scholarly journals Exploring the ATR-CHK1 pathway in the response of doxorubicin-induced DNA damages in acute lymphoblastic leukemia cells

2021 ◽  
Author(s):  
Andrea Ghelli Luserna Di Rorà ◽  
Martina Ghetti ◽  
Lorenzo Ledda ◽  
Anna Ferrari ◽  
Matteo Bocconcelli ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Cell Cycle Checkpoint ◽  
M Cell ◽  
Dna Damages ◽  
Cycle Checkpoint ◽  
Dna Double Helix

AbstractDoxorubicin (Dox) is one of the most commonly used anthracyclines for the treatment of solid and hematological tumors such as B−/T cell acute lymphoblastic leukemia (ALL). Dox compromises topoisomerase II enzyme functionality, thus inducing structural damages during DNA replication and causes direct damages intercalating into DNA double helix. Eukaryotic cells respond to DNA damages by activating the ATM-CHK2 and/or ATR-CHK1 pathway, whose function is to regulate cell cycle progression, to promote damage repair, and to control apoptosis. We evaluated the efficacy of a new drug schedule combining Dox and specific ATR (VE-821) or CHK1 (prexasertib, PX) inhibitors in the treatment of human B−/T cell precursor ALL cell lines and primary ALL leukemic cells. We found that ALL cell lines respond to Dox activating the G2/M cell cycle checkpoint. Exposure of Dox-pretreated ALL cell lines to VE-821 or PX enhanced Dox cytotoxic effect. This phenomenon was associated with the abrogation of the G2/M cell cycle checkpoint with changes in the expression pCDK1 and cyclin B1, and cell entry in mitosis, followed by the induction of apoptosis. Indeed, the inhibition of the G2/M checkpoint led to a significant increment of normal and aberrant mitotic cells, including those showing tripolar spindles, metaphases with lagging chromosomes, and massive chromosomes fragmentation. In conclusion, we found that the ATR-CHK1 pathway is involved in the response to Dox-induced DNA damages and we demonstrated that our new in vitro drug schedule that combines Dox followed by ATR/CHK1 inhibitors can increase Dox cytotoxicity against ALL cells, while using lower drug doses. Graphical abstract • Doxorubicin activates the G2/M cell cycle checkpoint in acute lymphoblastic leukemia (ALL) cells. • ALL cells respond to doxorubicin-induced DNA damages by activating the ATR-CHK1 pathway. • The inhibition of the ATR-CHK1 pathway synergizes with doxorubicin in the induction of cytotoxicity in ALL cells. • The inhibition of ATR-CHK1 pathway induces aberrant chromosome segregation and mitotic spindle defects in doxorubicin-pretreated ALL cells.

Abstract 294: Override the doxorubicin-induced G2/M checkpoint using cell-cycle checkpoint inhibitors on acute lymphoblastic leukemia

2017 ◽  
Author(s):  
Andrea Ghelli Luserna di Rorà ◽  
Ilaria Iacobucci ◽  
Enrica Imbrogno ◽  
Anna Ferrari ◽  
Valentina Robustelli ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Acute Lymphoblastic Leukemia ◽  
Checkpoint Inhibitors ◽  
Lymphoblastic Leukemia ◽  
Cell Cycle Checkpoint ◽  
Cycle Checkpoint

The Inhibition of Checkpoint Kinase 1 As a Promising Strategy to Increase the Effectiveness of Different Treatments in Acute Lymphoblastic Leukemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2478-2478
Author(s):  
Andrea Ghelli Luserna Di Rora ◽  
Ilaria Iacobucci ◽  
Enrica Imbrogno ◽  
Enrico Derenzini ◽  
Anna Ferrari ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Acute Lymphoblastic Leukemia ◽  
Cell Viability ◽  
Cytotoxic Activity ◽  
Cell Lines ◽  
Propidium Iodide ◽  
Lymphoblastic Leukemia ◽  
Single Agent ◽  
Dna Damages ◽  
Checkpoint Kinase

Abstract Nowadays the effectiveness of the treatments for adult Acute Lymphoblastic Leukemia (ALL) patients is still inadequate and frequently many patients after years of response to treatments develop relapses. Thus there is a need to find novel targets for specific therapies and to maximize the effect of the actual treatments. Recently different Checkpoint Kinase (Chk)1/Chk2 inhibitors has been assessed for the treatment of different type of cancers but only few studies have been performed on hematological diseases. We evaluated the effectiveness of the Chk1 inhibitor, LY2606368, as single agent and in combination with tyrosine kinase inhibitors (imatinib and dasatinib) or with the purine nucleoside antimetabolite clofarabine in B-/T- acute lymphoblastic leukemia (ALL) cell lines and in primary blasts. Human B (BV-173, SUPB-15, NALM-6, NALM-19 and REH) and T (MOLT-4, RPMI-8402 and CEM) ALL cell lines were incubated with increasing concentrations of drug (1-100 nM) for 24 and 48 hours and the reduction of the cell viability was evaluated using WST-1 reagent. LY2606368 deeply reduced the cell viability in a dose and time dependent manner in all the cell lines, with the BV-173 (6.33 nM IC50 24hrs) and RPMI-8402 (8.07 nM IC50 24hrs) being the most sensitive while SUP-B15 (61.4 nM IC50 24hrs) and REH (96.7 nM IC50 24hrs) being the less sensitive cell lines. Moreover the sensitivity to the compound was no correlated with the different sub-type of ALL or with the mutational status of p53, which is a marker of the functionality of the G1/S checkpoint. The cytotoxic activity was confirmed by the significant increment of apoptosis cells (Annexin V/Propidium Iodide), by the increment of gH2AX foci and by the activation of different apoptotic markers (Parp-1 and pro-Caspase3 cleavage). To understand the relationship between the activation of apoptosis and the effect on cell cycle and to identify hypothetical mechanisms of death, different cell cycle analyses were performed (Propidium Iodide staining). The inhibition of Chk1, deeply changed the cell cycle profile. Indeed in all the cell lines the percentage of cells in S phase and in G2/M phase were reduced by the treatment while the numbers of cells in sub-G1 and G1 phase were increased. The hypothetical function of LY2606368 as a chemosensitizer agent was evaluated combining the compound with different drugs normally used in clinical trials. For each drugs the combination strongly reduced the cell viability when compared to the cytotoxic effect of the single drugs. Moreover the combination showed an additive efficacy in term of induction of DNA damages as showed by the increase number of gH2AX foci and the activation of pChk1 (ser 317). The results found on the cell lines were confirmed also using primary leukemic blast isolated from adult Philadelphia-positive ALL patients. Indeed LY2606368 as single agent or in combination with the Tki, imatinib, was able to deeply reduce the cell viability and to induce DNA damages (gH2AX foci). In conclusion LY2606368 showed a strong cytotoxic activity on B-/T-All cell lines and primary blasts as single agent and in combination with other drugs. In our opinion this data are the basis for a future clinical evaluation of this compound in the treatment of leukemia. Supported by ELN, AIL, AIRC, progetto Regione-Università 2010-12 (L. Bolondi), FP7 NGS-PTL project. Disclosures Soverini: Novartis, Briston-Myers Squibb, ARIAD: Consultancy. Cavo:JANSSEN, CELGENE, AMGEN: Consultancy. Martinelli:ROCHE: Consultancy; Novartis: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau; Pfizer: Consultancy; Ariad: Consultancy; AMGEN: Consultancy; MSD: Consultancy.

scholarly journals Synergism Through WEE1 and CHK1 Inhibition in Acute Lymphoblastic Leukemia

Cancers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1654 ◽  
Author(s):  
Ghelli Luserna Di Rorà ◽  
Bocconcelli ◽  
Ferrari ◽  
Terragna ◽  
Bruno ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Death ◽  
Acute Lymphoblastic Leukemia ◽  
Cell Lines ◽  
Therapeutic Strategy ◽  
Synthetic Lethality ◽  
Ex Vivo ◽  
Lymphoblastic Leukemia ◽  
Cell Cycle Checkpoint ◽  
Induction Of Apoptosis

Introduction: Screening for synthetic lethality markers has demonstrated that the inhibition of the cell cycle checkpoint kinases WEE1 together with CHK1 drastically affects stability of the cell cycle and induces cell death in rapidly proliferating cells. Exploiting this finding for a possible therapeutic approach has showed efficacy in various solid and hematologic tumors, though not specifically tested in acute lymphoblastic leukemia. Methods: The efficacy of the combination between WEE1 and CHK1 inhibitors in B and T cell precursor acute lymphoblastic leukemia (B/T-ALL) was evaluated in vitro and ex vivo studies. The efficacy of the therapeutic strategy was tested in terms of cytotoxicity, induction of apoptosis, and changes in cell cycle profile and protein expression using B/T-ALL cell lines. In addition, the efficacy of the drug combination was studied in primary B-ALL blasts using clonogenic assays. Results: This study reports, for the first time, the efficacy of the concomitant inhibition of CHK1/CHK2 and WEE1 in ALL cell lines and primary leukemic B-ALL cells using two selective inhibitors: PF-0047736 (CHK1/CHK2 inhibitor) and AZD-1775 (WEE1 inhibitor). We showed strong synergism in the reduction of cell viability, proliferation and induction of apoptosis. The efficacy of the combination was related to the induction of early S-phase arrest and to the induction of DNA damage, ultimately triggering cell death. We reported evidence that the efficacy of the combination treatment is independent from the activation of the p53-p21 pathway. Moreover, gene expression analysis on B-ALL primary samples showed that Chek1 and Wee1 are significantly co-expressed in samples at diagnosis (Pearson r = 0.5770, p = 0.0001) and relapse (Pearson r= 0.8919; p = 0.0001). Finally, the efficacy of the combination was confirmed by the reduction in clonogenic survival of primary leukemic B-ALL cells. Conclusion: Our findings suggest that the combination of CHK1 and WEE1 inhibitors may be a promising therapeutic strategy to be tested in clinical trials for adult ALL.

scholarly journals BRD4 Proteolysis Targeting Chimera (PROTAC) ARV-825 Targets Both NOTCH1-MYC Regulatory Circuit and Leukemia-Microenvironment in T-ALL

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 716-716
Author(s):  
Sujan Piya ◽  
Hong Mu ◽  
Seemana Bhattacharya ◽  
Teresa McQueen ◽  
Richard E Davis ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Cell Lines ◽  
Research Funding ◽  
Lymphoblastic Leukemia ◽  
New Haven ◽  
Down Regulation ◽  
Regulatory Circuit ◽  
Cell Acute Lymphoblastic Leukemia

Abstract Background: Salvage options for patients with relapsed T cell acute lymphoblastic leukemia (T-ALL) are limited, with less than 25% of these patients achieving second remission 1, 2. 70% of T-ALL cases have activating mutations of the NOTCH1 pathway, which transcriptionally activates MYC by binding to its `superenhancer' region 3, 4. Other deregulated oncogenic pathways in T-ALL include PI3K/Akt, the anti-apoptotic Bcl-2 family, and CDKN2A/2B cell cycle regulators 5, 6. The NOTCH1-MYC regulatory circuit is an attractive therapeutic target, but clinical development of gamma-secretase inhibitors (GSI) to target NOTCH1 has been limited by 'on target' toxicities. A better target may be BRD4, a critical component of superenhancer complexes that binds to acetylated histone (3 and 4) and drives NOTCH1 mediated MYC transcription7. ARV-825 is a hetero-bifunctional PROteolysis TArgeting Chimera (PROTAC) that has 3 components: a thienodiazepine-based BRD4 ligand, a linker arm, and a cereblon-binding ligand. ARV-825 recruits BRD4 to the E3 ubiquitin ligase cereblon and leads to efficient and sustained degradation of BRD4, resulting in down-regulation of MYC. Methods: We investigated the effectiveness of ARV-825 against T-ALL cell lines, including GSI-resistant lines. Since microenvironmental signals are critical for the survival of T-ALL, we specifically tested the impact of BRD4 degradation on CD44/CD44v, which integrates cell-extrinsic microenvironmental signals and is part of cysteine transporter that maintains low intra-cellular reactive oxygen species (ROS), necessary for T-ALL survival and the persistence of disease. We also examined the anti-leukemic effect of ARV-825 in a T-ALL patient-derived xenograft (PDX) mouse model of disseminated leukemia with a constitutively active NOTCH1 mutation. Results: The IC50s for all tested T-ALL cell lines at 72 hours were in the low nanomolar range (< 50 nM). ARV-825 leads to sustained degradation of BRD4 and down-regulation of its transcriptional targets MYC, Bcl-2 and Bcl-XL and inhibits cell proliferation and induces apoptosis in GSI-sensitive (HPB-ALL, KOPT1) and GSI-resistant (MOLT4, SUPT1) cell lines. Mass cytometry based proteomic analysis (CyTOF) and immunoblotting showed that ARV-825 down-regulated cell intrinsic oncogenic molecules: transcription factors Myc and NFkB, cell cycle regulator CDK6, activated PI3K/Akt, and anti-apoptotic Bcl2 family proteins. In addition ARV-825 down regulated two key molecules involved in leukemia-stroma interaction; CD44 (Fig. 1), and CD98, a component of amino acid transporters xCT, LAT1 and 2, both essential in regulation of oxidative stress. Quantitative PCR and immunoblotting analysis confirmed the transcriptional down regulation of total CD44 and CD44 variants 8-10 (2-fold change treated vs . untreated). As a functional correlate of down-regulation of CD98/CD44/CD44v, flow cytometry confirmed increased intracellular ROS generation (Fig. 2). Finally, in a PDX mouse model of human T-ALL, ARV-825 treatment resulted in lower leukemia burden (confirmed by flow cytometry for human CD45+ cells in bone marrow) and better survival compared to vehicle-treated control mice (p=0.002) (Fig.3). Reference: 1. Marks DI, Rowntree C. Management of adults with T-cell lymphoblastic leukemia. Blood 2017; 129(9): 1134-1142. 2. Litzow MR, Ferrando AA. How I treat T-cell acute lymphoblastic leukemia in adults. Blood 2015; 126(7): 833-41. 3. Sanchez-Martin M, Ferrando A. The NOTCH1-MYC highway toward T-cell acute lymphoblastic leukemia. Blood 2017; 129(9): 1124-1133. 4. Demarest RM, Ratti F, Capobianco AJ. It's T-ALL about Notch. Oncogene 2008; 27(38): 5082-91. 5. Girardi T, Vicente C, Cools J, De Keersmaecker K. The genetics and molecular biology of T-ALL. Blood 2017; 129(9): 1113-1123. 6. Joshi I, Minter LM, Telfer J, Demarest RM, Capobianco AJ, Aster JC et al. Notch signaling mediates G1/S cell-cycle progression in T cells via cyclin D3 and its dependent kinases. Blood 2009; 113(8): 1689-98. 7. Loven J, Hoke HA, Lin CY, Lau A, Orlando DA, Vakoc CR et al. Selective inhibition of tumor oncogenes by disruption of super-enhancers. Cell 2013; 153(2): 320-34. Disclosures Qian: 4Arvinas, LLC. New Haven, CT: Employment. Raina: 4Arvinas, LLC. New Haven, CT: Employment. McKay: 6 ImmunoGen, Inc.Waltham, MA: Employment. Kantarjian: Novartis: Research Funding; Amgen: Research Funding; Delta-Fly Pharma: Research Funding; Bristol-Meyers Squibb: Research Funding; Pfizer: Research Funding; ARIAD: Research Funding. Andreeff: Daiichi Sankyo: Consultancy.

scholarly journals Therapeutic Stratification of PTEN-MYC Axis Appears to be Promising for Molecular Targeted Therapies in Refractory and Relapsed T-Cell Acute Lymphoblastic Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3883-3883
Author(s):  
Heinz Ahlert ◽  
Sanil Bhatia ◽  
Marc Remke ◽  
Melf Sönnichsen ◽  
Niklas Dienstbier ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Tumor Cells ◽  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Drug Combinations ◽  
Killing Effect ◽  
Cell Acute Lymphoblastic Leukemia ◽  
T Cell Lines

Therapy refractory and relapsed T-cell acute lymphoblastic leukemia (T-ALL) is still one of the most common causes for cancer related death in children. T-ALL is a highly heterogeneous disease with several established biomarkers, which promote its progression. These biomarkers are promising tools for patient stratification and can be used for targeted therapeutic approaches. For instance, PTEN is one of the most displayed mutations in pediatric T-ALL and plays an important role in proteolysis of the oncoprotein MYC. Therefore, it is not surprising that PTEN activity in T-ALL patients correlates with higher MYC protein levels. Importantly, PTEN mutations have recently been associated with poor overall survival in T-ALL patients, underscoring its importance for future treatment options using molecular targeted therapies. In this study, we validated the importance of PTEN as a MYC regulator in T-ALL and elucidated PTEN mutational status as a stratification marker for T-ALL patients. Comparative quantification of PTEN, phosphorylated AKT and MYC in leukemic T-cell lines (n=10) was analyzed at protein level, relative to healthy T-cells. PTEN loss or deceased expression was observed in half of the screened leukemic T-cell lines with concomitant high MYC expression and increased AKT phosphorylation. To identify the drug sensitivity of PTEN mutant (PTENm) and PTEN wild type (PTENwt) cell lines, high-throughput drug screening was performed with 180 inhibitors, including among others kinase-, BET- and gamma secretase inhibitors, as well as conventional chemotherapeutics. PTENm cell lines showed remarkable sensitivity in nanomolar ranges against PI3K inhibitors compared to PTENwt (P=0.001). Anticipating that tumor cells eventually escape the killing effect of single pathway targeted drugs, the need for molecular identification and characterization of synergistic drug combinations is evident. Therefore, diverse compound combinations were tested in an 11 by 11 matrix of different concentrations in PTENm and PTENwt cell lines. Synergism was predicted with Combenefit software using Loewe model to assess putative additive versus synergistic effects. We observed that simultaneous use of copanlisib (PI3K inhibitor) with JQ1 (BET inhibitor) had a strong killing effect in PTENm cell lines. To assess target downregulation after 24 hours of drug treatment, lysates were taken and visualized using western blot. A strong decrease of MYC expression was observed already with a combination of low concentrations of copanlisib and JQ1 with subsequent higher apoptosis induction as measured by Annexin V/PI staining. A second drug combination that showed synergy in PTENm was observed with copanlisib and alisertib, an Aurora kinase-A (AURKA) inhibitor, expecting changes in cell cycle and reduced MYC stability. Indeed, results of cell cycle analysis have revealed an inhibition during mitosis and cellular MYC levels were decreased, suggesting that this combination affects highly proliferative MYC-dependent tumor cells. Contrary to PTENm, in PTENwt cell lines, PI3K inhibition alone showed no cytotoxic effect, but synergy was detected in combination with the MEK inhibitor cobimetinib. Moreover, in this synergistic combination MYC was effectively downregulated on protein level accompanied with changes in regulatory pathways including AKT and MEK. Interestingly, phosphorylation of MYC changed from the stabilizing site (S62) to the degradative site (T58), proposing the progress of MYC degradation. In summary, we observed the importance of PTEN as a regulator for MYC proteolysis and related pathways including AKT and MEK. The loss of PTEN is accompanied with increased MYC. Synergy studies have observed effective drug combinations for PTENm and PTENwt with the aim to downregulate MYC and induce apoptosis in tumor cells. Based on these findings, PTEN-MYC axis seems suitable as a potential stratification marker for future therapy options in refractory and relapsed T-ALL. In the next step, promising drug combinations will be tested in a patient derived xenograft mouse model to validate these findings. Figure Disclosures No relevant conflicts of interest to declare.

The Prolonged Inhibition of Chk1/Chk2 Kinases Enhances Genetic Instability and Compromises the Efficacy of Chemotherapy Against Acute Lymphoblastic Leukemia Cells

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5047-5047
Author(s):  
Andrea Ghelli Luserna Di Rorà ◽  
Antonella Padella ◽  
Maria Chiara Fontana ◽  
Eugenio Fonzi ◽  
Anna Ferrari ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cancer Cells ◽  
Genetic Instability ◽  
Lymphoblastic Leukemia ◽  
Parental Cell ◽  
Point Of View ◽  
Cell Cycle Checkpoint ◽  
Dna Damages ◽  
Molecular Alterations ◽  
Cycle Checkpoint

Acute lymphoblastic leukemia (ALL) cells respond to chemotherapy, or more generally to DNA damages, by activating different DNA Damage Response (DDR) pathways. DDR-pathways regulate cell cycle progression and DNA damages repair. Molecular and functional alterations in key DDR-related genes drastically affect the effectiveness of DNA-damaging treatments in cancer cells. For this reasons selective DDR-inhibitors have been developed in order to sensitize cancer cells against conventional chemotherapy. Despite the proven efficacy of DDR-inhibitors in cancer treatment, only few studies have highlighted the biological consequences the prolonged inhibition of DDR-pathways in cancer cells. We hypothesized that the protracted inhibition of the DDR pathways may generate resistant clones characterized by an increased genetic instability. The aim of the study was to evaluate biological consequences of the prolonged inhibition of two crucial DDR-related kinase such as cell cycle checkpoint kinase 1 (Chk1) and 2 (Chk2) in B cells ALL. In particular, we investigated the consequences of Chk1/Chk2 inhibition in term of increase of genetic instability and in term of responsiveness to chemotherapy agents. Starting from B-ALL cell line NALM-6, we generated a resistant model (hereafter referred as N6R-PF8) by treating the parental cells with increasing concentration of PF-00477736 (Chk1/Chk2 inhibitor) for more than a year and increasing the IC50 value of 10-folds. From a molecular point of view, the N6R-PF8 accumulated significant molecular alterations. SNP microarray analysis highlighted different alterations in DDR-related genes and, in particular, in the ATM/CHK2 pathway. Three regions in copy number LOSS (CN=1) containing several genes involved in cell cycle checkpoint regulation (ATM and NPAT) and in the apoptosis (BIRC2, CASP1 and CASP5) were detectable only in NALM-6 parental cell lines and were copy number neutral in the resistant model. Immunoblotting analysis confirmed that in N6R-PF8 cells the ATM/CHK2 and ATR/CHK1 down-stream pathways were significant over-expressed and activated in comparison to the parental cell. Whole exome sequencing analysis showed that the two cell lines were characterized by different mutational profiles and that N6R-PF8 cells harboured significantly more genetic alterations in comparison with NALM-6 cells. Interestingly, crucial genes involved in DNA repair pathway (MLH3, NBN, POLD1 and PMS2) have been found altered only in N6R-PF8 cells. From a functional point of view, the molecular alterations characterizing the N6R-PF8 significantly compromised the cytotoxicity of PF-00477736 and of different DNA damaging agents in comparison to parental cells. Furthermore, the treatment with ATR/ATM inhibitor restored the sensitivity of N6R-PF8 to PF-00477736 and to different chemotherapy agents. In this scenario the level of expression of these two kinases seems to correlate with the sensitivity to DNA damaging agents and to PF-00477736. Finally, we confirmed that the protracted inhibition of crucial DDR-related kinase may increase the overall genetic instability in ALL cells and compromise the efficacy of DNA damaging based therapies. Disclosures Martinelli: Roche: Consultancy; ARIAD: Consultancy; Novartis: Consultancy; Pfizer: Consultancy; BMS: Consultancy.

scholarly journals Advantages of Tyrosine Kinase Anti-Angiogenic Cediranib over Bevacizumab: Cell Cycle Abrogation and Synergy with Chemotherapy

2021 ◽  
Vol 14 (7) ◽  
pp. 682
Author(s):  
Jianling Bi ◽  
Garima Dixit ◽  
Yuping Zhang ◽  
Eric J. Devor ◽  
Haley A. Losh ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Endometrial Cancer ◽  
Tyrosine Kinase ◽  
Cell Viability ◽  
Cell Lines ◽  
Cell Cycle Progression ◽  
Kinase Inhibitor ◽  
Cell Cycle Checkpoint ◽  
Mitotic Catastrophe ◽  
M Cell

Angiogenesis plays a crucial role in tumor development and metastasis. Both bevacizumab and cediranib have demonstrated activity as single anti-angiogenic agents in endometrial cancer, though subsequent studies of bevacizumab combined with chemotherapy failed to improve outcomes compared to chemotherapy alone. Our objective was to compare the efficacy of cediranib and bevacizumab in endometrial cancer models. The cellular effects of bevacizumab and cediranib were examined in endometrial cancer cell lines using extracellular signal-related kinase (ERK) phosphorylation, ligand shedding, cell viability, and cell cycle progression as readouts. Cellular viability was also tested in eight patient-derived organoid models of endometrial cancer. Finally, we performed a phosphoproteomic array of 875 phosphoproteins to define the signaling changes related to bevacizumab versus cediranib. Cediranib but not bevacizumab blocked ligand-mediated ERK activation in endometrial cancer cells. In both cell lines and patient-derived organoids, neither bevacizumab nor cediranib alone had a notable effect on cell viability. Cediranib but not bevacizumab promoted marked cell death when combined with chemotherapy. Cell cycle analysis demonstrated an accumulation in mitosis after treatment with cediranib + chemotherapy, consistent with the abrogation of the G2/M checkpoint and subsequent mitotic catastrophe. Molecular analysis of key controllers of the G2/M cell cycle checkpoint confirmed its abrogation. Phosphoproteomic analysis revealed that bevacizumab and cediranib had both similar and unique effects on cell signaling that underlie their shared versus individual actions as anti-angiogenic agents. An anti-angiogenic tyrosine kinase inhibitor such as cediranib has the potential to be superior to bevacizumab in combination with chemotherapy.

scholarly journals Gene expression signatures but not cell cycle checkpoint functions distinguish AT carriers from normal individuals

2013 ◽  
Vol 45 (19) ◽  
pp. 907-916
Author(s):  
Liwen Zhang ◽  
Dennis A. Simpson ◽  
Cynthia L. Innes ◽  
Jeff Chou ◽  
Pierre R. Bushel ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Cell Lines ◽  
Cell Cycle Checkpoint ◽  
G2 Checkpoint ◽  
P53 Signaling ◽  
Normal Individuals ◽  
Gene Expression Signatures ◽  
Cycle Checkpoint ◽  
Atm Cell

Ataxia telangiectasia (AT) is a rare autosomal recessive disease caused by mutations in the ataxia telangiectasia-mutated gene ( ATM). AT carriers with one mutant ATM allele are usually not severely affected although they carry an increased risk of developing cancer. There has not been an easy and reliable diagnostic method to identify AT carriers. Cell cycle checkpoint functions upon ionizing radiation (IR)-induced DNA damage and gene expression signatures were analyzed in the current study to test for differential responses in human lymphoblastoid cell lines with different ATM genotypes. While both dose- and time-dependent G1 and G2 checkpoint functions were highly attenuated in ATM−/− cell lines, these functions were preserved in ATM+/− cell lines equivalent to ATM+/+ cell lines. However, gene expression signatures at both baseline (consisting of 203 probes) and post-IR treatment (consisting of 126 probes) were able to distinguish ATM+/− cell lines from ATM+/+ and ATM−/− cell lines. Gene ontology (GO) and pathway analysis of the genes in the baseline signature indicate that ATM function-related categories, DNA metabolism, cell cycle, cell death control, and the p53 signaling pathway, were overrepresented. The same analyses of the genes in the IR-responsive signature revealed that biological categories including response to DNA damage stimulus, p53 signaling, and cell cycle pathways were overrepresented, which again confirmed involvement of ATM functions. The results indicate that AT carriers who have unaffected G1 and G2 checkpoint functions can be distinguished from normal individuals and AT patients by expression signatures of genes related to ATM functions.

scholarly journals BRCA1 Activates a G2-M Cell Cycle Checkpoint following 6-Thioguanine–Induced DNA Mismatch Damage

2007 ◽  
Vol 67 (13) ◽  
pp. 6286-6292 ◽  
Author(s):  
Kazuhiko Yamane ◽  
Jane E. Schupp ◽  
Timothy J. Kinsella
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Checkpoint ◽  
M Cell ◽  
Dna Mismatch ◽  
Cycle Checkpoint
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