Occurrence Of Apoptosis Research Articles

The lead optimization of the polyamine conjugate of flavonoid with a naphthalene motif: Synthesis and biological evaluation

Polyamine conjugated flavonoid with a naphthalene moiety (ZYY14) displayed excellent therapeutic activity against hepatocellular carcinoma. In this study, three different series of novel flavonoid-polyamine conjugates were designed and screened against tumor cell lines. The structure-activity relationship study demonstrated the importance of the naphthalene moiety (as the B-ring), the basic side chains in the A-ring, and the methoxy group linked to the C-ring. The optimized compound 9b displayed better antitumor potency in vitro and in vivo than the lead compound ZYY14. Fluorescent assays revealed that 9b could enter cancer cells via polyamine transporter (PAT) and locate in mitochondria and endoplasmic reticulum. Compound 9b and ZYY14 demonstrated similar apoptotic mechanism in the cytotoxicity studies and stimulated the expression of apoptosis-related proteins, such as p-p38, p-JNK, p53 and Bax. In addition, 9b can initiate autophagy which inhibited the occurrence of apoptosis. Thus, 9b can be used as a valuable lead for the future development of antitumor agents.

Iron Oxide Nanoparticles Induces Cell Cycle-Dependent Neuronal Apoptosis in Mice.

Iron oxide (Fe2O3) nanoparticles (NPs) with its unique magnetic and paramagnetic properties are popular in biomedical applications. Some of their neurotoxic mechanisms due to repeated administration are proven. However, we speculate that the neuronal damage might be due to apoptosis resulting from unusual cell cycle entry. Moreover, iron accumulation has been shown to be closely associated with most of the neurodegenerative disorders. Thus, in the current study, mice were orally (po) treated with the Fe2O3-NPs to investigate cell cycle-associated events/components and occurrence of apoptosis. A subsequent increase in oxidant levels was observed with the iron accumulation due to Fe2O3-NPs exposure. The accumulated β-amyloid and reduced level of cdk5 seem to aid in the cell cycle entry and forcing progression towards apoptosis. Expression of Cyclin D1 and pRb (Ser 795) indicate the cell cycle re-entry of neurons. Overexpression of RNA Pol II and PARP cleavage suggests DNA damage due to Fe2O3-NPs exposure. Further, hyperphosphorylation of p38 (Thr 180/Tyr 182) confirms the activation of DNA damage-dependent checkpoint. Expression patterns of pro- and anti-apoptotic markers, TUNEL and TEM indicate the occurrences of apoptosis.

Pentoxifylline-Induced Apoptosis in Chronic Lymphocytic Leukemia: New Insights into Molecular Mechanism.

Chronic lymphocytic leukemia (CLL) is an indolent B-lineage neoplasm, characterized by clonal expansion of CD5 positive B cells with constitutive activation of survival pathways including NF-kB. Pentoxifylline, a xanthine-derivative compound indicated for the treatment of microvascular disturbancies, has been suggested to have anti-proliferative and anti-metastatic activities in various types of cancer. In the present study we extend these data showing one of the potential molecular mechanisms through which Pentoxifylline may promote apoptosis in CLL clonal lymphocytes. Peripheral blood mononuclear cells were isolated from 15 CLL patients 0 RAI stage and 15 healthy volunteers and treated for 24 and 48 hours with Pentoxifylline. Apoptosis induction was evaluated through Annexin V and TUNEL assays. Mitochondrial membrane potential depolarization analysis, active Caspase-3 assay, reactive oxygen species generation and Western Blot were assessed to further investigate the alterations induced by Pentoxifylline. We observed a statistically significant occurrence of apoptosis, DNA fragmentation and active Caspase-3 in lymphocytes from CLL patients compared to healthy volunteers after 48 hours of Pentoxifylline treatment. To clarify the molecular mechanism of the drug, we also evaluated the expression levels of NF-kB/p65 and its related proteins. In treated CLL cells, NF-kB/p65 was significantly decreased in comparison to normal cells, whereas we observed a less marked reduction of Bcl-2 expression. The treatment also induced a decrease of Mcl-1 in CLL cells with a greater down-regulation of the anti-apoptotic alternatively spliced isoform. These findings showed that Pentoxifylline induced apoptosis in leukemic cells through a molecular mechanism that involves the NF-kB signaling.

Scrophularia Atropatana Extract Reverses TP53 Gene Promoter Hypermethylation and Decreases Survivin Antiapoptotic Gene Expression in Breast Cancer Cells

Background:In many cases of breast cancer, the aberrant methylation of TP53 gene leads to uncontrolled cell proliferation and apoptosis inhibition. Moreover, expression of oncogenes which are under the control of P53 protein could be altered. Survivin as a conspicuous example of this category plays important roles in tumorigenesis, drug resistance and apoptosis inhibition. The present study was done to reveal the effects of Scrophularia atropatana extract on epigenetic situation of TP53 gene promoter and the expression levels of anti-apoptotic gene, survivin and its potential for production of cancer epi-drugs.Methods:Cytotoxic effect of dichloromethane extracts of Scrophularia plant on MCF-7 cell line was assessed in our previous study. Cell death ELISA (enzyme-linked immunosorbent assay) and TUNEL (Terminal deoxynucleotidyl transferase dUTP nick end labeling) tests were used to investigate the occurrence of apoptosis in the treated cells. Methylation Specific PCR (MSP) was employed to assess the changes in methylation status of the TP53 gene promoter. Furthermore, quantitative real time PCR was utilized to evaluate the resulting changes in TP53 and survivin genes expression.Results:Cell death ELISA and TUNEL assays confirmed the occurrence of apoptosis. MSP test revealed a significant change in the methylation status of TP53 promoter. QRT-PCR showed an increased TP53 gene expression in the treated cells while a significant decrease in survivin mRNA was evident.Conclusions:According to the outcomes, dichloromethane extract of S. atropatana returned the TP53 gene promoter hypermethylation to normal state. This plant could be a promising source for production of epi-drugs due to its apoptotic effects and reversal of TP53 epigenetic alterations.

Induction of nuclear factor-κB signal-mediated apoptosis and autophagy by reactive oxygen species is associated with hydrogen peroxide-impaired growth performance of broilers

The oxidative study has always been particularly topical in poultry science. However, little information about the occurrence of cellular apoptosis and autophagy through the reactive oxygen species (ROS) generation in nuclear factor-κB (NF-κB) signal pathway was reported in the liver of broilers exposed to hydrogen peroxide (H2O2). So we investigated the change of growth performance of broilers exposed to H2O2 and further explored the occurrence of apoptosis and autophagy, as well as the expression of NF-κB in these signaling pathways in the liver. A total of 320 1-day-old Arbor Acres male broiler chickens were raised on a basal diet and randomly divided into five treatments which were arranged as non-injected treatment (Control), physiological saline (0.75%) injected treatment (Saline) and H2O2 treatments (H2O2(0.74), H2O2(1.48) and H2O2(2.96)) received an intraperitoneal injection of H2O2 with 0.74, 1.48 and 2.96 mM/kg BW. The results showed that compared to those in the control and saline treatments, 2.96 mM/kg BW H2O2-treated broilers exhibited significantly higher feed/gain ratio at 22 to 42 days and 1 to 42 days, ROS formation, the contents of oxidation products, the mRNA expressions of caspases (3, 6, 8), microtubule-associated protein 1 light chain 3 (LC3)-II/LC3-I, autophagy-related gene 6, Bcl-2 associated X and protein expressions of total caspase-3 and total LC3-II, and significantly lower BW gain at 22 to 42 days and 1 to 42 days, the activities of total superoxide dismutase and glutathione peroxidase, the expression of NF-κB in the liver. Meanwhile, significantly higher feed/gain ratio at 1 to 42 days, ROS formation, the contents of protein carbonyl and malondialdehyde, the mRNA expression of caspase-3 and the protein expressions of total caspase-3 and total LC3-II, as well as significantly lower BW gain at 22 to 42 days and 1 to 42 days were observed in broilers received 1.48 mM/kg BW H2O2 treatment than those in control and saline treatments. These results indicated that oxidative stress induced by H2O2 had a negative effect on histomorphology and redox status in the liver of broilers, which was associated with a decline in growth performance of broilers. This may attribute to apoptosis and autophagy processes triggered by excessive ROS that suppress the NF-κB signaling pathway.

TRAF6 Affects RAC1 Expression and Apoptosis in SK-Hep1 Cells

RAC1 is a small-molecule G protein that regulates multiple cell cycle, cytoskeletal reorganization, cell migration, and apoptosis. FADD-dependent TRAIL can promote tumor metastasis through RAC1 and PI3K, and down-regulating RAC1 expression can reduce FasL-induced apoptosis. In addition, RIP1 bound to GTP acts as an activating protein for RAC1 and is involved in cytoskeletal reorganization. TRAF6 promotes migration and metastasis by regulating the RAS pathway in tumors. Thus, it is necessary to understand the interaction between RAC1 and TRAF6 as well as FADD and RIP1. In this study, we cultured hepatoma SK-Hep1 cells in vitro, specifically blocked the necroptosis pathway with Nec-1, and silenced FADD, RIP1 and TRAF6 gene expression using RNAi technology. At the same time, the expression of RAC1 was evaluated separately using RT-PCR and Western blot. The hepatoma SK-Hep1 cells survival rate was highest when the concentration of Nec-1 was 60 μM and the concentration of Z-vad-fmk was 20 μM. And the apoptosis rate of the transfected RAC1 siRNA cells was 3.59% compared with transfected siRNA cells 10.01% which was significantly decreased (P < 0.01). RAC1 could promote the occurrence of apoptosis in SK-Hep1 cells. RAC1 expression was suppressed in both protein and gene level in SK-Hep1 cells when the TRAF6 gene was silenced, but there was no significant change in RAC1 gene and protein expression when FADD and RIP1 genes were silenced. TRAF6 affects RAC1 expression and apoptosis in SK-Hep1 cells, while the FADD and RIP1 genes do not affect the role of RAC1. The TRAF6 gene is an important target in liver cancer cells.

Possible occurrence of apoptosis in Endosuifan induced testicular toxicity in mice

Endosuifan an organochlorine pesticide is known to cause deleterious effect on ttie reproductive organs of humans. In the present investigation, Endosuifan at 3.0 mg/kg b.w was administered to Swiss albino mice for 4 weeks. Animals were sacrificed and their testicular tissues were fixed for Transmission Electron microscopic study. The Electron microscopic study reveals the degenerative changes in testis at subcellular level. The plasma membrane, nuclear membrane, chromatin material and mitochondria, etc. show degenerative changes. It was concluded that Endosuifan causes damage to spermatozoa in Swiss albino mice.

Response mechanisms to joint exposure of triclosan and its chlorinated derivatives on zebrafish (Danio rerio) behavior

Triclosan (TCS), 2,4,6-trichlorophenol (2,4,6-TCP) and 2,4-dichlorophenol (2,4-DCP) frequently co-exist in real-world aquatic environments; the latter two contaminants contributing to TCS photolytic products or chlorinated derivatives. There is a paucity of information regarding their joint toxicity to aquatic organisms leading us to study their effects on the swimming behavior of zebrafish (Danio rerio). Herein, we reported that 0.28 mg/L TDT exposure (mixtures of TCS, 2,4,6-TCP and 2,4-DCP) enhanced 24-hpf embryonic spontaneous movement frequency, 96-hpf larval activity; however, the 0.56 and 1.12 mg/L TDT treatments decreased all of these behavioral endpoints. All adult behavioral tests demonstrated that chronic TDT exposure (0.14 mg/L) led to hyperactivity and restlessness in adult zebrafish. A 0.14 mg/L TD DATE /@ "M/d/yyyy" 11/21/2017T treatment led to anxiety-like behavior in a bottom dwelling test and excessive panic and low hedging capacity in a conditioned place preference test. Social interaction test demonstrated that zebrafish preferred quiet and isolated space in response to TDT stress. Zebrafish memory was significantly decreased in a T-maze experiment. Whole mount in situ hybridization of pax2a and bcl2l11 genes revealed that their differential expression in the brain and skeleton were related to the corresponding phenotypic behavioral abnormality. A series of biomarker and estrogen receptor assays demonstrated that TDT acute exposure caused abnormal energy metabolism and neurological diseases. AO staining revealed that TDT exposure produced vascular ablation in the head, as well as the occurrence of massive apoptosis in the brain. TEM observation showed pyknosis of nucleus following TDT exposure. These results allow assessment of mechanisms for zebrafish abnormal behavior in response to TDT exposure, and are useful for early intervention and gene therapy of contaminant-induced diseases.

Endogenous sulfur dioxide regulates hippocampal neuron apoptosis in developing epileptic rats and is associated with the PERK signaling pathway.

Epilepsy is among the most common neurological diseases in children. Recurrent seizures can result in hippocampal damage and seriously impair learning and memory functions in children. However, the mechanisms underlying epilepsy-related brain injury are unclear. Neuronal apoptosis is among the most common neuropathological manifestations of brain injury. Endogenous sulfur dioxide (SO2) has been shown to be involved in seizures and related neuron apoptosis. However, the role of endogenous SO2 in epilepsy remains unclear. This study assessed whether endogenous SO2 is involved in epilepsy and its underlying mechanisms. Using a rat epilepsy model induced by an intraperitoneal injection of kainic acid (KA), we found that hippocampal neuron apoptosis was induced in epileptic rats, and the SO2 content and aspartate aminotransferase (AAT) activity in the plasma were increased compared to those in the control group. However, the inhibition of SO2 production by l-aspartate-β-hydroxamate (HDX) can subvert this response 72h after an epileptic seizure. No difference in apoptosis was observed 7 d after the epileptic seizure in the KA and KA+HDX groups. The protein expression levels of AAT2, glucose-regulated protein 78 (GRP78), pancreatic eIF2 kinase-like ER kinase (PERK) and phospho-PERK (p-PERK) were remarkably elevated in the hippocampi of the epileptic rats, while the HDX treatment was capable of reversing this process 7 d after the epileptic seizure. These results indicate that the inhibition of endogenous SO2 production can alleviate neuronal apoptosis and is associated with the PERK signaling pathway during the initial stages after epileptic seizure, but inhibiting SO2 production only delayed the occurrence of apoptosis and did not prevent neuronal apoptosis in the epileptic rats.

The effect of resveratrol on the developmental competence of porcine oocytes vitrified at germinal vesicle stage.

We tested the effects of resveratrol both as a pre-treatment and as a recovery treatment after warming during in vitro maturation (IVM) on the viability and developmental competence of porcine oocytes vitrified at the germinal vesicle stage. Pre-treatment before vitrification of oocytes for 3hr with 2μM resveratrol did not affect survival, oocyte maturation and embryo developmental competence to the blastocyst stage after parthenogenetic activation. However, supplementation of the medium with resveratrol during subsequent IVM after vitrification and warming significantly improved the ability of surviving oocytes to develop to the blastocyst stage, and this effect was observed only on vitrified, but not on non-vitrified oocytes. The intracellular levels of glutathione and hydrogen peroxide in oocytes were not affected by vitrification and resveratrol treatment. Also, there was no significant difference in the occurrence of apoptosis measured by annexin V binding between vitrified and non-vitrified oocytes, regardless of the resveratrol treatment. In conclusion, resveratrol did not prevent the cellular damages in immature porcine oocytes during vitrification; however, when added to the IVM medium, it specifically improved the developmental competence of vitrified oocytes. Further research will be necessary to clarify the mechanisms of action of resveratrol on the recovery of vitrified oocytes from vitrification-related damages.

CHST6 mutation screening and endoplasmatic reticulum stress in macular corneal dystrophy.

Macular corneal dystrophy (MCD) is an autosomal recessive disorder mainly caused by gene mutations of carbohydrate sulfotransferase (CHST6) leading to bilateral visual impairment. Because the mechanism underlying this degeneration remains poorly understood, we investigated molecular alterations and pathways that may be involved in MCD in this issue. Different mutation sites were screened by direct sequencing of the coding region of CHST6. In addition, we described morphological changes in MCD keratocytes by light microscopy and electron microscopy and determined the relationship between the development of this disease and the occurrence of apoptosis through flow cytometry, cell counting kit-8, colony formation assay and other experiments. Western blotting and quantitative real-time polymerase chain reaction were used to determine if endoplasmic reticulum (ER) stress was activated. We found 10 kinds of mutations among these families with 3 novel mutations included. The percentage of apoptotic keratocytes increased in MCD patients; furthermore, the expression of apoptosis related protein B-cell lymphoma-2 (Bcl-2) was down-regulated while Bcl-2 associated X protein was upregulated. Finally, ER stress was activated with the upregulation of glucose-regulated protein 78 and CCAAT-enhancer-binding protein homologous protein. Our clinical and in vitro results suggest that the CHST6 mutation associated with MCD is associated with apoptosis, and ER stress is probably involved in this apoptosis pathway.

Deactivation of cisplatin-resistant human lung/ovary cancer cells with pyropheophorbide-α methyl ester-photodynamic therapy

The aim of this study was to determine whether photodynamic therapy (PDT) alone or combined with cisplatin (DDP), can deactivate cisplatin-resistant cancer cells. Human cancer cell lines A549 and SKOV3, and chemoresistant sublines A549/DDP and SKOV3/DDP, were subjected to PDT, DDP, or PDT combined with DDP. Cell viability and apoptosis were analyzed, and then intracellular reactive oxygen species (ROS) and proteins related to apoptosis were determined. PDT caused cell death, and PDT combined with DDP led to the highest percentage of dead cells in 4 cell lines; similar results were detected in ROS; a quantification evaluation manifested that the combined effect was addition. DDP increased the percentage of apoptotic cells, and the ROS level in A549 and SKOV3 cells, which was not observed in A549/DDP and SKOV3/DDP cells. Western blot revealed an increase of caspase 3 and Bax, and a decrease of Bcl-2, demonstrating the occurrence of apoptosis. The data suggest that PDT can efficiently deactivate resistant cells and enhance the action of DDP against resistant cancer cells.

IL-17A Enhances Microglial Response to OGD by Regulating p53 and PI3K/Akt Pathways with Involvement of ROS/HMGB1.

Cerebral ischemia-reperfusion injury (IRI) has a complex pathogenesis, and interleukin-17 (IL-17) is a newly identified class of the cytokine family that plays an important role in ischemic inflammation. An oxygen-glucose deprivation (OGD) model showed that IL-17A expression was significantly up-regulated in microglial cells. After IL-17A siRNA transfection, the inhibition of proliferation, and the increased apoptosis in microglial cells, induced by OGD/reperfusion, was improved, and the elevation of Caspase-3, Caspase-8, Caspase-9, and poly ADP ribose polymerase (PARP) activities was inhibited. Mass spectrometry demonstrated that IL-17A functioned through a series of factors associated with oxidative stress and apoptosis and regulated Caspase-3 activity and apoptosis in microglial cells via the p53 and PI3K/Akt signaling pathways. IL-17A, HMGB1, and ROS were regulated mutually to exhibit a synergistic effect in the OGD model of microglial cells, but the down-regulation of IL-17A or HMGB1 expression did not completely inhibit the production of ROS. These findings demonstrated that ROS might be located upstream of IL-17A and HMGB1 so that ROS can regulate HMGB1/IL-17A expression to affect the p53 and PI3K/Akt signaling pathways and therefore promote the occurrence of apoptosis in microglial cells. These findings provide a novel evidence for the role of IL-17A in ischemic cerebral diseases.

Effects of Wolbachia on ovarian apoptosis in Culex quinquefasciatus (Say, 1823) during the previtellogenic and vitellogenic periods

BackgroundApoptosis is programmed cell death that ordinarily occurs in ovarian follicular cells in various organisms. In the best-studied holometabolous insect, Drosophila, this kind of cell death occurs in all three cell types found in the follicles, sometimes leading to follicular atresia and egg degeneration. On the other hand, egg development, quantity and viability in the mosquito Culex quinquefasciatus are disturbed by the infection with the endosymbiont Wolbachia. Considering that Wolbachia alters reproductive traits, we hypothesised that such infection would also alter the apoptosis in the ovarian cells of this mosquito. The goal of this study was to comparatively describe the occurrence of apoptosis in Wolbachia-infected and uninfected ovaries of Cx. quinquefasciatus during oogenesis and vitellogenesis. For this, we recorded under confocal microscopy the occurrence of apoptosis in all three cell types of the ovarian follicle. In the first five days of adult life we observed oogenesis and, after a blood meal, the initiation step of vitellogenesis.ResultsApoptoses in follicular cells were found at all observation times during both oogenesis and vitellogenesis, and less commonly in nurse cells and the oocyte, as well as in atretic follicles. Our results suggested that apoptosis in follicular cells occurred in greater numbers in infected mosquitoes than in uninfected ones during the second and third days of adult life and at the initiation step of vitellogenesis.ConclusionsThe presence of Wolbachia leads to an increase of apoptosis occurrence in the ovaries of Cx. quinquefasciatus. Future studies should investigate if this augmented apoptosis frequency is the cause of the reduction in the number of eggs laid by Wolbachia-infected females. Follicular atresia is first reported in the previtellogenic period of oogenesis. Our findings may have implications for the use of Wolbachia as a mosquito and pathogens control strategy.

ANTIOXIDANT AND ANTICANCER PROPERTIES OF SOLVENT PARTITIONED EXTRACTS OF Phyla nodiflora L.

We previously found that the crude extracts of Phyla nodiflora L. are capable to inhibit cancer cells. In this study, we reassessed their anticancer properties after solvent partition extraction of the methanolic extracts. We also determined their total phenolic content (TPC) and total flavonoid content (TFC). Water, ethyl acetate and methanolic extracts showed higher TPC and TFC than chloroform or hexane extracts. Most of stem extracts exhibited higher antioxidant activity than the leaf extracts except for leaf methanolic extracts. Six of the extracts showed 50% growth inhibition at the concentration of 36-80 µg/ml. Both stem and leaf ethyl acetate extracts showed profound inhibition. They also caused DNA fragmentation in MCF-7 cells, indicating the occurrence of apoptosis. Our findings demonstrated that liquid-liquid partition has successfully separated methanolic extracts into several fractions with antioxidant and anticancer properties. This will facilitate the future investigation in identifying bioactive compounds for chemotherapeutic intervention.

Selenium protects against cadmium-induced kidney apoptosis in chickens by activating the PI3K/AKT/Bcl-2 signaling pathway.

Cadmium (Cd) is a toxic heavy metal that can induce apoptosis. Selenium (Se) is a necessary trace element and can antagonize the toxicity of many heavy metals, including Cd. PI3K/AKT/Bcl-2 is a key survival signaling pathway that regulates cellular defense system against oxidative injury as well as cell proliferation, survival, and apoptosis. The antagonistic effects of Se on Cd-induced toxicity have been reported. However, little is known about the effect of Se on Cd-induced apoptosis in chicken kidneys via the PI3K/AKT/Bcl-2 signaling pathway. In the present study, we fed chickens with Se, Cd, or both Se and Cd supplements, and after 90days of treatment, we detected the related index. The results showed that the activity of inducible nitric oxide synthase (iNOS) and concentration of nitric oxide (NO) were increased; activities of the mitochondrial respiratory chain complexes (complexes I, II, and V) and ATPases (the Na+-K+-ATPase, the Mg2+-ATPase, and the Ca2+-ATPase) were decreased; expression of PI3K, AKT, and Bcl-2 were decreased; and expression of Bax, Bak, P53, Caspase-3, Caspase-9, and cytochrome c (Cyt c) were increased. Additionally, the results of the TUNEL assay showed that the number of apoptotic cells was increased in the Cd group. By contrast, there was a significant improvement of the correlation indicators and occurrence of apoptosis in the Se+Cd group compared to the Cd group. In conclusion, our results confirmed that Se had a positive effect on ameliorating Cd-induced apoptosis in chicken kidney tissue by activating the PI3K/AKT/Bcl-2 signaling pathway.

Modifications in Human Oral Fibroblast Ultrastructure, Collagen Production, and Lysosomal Compartment in Response to Electronic Cigarette Fluids.

Many smokers have recently turned to electronic cigarettes (e-cigarettes) because they have been marketed as a cheaper, safer smokeless alternative to traditional cigarettes and a possible smoking cessation tool. Although the safety of these electronic devices is still not fully known, there is evidence of their cytotoxicity on cells belonging to the oral cavity. In a previous study by the authors, the increase of reactive oxygen production and Bax expression, followed by the occurrence of apoptosis, was demonstrated in human gingival fibroblasts (HGFs). The aim of this paper is to further investigate the effects of the e-cigarette liquids (with and without nicotine) on the same experimental model. HGFs were treated with e-cigarette fluids containing nicotine (final concentration 1 mg/mL) and the equivalent volume of a fluid without nicotine, for periods ≤48 hours. Lactate dehydrogenase assay (LDH), electronic microscopy analysis, collagen I production, flow cytometry lysosome compartment evaluation, and western blotting light chain 3 (microtubule-associated protein 1A/1B-LC3) expression were performed. Fluids containing nicotine exerted cytotoxicity as demonstrated by increased levels of LDH, in parallel to the presence of numerous vacuoles in the cytoplasm, a decrease in collagen I production, and augmented LC3 II expression. Autophagic vesicles and more procollagen I molecules were present in the cytoplasm of fibroblasts exposed to nicotine-free fluids. In the same samples, time-dependent activation of the lysosomal compartment with no changes in LC3 expression was detected. E-cigarette fluids (with and without nicotine) trigger molecular and morphologic responses in oral fibroblasts, raising concerns about their role in the pathogenesis of oral diseases.

Abstract 2529: TTF-1/NKX2-1 induced miR-532-5p targets KRAS and MKL2 oncogenes and causes apoptosis in lung adenocarcinoma cells

Abstract Our group and others have previously identified TTF-1/NKX2-1 as a lineage survival oncogene in lung adenocarcinoma. Subsequent studies revealed double-edged sword characteristics of TTF-1 in the development of lung adenocarcinoma. TTF-1 elicits lineage-survival signaling by inducing transcriptional targets such as ROR1, while TTF-1 also inhibits tumor progression by decreasing cell motility through direct activation of genes such as MYBPH. It is thus clear that a more comprehensive picture of this still enigmatic lineage-survival oncogene needs to be elucidated. Whereas most of the previous studies on TTF-1 have focused on its regulation of protein-coding genes, very little is known about regulation of microRNAs by TTF-1. In the present study, we combined in vivo patient data with in vitro data from lung adenocarcinoma cell lines, aiming at identifying miRNAs, which are transcriptionally regulated by TTF-1. Our integrative approach identified miR-532-5p as a microRNA regulated by TTF-1. Expression of miR-532-5p decreased, when cell lines with a high endogenous level of TTF-1 were transfected with siRNA against TTF-1, while it was increased by overexpression of exogenous TTF-1 in TTF-1-negative cell lines. By ChIP and luciferase assays, TTF-1 was found to induce miR-532-5p expression through its binding to the MIR532 promoter region, identifying miR-532-5p as a direct target of TTF-1. We next employed microarray analysis and target prediction using TARGETSCAN to search for potential targets of miR-532-5p. We consequently identified KRAS and MKL2 as candidates and confirmed this by qRT-PCR, Western blot and luciferase analyses. Overexpression of miR-532-5p induced apoptosis and inhibited colony formation in lung adenocarcinoma cell lines, while depletion of MKL2 phenocopied the effects of miR-532-5p introduction, similarly exhibiting occurrence of marked apoptosis. In addition, miR-532-5p significantly decreased tumor formations in vivo in a mouse xenograft model. It was also of note that miR-532-5p inhibited lung adenocarcinoma cell lines regardless of the presence or absence of KRAS mutations. In summary, we have found that TTF-1 transactivates miR-532-5p, which potently induces apoptosis in lung adenocarcinoma cells. MiR-532-5p directly targets MKL2, which we have also uncovered to be crucially involved in lung adenocarcinoma survival. In addition, while previous reports have shown that TTF-1 inhibits KRAS-driven tumorigenesis, this study identifies KRAS as a target of miR-532-5p, providing their potential mechanistic link. Our results thus shed light on how TTF-1 plays a tumor-suppressive role in the process of lung carcinogenesis, which might ultimately lead to development of a novel therapeutic strategy for this devastating disease. Citation Format: Sebastian Griesing, Taisuke Kajino, Mei Chee Tai, Zhuoran Liu, Masahiro Nakatochi, Motoshi Suzuki, Takashi Takahashi. TTF-1/NKX2-1 induced miR-532-5p targets KRAS and MKL2 oncogenes and causes apoptosis in lung adenocarcinoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2529. doi:10.1158/1538-7445.AM2017-2529

6-shogaol induces autophagic cell death then triggered apoptosis in colorectal adenocarcinoma HT-29 cells

6-shogaol is a phytochemical of dietary ginger, we found that 6-shogaol could induced both autophagic and apoptotic death in human colon adenocarcinoma (HT-29) cells. Results of this study showed that 6-shogal induced cell cycle arrest, autophagy, and apoptosis in HT-29 cells in a time sequence. After 6h, 6-shogal induced apparent G2/M arrest, then the HT-29 cells formed numerous autophagosomes in each phase of the cell cycle. After 18h, increases in acidic vesicles and LAMP-1 (Lysosome-associated membrane proteins 1) showed that 6-shogaol had caused autophagic cell death. After 24h, cell shrinkage and Caspase-3/7 activities rising, suggesting that apoptotic cell death had increased. And after 48h, the result of TUNEL assay indicated the highest occurrence of apoptosis upon 6-shogaol treatment. It appeared that apoptosis is triggered by autophagy in 6-shogaol treated HT-29 cells, the damage of autophagic cell death initiated apoptosis program.

First total synthesis of a novel amide alkaloid derived from Aconitum taipeicum and its anticancer activity

A concise total synthesis of a naturally occurring 3-isopropyl-tetrahydropyrrolo[1, 2-a]pyrimidine-2, 4(1H, 3H)-dione (ITPD) isolated from Aconitum taipeicum with a three-step approach was depicted in this study for the first time. Two key intermediates, diethyl isopropylmalonate (2) and pyrrolidin-2-amine (3), being synthsesised separately from initial diethyl malonate (4) and 3, 4-dihydro-2H-pyrrol-5-amine (5), were utilised to obtain the compound entitled ITPD. ITPD showed a promising anticancer activity in vitro on SMMC-7721 cell lines. Flow cytometry and cell cycle analysis revealed that ITPD could induce apoptosis and cell cycle arrest in S phase. The occurrence of apoptosis possibly attributed to the mechanism that ITPD could mediate the mitochondrial pathway through activating caspase-3/9 and increasing the ratio of Bax/Bcl-2 to finally trigger cell apoptosis and DNA damage. Collectively, the possibility to produce sufficient quantity of synthetic ITPD provided the base for further bio-evaluation in vivo and in vitro. The bioactive assay suggested that it may be a potential candidate for further chemical optimisation and use in cancer therapy.