dicumarol and Lung-Neoplasms

Topics: Animals; Anticoagulants; Antineoplastic Agents; Dicumarol; Drug Synergism; Drug Therapy, Combination; Ear Neoplasms; Endothelium; Factor XIII; Fibrinolysin; Fibrinolytic Agents; Heparin; Humans; In Vitro Techniques; Iodine Radioisotopes; Lung Neoplasms; Lymphatic Metastasis; Mice; Microcirculation; Neoplasm Metastasis; Neoplasms, Experimental; Neoplastic Cells, Circulating; Platelet Adhesiveness; Rabbits; Thrombosis; Warfarin

The fundamental role that NAD(P)H/quinone oxidoreductase 1 (NQO1) plays, in normal cells, as a cytoprotective enzyme guarding against stress induced by reactive oxygen species (ROS) is well documented. However, what is not known is whether the observed overexpression of NQO1 in neoplastic cells contributes to their survival. The current study discovered that depleting NQO1 expression in A549 and H292 lung adenocarcinoma cells caused an increase in ROS formation, inhibited anchorage-independent growth, increased anoikis sensitization, and decreased three-dimensional tumor spheroid invasion. These in vivo data further implicate tumor-NQO1 expression in a protumor survival role, because its depletion suppressed cell proliferation and decreased lung tumor xenograft growth. Finally, these data reveal an exploitable link between tumor-NQO1 expression and the survival of lung tumors because NQO1 depletion significantly decreased the percentage of ALDH((high)) cancer cells within the tumor population.. Loss of tumor-NQO1 expression inhibits tumor growth and suggests that novel therapeutics directed at tumor-NQO1 may have clinical benefit.

Topics: Animals; Anoikis; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Dicumarol; Enzyme Inhibitors; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Lung Neoplasms; Mice; NAD(P)H Dehydrogenase (Quinone); Prognosis; Reactive Oxygen Species; Survival Analysis; Treatment Outcome; Xenograft Model Antitumor Assays

Because anaplastic lymphoma kinase (ALK) is dependent on Hsp90 for protein stability, Hsp90 inhibitors are effective in controlling growth of lung cancer cells with ALK rearrangement. We investigated the mechanism of acquired resistance to 17-(Dimethylaminoethylamino)-17-demethoxygeldanamycin (17-DMAG), a geldanamycin analogue Hsp90 inhibitor, in H3122 and H2228 non-small cell lung cancer cell lines with ALK rearrangement.. Resistant cell lines (H3122/DR-1, H3122/DR-2 and H2228/DR) were established by repeated exposure to increasing concentrations of 17-DMAG. Mechanisms for resistance by either NAD(P)H/quinone oxidoreductase 1 (NQO1), previously known as a factor related to 17-DMAG resistance, or P-glycoprotein (P-gp; ABCB1/MDR1) were queried using RT-PCR, western blot analysis, chemical inhibitors, the MTT cell proliferation/survival assay, and cellular efflux of rhodamine 123.. The resistant cells showed no cross-resistance to AUY922 or ALK inhibitors, suggesting that ALK dependency persists in cells with acquired resistance to 17-DMAG. Although expression of NQO1 was decreased in H3122/DR-1 and H3122/DR-2, NQO1 inhibition by dicumarol did not affect the response of parental cells (H2228 and H3122) to 17-DMAG. Interestingly, all resistant cells showed the induction of P-gp at the protein and RNA levels, which was associated with an increased efflux of the P-gp substrate rhodamine 123 (Rho123). Transfection with siRNA directed against P-gp or treatment with verapamil, an inhibitor of P-gp, restored the sensitivity to the drug in all cells with acquired resistance to 17-DMAG. Furthermore, we also observed that the growth-inhibitory effect of 17-DMAG was decreased in A549/PR and H460/PR cells generated to over-express P-gp by long-term exposure to paclitaxel, and these cells recovered their sensitivity to 17-DMAG through the inhibition of P-gp.. P-gp over-expression is a possible mechanism of acquired resistance to 17-DMAG in cells with ALK rearrangement.

Topics: Anaplastic Lymphoma Kinase; ATP Binding Cassette Transporter, Subfamily B; Benzoquinones; Cell Line, Tumor; Cell Proliferation; Cell Survival; Dicumarol; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Humans; Lactams, Macrocyclic; Lung Neoplasms; NAD(P)H Dehydrogenase (Quinone); Paclitaxel; Receptor Protein-Tyrosine Kinases