Synergistic Apoptosis Induction by Betulinic Acid and Established Cytotoxic Drugs in Leukemia Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3096-3096 ◽  
Author(s):  
Harald Ehrhardt ◽  
Ines Höfig ◽  
Irmela Jeremias

Abstract Abstract 3096 Poster Board III-33 Introduction Betulinic acid (BA) represents an effective inducer of apoptosis in a broad spectrum of solid tumor cells in vitro and in small animal models in vivo. Due to its low toxicity in animal trials, it represents a putative future anti-cancer drug. We first described that in addition to solid tumor cells, BA potently induces apoptosis in leukemia cells expanding the therapeutic use of BA to hematological malignancies (Ehrhardt et al., Leukemia 2004). Purpose Here we asked how BA might best be incorporated into polychemotherapy protocols used to treat acute leukemia and therefore searched for conventional cytotoxic drugs which enhance the anti-tumor effect of BA. Of suitable drugs discovered, we characterized the molecular mechanisms determining the synergistic interaction with BA. Methods We used both leukemia cell lines and primary tumor cells obtained from children with acute lymphoblastic or myeloid leukemia at diagnosis of disease or relapse. Primary, patient-derived tumor cells were further amplified in NOD/SCID mice. Most importantly, we transfected primary, patient-derived tumor cells to knock down endogenous apoptosis signaling proteins. Results – phenotype When conventional cytotoxic drugs in routine use to treat acute leukemia were screened on leukemic cell lines, three drugs were identified which induce synergistic induction when given together with BA: doxorubicin, asparaginase and vincristine. Accordingly, clonogenic survival was reduced in a super-additive way, when one of these drugs was combined with BA. Importantly, synergistic apoptosis induction by these drugs with BA was also found in primary, patient-derived leukemic tumor samples. Both in primary samples and cell lines, BA-induced apoptosis was enhanced by addition of the second drug, even if doxorubicin, asparaginase or vincristine alone were unable to induce apoptosis due to apoptosis resistance. Results – mechanism Synergistic apoptosis induction was accompanied by increased caspase activation and was inhibited by the addition of zVAD, by overexpression of XIAP or knockdown of Caspase-9. p53 was activated nearly exclusively, when doxorubicin, asparaginase or vincristine was combined with BA and knockdown of p53 inhibited synergistic apoptosis induction of the drug combinations. While expression of Bak, Bim, Bid, Bcl-2, Bcl-xL and PUMA remained unchanged by stimulation with BA and doxorubicin, asparaginase or vincristine, the p53 target gene NOXA was strongly upregulated exclusively when drugs were combined. When doxorubicin, asparaginase or vincristine were given together with BA, more apoptogenic factors like Smac and Cytochrome c were released from mitochondria and synergistic apoptosis induction by BA with either doxorubicin, asparaginase or vincristine depended on increased mitochondrial signaling. Knockdown of Bim, Bid or PUMA did not alter synergistic apoptosis induction by BA and doxorubicin, asparaginase or vincristine. In contrast, overexpression of Bcl-2 or Bcl-xL or knockdown of either Bak or NOXA inhibited synergistic apoptosis induction. Knockdown of p53 and NOXA in primary, patient-derived leukemia cells completely inhibited synergistic apoptosis induction by BA and doxorubicin, asparaginase or vincristine. Conclusion Our data show that BA induces synergistic apoptosis induction when given in combination with doxorubicin, asparaginase and vincristine based on increased activation of p53 which enables expression of NOXA and a NOXA – Bak dependent activation of mitochondria. BA should best be incorporated into future anti-leukemia polychemotherapy protocols in close proximity to doxorubicin, asparaginase or vincristine. Disclosures No relevant conflicts of interest to declare.

2014 ◽  
Vol 9 (11) ◽  
pp. 1934578X1400901
Author(s):  
Thiago Martino ◽  
Monica F. Pereira ◽  
Carlos R.M. Gayer ◽  
Sergio R. Dalmau ◽  
Marsen G.P. Coelho ◽  
...  

Cancer is the second leading cause of human mortality worldwide. Therefore, the search for new drugs or alternative therapy strategies has been required. Anticancer agents have been developed from plants since the 1950s and natural products still represent an important source of new and promising bioactive molecules. This work describes the cytotoxic effects of SF5 on tumor cells of high prevalence in the world and investigated some mechanisms of its antitumor action. The antitumor screening was performed with human lung carcinoma (A549), human breast (MCF-7) and prostate (PC-3) adenocarcinoma and chronic myeloid and acute lymphocytic leukemia cell lines. The acute lymphocytic leukemia Jurkat cells presented high sensitivity to the cytotoxic effects of SF5 (inhibition of 85–90%), compared with either the chronic myeloid leukemia K562 or solid tumor cell lines (lung, breast and prostate). SF5 arrested the cell cycle in G1 phase, which may be related with the observed downregulation of mRNA expression of c-Myc transcription factor at 24 h and 36 h. SF5 treatment induced cytochrome c release from mitochondria to cytosol, leading the Jurkat cells into apoptosis, which was evidenced by the internucleosomal fragmented DNA and increased number of annexin V-FITC positive cells. The SF5 showed high cytotoxicity for lymphocytic leukemia cells and low or none for solid tumor cells, without toxicity for peripheral mononuclear cells of healthy humans. SF5 altered gene expression, arrested the cell cycle and induced apoptosis via the mitochondrial pathway, similar to traditional antineoplastic chemotherapeutic drugs.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 665
Author(s):  
Margot S.F. Roeten ◽  
Johan van Meerloo ◽  
Zinia J. Kwidama ◽  
Giovanna ter Huizen ◽  
Wouter H. Segerink ◽  
...  

At present, 20–30% of children with acute leukemia still relapse from current chemotherapy protocols, underscoring the unmet need for new treatment options, such as proteasome inhibition. Ixazomib (IXA) is an orally available proteasome inhibitor, with an improved safety profile compared to Bortezomib (BTZ). The mechanism of action (proteasome subunit inhibition, apoptosis induction) and growth inhibitory potential of IXA vs. BTZ were tested in vitro in human (BTZ-resistant) leukemia cell lines. Ex vivo activity of IXA vs. BTZ was analyzed in 15 acute lymphoblastic leukemia (ALL) and 9 acute myeloid leukemia (AML) primary pediatric patient samples. BTZ demonstrated more potent inhibitory effects on constitutive β5 and immunoproteasome β5i proteasome subunit activity; however, IXA more potently inhibited β1i subunit than BTZ (70% vs. 29% at 2.5 nM). In ALL/AML cell lines, IXA conveyed 50% growth inhibition at low nanomolar concentrations, but was ~10-fold less potent than BTZ. BTZ-resistant cells (150–160 fold) displayed similar (100-fold) cross-resistance to IXA. Finally, IXA and BTZ exhibited anti-leukemic effects for primary ex vivo ALL and AML cells; mean LC50 (nM) for IXA: 24 ± 11 and 30 ± 8, respectively, and mean LC50 for BTZ: 4.5 ± 1 and 11 ± 4, respectively. IXA has overlapping mechanisms of action with BTZ and showed anti-leukemic activity in primary leukemic cells, encouraging further pre-clinical in vivo evaluation.


Leukemia ◽  
2009 ◽  
Vol 23 (7) ◽  
pp. 1270-1277 ◽  
Author(s):  
A Furuhata ◽  
M Murakami ◽  
H Ito ◽  
S Gao ◽  
K Yoshida ◽  
...  

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 286-286 ◽  
Author(s):  
Constantine S. Mitsiades ◽  
Cecile Rouleau ◽  
Krishna Menon ◽  
Beverly Teicher ◽  
Massimo Iacobelli ◽  
...  

Abstract Introduction: Defibrotide (DF) is a polydisperse oligonucleotide with anti-thrombotic, thrombolytic, anti-ischemic, and anti-adhesive properties, which selectively targets the microvasculature and has minimal hemorrhagic risk. DF is an effective treatment for veno-occlusive disease (VOD), an important regimen-related toxicity in stem cell transplantation characterized by endothelial cell injury. DF also augments stem cell mobilization by modulating adhesion in vivo. Because of its cytoprotective effect on the endothelium, we specifically investigated whether DF protects tumor cells from cytotoxic anti-tumor agents. Further, because of its broad anti-adhesive properties, we evaluated whether DF modulates the interaction of MM cells with bone marrow stromal cells (BMSCs), which confers growth, survival and drug resistance in the BM milieu. Methods: In vitro studies in isogenic dexamethasone (Dex)-sensitive and resistant MM cell lines (MM-1S and MM1R, respectively) showed that DF does not attenuate the sensitivity of MM cells to Dex, the proteasome inhibitor bortezomib (PS-341), melphalan (MEL), vinca alkaloids (vincristine, vinblastine), taxanes (paclitaxel) or platinum (cisplatin), but does decrease their sensitivity to doxorubicin. These selective effects in vitro of DF in protecting tumor cells against doxorubicin and modestly sensitizing MM cells to platinum was also confirmed in solid tumor breast (MCF-7) and colon (HT-29) carcinoma cell lines. Although DF had minimal in vitro inhibitory effect on MM or solid tumor cell growth in vitro, it showed in vivo activity as a single agent and enhanced the responsiveness of MM tumors to cytotoxic chemotherapeutics, such as MEL or cyclophosphamide, in human MM xenografts in SCID/NOD mice. The in vivo single-agent activity and chemosensitizing properties of DF, coupled with its lack of major in vitro activity, suggested that DF may not directly target tumor cells, but rather modulate tumor cell interaction with BMSCs. In an ex vivo model of co-culture of primary MM tumor cells with BMSCs (which protects MM cells against conventional chemotherapy), DF alone had a only modest effect on tumor cell viability, but it significantly enhanced MM cell sensitivity to cytotoxic chemotherapy (e.g. MEL), suggesting that a major component of the biological effects of DF may be attributable not to direct targeting of tumor cells, but to modulation of the interactions that tumor cells develop with the local stromal milieu. Conclusion: Our studies show that DF mediates in vivo anti-MM activity by abrogating interactions of MM cells with their BM milieu, thereby enhancing sensitivity and overcoming resistance to conventional chemotherapy. These data support future clinical trials of DF, in combination with both conventional and novel therapies, to improve patient outcome in MM.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1593-1593
Author(s):  
Tanyel Kiziltepe ◽  
Kenji Ishitsuka ◽  
Teru Hideshima ◽  
Noopur Raje ◽  
Norihiko Shiraishi ◽  
...  

Abstract Multiple myeloma (MM) is currently an incurable hematological malignancy. A major reason for the failure of currently existing therapies is the chemotherapeutic resistance acquired by the MM cells upon treatment. Overexpression of glutathione S-transferases (GST) has been shown as one possible mechanism of anti-cancer drug resistance in a broad spectrum of tumor cells. JS-K (O2-(2,4-Dinitrophenyl) 1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate) belongs to a class of pro-drugs which are designed to release nitric oxide (NO) on reaction with GST. JS-K can possibly turn GST overexpression to the tumor’s disadvantage by (1) consuming intracellular GSH and preventing drug inactivation; and (2) by exposing tumor cells to high intracellular concentrations of NO. JS-K has potent in vitro and in vivo anti-leukemic activity. The purpose of the present study is to examine the biological effects of JS-K on human MM cells. We demonstrate that JS-K has significant in vitro cytotoxicity on MM cell lines, with an IC50 of 0.3-2 mM at 48 hours. JS-K also induces cytotoxicity on cell lines that are resistant to conventional chemotherapy (i.e., MM1R, RPMI-Dox40, RPMI-LR5, RPMI-MR20). Importantly, no cytotoxic effects of JS-K were detected on peripheral blood mononuclear cells (PBMNC) obtained from healthy volunteers at these doses. Moreover, JS-K could overcome the survival and growth advantages conferred by interleukin-6 (IL-6) and insulin-like growth factor-1 (IGF-1), or by adherence of MM cells to bone marrow stromal cells (BMSC). JS-K caused a transient G2/M arrest followed by apoptosis, as determined by flow cytometric analysis using PI, Annexin V and Apo2.7 staining. JS-K-induced apoptosis was associated with caspase 8, 7, 9 and 3 activation. Interestingly, Fas was upregulated by JS-K, suggesting the involvement of death receptor pathway in induction of apoptosis. JS-K also triggered Mcl-1 cleavage and Bcl-2 phosphorylation, suggesting the involvement of mitochondrial pathway. In addition, apoptosis inducing factor (AIF), endonuclease G (EndoG) and cytochrome c were released into the cytosol during apoptosis. Taken together, these findings suggest the involvement of both intrinsic and extrinsic apoptotic pathways in JS-K-induced apoptosis in MM cells. In summary, our studies demonstrate that JS-K induces apoptosis and overcomes in vitro drug resistance in MM cells. Therefore, JS-K is a novel compound which carries significant potential to be included in the repertoire of existing treatment modalities for MM. Ongoing studies are delineating the mechanism of action of JS-K to provide the preclinical rationale for combination therapies to overcome drug resistance and improve patient outcome.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 5021-5021
Author(s):  
Amy Kimball ◽  
Mehmet Burcu ◽  
Kieran L O’Loughlin ◽  
Laurie A. Ford ◽  
Hans Minderman ◽  
...  

Abstract The mammalian target of rapamycin (mTOR), a serine/threonine protein kinase that regulates cell survival and proliferation, is constitutively activated in diverse malignancies, and constitutive mTOR activation has been implicated in both malignant transformation and resistance to chemotherapy. The mTOR inhibitor rapamycin, which inhibits mTOR signaling and has immunosuppressive effects at nanomolar concentrations, also has antineoplastic activity, but its reported effects on cell cycle and on apoptosis have been variable. Several studies evaluated lymphoid and myeloid cell lines after 24 or 48 hours of exposure to rapamycin and reported cell cycle arrest in G1, while others reported apoptosis. Rapamycin is being incorporated into treatment regimens in acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), and other hematologic malignancies, and knowledge of its growth inhibitory and cytotoxic effects will be useful in designing combination regimens. To this end, the concentration-dependent effects of rapamycin on survival, proliferation, cell cycle and apoptosis of myeloid and lymphoid cell lines and acute leukemia cells were studied. Assays were performed at serial time points extending to 96 hours. Cells studied included HL60 myeloid and Jurkat T-lymphoblastic leukemia, 8226 myeloma and U937 histiocytic lymphoma cells and ML-1 myeloid leukemia cells, which have intact p53, as well as multidrug resistant HL60/VCR, HL60/ADR and 8226/MR20 cells overexpressing the ATP-binding cassette (ABC) proteins ABCB1, ABCC1 and ABCG2, respectively. Pretreatment blasts from 9 patients with AML and 4 with ALL were also studied. Cell survival was measured following 96-hour (cell lines) or 48-hour (patient samples) culture with rapamycin at picomolar to micromolar concentrations using the WST-1 colorimetric assay. Cells grown in suspension culture without rapamycin and with 1 nanomolar to 100 micromolar rapamycin were counted at serial time points. Cell cycle was analyzed by propidium iodide labeling and bromodeoxyuridine incorporation, cell division by carboxyfluorescein succinimidyl ester (CFSE) staining and apoptosis by Annexin V labeling, all measured by flow cytometry. Concentration-dependent effects of rapamycin on cell lines and acute leukemia cells in the WST-1 assay were biphasic, occurring at nanomolar and again at micromolar concentrations, with a plateau from approximately 10 nanomolar to 10 micromolar. At nanomolar concentrations rapamycin prolonged cell doubling times by 20–40%, as evidenced by CFSE staining at serial time points, but it did not cause cell cycle arrest. Examined at serial time points, cells continuously exposed to rapamycin at nanomolar concentrations did not accumulate in any single phase of the cell cycle, nor did they become apoptotic. Doubling times increased, resulting in decreased cell numbers at each time point in relation to control cultures without rapamycin. When cells cultured with rapamycin were transferred to rapamycin-free medium, doubling times reverted to those in rapamycin-free cultures, demonstrating that cell cycle slowing resulted from continuous exposure to rapamycin and was fully reversible in the absence of rapamycin. In contrast to rapamycin at nanomolar concentrations, rapamycin at micromolar concentrations caused apoptosis of cell lines and acute leukemia cells. Thus rapamycin at nanomolar concentrations increases the doubling time of myeloid and lymphoid cell lines and acute leukemia cells, while rapamycin at micromolar concentrations causes apoptosis. Rapamycin doses used in immunosuppressive regimens are well tolerated and yield nanomolar plasma concentrations. Our data suggest that continuous oral administration of rapamycin or its analogs at the doses used in immunosuppressive regimens may slow growth of leukemia cells and might have utility as maintenance therapy in the minimal residual disease setting, given the known lack of effect on normal cells. Higher doses of rapamycin are being studied in phase I clinical trials. Finally, increased understanding of rapamycin’s effect on leukemia cell growth will help direct its incorporation into combination therapy.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1293-1293
Author(s):  
Daniela E. Egas Bejar ◽  
Joy M. Fulbright ◽  
Fernando F. Corrales-Medina ◽  
Mary E. Irwin ◽  
Blake Johnson ◽  
...  

Abstract Anthracyclines are among the most powerful drugs used for the treatment of leukemia, however their use has been associated with cardiotoxicity. Reactive oxygen species (ROS) are generated in both cancer and normal cells after anthracycline exposure and have been implicated in both early and late onset cardiotoxicity. Counteracting this ROS generation are intracellular antioxidants such as the ubiquitous antioxidant glutathione (GSH), levels of which are depleted upon anthracycline exposure. Basal expression of GSH pathway components and other antioxidants vary greatly between different cell types. Due to this differential expression of cellular antioxidants in cardiomyocytes versus leukemia cells, we posit that anthracyclines exert distinct effects on oxidative stress and consequent apoptosis induction in leukemia cells and nontransformed hematopoietic cells (PBMC) relative to cardiomyocytes. As a result, we expect potentially varied mechanisms of cell death induction in these cell lines after anthracycline treatment. To test this hypothesis, the acute leukemia cell lines Jurkat and ML-1 and the cardiomyocyte line H9C2 were used. Dose responses with the anthracyclines, doxorubicin and daunorubicin, were carried out and trypan blue exclusion and propidium iodide staining followed by flow cytometry were used to assess viability and DNA fragmentation respectively. Cardiomyocytes had a 25-150 fold higher IC50 value than the acute leukemia cell lines, indicating selectivity. To assess whether apoptosis was induced by anthracyclines, caspase 3 activity was measured and found to be increased at 24 hours in Jurkat cells which preceded decreases in viability, supporting an apoptotic mechanism of cell death. GSH levels also decreased markedly after 24 hours of treatment with anthracyclines in this cell line, however, a pan-caspase inhibitor did not block GSH depletion, indicating that these events occur independent of each other. To evaluate whether antioxidants conferred protection against loss of viability in all cell types, cells were pretreated for at least 30 minutes with antioxidants and then treated with doxorubicin and daunorubicin for 24 hours. Antioxidants used were N-acetylcysteine (NAC, a GSH precursor and amino acid source), GSH ethyl ester (cell permeable form of GSH), tiron (free radical scavenger) and trolox (a water soluble form of vitamin E). GSH ethylester did not prevent cytotoxicity of anthracyclines in acute leukemia lines or cardiomyocytes. Therefore boosting GSH levels in leukemia cells does not reverse cytotoxicity. Trolox, however, did block anthracycline induced cell death in ML-1 cells, suggesting that vitamin E supplementation would counteract leukemia cell specific effects of anthracyclines on AML cells. Tiron protected PBMC from doxorubicin cytotoxicity but did not protect leukemia cells or cardiomyocytes, hinting at a protective strategy for normal non-leukemia blood cells. Interestingly, NAC did not interfere with the cytotoxic effects of anthracyclines on acute leukemia cells or PBMC, but protected H9C2 cells from daunorubicin cytotoxicity. Taken together, these data reveal differential protective effects of antioxidants in cardiomyocytes and PBMCs relative to ALL and AML cells. Our work indicates that NAC can protect cardiomyocytes without interfering with anthracycline cytotoxicity in acute leukemia cells. In humans, one randomized control trial tested the addition of NAC to doxorubicin therapy, detecting no evidence of cardioprotective activity by chronic administration of NAC. However, the schedule used for administration of NAC in that study may not have been optimal, and biomarkers for oxidative stress reduction by NAC were not incorporated into the trial. Previously, other antioxidants have been used with very limited clinical success and possible contributing factors include inadequate sample size, choice of agent, dose used, duration of intervention and the lack of biomarker endpoints. Designing a cardioprotective and antioxidant strategy with attention to these factors may prove to be efficacious in protecting cardiac cells without interfering with the antitumoral effect of anthracyclines. To this end, our data suggests that trolox and vitamin E analogues should not be used in acute leukemia as they may interfere with the cytotoxic action of anthracyclines but NAC or cysteine may be used as cardioprotectants. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
1998 ◽  
Vol 91 (12) ◽  
pp. 4624-4631 ◽  
Author(s):  
I. Jeremias ◽  
C. Kupatt ◽  
B. Baumann ◽  
I. Herr ◽  
T. Wirth ◽  
...  

Death-inducing ligands (DILs) such as tumor necrosis factor α (TNFα) or the cytotoxic drug doxorubicin have been shown to activate a nuclear factor κB (NFκB)-dependent program that may rescue cells from apoptosis induction. We demonstrate here that TRAIL (TNF-related apoptosis-inducing ligand), a recently identified DIL, also activates NFκB in lymphoid cell lines in a kinetic similar to TNFα. NFκB activity is independent from FADD, caspases, and apoptosis induction. To study the influence of NFκB activity on apoptosis mediated by TRAIL, CD95, TNFα, or doxorubicin, NFκB activation was inhibited using the proteasome inhibitor N-acetyl-L-leucinyl-L-leucinyl-L-norleucinal or transient overexpression of mutant IκBα. Sensitivity for induction of apoptosis was markedly increased by these treatments in apoptosis sensitive cell lines. Moreover, both in cell lines and in primary leukemia cells that are resistant towards induction of apoptosis by DILs and doxorubicin, antagonization of NFκB activity partially restored apoptosis sensitivity. These data suggest that inhibition of NFκB activation may provide a molecular approach to increase apoptosis sensitivity in anticancer treatment.


2021 ◽  
Author(s):  
Yifan Zeng ◽  
Xing-Hua Liang ◽  
Yong Xia ◽  
Wen-Yin He

Abstract Objective To explore the mechanism of JQ1 on leukemia cells. Methods This study takes two myeloid leukemia cell lines as a research model. Cells treated with high concentration of JQ1 were collected for quantitative real-time PCR, immunoblot and flow cytometry to verify the effects of JQ1 on myeloid leukemia tumor cells. Combined with mRNA sequencing of cell lines to identify the differences in mRNA expression of different cell lines. Results Two cell lines changed cell morphology under JQ1 treatment. The cell membrane appeared in varying degrees of wrinkled internal subsidence. K562 cell lines can maintain stable proliferation after being induced by a specific concentration of JQ1. However, JQ1 cannot induce the death of the K562 cells. Although the MYC and BCL2 gene expression decreased, JQ1 did not affect the c-Myc targeted genes to affect the cell cycle, nor did it trigger the BCL2-mediated apoptosis pathway. On the contrary, after JQ1 induced the MV-4-11 cells, the MYC-mediated cell cycle significantly slowed down and arrested at the G0/G1 phase. The death of MV-4-11 tumor cells through the apoptosis pathway regulated by BCL-2 family. Conclusion JQ1 has different pharmacological effects on two myeloid leukemia cell lines. For MV-4-11, JQ1 mainly inhibited cell cycle by regulating MYC pathway and induced BCL-2-mediated apoptosis to kill myeloid leukemia tumor cells and thus perform anti-tumor effects. K-562 cells showed drug resistance to JQ1 which confirmed that the K-562 cell line has a feedback mechanism that prevents JQ1-induced apoptosis.


2020 ◽  
Vol 66 (5) ◽  
pp. 563-571
Author(s):  
Anna Danilova ◽  
N. Avdonkina ◽  
Ye. Gubareva ◽  
I. Baldueva ◽  
Anton Zozulya ◽  
...  

Circadian clock is a complex mechanism regulating many different physiological processes. Preclinical, epidemiological and clinical studies demonstrate association between circadian rhythms disruption and tumor initiation. Study of modulation of solid tumor cells biological properties through enhancement of clock mechanisms could attribute to the development of more effective chemo- and hormone therapy approaches. Aim: Evaluate the effects of ovarian and lung tumor cells synchronization with dexamethasone in vitro on cells sensitivity to cisplatin. Materials and methods: Metastatic ovarian cancer (n=3) and lung cancer (n=3) cell lines were obtained from patients tumors. Tumor cell cultivation was performed in accordance with the protocol. Artificial synchronization was performed with dexamethasone 200 nM introduction to the cell cultures. Doses of cisplatin used were 1.5 and 3.0 mg/ml. xCELLigence Real-Time Cell Analysis and Cell-IQ was used to measure proliferation and chemoresistance of tumor cells. Results: Each cell-line had individual morphological characteristics and proliferation parameters. Preliminary incubation with dexamethasone (2 h) had a stimulating effect on proliferation of all tumor cell lines (Slope min -4.3(0.3)хЕ ‘х10-3 - max 36.8(0.6)хЫх10'3, min 2.2(0.2)хЕ1х10'3- max 50.4(0.8)хЕ1х10'3), and increased their sensitivity to cisplatin (min -43(2.6)хЕ1х10-3 - max 57.5(0.6)хЕ1х10-3 и min -217,3(2,2) -1,9(0,1)хч-1х10-3 - max -1,9(0,1)хч'1х10'3, respectively. Conclusion: These results should be the platform for future studies of the interaction of clock mechanisms, cell cycle regulation and viability of tumor cells.


Sign in / Sign up

Export Citation Format

Share Document