sulindac-sulfide and Lung-Neoplasms

β-lapachone, a major component in an ethanol extract of Tabebuia avellanedae bark, is a promising potential therapeutic drug for various tumors, including lung cancer, the leading cause of cancer-related deaths worldwide. In the first part of this study, we found that apoptotic cell death induced in lung cancer cells by high concentrations of β-lapachone was mediated by increased activation of the pro-apoptotic factor JNK and decreased activation of the cell survival/proliferation factors PI3K, AKT, and ERK. In addition, β-lapachone toxicity was positively correlated with the expression and activity of NAD(P)H quinone oxidoreductase 1 (NQO1) in the tumor cells. In the second part, we found that the FDA-approved non-steroidal anti-inflammatory drug sulindac and its metabolites, sulindac sulfide and sulindac sulfone, increased NQO1 expression and activity in the lung adenocarcinoma cell lines CL1-1 and CL1-5, which have lower NQO1 levels and lower sensitivity to β-lapachone treatment than the A549 cell lines, and that inhibition of NQO1 by either dicoumarol treatment or NQO1 siRNA knockdown inhibited this sulindac-induced increase in β-lapachone cytotoxicity. In conclusion, sulindac and its metabolites synergistically increase the anticancer effects of β-lapachone primarily by increasing NQO1 activity and expression, and these two drugs may provide a novel combination therapy for lung cancers.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Anti-Inflammatory Agents, Non-Steroidal; Antineoplastic Agents; Cell Line, Tumor; Drug Synergism; Humans; Lung Neoplasms; NAD(P)H Dehydrogenase (Quinone); Naphthoquinones; Sulindac; Up-Regulation

Nonsteroidal anti-inflammatory drugs such as sulindac sulfide have shown promising antineoplastic activity in multiple tumor types, but toxicities resulting from COX inhibition limit their use in cancer therapy. We recently described a N,N-dimethylethyl amine derivative of sulindac sulfide, sulindac sulfide amide (SSA), that does not inhibit COX-1 or -2, yet displays potent tumor cell growth-inhibitory activity. Here, we studied the basis for the growth-inhibitory effects of SSA on human lung adenocarcinoma cell lines. SSA potently inhibited the growth of lung tumor cells with IC50 values of 2 to 5 μmol/L compared with 44 to 52 μmol/L for sulindac sulfide. SSA also suppressed DNA synthesis and caused a G0-G1 cell-cycle arrest. SSA-induced cell death was associated with characteristics of autophagy, but significant caspase activation or PARP cleavage was not observed after treatment at its IC50 value. siRNA knockdown of Atg7 attenuated SSA-induced autophagy and cell death, whereas pan-caspase inhibitor ZVAD was not able to rescue viability. SSA treatment also inhibited Akt/mTOR signaling and the expression of downstream proteins that are regulated by this pathway. Overexpression of a constitutively active form of Akt was able to reduce autophagy markers and confer resistance to SSA-induced cell death. Our findings provide evidence that SSA inhibits lung tumor cell growth by a mechanism involving autophagy induction through the suppression of Akt/mTOR signaling. This unique mechanism of action, along with its increased potency and lack of COX inhibition, supports the development of SSA or related analogs for the prevention and/or treatment of lung cancer.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Antineoplastic Agents; Autophagy; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cell Survival; Humans; Inhibitory Concentration 50; Lung Neoplasms; Proto-Oncogene Proteins c-akt; Ribosomal Protein S6 Kinases, 70-kDa; Signal Transduction; Sulindac; TOR Serine-Threonine Kinases

Pharmacological activators of peroxisome proliferator-activated receptor-gamma (PPARgamma) inhibit growth of non-small-cell lung cancer (NSCLC) cell lines in vitro and in xenograft models. Because these agents engage off-target pathways, we have assessed the effects of PPARgamma by overexpressing the protein in NSCLC cells. We reported previously that increased PPARgamma inhibits transformed growth and invasiveness and promotes epithelial differentiation in a panel of NSCLC expressing oncogenic K-Ras. These cells express high levels of cyclooxygenase-2 (COX-2) and produce high levels of prostaglandin E(2) (PGE(2)). The goal of these studies was to identify the molecular mechanisms whereby PPARgamma inhibits tumorigenesis. Increased PPARgamma inhibited expression of COX-2 protein and promoter activity, resulting in decreased PGE(2) production. Suppression of COX-2 was mediated through increased activity of the tumor suppressor phosphatase and tensin homolog, leading to decreased levels of phospho-Akt and inhibition of nuclear factor-kappaB activity. Pharmacological inhibition of PGE(2) production mimicked the effects of PPARgamma on epithelial differentiation in three-dimensional culture, and exogenous PGE(2) reversed the effects of increased PPARgamma activity. Transgenic mice overexpressing PPARgamma under the control of the surfactant protein C promoter had reduced expression of COX-2 in type II cells and were protected against developing lung tumors in a chemical carcinogenesis model. These data indicate that high levels of PGE(2) as a result of elevated COX-2 expression are critical for promoting lung tumorigenesis and that the antitumorigenic effects of PPARgamma are mediated in part through blocking this pathway.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Culture Media; Cyclooxygenase 2; Dinoprostone; Dose-Response Relationship, Drug; Enzyme Activation; Enzyme Inhibitors; Fluorescent Antibody Technique, Indirect; Humans; Luciferases; Lung Neoplasms; Mice; Mice, Mutant Strains; Mice, Transgenic; Neoplasms, Experimental; NF-kappa B; Organ Culture Techniques; PPAR gamma; Promoter Regions, Genetic; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Sulindac; Transfection; Transgenes

Cyclooxygenase (COX) inhibitors have antitumorigenic activity and increase the expression of the early growth response gene Egr-1, a tumor suppressor gene and transcription factor. In this study, we have investigated the gene regulatory and anti-invasive activity of two traditional nonsteroidal anti-inflammatory drugs (NSAID), sulindac sulfide and indomethacin. These compounds inhibited tumor cell invasion and induced Egr-1 expression in lung adenocarcinoma A549 cells. Overexpression of Egr-1 reduced cellular invasion in the Matrigel system, whereas suppression of Egr-1 by small interference RNA (siRNA) attenuated the inhibition of Matrigel invasion by these compounds, indicating that Egr-1 is responsible for the decrease in invasion reported following treatment with NSAIDs. Egr-1-overexpressing cells were analyzed for genes involved in invasion and metastasis. Thrombospondin-1 (TSP-1) an antiangiogenic and anti-invasion protein was up-regulated by Egr-1 overexpression, which was confirmed following treatment with sulindac sulfide. Furthermore, the induction of TSP-1 by sulindac sulfide was blocked by Egr-1 siRNA. When TSP-1 was sequestered by the addition of anti-TSP-1 antibody, the inhibition of invasion by sulindac sulfide was attenuated, indicating that TSP-1 is involved in the inhibition of invasion by NSAIDs. We used the Min mouse model to determine if sulindac sulfide would increase Egr-1 and TSP-1 in vivo, because this model is widely used to study the effects of NSAIDs on tumor formation. Treatment of Min mice with concentrations of sulindac sulfide that inhibit tumor formation increased the expression of Egr-1 and TSP-1 in colonic tissues and in the polyps of these mice. This is the first report suggesting that COX inhibitors suppress tumor cell invasion via TSP-1, which occurs downstream of Egr-1.

Topics: Adenocarcinoma; Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Line, Tumor; Colorectal Neoplasms; Cyclooxygenase Inhibitors; Early Growth Response Protein 1; Genes, Tumor Suppressor; Humans; Indomethacin; Lung Neoplasms; Mice; Neoplasm Invasiveness; RNA, Messenger; RNA, Small Interfering; Sulindac; Thrombospondin 1

Cell migration is essential for invasive and metastatic phenotypes of cancer cells. Potential chemopreventive agents of cancer-sulindac sulfide, caffeic acid phenethyl ester (CAPE), curcumin, and (+)-catechin-have been reported to interfere with several types of intracellular signaling. In this study, we examined the effects of these agents on transforming growth factor-beta(TGF-beta)-induced motility and Akt phosphorylation in A549 cells. Judged by gold particle phagokinesis assay, sulindac sulfide, CAPE, and curcumin suppressed the motility of A549 cells promoted by TGF-beta. LY294002, a specific inhibitor of phosphatidylinositol 3-kinase(PI3K)/Akt signaling, also suppressed TGF-beta-induced motility and Akt phosphorylation. Sulindac sulfide and CAPE, but not curcumin, suppressed TGF-beta-induced Akt phosphorylation. We conclude that sulindac sulfide and CAPE suppress the motility promoted by TGF-beta in lung adenocarcinoma cells through the suppression of Akt. Our observations raise the possibility that these agents, except for (+)-catechin, can be applied not only as chemopreventive agents but also as anti-metastatic therapy.

Topics: Adenocarcinoma; Antineoplastic Agents; Caffeic Acids; Catechin; Cell Movement; Curcumin; Humans; Lung Neoplasms; Neovascularization, Pathologic; NF-kappa B; Phenylethyl Alcohol; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Sulindac; Transforming Growth Factor beta; Tumor Cells, Cultured

Arsenic trioxide has shown substantial efficacy in treating patients with relapsed or refractory acute promyelocytic leukemia (APL) as well as solid tumors. Arsenic can act through a considerable number of different pathways including mitochondrial respiration and tubulin formation, affecting growth, blood flow, differentiation, and apoptosis. Recent studies on the apoptotic potential of arsenic trioxide have elucidated some of its causal mechanisms, including elevation of intracellular H2O2, inhibition of NF-kappaB activity, and inhibition of GTP-induced polymerization of tubulin. Because of the variety in cellular approaches available to arsenic, it has been hypothesized that the combination of arsenic trioxide and other chemotherapeutic agents may result in cytotoxic synergy. Recent studies have proven this true, with all-trans retinoic acid, IFN-alpha, and ascorbic acid all yielding promising results when used in conjunction with arsenic trioxide. In this study we tested sulindac sulfide, a nonsteroidal anti-inflammatory drug (NSAID) to test its effects with arsenic. Sulindac was used because it functions by some of the same pathways as arsenic, including the mitochondrial apoptotic pathway and the NF-kappaB pathway. Our results show that sulindac sulfide enhances cytotoxicity when combined with arsenic trioxide, and that further studies on the exact mechanisms of their interaction are needed.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Arsenic Trioxide; Arsenicals; Humans; In Vitro Techniques; Lung Neoplasms; Oxides; Sulindac; Tumor Cells, Cultured; Tumor Stem Cell Assay