrest, despite radiation. We further show that the transcriptional regulation of cyclin D1 and cell cycle control by TFII-I are dependent on its tyrosine phosphorylation at positions 248 and 611, sites required for its growth signal-mediated transcriptional activity. Taken together, our data define TFII-I as a growth signal-dependent transcriptional activator that is critical for cell cycle control and proliferation and further reveal that genotoxic stress-induced degradation of TFII-I results in cell cycle arrest.

Pisosterol Induces G2/M Cell Cycle Arrest and Apoptosis via the ATM/ATR Signaling Pathway in Human Glioma Cells

2020 ◽  
Vol 20 (6) ◽  
pp. 734-750
Author(s):  
Wallax A.S. Ferreira ◽  
Rommel R. Burbano ◽  
Claudia do Ó. Pessoa ◽  
Maria L. Harada ◽  
Bárbara do Nascimento Borges ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Signaling Pathway ◽  
Glioma Cell ◽  
Molecular Mechanisms ◽  
Glioma Cells ◽  
Dependent Manner ◽  
M Cell ◽  
Trypan Blue Exclusion ◽  
Cycle Arrest

Background: Pisosterol, a triterpene derived from Pisolithus tinctorius, exhibits potential antitumor activity in various malignancies. However, the molecular mechanisms that mediate the pisosterol-specific effects on glioma cells remain unknown. Objective: This study aimed to evaluate the antitumoral effects of pisosterol on glioma cell lines. Methods: The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and trypan blue exclusion assays were used to evaluate the effect of pisosterol on cell proliferation and viability in glioma cells. The effect of pisosterol on the distribution of the cells in the cell cycle was performed by flow cytometry. The expression and methylation pattern of the promoter region of MYC, ATM, BCL2, BMI1, CASP3, CDK1, CDKN1A, CDKN2A, CDKN2B, CHEK1, MDM2, p14ARF and TP53 was analyzed by RT-qPCR, western blotting and bisulfite sequencing PCR (BSP-PCR). Results: Here, it has been reported that pisosterol markedly induced G2/M arrest and apoptosis and decreased the cell viability and proliferation potential of glioma cells in a dose-dependent manner by increasing the expression of ATM, CASP3, CDK1, CDKN1A, CDKN2A, CDKN2B, CHEK1, p14ARF and TP53 and decreasing the expression of MYC, BCL2, BMI1 and MDM2. Pisosterol also triggered both caspase-independent and caspase-dependent apoptotic pathways by regulating the expression of Bcl-2 and activating caspase-3 and p53. Conclusions: It has been, for the first time, confirmed that the ATM/ATR signaling pathway is a critical mechanism for G2/M arrest in pisosterol-induced glioma cell cycle arrest and suggests that this compound might be a promising anticancer candidate for further investigation.

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