Dataset Information

Chloroquine potentiates the anti-cancer effect of lidamycin on non-small cell lung cancer cells in vitro.

ABSTRACT: To assess the synergistic actions of lidamycin (LDM) and chloroquine (CQ), a lysosomal enzyme inhibitor, in human non-small cell lung cancer (NSCLC) cells, and to elucidate the potential mechanisms.Human NSCLC cell lines A549 and H460 were treated with CQ and/or LDM. Cell proliferation was analyzed using MTT assay, and apoptosis was quantified using flow cytometry. Western blotting was used to detect the protein levels of caspase 3, PARP, Bcl-2, Bax, p53, LC3-I and LC3-II. A H460 cell xenograft model in BALB/c nude mice was used to evaluate the anticancer efficacy of CQ and LDM in vivo.Both LDM and CQ concentration-dependently suppressed the proliferation of A549 and H460 cells in vitro (the IC50 values of LDM were 1.70 ± 0.75 and 0.043 ± 0.026 nmol/L, respectively, while the IC50 values of CQ were 71.3 ± 6.1 and 55.6 ± 12.5 μmol/L, respectively). CQ sensitized both NSCLC cell lines to LDM, and the majority of the coefficients of drug interaction (CDIs) for combination-doses were less than 1. The ratio of apoptosis of H460 cells induced by a combined treatment of CQ and LDM (77.0% ± 5.2%) was significantly higher than those caused by CQ (23.1% ± 4.2%) or by LDM (65.1% ± 4.1%) alone. Furthermore, the combined treatment markedly increased the cleaved PARP and cleaved caspase 3 in H460 cells, which were partly reversed by pretreatment with the caspase inhibitor zVAD.fmk. zVAD.fmk also partially reversed the inhibitory effect of the combination treatment on the proliferation of H460 cells. The combination therapy group had a notable increase in expression of Bax and a very slight decrease in expression of Bcl-2 and p53 protein. LDM alone scarcely affected the level of LC3-II in H460 cells, but slightly reduced CQ-induced LC3-II expression. 3-MA, an autophagy inhibitor also sensitized H460 cells to LDM. In nude mice bearing H460 cell xenograft, administration of LDM (25 μg/kg, iv) and CQ (60 mg/kg, ip) suppressed tumor growth by 57.14% and 73.02%, respectively.The synergistic anticancer effect of LDM and CQ in vitro results from activation of a caspase-dependent and p53-independent apoptosis pathway as well as inhibition of cytoprotective autophagy.

SUBMITTER: Liu F

PROVIDER: S-EPMC4814038 | biostudies-other | 2014 May

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:Objectives: Immune checkpoint (ICP) expression in tumor cells could directly or indirectly affect the results of immunotherapy. ICP ligands on tumor cells usually bind their immune cell receptors to inhibit the activity, resulting in tumor immune escape. Thus, the purpose of this study was to ascertain the impact of various chemotherapeutic drugs on ICP expression in non-small cell lung cancer (NSCLC) cell lines with different pathological subtypes to provide a basis for the development of a superior regimen of chemotherapy combined with ICP blockade. Methods: Several first-line chemotherapy agents (cisplatin, carboplatin, paclitaxel, gemcitabine, vinorelbine, and pemetrexed) were selected to treat different NSCLC cell lines (squamous carcinoma H1703, adenocarcinoma A549, and large cell cancer H460) for 72 hours, and then the changes in ICP expression in the tumor cells were observed through flow cytometry. Results: Cisplatin, carboplatin, and paclitaxel upregulated the expressions of programmed cell death ligand 1 (PD-L1) and programmed cell death ligand 2 (PD-L2) in A549 and H460 cell lines. Meanwhile, vinorelbine and pemetrexed upregulated PD-L1 and PD-L2 in H1703, A549, and H460 cell lines. Paclitaxel, gemcitabine, vinorelbine, and pemetrexed significantly upregulated the expressions of both galectin-9 and high-mobility group box protein 1 (HMGB1) in the A549 cell line. Cisplatin and paclitaxel significantly upregulated the expressions of major histocompatibility complex-II (MHC-II), galectin-3, α-synuclein, and fibrinogen-like protein 1 (FGL1) in A549 and H460 cell lines. In addition, cisplatin and vinorelbine significantly upregulated the expressions of both CD155 and CD112 in the H460 cell line. Vinorelbine upregulated MHC-I in all three cell lines. Conclusion: Chemotherapy agents have different effects on the expression of ICP ligands in tumor cells with different pathological types, and this may affect the efficacy of combined immunotherapy. These results provide a theoretical basis for further selection and optimization of the combination of chemotherapy and immunotherapy.

Project description:PurposePoly(ADP-ribose) polymerase (PARP) inhibitors potentiate radiation therapy in preclinical models of human non-small cell lung cancer (NSCLC) and other types of cancer. However, the mechanisms underlying radiosensitization in vivo are incompletely understood. Herein, we investigated the impact of hypoxia on radiosensitization by the PARP inhibitor olaparib in human NSCLC xenograft models.Methods and materialsNSCLC Calu-6 and Calu-3 cells were irradiated in the presence of olaparib or vehicle under normoxic (21% O2) or hypoxic (1% O2) conditions. In vitro radiosensitivity was assessed by clonogenic survival assay and γH2AX foci assay. Established Calu-6 and Calu-3 subcutaneous xenografts were treated with olaparib (50 mg/kg, daily for 3 days), radiation (10 Gy), or both. Tumors (n=3/group) were collected 24 or 72 hours after the first treatment. Immunohistochemistry was performed to assess hypoxia (carbonic anhydrase IX [CA9]), vessels (CD31), DNA double strand breaks (DSB) (γH2AX), and apoptosis (cleaved caspase 3 [CC3]). The remaining xenografts (n=6/group) were monitored for tumor growth.ResultsIn vitro, olaparib showed a greater radiation-sensitizing effect in Calu-3 and Calu-6 cells in hypoxic conditions (1% O2). In vivo, Calu-3 tumors were well-oxygenated, whereas Calu-6 tumors had extensive regions of hypoxia associated with down-regulation of the homologous recombination protein RAD51. Olaparib treatment increased unrepaired DNA DSB (P<.001) and apoptosis (P<.001) in hypoxic cells of Calu-6 tumors following radiation, whereas it had no significant effect on radiation-induced DNA damage response in nonhypoxic cells of Calu-6 tumors or in the tumor cells of well-oxygenated Calu-3 tumors. Consequently, olaparib significantly increased radiation-induced growth inhibition in Calu-6 tumors (P<.001) but not in Calu-3 tumors.ConclusionsOur data suggest that hypoxia potentiates the radiation-sensitizing effects of olaparib by contextual synthetic killing, and that tumor hypoxia may be a potential biomarker for selecting patients who may get the greatest benefit from the addition of olaparib to radiation therapy.

Dataset Information

Chloroquine potentiates the anti-cancer effect of lidamycin on non-small cell lung cancer cells in vitro.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets