Yao Fong

The antiproliferative effect of C2-ceramide on lung cancer cells through apoptosis by inhibiting Akt and NFκB

The anticancer effects of ceramide have been reported in many types of cancers but less in lung cancer. In this study, we used C2-ceramide to further investigate its possible anticancer effects and mechanisms on non-small cell lung cancer (NSCLC) H1299 cells. The result of cell proliferation in terms of trypan blue assay showed high dose of C2-ceramide inhibited cell survival after 24 h treatment. The flow cytometry-based assays indicated the effect of apoptosis, chromatin condensation, and G1 arrest in terms of Annexin V/propidium iodide (PI), DAPI, and PI stainings, respectively. Moreover, the decreased protein level of p-Akt, p-NFκB, survivin and cyclin A2 were detected by Western blot assay. Taken together, these results indicated the antiproliferative effect of C2-ceramide is majorly responsible for cell apoptosis in lung cancer H1299 cells.

Protective Effect of Caffeic Acid on Paclitaxel Induced Anti-Proliferation and Apoptosis of Lung Cancer Cells Involves NF-κB Pathway

Caffeic acid (CA), a natural phenolic compound, is abundant in medicinal plants. CA possesses multiple biological effects such as anti-bacterial and anti-cancer growth. CA was also reported to induce fore stomach and kidney tumors in a mouse model. Here we used two human lung cancer cell lines, A549 and H1299, to clarify the role of CA in cancer cell proliferation. The growth assay showed that CA moderately promoted the proliferation of the lung cancer cells. Furthermore, pre-treatment of CA rescues the proliferation inhibition induced by a sub-IC50 dose of paclitaxel (PTX), an anticancer drug. Western blot showed that CA up-regulated the pro-survival proteins survivin and Bcl-2, the down-stream targets of NF-κB. This is consistent with the observation that CA induced nuclear translocation of NF-κB p65. Our study suggested that the pro-survival effect of CA on PTX-treated lung cancer cells is mediated through a NF-κB signaling pathway. This may provide mechanistic insights into the chemoresistance of cancer calls.

The Antiproliferative and Apoptotic Effects of Sirtinol, a Sirtuin Inhibitor on Human Lung Cancer Cells by Modulating Akt/β-Catenin-Foxo3A Axis

Sirtuins, NAD+-dependent deacetylases, could target both histones and nonhistone proteins in mammalian cells. Sirt1 is the major sirtuin and has been shown to involve various cellular processes, including antiapoptosis, cellular senescence. Sirt1 was reported to be overexpressed in many cancers, including lung cancer. Sirtinol, a specific inhibitor of Sirt1, has been shown to induce apoptosis of cancer cells by elevating endogenous level of reactive oxygen species. In the study, we investigated the effect of sirtinol on the proliferation and apoptosis of nonsmall cell lung cancer (NSCLC) H1299 cells. The results of proliferation assay and colony formation assay showed the antigrowth effect of sirtinol. The annexin-V staining further confirmed the apoptosis induction by sirtinol treatment. Interestingly, the levels of phosphorylated Akt and β-catenin were significantly downregulated with treating the apoptotic inducing doses. On the contrary, sirtinol treatment causes the significantly increased level of FoxO3a, a proapoptotic transcription factor targeted by Sirt1. These above results suggested that sirtinol may inhibit cell proliferation of H1299 cells by regulating the axis of Akt-β-catenin-FoxO3a. Overall, this study demonstrates that sirtinol attenuates the proliferation and induces apoptosis of NSCLC cells, indicating the potential treatment against NSCLC cells by inhibiting Sirt1 in future applications.

Feruloyl-l-arabinose attenuates migration, invasion and production of reactive oxygen species in H1299 lung cancer cells

Ferulic acid (FA), a phenolic compound, is an abundant dietary antioxidant and exerts the mitogenic effect on cells. Recently, we isolated an active FA derivative, namely feruloyl-L-arabinose (FAA), from coba husk. The aim of this study was to investigate the effects of FAA on the proliferation, migration and invasion of H1299 human lung cancer cells. Our results showed a strong antioxidant potential of FAA. Additionally, FAA inhibited the migration and invasion ability, while causing a significant accumulation of G2/M-population, of H1299 tumor cells in a dose-dependent manner, whereas no significant change on cell proliferation was observed. Results from the wound healing assay revealed that cell migration ability was markedly inhibited by FAA treatments. Similarly, results of gelatin zymography study showed that FAA treatments significantly decreased the activities of matrix metalloproteinase (MMP)-2 and MMP-9, suggesting that FAA-mediated inhibition on migration and invasion of lung cancer cells may be achieved by the down-regulation of the MMPs activities. Taken together, our present work provides a new insight into the novel inhibitory function of FAA on cell migration in H1299 cells, suggesting its promising role in the chemoprevention of lung cancer.

BPIQ, a novel synthetic quinoline derivative, inhibits growth and induces mitochondrial apoptosis of lung cancer cells in vitro and in zebrafish xenograft model

Background2,9-Bis[2-(pyrrolidin-1-yl)ethoxy]-6-{4-[2-(pyrrolidin-1-yl)ethoxy] phenyl}-11H-indeno[1,2-c]quinolin-11-one (BPIQ) is a derivative from 6-arylindeno[1,2-c]quinoline. Our previous study showed the anti-cancer potential of BPIQ compared to its two analogues topotecan and irinotecan. In the study, the aim is to investigate the potency and the mechanism of BPIQ against lung cancer cells.MethodsBoth in vitro and zebrafish xenograft model were performed to examine the anti-lung cancer effect of BPIQ. Flow cytometer-based assays were performed for detecting apoptosis and cell cycle distribution. Western blot assay was used for detecting the changes of apoptotic and cell cycle-associated proteins. siRNA knockdown assay was performed for confirming the apoptotic role of Bim.ResultsBoth in vitro and zebrafish xenograft model demonstrated the anti-lung cancer effect of BPIQ. BPIQ-induced proliferative inhibition of H1299 cells was achieved through the induction of G2/M-phase arrest and apoptosis. The results of Western blot showed that BPIQ-induced G2/M-phase arrest was associated with a marked decrease in the protein levels of cyclin B and cyclin-dependent kinase 1 (CDK1). The up-regulation of pro-apoptotic Bad, Bim and down-regulation of pro-survival XIAP and survivin was observed following BPIQ treatment.ConclusionsBPIQ-induced anti-lung cancer is involved in mitochondrial apoptosis. BPIQ could be a promising anti-lung cancer drug for further applications.

Dual roles of extracellular signal-regulated kinase (ERK) in quinoline compound BPIQ-induced apoptosis and anti-migration of human non-small cell lung cancer cells

Background2,9-Bis[2-(pyrrolidin-1-yl)ethoxy]-6-{4-[2-(pyrrolidin-1-yl)ethoxy] phenyl}-11H-indeno[1,2-c]quinoline-11-one (BPIQ), is a synthetic quinoline analog. A previous study showed the anti-cancer potential of BPIQ through modulating mitochondrial-mediated apoptosis. However, the effect of BPIQ on cell migration, an index of cancer metastasis, has not yet been examined. Furthermore, among signal pathways involved in stresses, the members of the mitogen-activated protein kinase (MAPK) family are crucial for regulating the survival and migration of cells. In this study, the aim was to explore further the role of MAPK members, including JNK, p38 and extracellular signal-regulated kinase (ERK) in BPIQ-induced apoptosis and anti-migration of human non-small cell lung cancer (NSCLC) cells.MethodsWestern Blot assay was performed for detecting the activation of MAPK members in NSCLC H1299 cells following BPIQ administration. Cellular proliferation was determined using a trypan blue exclusion assay. Cellular apoptosis was detected using flow cytometer-based Annexin V/propidium iodide dual staining. Cellular migration was determined using wound-healing assay and Boyden’s chamber assay. Zymography assay was performed for examining MMP-2 and -9 activities. The assessment of MAPK inhibition was performed for further validating the role of JNK, p38, and ERK in BPIQ-induced growth inhibition, apoptosis, and migration of NSCLC cells.ResultsWestern Blot assay showed that BPIQ treatment upregulates the phosphorylated levels of both MAPK proteins JNK and ERK. However, only ERK inhibitor rescues BPIQ-induced growth inhibition of NSCLC H1299 cells. The results of Annexin V assay further confirmed the pro-apoptotic role of ERK in BPIQ-induced cell death of H1299 cells. The results of wound healing and Boyden chamber assays showed that sub-IC50 (sub-lethal) concentrations of BPIQ cause a significant inhibition of migration in H1299 cells accompanied with downregulating the activity of MMP-2 and -9, the motility index of cancer cells. Inhibition of ERK significantly enhances BPIQ-induced anti-migration of H1299 cells.ConclusionsOur results suggest ERK may play dual roles in BPIQ-induced apoptosis and anti-migration, and it would be worthwhile further developing strategies for treating chemoresistant lung cancers through modulating ERK activity.

An Acetamide Derivative as a Camptothecin Sensitizer for Human Non-Small-Cell Lung Cancer Cells through Increased Oxidative Stress and JNK Activation.

In recent years, combination chemotherapy is a primary strategy for treating lung cancer; however, the issues of antagonism and side effects still limit its applications. The development of chemosensitizer aims to sensitize chemoresistant cancer cells to anticancer drugs and therefore improve the efficacy of chemotherapy. In this study, we examined whether N-[2-(morpholin-4-yl)phenyl]-2-{8-oxatricyclo[7.4.0.0,2,7]trideca-1(9),2(7),3,5,10,12-hexaen-4-yloxy}acetamide (NPOA), an acetamide derivative, sensitizes human non-small-cell lung cancer (NSCLC) H1299 cells towards camptothecin- (CPT-) induced apoptosis effects. Our results demonstrate that the combination of CPT and NPOA enhances anti-lung-cancer effect. The cytometer-based Annexin V/propidium iodide (PI) staining showed that CPT and NPOA cotreatment causes an increased population of apoptotic cells compared to CPT treatment alone. Moreover, Western blotting assay showed an enhancement of Bax expression and caspase cascade leading to cell death of H1299 cells. Besides, CPT and NPOA cotreatment-mediated disruption of mitochondrial membrane potential (MMP) in H1299 cells may function through increasing the activation of the stressed-associated c-Jun N-terminal kinase (JNK). These results showed that NPOA treatment sensitizes H1299 cells towards CPT-induced accumulation of cell cycle S phase and mitochondrial-mediated apoptosis through regulating endogenous ROS and JNK activation. Accordingly, NPOA could be a candidate chemosensitizer of CPT derivative agents such as irinotecan or topotecan in the future.

A Quinone-Containing Compound Enhances Camptothecin-Induced Apoptosis of Lung Cancer Through Modulating Endogenous ROS and ERK Signaling.

The natural compound camptothecin (CPT) derivatives have widely been used for anti-cancer treatments, including lung cancer. However, many chemoresistant cancer cells often develop a relatively higher threshold for inducing apoptosis, causing a limited efficacy of anti-cancer drugs. Likewise, lung cancer cells acquire chemoresistance against CPT analogs, such as irinotecan and topotecan, finally resulting in an unsatisfied outcome and poor prognosis of lung cancer patients. TFPP is a quinone-containing compound as a candidate for CPT-based combination chemotherapy. In this study, we examined the effect of TFPP and CPT cotreatment on non-small cell lung cancer (NSCLC) cells. Cell proliferation and flow cytometry-based Annexin-V/PI staining assays demonstrated the synergistic effect of TFPP on CPT-induced apoptosis in both NSCLC A549 and H1299 cells. The results of CPT and TFPP cotreatment cause the regulation of the ERK-Bim axis and the activation of mitochondrial-mediated caspase cascade, including caspase-9 and caspase-3. Besides, TFPP significantly enhanced CPT-induced endogenous reactive oxygen species (ROS) in the two NSCLC cells. In contrast, the treatment of N-acetyl-l-cysteine (NAC), an ROS scavenger, rescues the apoptosis of NSCLC cells induced by TFPP and CPT cotreatment, suggesting that the synergistic effect of TFPP on CPT-induced anti-NSCLC cells is through upregulating ROS production. Consequently, our results suggest that TFPP sensitizes NSCLC towards CPT-based chemotherapy may act through decreasing the apoptosis-initiating threshold. Therefore, TFPP may be a promising chemosensitizer for lung cancer treatment, and the underlying mechanism warrants further.

Exogenous C8-Ceramide Induces Apoptosis by Overproduction of ROS and the Switch of Superoxide Dismutases SOD1 to SOD2 in Human Lung Cancer Cells

Ceramides, abundant sphingolipids on the cell membrane, can act as signaling molecules to regulate cellular functions including cell viability. Exogenous ceramide has been shown to exert potent anti-proliferative effects against cancer cells, but little is known about how it affects reactive oxygen species (ROS) in lung cancer cells. In this study, we investigated the effect of N-octanoyl-D-erythro-sphingosine (C8-ceramide) on human non-small-cell lung cancer H1299 cells. Flow cytometry-based assays indicated that C8-ceramide increased the level of endogenous ROS in H1299 cells. Interestingly, the ratio of superoxide dismutases (SODs) SOD1 and SOD2 seem to be regulated by C8-ceramide treatment. Furthermore, the accumulation of cell cycle G1 phase and apoptotic populations in C8-ceramide-treated H1299 cells was observed. The results of the Western blot showed that C8-ceramide causes a dramatically increased protein level of cyclin D1, a critical regulator of cell cycle G1/S transition. These results suggest that C8-ceramide acts as a potent chemotherapeutic agent and may increase the endogenous ROS level by regulating the switch of SOD1 and SOD2, causing the anti-proliferation, and consequently triggering the apoptosis of NSCLC H1299 cells. Accordingly, our works may give a promising strategy for lung cancer treatment in the future.

9-bis[2-(pyrrolidin-1-yl)ethoxy]-6-{4-[2-(pyrrolidin-1-yl)ethoxy]phenyl}-11H-indeno[1,2-c]quinolin-11-one (BPIQ), a quinoline derivative inhibits human hepatocellular carcinoma cells by inducing ER stress and apoptosis

BACKGROUND Hepatocellular carcinoma (HCC) is one of the leading cancers in the world, including Taiwan. The chemoresistance of advanced HCC frequently results in the poor prognosis of patients. Previous studies demonstrated the quinoline derivative, 9-bis[2-(pyrrolidin-1-yl)ethoxy]-6-{4-[2-(pyrrolidin-1-yl)ethoxy]phenyl}-11Hindeno[ 1,2-c]quinolin-11-one (BPIQ) exerts the inhibitory potential against several cancer cells, including liver cancer cells. OBJECTIVE We further investigated the anti-HCC effects of BPIQ, including apoptosis and the modulation of ER stress. METHODS Both trypan blue exclusion assay and colony formation assay were performed to examine whether BPIQ affects the growth of HCC cell lines Ha22T and Huh7. Flow cytometry-based assay was performed for determining the cell cycle distribution and apoptosis. Western blot assay was conducted for detecting the changes in apoptosis- and endoplasmic reticulum (ER) stress-associated proteins. RESULTS BPIQ inhibits cell growth and induces the apoptosis of both Ha22T and Huh7 cell lines significantly. The level of γH2AX, an endogenous DNA damage biomarker was dramatically increased suggesting the involvement of DNA damage pathway in BPIQ-induced apoptosis. Further, BPIQ down-regulates the pro-survival proteins, survivin, XIAP and cyclin D1. BPIQ also may regulate ER stress response through modulating the levels of ER stress-related proteins Glucose-regulated protein of 78 kD (GRP78), Inositol-requiring kinase-1α (IREα), C/EBP homologous protein (Chop) and calnexin. CONCLUSIONS The anti-HCC effect of BPIQ may occur through down-regulating pro-survival proteins, and the modulation of ER stress may contribute to the BPIQ-induced apoptosis of HCC cells. The chemotherapeutic or chemopreventive applications of BPIQ for HCC treatment will be worthy of further investigation in future.