GSK3β Inhibition Synergizes with PARP Inhibitors through the Induction of Homologous Recombination Deficiency in Colorectal Cancer

2020 ◽  
Author(s):  
Ning Zhang ◽  
Yu-Nan Tian ◽  
Li-Na Zhou ◽  
Meng-Zhu Li ◽  
Shan-Shan Song ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Homologous Recombination ◽  
High Throughput Screening ◽  
Glycogen Synthase ◽  
Objective Response ◽  
Xenograft Model ◽  
Parp Inhibitors ◽  
High Rate ◽  
Parp Inhibition ◽  
Mouse Xenograft Model

Abstract Background: Monotherapy with poly ADP-ribose polymerase (PARP) inhibitors results in limited objective response rate (≤ 60% in most cases) in patients with homologous recombination repair (HRR)-deficient cancer, which suggests a high rate of resistance in this subset of patients to PARP inhibitors (PARPi). To overcome resistance to PARPi and to broaden their clinical use, we performed high-throughput screening of 99 anticancer drugs in combination with PARPi to identify potential therapeutic combinations. Methods: The effects of PARPi combined with glycogen synthase kinase 3 (GSK3) inhibitors were investigated in vitro with respect to cell viability, cell cycle and apoptosis. The synergy was assessed by calculation of the combination index (CI). GSK3α null and GSK3β null cells were generated using CRISPR/Cas9 technique. The underlying mechanism was examined by western blotting, flow cytometry, qRT-PCR and fluorescence microscopy. This combination was also evaluated in the mouse xenograft model; tumor growth and tumor lysates were analyzed, and the immunohistochemistry assay was performed. All data are presented as mean ± SD. Comparison between two groups was performed with the Student’s t-test.Result: The data showed that ~25% of oncological drugs and kinase inhibitors that were evaluated displayed synergy with PARPi in HCT-15 cells. Among the tested agents, GSK3 inhibitors (GSK3i) exhibited the strongest synergistic effect with PARPi. Moreover, the synergistic antitumor effect of GSK3 and PARP inhibition was confirmed in a panel of colorectal cancer (CRC) cell lines with diverse genetic backgrounds. Additionally, inhibition or genetic depletion of GSK3β was found to impair HRR of DNA and reduce the mRNA and protein level of BRCA1. Finally, we demonstrated that inhibition or depletion of GSK3β could enhance the in vivo sensitivity to simmiparib without toxicity.Conclusion: Our results provide a mechanistic understanding of combination of PARP and GSK3 inhibition, and support the clinical development of this combination therapy for CRC patients.

scholarly journals Glycogen synthase kinase 3β inhibition synergizes with PARP inhibitors through the induction of homologous recombination deficiency in colorectal cancer

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Ning Zhang ◽  
Yu-Nan Tian ◽  
Li-Na Zhou ◽  
Meng-Zhu Li ◽  
Hua-Dong Chen ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Homologous Recombination ◽  
High Throughput Screening ◽  
Glycogen Synthase ◽  
Objective Response ◽  
Parp Inhibitors ◽  
High Rate ◽  
Parp Inhibition ◽  
Dna Double Strand Breaks

AbstractMonotherapy with poly ADP-ribose polymerase (PARP) inhibitors results in a limited objective response rate (≤60% in most cases) in patients with homologous recombination repair (HRR)-deficient cancer, which suggests a high rate of resistance in this subset of patients to PARP inhibitors (PARPi). To overcome resistance to PARPi and to broaden their clinical use, we performed high-throughput screening of 99 anticancer drugs in combination with PARPi to identify potential therapeutic combinations. Here, we found that GSK3 inhibitors (GSK3i) exhibited a strong synergistic effect with PARPi in a panel of colorectal cancer (CRC) cell lines with diverse genetic backgrounds. The combination of GSK3β and PARP inhibition causes replication stress and DNA double-strand breaks, resulting in increased anaphase bridges and abnormal spindles. Mechanistically, inhibition or genetic depletion of GSK3β was found to impair the HRR of DNA and reduce the mRNA and protein level of BRCA1. Finally, we demonstrated that inhibition or depletion of GSK3β could enhance the in vivo sensitivity to simmiparib without toxicity. Our results provide a mechanistic understanding of the combination of PARP and GSK3 inhibition, and support the clinical development of this combination therapy for CRC patients.

scholarly journals Oncogenic lncRNA ZNF561-AS1 is essential for colorectal cancer proliferation and survival through regulation of miR-26a-3p/miR-128-5p-SRSF6 axis

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Zizhen Si ◽  
Lei Yu ◽  
Haoyu Jing ◽  
Lun Wu ◽  
Xidi Wang
Keyword(s):  
Colorectal Cancer ◽  
Rna Binding ◽  
Xenograft Model ◽  
Luciferase Reporter ◽  
Cancer Proliferation ◽  
Mouse Xenograft ◽  
Mouse Xenograft Model

Abstract Background Long non-coding RNAs (lncRNA) are reported to influence colorectal cancer (CRC) progression. Currently, the functions of the lncRNA ZNF561 antisense RNA 1 (ZNF561-AS1) in CRC are unknown. Methods ZNF561-AS1 and SRSF6 expression in CRC patient samples and CRC cell lines was evaluated through TCGA database analysis, western blot along with real-time PCR. SRSF6 expression in CRC cells was also examined upon ZNF561-AS1 depletion or overexpression. Interaction between miR-26a-3p, miR-128-5p, ZNF561-AS1, and SRSF6 was examined by dual luciferase reporter assay, as well as RNA binding protein immunoprecipitation (RIP) assay. Small interfering RNA (siRNA) mediated knockdown experiments were performed to assess the role of ZNF561-AS1 and SRSF6 in the proliferative actives and apoptosis rate of CRC cells. A mouse xenograft model was employed to assess tumor growth upon ZNF561-AS1 knockdown and SRSF6 rescue. Results We find that ZNF561-AS1 and SRSF6 were upregulated in CRC patient tissues. ZNF561-AS1 expression was reduced in tissues from treated CRC patients but upregulated in CRC tissues from relapsed patients. SRSF6 expression was suppressed and enhanced by ZNF561-AS1 depletion and overexpression, respectively. Mechanistically, ZNF561-AS1 regulated SRSF6 expression by sponging miR-26a-3p and miR-128-5p. ZNF561-AS1-miR-26a-3p/miR-128-5p-SRSF6 axis was required for CRC proliferation and survival. ZNF561-AS1 knockdown suppressed CRC cell proliferation and triggered apoptosis. ZNF561-AS1 depletion suppressed the growth of tumors in a model of a nude mouse xenograft. Similar observations were made upon SRSF6 depletion. SRSF6 overexpression reversed the inhibitory activities of ZNF561-AS1 in vivo, as well as in vitro. Conclusion In summary, we find that ZNF561-AS1 promotes CRC progression via the miR-26a-3p/miR-128-5p-SRSF6 axis. This study reveals new perspectives into the role of ZNF561-AS1 in CRC.

scholarly journals Rucaparib in patients presenting a metastatic breast cancer with Homologous Recombination Deficiency, without germline BRCA1/2 mutation

2020 ◽  
Author(s):  
Anne Patsouris ◽  
M'boyba Khadija DIOP ◽  
Olivier Tredan ◽  
Daniel Nenciu ◽  
Anthony Goncalves ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Homologous Recombination ◽  
Statistical Significance ◽  
Objective Response ◽  
Metastatic Breast ◽  
Parp Inhibitors ◽  
Small Subset ◽  
Durable Response ◽  
Homologous Recombination Deficiency

Abstract Breast cancer may present genomic alterations leading to homologous recombination deficiency. PARP inhibitors have proved their efficacy in patients with HER2-negative metastatic breast cancer (mBC) harboring germline (g) BRCA1/2 mutations. We conducted the phase 2 RUBY trial to assess the efficacy of rucaparib in HER2-negative mBC with high genomic loss of heterozygosity (LOH) score or somatic, without gBRCA1/2 mutation. 220 of 711 patients with mBC screened for LOH presented high LOH score which was associated with a higher likelihood of death (HR = 1.39, 95% CI: 1.11-1.75, p = 0.005). The primary objective was not reached with a clinical benefit rate (objective response or SD>16 weeks) of 13.5%. Two LOH-high patients, without somatic BRCA1/2 mutation, presented a complete and durable response (14 and 32 months). HRDetect tended to be associated with response to rucaparib, whithout reaching statistical significance (median HRDetect responders versus non responders: 0.465 versus, 0.040, p = 0.2135). Our data suggests that a small subset of patients with high LOH score could derive benefit from PARP inhibitors.

scholarly journals Frequency and prognostic value of mutations associated with the homologous recombination DNA repair pathway in a large pan cancer cohort

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Daniel R. Principe ◽  
Matthew Narbutis ◽  
Regina Koch ◽  
Ajay Rana
Keyword(s):  
Dna Repair ◽  
Homologous Recombination ◽  
Synthetic Lethality ◽  
Parp Inhibitors ◽  
The Cancer Genome Atlas ◽  
Parp Inhibition ◽  
Repair Pathway ◽  
Wide Range ◽  
Recombination Pathway ◽  
Pan Cancer

AbstractPARP inhibitors have shown remarkable efficacy in the clinical management of several BRCA-mutated tumors. This approach is based on the long-standing hypothesis that PARP inhibition will impair the repair of single stranded breaks, causing synthetic lethality in tumors with loss of high-fidelity double-strand break homologous recombination. While this is now well accepted and has been the basis of several successful clinical trials, emerging evidence strongly suggests that mutation to several additional genes involved in homologous recombination may also have predictive value for PARP inhibitors. While this notion is supported by early clinical evidence, the mutation frequencies of these and other functionally related genes are largely unknown, particularly in cancers not classically associated with homologous recombination deficiency. We therefore evaluated the mutation status of 22 genes associated with the homologous recombination DNA repair pathway or PARP inhibitor sensitivity, first in a pan-cancer cohort of 55,586 patients, followed by a more focused analysis in The Cancer Genome Atlas cohort of 12,153 patients. In both groups we observed high rates of mutations in a variety of HR-associated genes largely unexplored in the setting of PARP inhibition, many of which were associated also with poor clinical outcomes. We then extended our study to determine which mutations have a known oncogenic role, as well as similar to known oncogenic mutations that may have a similar phenotype. Finally, we explored the individual cancer histologies in which these genomic alterations are most frequent. We concluded that the rates of deleterious mutations affecting genes associated with the homologous recombination pathway may be underrepresented in a wide range of human cancers, and several of these genes warrant further and more focused investigation, particularly in the setting of PARP inhibition and HR deficiency.

scholarly journals MicroRNA-587 antagonizes 5-FU-induced apoptosis and confers drug resistance by regulating PPP2R1B expression in colorectal cancer

2015 ◽  
Vol 6 (8) ◽  
pp. e1845-e1845 ◽  
Author(s):  
Y Zhang ◽  
G Talmon ◽  
J Wang
Keyword(s):  
Colorectal Cancer ◽  
Drug Resistance ◽  
Cancer Treatment ◽  
Xenograft Model ◽  
Akt Inhibitor ◽  
Akt Phosphorylation ◽  
Xiap Expression ◽  
Mouse Xenograft Model ◽  
Response To Chemotherapy ◽  
Induced Apoptosis

Abstract Drug resistance is one of the major hurdles for cancer treatment. However, the underlying mechanisms are still largely unknown and therapeutic options remain limited. In this study, we show that microRNA (miR)-587 confers resistance to 5-fluorouracil (5-FU)-induced apoptosis in vitro and reduces the potency of 5-FU in the inhibition of tumor growth in a mouse xenograft model in vivo. Further studies indicate that miR-587 modulates drug resistance through downregulation of expression of PPP2R1B, a regulatory subunit of the PP2A complex, which negatively regulates AKT activation. Knockdown of PPP2R1B expression increases AKT phosphorylation, which leads to elevated XIAP expression and enhanced 5-FU resistance; whereas rescue of PPP2R1B expression in miR-587-expressing cells decreases AKT phosphorylation/XIAP expression, re-sensitizing colon cancer cells to 5-FU-induced apoptosis. Moreover, a specific and potent AKT inhibitor, MK2206, reverses miR-587-conferred 5-FU resistance. Importantly, studies of colorectal cancer specimens indicate that the expression of miR-587 and PPP2R1B positively and inversely correlates with chemoresistance, respectively, in colorectal cancer. These findings indicate that the miR-587/PPP2R1B/pAKT/XIAP signaling axis has an important role in mediating response to chemotherapy in colorectal cancer. A major implication of our study is that inhibition of miR-587 or restoration of PPP2R1B expression may have significant therapeutic potential to overcome drug resistance in colorectal cancer patients and that the combined use of an AKT inhibitor with 5-FU may increase efficacy in colorectal cancer treatment.

scholarly journals Aptamer-mediated survivin RNAi enables 5-fluorouracil to eliminate colorectal cancer stem cells

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Hadi AlShamaileh ◽  
Tao Wang ◽  
Dongxi Xiang ◽  
Wang Yin ◽  
Phuong Ha-Lien Tran ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Stem Cells ◽  
Cancer Stem Cells ◽  
Xenograft Model ◽  
Chemotherapeutic Agents ◽  
Mouse Xenograft Model ◽  
Colorectal Cancer Cells ◽  
Colorectal Cancer Stem Cells ◽  
Molecular Therapeutic

AbstractThe development of chemoresistance and inability in elimination of cancer stem cells are among the key limitations of cancer chemotherapy. Novel molecular therapeutic strategies able to overcome such limitations are urgently needed for future effective management of cancer. In this report, we show that EpCAM-aptamer-guided survivin RNAi effectively downregulated survivin both in colorectal cancer cells in vitro and in a mouse xenograft model for colorectal cancer. When combined with the conventional chemotherapeutic agents, the aptamer-guided survivin RNAi was able to enhance the sensitivity towards 5-FU or oxaliplatin in colorectal cancer stem cells, increase apoptosis, inhibit tumour growth and improve the overall survival of mice bearing xenograft colorectal cancer. Our results indicate that survivin is one of the key players responsible for the innate chemoresistance of colorectal cancer stem cells. Thus, aptamer-mediated targeting of survivin in cancer stem cells in combination with chemotherapeutic drugs constitutes a new avenue to improve treatment outcome in oncologic clinics.

scholarly journals PARP Inhibitors in Ovarian Cancer: The Route to “Ithaca”

Diagnostics ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 55 ◽  
Author(s):  
Boussios ◽  
Karathanasi ◽  
Cooke ◽  
Neille ◽  
Sadauskaite ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Dna Repair ◽  
Homologous Recombination ◽  
Brca Mutation ◽  
Parp Inhibitor ◽  
Parp Inhibitors ◽  
Parp Inhibition ◽  
Current Evidence ◽  
Repair Pathway ◽  
Significant Efficacy

Poly (ADP-ribose) polymerase (PARP) inhibitors are a novel class of therapeutic agents that target tumors with deficiencies in the homologous recombination DNA repair pathway. Genomic instability characterizes high-grade serous ovarian cancer (HGSOC), with one half of all tumors displaying defects in the important DNA repair pathway of homologous recombination. Early studies have shown significant efficacy for PARP inhibitors in patients with germline breast related cancer antigens 1 and 2 (BRCA1/2) mutations. It has also become evident that BRCA wild-type patients with other defects in the homologous recombination repair pathway benefit from this treatment. Companion homologous recombination deficiency (HRD) scores are being developed to guide the selection of patients that are most likely to benefit from PARP inhibition. The choice of which PARP inhibitor is mainly based upon the number of prior therapies and the presence of a BRCA mutation or HRD. The identification of patients most likely to benefit from PARP inhibitor therapy in view of HRD and other biomarker assessments is still challenging. The aim of this review is to describe the current evidence for PARP inhibitors in ovarian cancer, their mechanism of action, and the outstanding issues, including the rate of long-term toxicities and the evolution of resistance.

A phase II randomized study of bortezomib/dexamethasone (Bort/Dex) with or without elotuzumab (Elo) in patients (pts) with relapsed/refractory multiple myeloma (RR MM) (CA204-009).

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. TPS8114-TPS8114
Author(s):  
Andrzej J. Jakubowiak ◽  
Darrell White ◽  
Philippe Moreau ◽  
Thierry Facon ◽  
Ravi Vij ◽  
...  
Keyword(s):  
Nk Cell ◽  
Randomized Study ◽  
Objective Response ◽  
Xenograft Model ◽  
Progression Free Survival ◽  
Surface Glycoprotein ◽  
Cell Surface Glycoprotein ◽  
Normal Tissues ◽  
Mouse Xenograft Model ◽  
Secondary Endpoints

TPS8114 Background: MM is rarely curable and pts typically relapse or become refractory to current treatments. Elo is a humanized monoclonal IgG1 antibody targeting the cell surface glycoprotein CS1, which is highly expressed on >95% of MM cells with little to no expression on normal tissues. The mechanism of action of Elo is primarily natural killer (NK) cell-mediated antibody-dependent cellular cytotoxicity (ADCC) against myeloma cells. Elo + Bort significantly enhanced antimyeloma activity in a mouse xenograft model vs either agent alone. The addition of Bort enhanced the ADCC activity of Elo in preclinical studies. In a phase I study of Elo + Bort in pts with RR MM, objective response rate (ORR) was 48%, median progression-free survival (PFS) was 9.5 months, and activity was observed in 2/3 patients (67%) refractory to Bort (Jakubowiak et al. J Clin Oncol, in press). This study will assess if the addition of Elo to Bort/Dex improves PFS and, if so, whether magnitude of the improvement is linked to FcγRIIIa polymorphism. Methods: Pts (N=150) with RR MM after 1 or 2 prior therapies will be randomized in a 1:1 ratio to receive Bort 1.3 mg/m2 IV or SQ (Cycles 1-8: days 1, 4, 8, and 11; Cycles ≥9: days 1, 8, and 15) and Dex with or without Elo. Elo dose and schedule is 10 mg/kg IV (Cycles 1-2: days 1, 8, and 15 [21-day cycles]; Cycles 3-8: days 1 and 11 [21-day cycles]; Cycles ≥9: days 1 and 15 [28-day cycles]). In the arm without Elo, Dex 20 mg PO is scheduled for Cycles 1-8: days 1, 2, 4, 5, 8, 9, 11, and 12; and Cycles ≥9: days 1, 2, 8, 9, 15, 16. In the arm with Elo, Dex 20 mg PO is scheduled for Cycles 1-2: days 2, 4, 5, 9, and 11; Cycles 3-8: days 2, 4, 5, 8, 9, 12; Cycles ≥9: days 2, 8, 9, and 16) on weeks without Elo, and on weeks with Elo, Dex 8 mg PO and 8 mg IV is scheduled on the same day as Elo. Treatment will continue until disease progression, unacceptable toxicity, or withdrawal of consent. Patients refractory or intolerant to Bort will be excluded. Efficacy will be assessed on day 1 of each cycle by IMWG criteria. The primary endpoint is PFS. Secondary endpoints include ORR and PFS/ORR in pts with ≥1 FcγRIIIa V allele. As of February 1, 2012, 1 pt was enrolled. NCT01478048.

scholarly journals O7 A bispecific VHH approach to leverage the potent and widely applicable tumor cytolytic capacity of Vγ9Vδ2 T cells

2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A6.2-A7
Author(s):  
LA King ◽  
R Lameris ◽  
RC Roovers ◽  
P Parren ◽  
TD de Gruijl ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
T Cells ◽  
T Cell ◽  
Xenograft Model ◽  
Cell Receptor ◽  
Target Cells ◽  
Mouse Xenograft Model ◽  
Vγ9vδ2 T Cells

Vγ9Vδ2-T cells include a unique and potent subset of T cells which play an important role in tumor defense. Vγ9Vδ2-T cells recognize and can lyse butyrophilin 3A1-expressing target cells with elevated levels of non-peptide phosphoantigens (pAg), induced by cell stress or malignancy. To date, Vγ9Vδ2-T cell based cancer immunotherapeutic approaches were well tolerated and in some cases capable of inducing relevant clinical responses. In an effort to improve the efficacy and consistency of Vγ9Vδ2-T cell based cancer immunotherapy, we designed a bispecific VHH that binds to both Vγ9Vδ2-T cells and EGFR expressed by tumor cells and results in the target-specific activation of Vγ9Vδ2-T cells and subsequent lysis of colorectal cancer cell lines and primary colorectal cancer samples both in vitro and in an in vivo mouse xenograft model. Of note, tumor cell lysis was independent of mutations in KRAS and BRAF that are known to impair the efficacy of clinically registered anti-EGFR monoclonal antibodies as well as common Vγ9Vδ2-T cell receptor sequence variations. In combination with the conserved monomorphic nature of the Vγ9Vδ2-TCR and the facile replacement of the tumor-specific VHH, this immunotherapeutic approach can in principle be applied to a large group of cancer types.Disclosure InformationL.A. King: None. R. Lameris: None. R.C. Roovers: None. P. Parren: None. T.D. de Gruijl: None. H.J. van der Vliet: None.

scholarly journals Hepatic Vitamin A Preloading Reduces Colorectal Cancer Metastatic Multiplicity in a Mouse Xenograft Model

2012 ◽  
Vol 64 (5) ◽  
pp. 732-740 ◽  
Author(s):  
Eun Young Park ◽  
Daniel Pinali ◽  
Krista Lindley ◽  
Michelle A. Lane
Keyword(s):  
Colorectal Cancer ◽  
Vitamin A ◽  
Xenograft Model ◽  
Mouse Xenograft ◽  
Mouse Xenograft Model
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