scholarly journals A non-genetic, cell cycle dependent mechanism of platinum resistance in lung adenocarcinoma

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Alvaro Gonzalez Rajal ◽  
Kamila A Marzec ◽  
Rachael A McCloy ◽  
Max Nobis ◽  
Venessa Chin ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Lung Adenocarcinoma ◽  
Genetic Mechanism ◽  
Platinum Resistance ◽  
Cell Fates ◽  
Mechanism Of Resistance ◽  
Cycle Dependent

We previously used a pulse-based in vitro assay to unveil targetable signalling pathways associated with innate cisplatin resistance in lung adenocarcinoma (Hastings et al., 2020). Here we advanced this model system and identified a non-genetic mechanism of resistance that drives recovery and regrowth in a subset of cells. Using RNAseq and a suite of biosensors to track single cell fates both in vitro and in vivo, we identified that early S phase cells have a greater ability to maintain proliferative capacity, which correlated with reduced DNA damage over multiple generations. In contrast, cells in G1, late S or those treated with PARP/RAD51 inhibitors, maintained higher levels of DNA damage and underwent prolonged S/G2 phase arrest and senescence. Combined with our previous work, these data indicate that there is a non-genetic mechanism of resistance in human lung adenocarcinoma that is dependent on the cell cycle stage at the time of cisplatin exposure.

scholarly journals Resistance to platinum chemotherapy in lung adenocarcinoma is driven by a non-genetic, cell-cycle dependent mechanism

2020 ◽  
Author(s):  
Alvaro Gonzalez-Rajal ◽  
Rachael McCloy ◽  
Max Nobis ◽  
Kamila A Marzec ◽  
Venessa Chin ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Lung Adenocarcinoma ◽  
Parp Inhibitors ◽  
Genetic Mechanism ◽  
Cell Fates ◽  
Mechanism Of Resistance ◽  
Cycle Dependent ◽  
Platinum Chemotherapy

AbstractInnate resistance to platinum-based chemotherapies has significantly reduced their impact in lung adenocarcinoma. We previously used a pulse-based in vitro assay to unveil targetable signalling pathways associated with this resistant phenotype (Hastings et al., 2020). Here we advanced this model system and identify a non-genetic mechanism of resistance that drives recovery and regrowth in a subset of cells. Using RNAseq and a suite of biosensors to track single cell fates both in vitro and in vivo, we identified that early S phase cells have a greater capacity to repair damage over multiple generations. In contrast, cells in G1, late S or those treated with PARP inhibitors, were unable to sufficiently repair the damage and underwent prolonged S/G2 phase arrest and senescence. These data indicate that there is a fundamental non-genetic mechanism of resistance in lung adenocarcinoma that is dependent on the cell cycle stage at the time of cisplatin exposure.

A Novel Camptothecin Derivative 3j Inhibits Nsclc Proliferation Via Induction of Cell Cycle Arrest By Topo I-Mediated DNA Damage

2019 ◽  
Vol 19 (3) ◽  
pp. 365-374 ◽  
Author(s):  
Yang Liu ◽  
Jingyin Zhang ◽  
Shuyun Feng ◽  
Tingli Zhao ◽  
Zhengzheng Li ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Flow Cytometry ◽  
Dna Damage ◽  
Cyclin D ◽  
Dna Relaxation ◽  
Cycle Arrest ◽  
H460 Cell ◽  
H1975 Cell

Objective: The aim of this study is to investigate the inhibitory effect of camptothecin derivative 3j on Non-Small Cell Lung Cancer (NSCLCs) cells and the potential anti-tumor mechanisms. Background: Camptothecin compounds are considered as the third largest natural drugs which are widely investigated in the world and they suffered restriction because of serious toxicity, such as hemorrhagic cystitis and bone marrow suppression. Methods: Using cell proliferation assay and S180 tumor mice model, a series of 20(S)-O-substituted benzoyl 7- ethylcamptothecin compounds were screened and evaluated the antitumor activities in vitro and in vivo. Camptothecin derivative 3j was selected for further study using flow cytometry in NSCLCs cells. Cell cycle related protein cyclin A2, CDK2, cyclin D and cyclin E were detected by Western Blot. Then, computer molecular docking was used to confirm the interaction between 3j and Topo I. Also, DNA relaxation assay and alkaline comet assay were used to investigate the mechanism of 3j on DNA damage. Results: Our results demonstrated that camptothecin derivative 3j showed a greater antitumor effect in eleven 20(S)-O-substituted benzoyl 7-ethylcamptothecin compounds in vitro and in vivo. The IC50 of 3j was 1.54± 0.41 µM lower than irinotecan with an IC50 of 13.86±0.80 µM in NCI-H460 cell, which was reduced by 8 fold. In NCI-H1975 cell, the IC50 of 3j was 1.87±0.23 µM lower than irinotecan (IC50±SD, 5.35±0.38 µM), dropped by 1.8 fold. Flow cytometry analysis revealed that 3j induced significant accumulation in a dose-dependent manner. After 24h of 3j (10 µM) treatment, the percentage of NCI-H460 cell in S-phase significantly increased (to 93.54 ± 4.4%) compared with control cells (31.67 ± 3.4%). Similarly, the percentage of NCI-H1975 cell in Sphase significantly increased (to 83.99 ± 2.4%) compared with control cells (34.45 ± 3.9%) after treatment with 10µM of 3j. Moreover, increased levels of cyclin A2, CDK2, and decreased levels of cyclin D, cyclin E further confirmed that cell cycle arrest was induced by 3j. Furthermore, molecular docking studies suggested that 3j interacted with Topo I-DNA and DNA-relaxation assay simultaneously confirmed that 3j suppressed the activity of Topo I. Research on the mechanism showed that 3j exhibited anti-tumour activity via activating the DNA damage response pathway and suppressing the repair pathway in NSCLC cells. Conclusion: Novel camptothecin derivative 3j has been demonstrated as a promising antitumor agent and remains to be assessed in further studies.

scholarly journals Dynamic analysis of pulsed cisplatin identifies effectors of resistance in lung adenocarcinoma

2019 ◽  
Author(s):  
Jordan F. Hastings ◽  
Alvaro Gonzalez-Rajal ◽  
Jeremy Z.R. Han ◽  
Rachael A. McCloy ◽  
Yolande E.I. O’Donnell ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Lung Adenocarcinoma ◽  
Patient Specific ◽  
Dna Breaks ◽  
Mutation Status ◽  
Cisplatin Sensitivity ◽  
Mutant Lines ◽  
Platinum Chemotherapy

AbstractIdentification of clinically viable strategies for overcoming resistance to platinum chemotherapy in lung adenocarcinoma has been hampered by inappropriately tailored in vitro assays of drug response. Therefore, using a pulse model that closely recapitulates the in vivo pharmacokinetics of platinum therapy, we profiled cisplatin-induced signalling, DNA damage and apoptotic responses across a panel of lung adenocarcinoma cell lines. By coupling this data with real-time, single cell imaging of cell cycle and apoptosis, we show that TP53 mutation status influenced the mode of cisplatin induced cell cycle arrest, but could not predict cisplatin sensitivity. In contrast, P70S6K-mediated signalling promoted resistance by increasing p53/p63 and p21 expression, reducing double-stranded DNA breaks and apoptosis. Targeting P70S6K sensitised both TP53 wildtype and null lines to cisplatin, but not TP53 mutant lines. In summary, using in vitro assays that mimic in vivo pharmacokinetics identified P70S6K as a robust mediator of cisplatin resistance and highlighted the importance of considering somatic mutation status when designing patient-specific combination therapies.

scholarly journals The Rational Design and Biological Mechanisms of Nanoradiosensitizers

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 504 ◽  
Author(s):  
Hainan Sun ◽  
Xiaoling Wang ◽  
Shumei Zhai
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Dna Damage ◽  
Rational Design ◽  
Design Strategies ◽  
Biological Mechanisms ◽  
Normal Tissues ◽  
Current State

Radiotherapy (RT) has been widely used for cancer treatment. However, the intrinsic drawbacks of RT, such as radiotoxicity in normal tissues and tumor radioresistance, promoted the development of radiosensitizers. To date, various kinds of nanoparticles have been found to act as radiosensitizers in cancer radiotherapy. This review focuses on the current state of nanoradiosensitizers, especially the related biological mechanisms, and the key design strategies for generating nanoradiosensitizers. The regulation of oxidative stress, DNA damage, the cell cycle, autophagy and apoptosis by nanoradiosensitizers in vitro and in vivo is highlighted, which may guide the rational design of therapeutics for tumor radiosensitization.

Induction of G1 Cell Cycle Arrest in Human Glioma Cells by Salinomycin Through Triggering ROS-Mediated DNA Damage In Vitro and In Vivo

2016 ◽  
Vol 42 (4) ◽  
pp. 997-1005 ◽  
Author(s):  
Shi-Jun Zhao ◽  
Xian-Jun Wang ◽  
Qing-Jian Wu ◽  
Chao Liu ◽  
Da-Wei Li ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Arrest ◽  
Glioma Cells ◽  
Human Glioma ◽  
Human Glioma Cells ◽  
Cycle Arrest ◽  
G1 Cell Cycle Arrest

scholarly journals Presence of a Poly(A) Binding Protein and Two Proteins with Cell Cycle-Dependent Phosphorylation in Crithidia fasciculata mRNA Cycling Sequence Binding Protein II

2004 ◽  
Vol 3 (5) ◽  
pp. 1185-1197 ◽  
Author(s):  
Bidyottam Mittra ◽  
Dan S. Ray
Keyword(s):  
Cell Cycle ◽  
Binding Protein ◽  
High Specificity ◽  
Binding Activity ◽  
Mrna Levels ◽  
Crithidia Fasciculata ◽  
Target Mrna ◽  
Cycle Dependent

ABSTRACT Crithidia fasciculata cycling sequence binding proteins (CSBP) have been shown to bind with high specificity to sequence elements present in several mRNAs that accumulate periodically during the cell cycle. The first described CSBP has subunits of 35.6 (CSBPA) and 42 kDa (CSBPB). A second distinct binding protein termed CSBP II has been purified from CSBPA null mutant cells, lacking both CSBPA and CSBPB proteins, and contains three major polypeptides with predicted molecular masses of 63, 44.5, and 33 kDa. Polypeptides of identical size were radiolabeled in UV cross-linking assays performed with purified CSBP II and 32P-labeled RNA probes containing six copies of the cycling sequence. The CSBP II binding activity was found to cycle in parallel with target mRNA levels during progression through the cell cycle. We have cloned genes encoding these three CSBP II proteins, termed RBP63, RBP45, and RBP33, and characterized their binding properties. The RBP63 protein is a member of the poly(A) binding protein family. Homologs of RBP45 and RBP33 proteins were found only among the kinetoplastids. Both RBP45 and RBP33 proteins and their homologs have a conserved carboxy-terminal half that contains a PSP1-like domain. All three CSBP II proteins show specificity for binding the wild-type cycling sequence in vitro. RBP45 and RBP33 are phosphoproteins, and RBP45 has been found to bind in vivo specifically to target mRNA containing cycling sequences. The levels of phosphorylation of both RBP45 and RBP33 were found to cycle during the cell cycle.

scholarly journals Subunit composition determines E2F DNA-binding site specificity.

1997 ◽  
Vol 17 (12) ◽  
pp. 6994-7007 ◽  
Author(s):  
Y Tao ◽  
R F Kassatly ◽  
W D Cress ◽  
J M Horowitz
Keyword(s):  
Cell Cycle ◽  
Dna Binding ◽  
Binding Sites ◽  
Dna Bending ◽  
Susceptibility Gene ◽  
Specific Sequence ◽  
Cellular Genes ◽  
Cycle Dependent

The product of the retinoblastoma (Rb) susceptibility gene, Rb-1, regulates the activity of a wide variety of transcription factors, such as E2F, in a cell cycle-dependent fashion. E2F is a heterodimeric transcription factor composed of two subunits each encoded by one of two related gene families, denoted E2F and DP. Five E2F genes, E2F-1 through E2F-5, and two DP genes, DP-1 and DP-2, have been isolated from mammals, and heterodimeric complexes of these proteins are expressed in most, if not all, vertebrate cells. It is not yet clear whether E2F/DP complexes regulate overlapping and/or specific cellular genes. Moreover, little is known about whether Rb regulates all or a subset of E2F-dependent genes. Using recombinant E2F, DP, and Rb proteins prepared in baculovirus-infected cells and a repetitive immunoprecipitation-PCR procedure (CASTing), we have identified consensus DNA-binding sites for E2F-1/DP-1, E2F-1/DP-2, E2F-4/DP-1, and E2F-4/DP-2 complexes as well as an Rb/E2F-1/DP-1 trimeric complex. Our data indicate that (i) E2F, DP, and Rb proteins each influence the selection of E2F-binding sites; (ii) E2F sites differ with respect to their intrinsic DNA-bending properties; (iii) E2F/DP complexes induce distinct degrees of DNA bending; and (iv) complex-specific E2F sites selected in vitro function distinctly as regulators of cell cycle-dependent transcription in vivo. These data indicate that the specific sequence of an E2F site may determine its role in transcriptional regulation and suggest that Rb/E2F complexes may regulate subsets of E2F-dependent cellular genes.

scholarly journals C1orf109L promote R-loop accumulation induced DNA damage to inhibit cell growth

2019 ◽  
Author(s):  
Dou Peng ◽  
Li Yiqun ◽  
Xie Wanqiu ◽  
Zhang Xiaoqing ◽  
Zhang Dandan ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Death ◽  
Cell Growth ◽  
Genome Instability ◽  
Cell Death Pathway ◽  
Unknown Gene ◽  
Lower Expression

AbstractAs a function unknown gene, C1orf109 is lower expression in various cells. Here, we reported that C1orf109L, the longest variant of C1orf109, which interacted with R-loop-regulating proteins to trigger R-loop, a three-stranded nucleic acid structure frequently mediated genome instability, accumulation. C1orf109L induce chronic DNA damage to promote P21 upregulation and strongly inhibits cell growth in vitro and in vivo by arresting the cell cycle in the G2 phase. With camptothecin (CPT), an R-loop activator, treatment, C1orf109L further triggers R-loop accumulation-induced DNA damage and promotes cell death by activating cell-death pathway. Furthermore, CPT treatment increases C1orf109L ubiquitination and turnover, which inhibits cell death and promotes the G0/G1 phase of the cell cycle. Therefore, our data illustrated the mechanisms underlying C1orf109L-related cell growth inhibition and provide feasibility and limitations for C1orf109L as a potential target for cancer therapy.

scholarly journals The Synergistic Anticancer Effect of a Combination of Chidamide and Etoposide Against NK/T Cell Lymphoma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3987-3987
Author(s):  
Wenting Song ◽  
Zhan Chen ◽  
Cunzhen Shi ◽  
Yuyang Gao ◽  
Xiaoyan Feng ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
T Cell ◽  
Histone Acetylation ◽  
Hematological Malignancies ◽  
Cell Lymphoma ◽  
Dna Damaging Agents ◽  
Etoposide Treatment

Abstract Natural killer/T cell lymphoma (NKTCL) is a highly aggressive hematological malignancy. However, there is currently no consensus on first-line therapies for refractory/relapsed patients. Chidamide is a self-researched and developed HDACs inhibitor, and when combined with DNA-damaging agents, exhibited a clinical synergistic effect for the treatment of some solid tumors and hematological malignancies. Thus in this study, a series of in vitro and in vivo experiments were conducted to explore the efficacy and potential mechanisms of combined chidamide and etoposide treatment in NKTCL. We demonstrated that chidamide or etoposide alone dose- and time-dependently inhibited the cell viability of NKTCL cell lines, YT, NKYS and KHYG-1. Functional experiments suggested that combined chidamide and etoposide treatment exerted synergistic antiproliferation effect and enhanced cell apoptotic death both in vitro and in vivo. Furthermore, the expression of DNA damage related proteins was detected and we also examined the alternations in histone acetylation, cell cycle progression, and mitochondrial membrane potential (MMP). The results suggested that increased histone acetylation, cell cycle arrest at the G2/M phase and loss of MMP, converging to greater DNA damage, might account for the synergism of the combination of chidamide and etoposide in NKTCL. Taken together, our study supplements the clinical application of combining HDACs inhibitors and DNA-damaging agents on treating hematological malignancies but also provide an experimental basis for improved therapeutic efficacy and decreased complications for patients with NKTCL. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

scholarly journals LARP7 is a BRCA1 ubiquitinase substrate and regulates genome stability and tumorigenesis

2019 ◽  
Author(s):  
Fang Zhang ◽  
Pengyi Yan ◽  
Huijing Yu ◽  
Huangying Le ◽  
Zixuan li ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Rna Binding ◽  
Tumor Therapy ◽  
Genotoxic Stress ◽  
Therapy Resistance ◽  
List Type ◽  
M Cell

SummaryAttenuated DNA repair leads to genomic instability and tumorigenesis. BRCA1/BARD1 are the best known tumor suppressors that promote homology recombination (HR) and arrest cell cycle at G2/M checkpoint. As E3 ubiquitin ligases, their ubiquitinase activity has been known to involve in the HR and tumor suppression, but the mechanism remains ambiguous. Here, we demonstrated upon genotoxic stress, BRCA1 together with BARD1 catalyzed the K48 ployubiquitination on LARP7, a 7SK RNA binding protein known to control RNAPII pausing, and thereby degraded it through 26S ubiquitin-proteasome pathway. Depleting LARP7 suppressed the expression of CDK1 complex, arrested cell at G2/M DNA damage checkpoint and reduced BRCA2 phosphorylation which thereby facilitated RAD51 recruitment to damaged DNA to enhance HR. Importantly, LARP7 depletion observed in breast patients lead to the chemoradiotherapy resistance both in vitro and in vivo. Together, this study unveils a mechanism by which BRCA1/BARD1 utilizes their E3 ligase activity to control HR and cell cycle, and highlights LARP7 as a potential target for cancer prevention and therapy.HighlightsDNA damage response downregulates LARP7 through BRCA1/BARD1BRCA1/BARD1 catalyzes the K48 polyubiquitination on LARP7LARP7 promotes G2/M cell cycle transition and tumorigenesis via CDK1 complexLARP7 disputes homology-directed repair that leads to tumor therapy resistance

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