benzofurans and Adenocarcinoma-of-Lung

BPAP is a potent enhancer substance with catecholaminergic and serotoninergic activity in the brain. It was discovered that it is also effective against certain types of experimental cancers, showing the most promising results in case of lung cancer. That is why we tested its efficacy in two different doses in a newly developed EGFR wild type mouse lung adenocarcinoma xenograft model. Experiments were conducted on FVB/N and SCID mouse strains treated with low and high dose of BPAP. Body weight, survival, and tumor volumes were recorded. Furthermore, the activity of major signaling pathways of NSCLC such as MAPK and Akt/mTOR as well as cell cycle regulation were determined. Significant inhibition of tumor growth was exerted by both doses, but the mechanism of action was different. High dose directly inhibited, whereas low dose activated the main signaling pathways. Exposure to low dose BPAP resulted in elevated activity of the mTOR pathway together with p16

Topics: Adenocarcinoma of Lung; Animals; Benzofurans; Cell Cycle Checkpoints; Humans; Lung Neoplasms; Mice; Signal Transduction; Xenograft Model Antitumor Assays

Tumor vessels are known to be abnormal, with typically aberrant, leaky and disordered vessels. Here, we investigated whether polarized macrophage phenotypes are involved in tumor abnormal angiogenesis and what is its mechanism. We found that there was no difference in chemotaxis of polarized M1 and M2 macrophages to lewis lung carcinoma (LLC) cells and that either M1 or M2 macrophage-conditioned media had no effect on LLC cell proliferation. Unexpectedly, the M2 but not M1 macrophage-conditioned media promoted the proliferation of human umbilical vein endothelial cells (HUVECs) and simultaneously increased endothelial cell permeability in vitro and angiogenic index in the chick embryo chorioallantoic membrane (CAM). The treatment with M2 but not M1 macrophage-conditioned media increased autophagosomes as well as microtubule-associated protein light chain 3B (LC3-B) expression (a robust marker of autophagosomes) but decreased p62 protein expression (a selective autophagy substrate) in HUVECs, the treatment with chloroquine that blocked autophagy abrogated the abnormal angiogenic efficacy of M2 macrophage-conditioned media. These results were confirmed in urethane-induced lung carcinogenic progression. Urethane-induced lung carcinogenesis led to more M2 macrophage phenotype and increased abnormal angiogenesis concomitant with the upregulation of LC3-B and the downregulation of p62. Clodronate liposome-induced macrophage depletion, chloroquine-induced autophagic prevention or salvianolic acid B-induced vascular protection decreased abnormal angiogenesis and lung carcinogenesis. In addition, we found that the tendency of age-related M2 macrophage polarization also promoted vascular permeability and carcinogenesis in urethane carcinogenic progression. These findings indicate that the M2 macrophages induce autophagic vascular disorder to promote lung cancer progression, and the autophagy improvement represents an efficacious strategy for abnormal angiogenesis and cancer prevention.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Animals; Apoptosis; Autophagy; Benzofurans; Capillary Permeability; Carcinogenesis; Carcinoma, Lewis Lung; Cell Differentiation; Cell Line, Tumor; Cell Movement; Cell Proliferation; Chick Embryo; Chloroquine; Clodronic Acid; Culture Media, Conditioned; Endothelial Cells; Female; Human Umbilical Vein Endothelial Cells; Humans; Lung Neoplasms; Macrophages; Mice; Mice, Inbred C57BL; Microtubule-Associated Proteins; Neovascularization, Pathologic; Phosphoproteins; Trans-Activators; Urethane

Lung cancer concerns a worldwide health problem and the efficacy of available treatments is unsatisfactory. Recently, thromboxane A2 (TXA2) synthase (TXAS) and receptor (TXA2R) have been documented to play a role in lung cancer development. Therefore, dual TXA2R modulator (i.e., the dual blocker of TXAS and TXA2R) may be more efficacious to kill lung tumor cells than single TXAS inhibitor or TXA2R antagonism. The close relationship between cyclooxygenase (COX)-2 and TXAS also raises whether or how TXA2 contributes to the oncogenic activity of COX-2. This study is therefore conducted to answer these questions.. Various inhibitors and siRNA were used to evaluate the roles of TXA2 and COX-2 in the proliferation and apoptosis of lung adenocarcinoma cells. Cell proliferation was detected using both MTS ELISA and BrdU labeling ELISA. Cell cycle distribution and apoptosis were examined by flow cytometric analysis. TXB2 level, reflecting the biosynthesis of TXA2, was detected by peroxidase-labeled TXB2 conjugates using an enzyme immunoassay kit. Western blotting was performed to evaluate many biomarkers for cell cycles, apoptosis and proliferation. The levels of COXs were screened by reverse transcriptase and real-time quantitative PCR.. We found either single TXAS inhibitor/TXA2R antagonist or the dual TXA2 modulators offered a similar inhibition on cell proliferation. Moreover, inhibition of TXA2 arrested cells at the G2/M phase and induced apoptosis. It is further demonstrated that TXA2 was able to function as a critical mediator for tumor-promoting effects of COX-2 in lung adenocarcinoma cells.. The present study has for the first shown that dual TXA2 modulators and the single blocker of TXAS or TXA2R offer a similar inhibitory role in lung adenocarcinoma cell proliferation and that the tumor-promoting effects of COX-2 can largely be relayed by TXA2. Thus, TXA2 should be regarded as a critical molecule in COX-2-mediated tumor growth and a valuable target against lung cancer.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Adenocarcinoma; Adenocarcinoma of Lung; Antineoplastic Agents; Apoptosis; Benzofurans; Blotting, Western; Bridged Bicyclo Compounds, Heterocyclic; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclooxygenase 2; Cyclooxygenase Inhibitors; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Fatty Acids, Unsaturated; Flow Cytometry; Humans; Hydrazines; Immunoenzyme Techniques; Lung Neoplasms; Nitrobenzenes; Real-Time Polymerase Chain Reaction; Receptors, Thromboxane; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Sulfonamides; Sulfonylurea Compounds; Thromboxane A2; Thromboxane-A Synthase