DNA-PK inhibition by M3814 enhances chemosensitivity in non-small cell lung cancer.
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ABSTRACT:
SUBMITTER: Wang M
PROVIDER: S-EPMC8727896 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BACKGROUND:DNA double-strand breaks (DSBs) are the most cytotoxic form of DNA damage and are induced by ionizing radiation and specific chemotherapeutic agents, such as topoisomerase inhibitors. Cancer cells acquire resistance to such therapies by repairing DNA DSBs. A major pathway for the repair of DNA DSBs is non-homologous end-joining (NHEJ), which requires DNA-dependent protein kinase (DNA-PK) activity. In this study, we investigated the effect of NU7441, a synthetic small-molecule compound, as a specific inhibitor of DNA-PK on the chemosensitization of non-small cell lung carcinoma (NSCLC) A549 cells. METHODS:The combined effects of chemotherapeutic agents and NU7441 were evaluated by isobologram analysis using Cell Counting Kit-8. DNA DSBs were assessed by immunofluorescence assay. Apoptosis was examined by flow cytometry using an Annexin V apoptosis kit. Activation of DNA-PK was assayed by western blotting. RESULTS:The combination of NU7441 and topoisomerase inhibitors such as amrubicin and irinotecan had a synergistic effect on cell proliferation in A549 cells. NU7441 increased 53BP1 foci and apoptosis induced by topoisomerase inhibitors and decreased phospho-DNA-dependent protein kinase, catalytic subunit (pDNA-PKcs) (S2056) protein expression caused by topoisomerase inhibitors. Interestingly, mitotic inhibitors such as pacritaxel did not cause the pDNA-PKcs (S2056) protein expression and the combination of NU7441 and pacritaxel had an only additive effect. CONCLUSION:NU7441 inhibited the growth of NSCLC cells and enhanced the chemosensitization to topoisomerase inhibitors by blocking DNA repair. A combination of NU7441 and topoisomerase inhibitor may be a promising treatment for NSCLC.
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Project description:Long non-coding RNA taurine up-regulated gene 1 (TUG1) emerges as new players in gene regulation in several cancers; however, its mechanism of action in non-small cell lung cancer (NSCLC) has not been well-studied. Herein, we determined expression pattern of TUG1 in NSCLC and further identified its effect on the chemosensitivity of NSCLC. Low expression of TUG1 was found in NSCLC tissues obtained from non-responders to platinum-based chemotherapy and reflected poor overall survival. TUG1 overexpression was shown to inhibit cell proliferation, migration, invasion, but facilitate apoptosis and autophagy in NSCLC cells resistant to cisplatin (DDP). Smaller size of tumor xenografts of DDP resistant NSCLC cells in the presence of TUG1 demonstrated enhancement of chemosensitivity by TUG1 in vivo. High expression of miR-221 and low expression of PTEN were determined in cancer tissues obtained from non-responders to platinum-based chemotherapy and reflected poor overall survival. TUG1 inhibited miR-221 that targeted PTEN, as evidenced by an elevated expression of PTEN in the presence of miR-221 or the absence of TUG1. Our present study reveals a model of enhancement of chemosensitivity that consists of TUG1, miR-221 and PTEN. Modulation of their levels may offer a new approach for improving anti-tumor efficacy for chemotherapeutic agents in NSCLC.
| S-EPMC6782002 | biostudies-literature
Project description:Non-small cell lung cancer (NSCLC) is a prevalent and devastating disease that claims more lives than breast, prostate, colon and pancreatic cancers combined. Current research suggests that standard chemotherapy regimens have been optimized to maximal efficiency. Promising new treatment strategies involve novel agents targeting molecular aberrations present in subsets of NSCLC. We evaluated 88 human NSCLC tumors of diverse histology and identified Mer and Axl as receptor tyrosine kinases (RTKs) overexpressed in 69% and 93%, respectively, of tumors relative to surrounding normal lung tissue. Mer and Axl were also frequently overexpressed and activated in NSCLC cell lines. Ligand-dependent Mer or Axl activation stimulated MAPK, AKT and FAK signaling pathways indicating roles for these RTKs in multiple oncogenic processes. In addition, we identified a novel pro-survival pathway-involving AKT, CREB, Bcl-xL, survivin, and Bcl-2-downstream of Mer, which is differentially modulated by Axl signaling. We demonstrated that short hairpin RNA (shRNA) knockdown of Mer or Axl significantly reduced NSCLC colony formation and growth of subcutaneous xenografts in nude mice. Mer or Axl knockdown also improved in vitro NSCLC sensitivity to chemotherapeutic agents by promoting apoptosis. When comparing the effects of Mer and Axl knockdown, Mer inhibition exhibited more complete blockade of tumor growth while Axl knockdown more robustly improved chemosensitivity. These results indicate that Mer and Axl have complementary and overlapping roles in NSCLC and suggest that treatment strategies targeting both RTKs may be more effective than singly-targeted agents. Our findings validate Mer and Axl as potential therapeutic targets in NSCLC and provide justification for development of novel therapeutic compounds that selectively inhibit Mer and/or Axl.
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Project description:FGFRs are commonly altered in non-small cell lung cancer (NSCLC). FGFRs activate multiple pathways including RAS/RAF/MAPK, PI3K/AKT, and STAT, which may play a role in the cellular response to radiation. We investigated the effects of combining the selective FGFR 1-3 tyrosine kinase inhibitor AZD4547 with radiation in cell line and xenograft models of NSCLC. NSCLC cell lines were assessed with proliferation, clonogenic survival, apoptosis, autophagy, cell cycle, and DNA damage signaling and repair assays. In vivo xenografts and IHC were used to confirm in vitro results. NSCLC cell lines demonstrated varying degrees of FGFR protein and mRNA expression. In vitro clonogenic survival assays showed radiosensitization with AZD4547 in two NSCLC cell lines. In these two cell lines, an increase in apoptosis and autophagy was observed with combined radiation and AZD4547. The addition of AZD4547 to radiation did not significantly affect γH2AX foci formation. Enhanced xenograft tumor growth delay was observed with the combination of radiation and AZD4547 compared with radiation or drug alone. IHC results revealed inhibition of pMAPK and pS6 and demonstrated an increase in apoptosis in the radiation plus AZD4547 group. This study demonstrates that FGFR inhibition by AZD4547 enhances the response of radiation in FGFR-expressing NSCLC in vitro and in vivo model systems. These results support further investigation of combining FGFR inhibition with radiation as a clinical therapeutic strategy.
| S-EPMC7272291 | biostudies-literature
Project description:SET is known as a potent PP2A inhibitor, however, its oncogenic role including its tumorigenic potential and involvement in the development of chemoresistance in non-small cell lung cancer (NSCLC) has not yet been fully discussed. In present study, we investigated the oncogenic role of SET by SET-knockdown and showed that SET silencing impaired cell growth rate, colony formation and tumor sphere formation in A549 cells. Notably, silencing SET enhanced the pro-apoptotic effects of paclitaxel, while ectopic expression of SET diminished the sensitivity of NSCLC cells to paclitaxel. Since the SET protein was shown to affect chemosensitivity, we next examined whether combining a novel SET antagonist, EMQA, sensitized NSCLC cells to paclitaxel. Both the in vitro and in vivo experiments suggested that EMQA and paclitaxel combination treatment was synergistic. Importantly, we found that downregulating p-Akt by inhibiting SET-mediated protein phosphatase 2A (PP2A) inactivation determined the pro-apoptotic effects of EMQA and paclitaxel combination treatment. To dissect the critical site for EMQA functioning, we generated several truncated SET proteins. By analysis of the effects of EMQA on the binding affinities of different truncated SET proteins to PP2A-catalytic subunits, we revealed that the 227-277 amino-acid sequence is critical for EMQA-induced SET inhibition. Our findings demonstrate the critical role of SET in NSCLC, particularly in the development of chemoresistance. The synergistic effects of paclitaxel and the SET antagonist shown in current study encourage further validation of the clinical potential of this combination.
| S-EPMC4808023 | biostudies-literature
Project description:Molecularly-targeted agents are still urgently needed for better non-small cell lung cancer (NSCLC) therapy. CC-115 is a potent DNA-dependent protein kinase (DNA-PK) and mammalian target of rapamycin (mTOR) dual blocker. We evaluated its activity in different human NSCLC cells. In various primary human NSCLC cells and A549 cells, CC-115 potently inhibited viability, cell proliferation, cell cycle progression, and hindered cell migration/invasion. Apoptosis was provoked in CC-115-stimulated NSCLC cells. The dual inhibitor, however, was unable to induce significant cytotoxic and pro-apoptotic activity in the lung epithelial cells. In primary NSCLC cells, CC-115 blocked activation of mTORC1/2 and DNA-PK. Yet, CC-115-induced primary NSCLC cell death was more potent than combined inhibition of DNA-PK plus mTOR. Further studies found that CC-115 provoked robust oxidative injury in primary NSCLC cells, which appeared independent of mTOR-DNA-PK dual blockage. In vivo studies showed that CC-115 oral administration in nude mice remarkably suppressed primary NSCLC cell xenograft growth. In CC-115-treated NSCLC xenograft tissues, mTOR-DNA-PK dual inhibition and oxidative injury were detected. Together, CC-115 potently inhibits NSCLC cell growth.
| S-EPMC9206683 | biostudies-literature
Project description:The aim of this study is to elucidate whether and how miR-107 participates in the modulation of paclitaxel sensitivity in non small cell lung cancer (NSCLC). By qRT-PCR, we found that miR-107 is significantly down-regulated in paclitaxel-resistant A549/Taxol cells compared with corresponding paclitaxel-sensitive counterparts. Overexpression of miR-107 suppresses paclitaxel resistance of A549/Taxol cells through directly inhibiting Bcl-w. Overexpression of miR-107 promotes apoptosis and inhibits proliferation and mobility of A549/Taxol cells under treatment with paclitaxel in vitro. Moreover, miR-107 inhibits in vivo paclitaxel resistance in xenograft model. MiR-107/Bcl-w axis regulates paclitaxel chemoresistance through PI3K-Akt pathway. Our results suggest that up-regulation of miR-107 resensitizes paclitaxel-resistant NSCLC cells by targeting Bcl-w, which reveals a potential mechanism of miR-107 in reversing drug resistance.
| S-EPMC5622221 | biostudies-other
Project description:The cyclic GMP-AMP synthase/stimulator of IFN genes (cGAS/STING) pathway detects cytosolic DNA to activate innate immune responses. Poly(ADP-ribose) polymerase inhibitors (PARPi) selectively target cancer cells with DNA repair deficiencies such as those caused by BRCA1 mutations or ERCC1 defects. Using isogenic cell lines and patient-derived samples, we showed that ERCC1-defective non-small cell lung cancer (NSCLC) cells exhibit an enhanced type I IFN transcriptomic signature and that low ERCC1 expression correlates with increased lymphocytic infiltration. We demonstrated that clinical PARPi, including olaparib and rucaparib, have cell-autonomous immunomodulatory properties in ERCC1-defective NSCLC and BRCA1-defective triple-negative breast cancer (TNBC) cells. Mechanistically, PARPi generated cytoplasmic chromatin fragments with characteristics of micronuclei; these were found to activate cGAS/STING, downstream type I IFN signaling, and CCL5 secretion. Importantly, these effects were suppressed in PARP1-null TNBC cells, suggesting that this phenotype resulted from an on-target effect of PARPi on PARP1. PARPi also potentiated IFN-γ-induced PD-L1 expression in NSCLC cell lines and in fresh patient tumor cells; this effect was enhanced in ERCC1-deficient contexts. Our data provide a preclinical rationale for using PARPi as immunomodulatory agents in appropriately molecularly selected populations.
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Project description:ObjectiveWe previously postulated that 2-deoxyglucose (2-DG) activates multiple pro-survival pathways through IGF1R to negate its inhibitory effect on glycolysis. Here, we evaluated whether IGF1R inhibitor synergizes with 2-DG to impede the growth of non-small cell lung cancer (NSCLC).Materials and methodsThe activation of IGF1R signaling was assessed by the phosphorylation of IGF1R and its downstream target AKT using immunoblot. Drug dose response and combination index analyses were carried out according to the method of Chou and Talalay. Flow cytometry was used to evaluate cell cycle progression. Apoptosis was monitored by caspase-3/PARP cleavages or Annexin V staining. A subcutaneous xenograft model was used to assess this combination in vivo.Results2-DG induces the phosphorylation of IGF1R in its kinase domain, which can be abolished by the IGF1R inhibitor BMS-754807. Furthermore, the combination of 2-DG and BMS-754807 synergistically inhibited the survival of several non-small cell lung cancer (NSCLC) cell lines both in vitro and in vivo. The mechanistic basis of this synergy was cell line-dependent, and LKB1-inactivated EKVX cells underwent apoptosis following treatment with a subtoxic dose of 2-DG and BMS-754807. For these cells, the restoration of LKB1 kinase activity suppressed apoptosis induced by this combination but enhanced G1 arrest. In H460 cells, the addition of 2-DG did not enhance the low level of apoptosis induced by BMS-754807. However, treatment with 0.75 μM of BMS-754807 resulted in the accumulation of H460 cells with 8n-DNA content without affecting cell density increases. Hence, H460 cells may escape BMS-754807-induced G2/M cell cycle arrest through polyploidy. The inclusion of 2-DG blocked formation of the 8n-DNA cell population and restored G2/M phase cell cycle arrest.ConclusionThe combination of 2-DG and IGF1R inhibitor BMS-754807 may be used to suppress the proliferation of NSCLC tumors through different mechanisms.
| S-EPMC6447049 | biostudies-literature
Project description:KRAS mutations are the most common mutations in non-small cell lung cancer (NSCLC) with adenocarcinoma histology. KRAS mutations result in the activation of the RAF-MEK-ERK pathway, and agents that target RAF-MEK-ERK pathways have been investigated in KRAS mutant NSCLC. The two agents furthest in development are selumetinib and trametinib. Trametinib has greater binding for the MEK1/2 allosteric site, and generally has superior pharmacokinetics. A randomized phase II trial of docetaxel with and without selumetinib revealed that the combination resulted numerically superior overall survival, and a statistically significant improvement in progression-free survival and objective response rate. However, a concerning rate of hospital admission, grade 3 or 4 neutropenia, and febrile neutropenia was observed with the combination. Trials have investigated MEK inhibitors as single agents and in combination with erlotinib, and the data do not support the further development. The activity of MEK inhibitors appears to be similar in patients with KRAS mutant and wild-type NSCLC suggesting KRAS mutation status is not a reliable biomarker for efficacy. It is possible that mutations of genes in addition to KRAS mutations impact the activity of MEK inhibitors, or specific subsets of KRAS mutations may be resistant or susceptible to MEK inhibition. Other potential explanations are gene amplifications, alternative RNA splicing of genes resulting in activation of their protein products, and deregulation of noncoding RNAs and consequent altered protein expression.
| S-EPMC4406476 | biostudies-literature