px-478 and Lung-Neoplasms

Accumulating evidence has shown an increased tumor incidence and reduced survival rate in cancer patients with obstructive sleep apnea (OSA). Although intermittent hypoxia is known to play a crucial role, the molecular mechanism by which intermittent hypoxia accelerates lung cancer progression remains to be elucidated.A lung cancer xenograft mouse model was established by subcutaneously injecting LLC cells into C57BL/6 mice. The tumor-bearing mice were exposed to either normoxia or intermittent hypoxia and received either IgG2a, anti-programmed death ligand-1 (PD-L1), PX-478, or anti-PD-L1 + PX-478 treatment.A significant upregulation of tumor associated macrophages (TAMs) papulation and PD-L1 levels was observed in lung adenocarcinoma patients with OSA. We further confirmed that hypoxia-inducible factor-1 alpha (HIF-1α) regulates PD-L1 at transcriptional levels, mainly through binding to the hypoxia response element 4. Using a lung cancer xenograft mouse model, we observed that intermittent hypoxia exposed tumors grew faster and bigger with upregulated HIF-1α and PD-L1 expression, enhanced TAMs and Treg populations, and reduced cytotoxic T cells and cytokine secretion. Finally, we found a combination of PX-478 and anti-PD-L1 exerted an encouraging tumor inhibition effect compared to single treatment. Combination therapies based on HIF-1α and PD-L1 blockade might serve as a promising strategy to treat lung cancer patients with OSA.

Topics: Animals; B7-H1 Antigen; Humans; Hypoxia; Immunity; Lung Neoplasms; Mice; Mice, Inbred C57BL; Sleep Apnea, Obstructive; Tumor-Associated Macrophages

Micro-ribonucleic acids (miRNAs) are involved in the occurrence of various cancers, and the hypoxia-inducible factor 1-α (HIF-1α) is the main regulator of cell proliferation induced by hypoxia. The relationships of miR-199a and HIF-1α expressions with non-small cell lung cancer (NSCLC) remain unclear, so they were explored in this work.. On the basis of establishing the rat model of NSCLC, the messenger RNA (mRNA) expressions of miR-199a, HIF-1α and the vascular endothelial growth factor (VEGF) were analyzed in NSCLC rats, and the correlations of miR-199a with the mRNAs of HIF-1α and VEGF and cancer staging were investigated. To further study the role of miR-199a in NSCLC cell proliferation via the HIF-1α/VEGF signaling pathway, NSCLC cells were treated with the signaling pathway inhibitor and transfected with miR-199a mimics, respectively. Also,  the roles of the inhibitor PX-478 and miR-199a mimics in the expressions of miR-199a, HIF-1α, and VEGF proteins, as well as their influences on cell proliferation ability were detected.. In NSCLC rats, the expression of miR-199a was substantially decreased (p<0.01), but the expressions of HIF-1α and VEGF were notably raised (p<0.01). MiR-199a was negatively correlated with the expression of VEGF. As cancer developed, the expression of miR-199a was gradually lowered, but the expressions of HIF-1α and VEGF were gradually increased. Both HIF-1α/VEGF signaling pathway inhibitor PX-478 and miR-199a mimics significantly reduced the expressions of HIF-1α and VEGF proteins (p<0.01) and suppressed the cell proliferation activity.. MiR-199a prevents the proliferation of NSCLC cells via the targeted down-regulation of the HIF-1α/VEGF signaling pathway.

Topics: Animals; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Female; Gene Expression Regulation, Neoplastic; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Lung Neoplasms; MicroRNAs; Mustard Compounds; Phenylpropionates; Rats; Signal Transduction; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

PX-478 is a potent small-molecule inhibitor of hypoxia-inducible factor 1alpha (HIF-1alpha). In prior preclinical studies, it had antitumor activity against various solid tumors in subcutaneous xenografts but had no measurable activity against a non-small cell lung cancer (NSCLC) xenograft. To determine the effectiveness of PX-478 against lung tumors, we investigated HIF-1alpha expression in several lung cancer cell lines, both in vitro and in vivo, and treated orthotopic mouse models of human lung cancer with PX-478.. Cells from two human lung adenocarcinoma cell models (PC14-PE6 and NCI-H441) or two human small cell lung cancer (SCLC) models (NCI-H187 and NCI-N417) were injected into the left lungs of nude mice and were randomized 16 to 18 days after injection with daily oral treatment with PX-478 or vehicle for 5 days.. In the PC14-PE6 NSCLC model, treatment with 20 mg/kg PX-478 significantly reduced the median primary lung tumor volume by 87% (p = 0.005) compared with the vehicle-treated group. PX-478 treatment also markedly reduced mediastinal metastasis and prolonged survival. Similar results were obtained in a second NSCLC model. In SCLC models, PX-478 was even more effective. In the NCI-H187 model, the median primary lung tumor volume was reduced by 99% (p = 0.0001). The median survival duration was increased by 132%. In the NCI-N417 model, the median primary lung tumor volume was reduced by 97% (p = 0.008).. We demonstrated that the PX-478, HIF-1alpha inhibitor, had significant antitumor activity against two orthotopic models of lung adenocarcinomas and two models of SCLC. These results suggest the inclusion of lung cancer patients in phase I clinical trials of PX-478.

Topics: Adenocarcinoma; Animals; Apoptosis; Blotting, Western; Carcinoma, Non-Small-Cell Lung; Disease Progression; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Immunoenzyme Techniques; Lung Neoplasms; Lymphatic Metastasis; Male; Mice; Mice, Nude; Mustard Compounds; Phenylpropionates; Small Cell Lung Carcinoma; Survival Rate; Treatment Outcome; Tumor Cells, Cultured