Bisphenol A induced male germ cell apoptosis via IFNß-XAF1-XIAP pathway in adult mice.

Bisphenol A (BPA) impairs male fertility by acting as an endocrine disruptor. However, the mechanisms by which BPA cause reproductive toxicity are not fully elucidated. Here, we explored the role of XAF1, a novel pro-apoptosis molecule, in BPA-induced abnormal spermatogenesis and the transcriptional regulation mechanism of BPA-induced XAF1. BPA exposure detrimentally impacted spermatogenesis by inducing excessive germ cell apoptosis. XAF1 was upregulated in germ cells after BPA exposure, which was involved in the apoptosis pathway. In addition, the expression levels of XIAP and XAF1 were inversely correlated after BPA exposure. Knockdown of XAF1 expression partially inhibited the apoptosis of GC-2 cells, suppressed the activation of caspase 3 and improved the BPA-induced XIAP expression. Moreover, IFNß expression levels were significantly upregulated after BPA exposure both in vitro and in vivo, and these levels were positively related to the expression of XAF1. Furthermore, IFNß knockdown reduced the expression of XAF1 and increased the expression of XIAP in BPA-treated GC-2 cells. Together, these data indicated that BPA triggers male germ cell apoptosis in mice via the IFNß-XAF1-XIAP pathway, which may contribute to BPA-induced testis toxicity.

Artepillin C as a targeting survivin molecule in oral squamous cell carcinoma cells in vitro: A preliminary study.

BACKGROUND: Survivin, a member of the inhibitor of apoptosis family, is overexpressed in most human tumors, but undetectable in normal adult tissues. It is a promising target molecule in cancer treatment, as interference in its function promotes apoptosis. Artepillin C, a major, biologically active ingredient of Brazilian propolis, possesses anticancer activity against several cancer cells with different tissue origins. However, little is known about its bioactivity on oral squamous cell carcinoma cells or its effect on survivin expression. The aim of this study was to investigate the cytotoxic and antisurvivin activities of artepillin C in oral squamous cell carcinoma cells. METHODS: HSC-3 human oral squamous cell carcinoma cells were treated with varying doses of artepillin C for up to 72 hours. Cell viability was measured by WST-1, and the cytotoxic effects of artepillin C on HSC-3 cells were quantified with flow cytometry. The survivin levels were determined by ELISA. RESULTS: Artepillin C exhibited dose- and time-dependent cytotoxic effects on HSC-3 cells. Flow cytometric analysis showed that 22% of untreated HSC-3 cells underwent spontaneous cell death, whereas 77.32% of the cells were killed in response to the highest dose of artepillin C at 72 hours. Survivin expression was reduced in treated cells. CONCLUSIONS: HSC-3 cells are vulnerable to artepillin C in a dose- and time-dependent manner. HSC-3 cell death induced by artepillin C, at least in part, was a result of a decrease in survivin levels.

Inhibition of survivin expression after using oxaliplatin and vinflunine to induce cytogenetic damage in vitro in lymphocytes from colon cancer patients and healthy individuals.

Chemotherapy drugs usually inflict a lethal dose to tumour cells with the consequence that these cells are being killed by cell death. However, each round of chemotherapy also causes damage to normal somatic cells. The DNA cross-linking agent oxaliplatin (OXP), which causes DNA double-strand breaks, and vinflunine (VFN), which disrupts the mitotic spindle, are two of these chemotherapy drugs which were evaluated in vitro using peripheral lymphocytes from colorectal cancer patients and healthy individuals to determine any differential response. Endpoints examined included micronucleus (MN) induction using the cytokinesis-blocked micronucleus (CBMN) assay and pancentromeric fluorescence in situ hybridisation. Also, survivin expression was monitored since it regulates the mitotic spindle checkpoint and inhibits apoptosis. OXP produced cytogenetic damage (micronuclei in binucleated cells) via its clastogenic but also previously unknown aneugenic action, possibly through interfering with topoisomerase II, whilst VFN produced micronuclei in mononucleated cells because of incomplete karyokinesis. Survivin expression was found to be significantly reduced in a concentration-dependent manner by not only OXP but surprisingly also VFN. This resulted in large numbers of multinucleated cells found with the CBMN assay. As survivin is upregulated in cancers, eliminating apoptosis inhibition might provide a more targeted chemotherapy approach; particularly, when considering VFN, which only affects cycling cells by inhibiting their mitotic spindle, and alongside possibly other pro-apoptotic compounds. Hence, these newly found properties of VFN -the inhibition of survivin expression-might demonstrate a promising chemotherapeutic approach as VFN induces less DNA damage in normal somatic cells compared to other chemotherapeutic compounds.

Survivin, a molecular target for therapeutic interventions in squamous cell carcinoma.

Squamous cell carcinoma (SCC) is the most common cancer worldwide. The treatment of locally advanced disease generally requires various combinations of radiotherapy, surgery, and systemic therapy. Despite aggressive multimodal treatment, most of the patients relapse. Identification of molecules that sustain cancer cell growth and survival has made molecular targeting a feasible therapeutic strategy. Survivin is a member of the Inhibitor of Apoptosis Protein (IAP) family, which is overexpressed in most of the malignancies including SCC and totally absent in most of the normal tissues. This feature makes survivin an ideal target for cancer therapy. It orchestrates several important mechanisms to support cancer cell survival including inhibition of apoptosis and regulation of cell division. Overexpression of survivin in tumors is also associated with poor prognosis, aggressive tumor behavior, resistance to therapy, and high tumor recurrence. Various strategies have been developed to target survivin expression in cancer cells, and their effects on apoptosis induction and tumor growth attenuation have been demonstrated. In this review, we discuss recent advances in therapeutic potential of survivin in cancer treatment.

Anticancer activity of a trans-platinum(II) complex of 3-aminoflavone to ovarian cancer cells.

OBJECTIVES: Cisplatin is a classical anticancer drug used in the treatment of ovarian cancer. Unfortunately, the treatment is associated with numerous adverse effects. Studies concerning new platinum derivatives with less organ toxicity are conducted. The aim of this study was to analyse the effect of a new trans-platinum(II) complex of 3-aminoflavone on the viability and mortality of the cells from OVCAR 3 and CAOV 3 ovarian cancer cell lines and on the expression of the selected genes involved in the process of apoptosis. MATERIAL AND METHODS: The viability of ovarian cancer cells and the cytotoxicity of a trans-platinum(II) complex of 3-amino-flavone: [trans-Pt(3-af )2Cl2), trans-bis-(3-aminoflavone) dichloridoplatinum(II)] and cisplatin were analysed using a spectrophotometric method with the use of MTT assay and LDH assay. BAX, BCL2, BIRC5 gene expression analysis on mRNA level was conducted with the use of Real-Time PCR method. RESULTS: It was observed that parallel to an increase in the concentration of the new complex compound and cisplatin there is a decrease in viability and an increase in mortality of ovarian cancer cells. As a result of exposure to the studied compound and cisplatin, an increased BAX gene expression and decreased BCL2 and BIRC5 gene expression were observed in the studied ovarian cancer cell lines. CONCLUSION: Trans-Pt(3-af )2Cl2 exhibits anticancer activity towards OVCAR 3 and CAOV 3 ovarian cancer cell lines. The studied complex compound can be considered as a potential anticancer drug.

[The effect of tanshinone â ¡A potentiates the effects of Cisplatin in Fadu cells in vitro through downregulation of survivin].

Objective:The aim of this study is to investigate the inhibitory effect and mechanism of tanshinone ⅡA combined with cisplatin on tumor Fadu cells in pharyngeal squamous cell carcinoma. Method:Cytotoxicity was determined by CCK8 assay. Flow cytometry was used to detect apoptosis and cell cycle distribution. Western blotting was used to assess the protein expression of related signaling proteins. Result:Compared with the two single drug groups treated with Tan ⅡA and DDP respectively, the combination group showed significantly higher anti-proliferative rate (P<0.01), arrested cell cycle at S phase, and resulted in observably higher apoptotic cell fractions in human hypopharyngeal squamous cell carcinomas Fadu cells; Western blotting showed that the protein expression of cleaved caspase 3 and cleaved PARP increased ,while survivin significantly decreased in the cells treated with the combination of tanshinone ⅡA and cisplatin. Conclusion:Tanshinone ⅡA potentiates the efficacy of Cisplatin in Fadu cells, which may be attributed to the downregulation of survivin protein expression.

The IAP Protein Family, SMAC Mimetics and Cancer Treatment.

Since the acquired resistance of cells to apoptosis is one of the major hallmarks of cancer, the endogenous inhibitors of apoptosis can be regarded as promising targets in the design of anticancer therapeutics. In addition to their antiapoptotic activity, inhibitor of apoptosis proteins (IAPs) are able to regulate numerous other cell functions, including proliferation, differentiation, and migration, as well as proinflammatory and immune responses. Study of the IAP family as target molecules in targeted therapies has recently focused on SMAC mimetics as synthetic IAP antagonists that have been under development as promising therapeutics. To overview the background of IAP proteins and to focus on the development of SMAC mimetics, the present review first looks at the mechanisms of IAP proteins' antiapoptotic activities and those for controlling those activities; then the SMAC mimetics, including birinapant, LCL161, and DEBIO1143/AT-406, and their clinical trials are introduced. To further clarify the processes to exert the efficacies of SMAC mimetics, it is necessary to determine therapeutic biomarkers that predict and assess them, which may include caspases and factors in the TNFα pathway.

[Effect of DJ-1 silencing by RNA interference on growth of xenografted human laryngeal squamous cell carcinoma Hep-2 cells in nude mice].

Objective: To investigate the effect of silencing DJ-1 on xenografted human laryngeal squamous cell carcinoma (LSCC) Hep-2 cells in nude mice. Methods: Xenograft model of human LSCC was established by subcutaneous transplantation of Hep-2 cells in 24 nude mice. The LSCC-bearing nude mice were randomly divided into 3 groups (n=8 in each):DJ-1 siRNA low dose group and DJ-1 siRNA high dose group were injected in tumors with 20 µg of DJ-1 siRNA or 40 µg of DJ-1 siRNA in 50 µL, respectively; control group was injected with 5% glucose solution in 50 µL, twice a week for 3 weeks. The weight and size of tumors were measured before injection. The animals were sacrificed 48 h after the final treatment, and the tumors were harvested and weighed. The apoptosis and proliferation of tumor cells were determined; the expressions of Caspase-3 and Ki-67 in tumor specimens were detected with immunohistochemistry. The expression of DJ-1, PTEN, survivin mRNA and protein in tumor tissues were detected by RT-PCR and Western blotting, respectively. Results: Tumor weight in low dose group[(0.66±0.15)g] and high dose group[(0.48±0.11)g] were significantly lower than that in control group[(0.83±0.16)g, all P<0.05]. The inhibition rates of low dose group and high dose group were (20.48±0.18)% and (42.16±0.13)%, respectively. Immunohistochemistry showed that the expression of Caspase-3 was increased and Ki-67 was reduced in tumor specimens, compared with the control group (all P<0.05). RT-PCR and Western blot results showed that in low dose group and high dose group the mRNA and protein expression of DJ-1 and survivin significantly decreased (all P<0.05), while PTEN mRNA and protein content increased (all P<0.05). Conclusion: High dose DJ-1 siRNA can inhibit the tumor growth in human LSCC xenograft nude mouse model, which indicates that down-regulating DJ-1 and survivin, and up-regulating PTEN expression may lead to blockage of PI3K-PKB/Akt signaling pathway and promoting tumor cell apoptosis.

Proteomics Suggests a Role for APC-Survivin in Response to Somatostatin Analog Treatment of Neuroendocrine Tumors.

CONTEXT: Somatostatin analogs are established in the treatment of neuroendocrine tumors (NETs) including small intestinal NET; however, the molecular mechanisms are not well known. Here, we examined the direct effects of lanreotide in NET cell line models. SETTING AND DESIGN: The cell lines HC45 and H727 were treated with 10nM lanreotide for different time periods and alterations of the proteome were analyzed by in-depth high-resolution isoelectric focusing tandem liquid chromatography-mass spectrometry. We next investigated whether the observed suppression of survivin was mediated by adenomatous polyposis coli (APC) and possible effects on tumor proliferation in vitro. Expression of survivin was assessed by immunohistochemistry in 112 NET cases and compared with patient outcome. RESULTS: We quantified 6451 and 7801 proteins in HC45 and H727, respectively. After short time lanreotide treatment APC was increased and survivin reduced. Overexpression of APC in H727 cells decreased, and APC knock-down elevated the survivin level. The lanreotide regulation of APC-survivin could be suppressed by small interfering RNA against somatostatin receptor 2. Although lanreotide only gave slight inhibition of proliferation, targeting of survivin with the small molecule YM155 dramatically reduced proliferation. Moderate or high as compared with low or absent total survivin expression was associated with shorter progression-free survival, independent of tumor stage, grade, and localization. CONCLUSIONS: We report a proteome-wide analysis of changes in response to lanreotide in NET cell lines. This analysis suggests a connection between somatostatin analog, APC, and survivin levels. Survivin is a possible prognostic factor and a new potential therapeutic target in NETs.

Survivin-targeted nanoparticles for pancreatic tumor imaging in mouse model.

We investigated the potential of targeting survivin, an inhibitor of apoptosis, in visualize pancreatic tumor in mouse model using targeted magnetic nanoparticles (MNPs) and magnetic resonance imaging (MRI). Chitosan-coated MNPS and survivin antisense oligonucleotide(ASON) were conjugated to give Sur-MNPs. Accumulations of targeted, non-targeted nanoparticles or nonsense oligonucleotide-MNPs (NSON-MNPs) in the liver, spleen, kidney and tumors were determined. Targeted nanoparticles were highly accumulated in BxPC-3 cells but not in non-cancer cells. In vivo MRI showed a significant T2 signal reduction in tumors of mice injected with targeted nanoparticles but slight signal change in tumors of mice injected with non-targeted nanoparticles or NSON-MNPs. Prussian blue staining demonstrated highly accumulated Sur-MNPs in tumor mass compared with normal pancreatic, kidney and liver tissues. Our data show that the MNPs functionalized with ASON lead to the targeted localization in pancreatic tumors. Survivin targeted nanoparticles could be used for detection of pancreatic tumors.

PTEN deficiency promotes macrophage infiltration and hypersensitivity of prostate cancer to IAP antagonist/radiation combination therapy.

PTEN loss is prognostic for patient relapse post-radiotherapy in prostate cancer (CaP). Infiltration of tumor-associated macrophages (TAMs) is associated with reduced disease-free survival following radical prostatectomy. However, the association between PTEN loss, TAM infiltration and radiotherapy response of CaP cells remains to be evaluated. Immunohistochemical and molecular analysis of surgically-resected Gleason 7 tumors confirmed that PTEN loss correlated with increased CXCL8 expression and macrophage infiltration. However PTEN status had no discernable correlation with expression of other inflammatory markers by CaP cells, including TNF-α. In vitro, exposure to conditioned media harvested from irradiated PTEN null CaP cells induced chemotaxis of macrophage-like THP-1 cells, a response partially attenuated by CXCL8 inhibition. Co-culture with THP-1 cells resulted in a modest reduction in the radio-sensitivity of DU145 cells. Cytokine profiling revealed constitutive secretion of TNF-α from CaP cells irrespective of PTEN status and IR-induced TNF-α secretion from THP-1 cells. THP-1-derived TNF-α increased NFκB pro-survival activity and elevated expression of anti-apoptotic proteins including cellular inhibitor of apoptosis protein-1 (cIAP-1) in CaP cells, which could be attenuated by pre-treatment with a TNF-α neutralizing antibody. Treatment with a novel IAP antagonist, AT-IAP, decreased basal and TNF-α-induced cIAP-1 expression in CaP cells, switched TNF-α signaling from pro-survival to pro-apoptotic and increased radiation sensitivity of CaP cells in co-culture with THP-1 cells. We conclude that targeting cIAP-1 can overcome apoptosis resistance of CaP cells and is an ideal approach to exploit high TNF-α signals within the TAM-rich microenvironment of PTEN-deficient CaP cells to enhance response to radiotherapy.

Berberine and Curcumin Target Survivin and STAT3 in Gastric Cancer Cells and Synergize Actions of Standard Chemotherapeutic 5-Fluorouracil.

Aberrantly expressed survivin and STAT3 signaling have emerged as major determinants of chemoresistance in gastric cancer. We evaluated effects of potent herbal derivatives curcumin, berberine, and quercetin on STAT3 signaling, survivin expression, and response to 5-fluorouracil (5-FU) treatment in gastric cancer cells (AGS). Cytotoxic and inhibitory effects of berberine, curcumin, and quercetin alone or in combination with 5-FU were examined by MTT assay, and their effect on survivin, STAT3, and the phosphorylated active STAT3 (pSTAT3) expression was examined by western blotting. Effect of these herbal derivatives on STAT3 DNA binding activity was measured by electrophoretic mobility shift assay. Curcumin, berberine, and quercetin effectively downregulated pSTAT3 levels, survivin expression, and gastric cancer cells viability in a dose-dependent manner (with corresponding IC50 values of 40.3µM, 29.2µM and 37.5µM, respectively). Berberine was more effective in inhibiting survivin expression as compared to other herbal agents. 5-FU in combination with berberine or curcumin showed a synergistic inhibition of survivin and STAT3 level resulting in enhanced cell death in gastric cancer cells. Overall, our data suggest use of berberine and curcumin as adjunct therapeutics to overcome chemoresistance during treatment of gastric malignancies.

Paclitaxel tumor priming promotes delivery and transfection of intravenous lipid-siRNA in pancreatic tumors.

The major barrier for using small interfering RNA (siRNA) as cancer therapeutics is the inadequate delivery and transfection in solid tumors. We have previously shown that paclitaxel tumor priming, by inducing apoptosis, expands the tumor interstitial space, improves the penetration and dispersion of nanoparticles and siRNA-lipoplexes in 3-dimensional tumor histocultures, and promotes the delivery and transfection efficiency of siRNA-lipoplexes under the locoregional setting in vivo (i.e., intraperitoneal treatment of intraperitoneal tumors). The current study evaluated whether tumor priming is functional for systemically delivered siRNA via intravenous injection, which would subject siRNA to several additional delivery barriers and elimination processes. We used the same pegylated cationic (PCat)-siRNA lipoplexes as in the intraperitoneal study to treat mice bearing subcutaneous human pancreatic Hs766T xenograft tumors. The target gene was survivin, an inducible chemoresistance gene. The results show single agent paclitaxel delayed tumor growth but also significantly induced the survivin protein level in residual tumors, whereas addition of PCat-siSurvivin completely reversed the paclitaxel-induced survivin and enhanced the paclitaxel activity (p<0.05). In comparison, PCat-siSurvivin alone did not yield survivin knockdown or antitumor activity, indicating the in vivo effectiveness of intravenous siRNA-mediated gene silencing requires paclitaxel cotreatment. Additional in vitro studies showed that paclitaxel promoted the cytoplasmic release of siGLO, a 22 nucleotide double-stranded RNA that has no mRNA targets, from its PCat lipoplex and/or endosomes/lysosomes. Taken together, our earlier and current data show paclitaxel tumor priming, by promoting the interstitial transport and cytoplasmic release, is critical to promote the delivery and transfection of siRNA in vivo. In addition, because paclitaxel has broad spectrum activity and is used to treat multiple types of solid tumors including the hard-to-treat pancreatic cancer, the synergistic paclitaxel+siSurvivin combination represents a potentially useful chemo-gene therapy.

An apoptosis-enhancing drug overcomes platinum resistance in a tumour-initiating subpopulation of ovarian cancer.

High-grade serous ovarian cancers (HGSCs) are deadly malignancies that relapse despite carboplatin chemotherapy. Here we show that 16 independent primary HGSC samples contain a CA125-negative population enriched for carboplatin-resistant cancer initiating cells. Transcriptome analysis reveals upregulation of homologous recombination DNA repair and anti-apoptotic signals in this population. While treatment with carboplatin enriches for CA125-negative cells, co-treatment with carboplatin and birinapant eliminates these cells in HGSCs expressing high levels of the inhibitor of apoptosis protein cIAP in the CA125-negative population. Birinapant sensitizes CA125-negative cells to carboplatin by mediating degradation of cIAP causing cleavage of caspase 8 and restoration of apoptosis. This co-therapy significantly improves disease-free survival in vivo compared with either therapy alone in tumour-bearing mice. These findings suggest that therapeutic strategies that target CA125-negative cells may be useful in the treatment of HGSC.

Fragment-Based Drug Discovery Targeting Inhibitor of Apoptosis Proteins: Discovery of a Non-Alanine Lead Series with Dual Activity Against cIAP1 and XIAP.

Inhibitor of apoptosis proteins (IAPs) are important regulators of apoptosis and pro-survival signaling pathways whose deregulation is often associated with tumor genesis and tumor growth. IAPs have been proposed as targets for anticancer therapy, and a number of peptidomimetic IAP antagonists have entered clinical trials. Using our fragment-based screening approach, we identified nonpeptidic fragments binding with millimolar affinities to both cellular inhibitor of apoptosis protein 1 (cIAP1) and X-linked inhibitor of apoptosis protein (XIAP). Structure-based hit optimization together with an analysis of protein-ligand electrostatic potential complementarity allowed us to significantly increase binding affinity of the starting hits. Subsequent optimization gave a potent nonalanine IAP antagonist structurally distinct from all IAP antagonists previously reported. The lead compound had activity in cell-based assays and in a mouse xenograft efficacy model and represents a highly promising start point for further optimization.

Tetramethylpyrazine inhibits the proliferation of acute lymphocytic leukemia cell lines via decrease in GSK-3ß.

Tetramethylpyrazine (TMP) has been proven to be an anticancer agent in many studies. However, its effectiveness in acute lymphoblastic leukemia (ALL) and its molecular mechanisms are still unclear. The present study aimed to evaluate the effect of TMP against Jurkat and SUP-B15 ALL cell lines and to investigate the possible detailed mechanism of action of TMP. A Cell Counting Kit-8 (CCK-8) assay was employed to examine the proliferation of Jurkat and SUP-B15 cells. Flow cytometric analysis was conducted to detect the cell cycle distribution and apoptotic rate. The expression of total glycogen synthase kinase-3ß (GSK-3ß), cox-2, survivin, bcl-2 and p27 RNA and protein levels was detected by quantitative real-time PCR and western blot assay, respectively. Additionally, western blot analysis was used to determine the whole-cell and nuclear protein levels of GSK-3ß downstream transcription factors, NF-κB (p65) and c-myc. TMP inhibited the proliferation of Jurkat and SUP-B15 cells in a dose- and time-dependent manner, with IC50 values of 120 and 200 µg/ml, respectively at 48 h. TMP induced the apoptosis of Jurkat and SUP-B15 cells and synergistically blocked cell cycle progression at the G0/G1 phase. Cells treated with TMP exhibited significantly attenuated GSK-3ß, NF-κB (p65) and c-myc expression, followed by downregulation of bcl-2, cox-2 and survivin and an upregulation of p27. The results showed that TMP induced apoptosis and caused cell cycle arrest in Jurkat and SUP-B15 cells through the downregulation of GSK-3ß, which may have further prevented the induced translocation of NF-κB and c-myc from the cytoplasm to the nucleus.

DHT inhibits the Aß25-35-induced apoptosis by regulation of seladin-1, survivin, XIAP, bax, and bcl-xl expression through a rapid PI3-K/Akt signaling in C6 glial cell lines.

Previous evidences indicate that androgen is neuroprotective in the brain. However, the underling mechanisms remain to be fully elucidated. Moreover, it is controversial whether dihydrotestosterone (DHT) modulates the expression of apoptosis-related effectors, such as survivin, XIAP, bax, and bcl-xl proteins mediated by the PI3-K/Akt pathway, which contributes to androgen neuroprotection. In this study using a C6 glial cell model, apoptotic cells were detected by flow cytometry. Akt, seladin-1, survivin, XIAP, bcl-xl, and bax protein expression is investigated by Western blot. After amyloid ß-protein fragment (Aß25-35) treatment, apoptotic cells at early (annexin V+, PI-) and late (annexin V+, PI+) stages were significantly increased. Apoptosis at early and late was obviously inhibited in the presence of DHT. The effect of DHT was markedly blocked by PI3-K inhibitor LY294002.To elicit the mechanism of DHT protection, the expression of seladin-1, survivin, XIAP, bax, and bcl-xl protein was determined in C6 cells treated with Aß25-35, DHT, or LY294002. Aß25-35 significantly downregulated the expression of seladin-1, survivin, XIAP, bcl-xl protein and upregulated the expression of bax protein. DHT significantly inhibited the expression of bax, seladin-1, survivin, XIAP, and bcl-xl protein induced by Aß25-35. Further, we found the effect of DHT was significantly inhibited by LY294002. Collectively, in a C6 glial cell model, we firstly found that DHT inhibits Aß25-35-induced apoptosis by a rapid nongenic PI-3K/Akt activation as well as regulation of seladin-1, survivin, XIAP, bcl-xl, and bax proteins.

Dual role of autophagy in lipopolysaccharide-induced preodontoblastic cells.

Odontoblasts derive from neural crest-derived odontogenic mesenchymal cells, and they are an important barrier of defense for the host. Survival and immunity of odontoblasts play important roles in protecting the dentin-pulp structure. Autophagy can eliminate damaged organelles and recycle cellular components to facilitate cellular homeostasis. Autophagy can be activated with external stressors, such as starvation, hypoxia, and infection. In this study, the role of autophagy in inflamed odontoblasts was explored, and its possible mechanism was investigated. Cell viability was not affected by mild lipopolysaccharide (LPS) stimulation, and autophagy was activated during this process. Immunofluorescence of light chain 3 confirmed that autophagy was induced with LPS treatment. Early-stage autophagy inhibition resulted in down-regulated cell viability, contrary to the up-regulated cell viability at late-stage autophagy inhibition. Western blot suggested that p-Akt and survivin were not activated in the early stage, and they gradually increased and peaked in the late stage. Meanwhile, autophagy was down-regulated through the Akt/mTOR/survivin pathway in the late stage. Thus, autophagy has a dual role in inflamed odontoblasts, which indicates its importance in maintaining the microenvironment homeostasis of odontoblasts. Autophagy was induced as a survival mechanism in the early stage, and it decreased through the Akt/mTOR/survivin signaling pathway in the late stage.

Ursodeoxycholic acid induces apoptosis of hepatocellular carcinoma cells in vitro.

OBJECTIVE: Ursodeoxycholic acid (UDCA) is widely used to treat chronic liver diseases, and its cytoprotective effect on normal hepatocytes has been shown. This study aimed to investigate the apoptotic effects of UDCA on hepatocellular carcinoma (HCC) cells and the underlying molecular events in vitro. METHODS: HCC cells were treated by UDCA at different doses and periods of time to assess cell morphology, viability, apoptosis and gene expression using methyl thiazolyl tetrazolium (MTT), Annexin V/propidium iodide (PI) stain, transferase dUTP nick end labeling (TUNEL), enzyme-linked immunosorbent assay (ELISA), immunocytochemistry and quantitative reverse transcription polymerase chain reaction, respectively. RESULTS: UDCA treatment reduced cell viability but induced HCC cell apoptosis in dose-dependent and time-dependent manners. UDCA arrested HepG2 cells at phase S of the cell cycle. At the gene levels, UDCA downregulated Bcl-2 and second mitochondria-derived activator of caspase (Smac) protein expressions, but upregulated Bax and Livin proteins in HCC cells. At the highest concentration, UDCA inhibited Livin mRNA expression but increased Smac and caspase-3 mRNA expressions as well as the activity of caspase-3 in HCC cells. CONCLUSIONS: The induction of HCC cell apoptosis by UDCA was dose-dependent and time-dependent and was mediated by the regulation of Bax to Bcl-2 ratio, the expressions of Smac and Livin, and caspase-3 expression and activity.

Methanol extract of Flacourtia indica aerial parts induces apoptosis via generation of ROS and activation of caspases in human colon cancer HCT116 cells.

Different plant parts of Flacourtia indica have long been used in Ayurvedic medicine. Previous studies have demonstrated that the methanolic extract of F. indica possess anti-inflammatory properties. The present study was aimed at investigating the anticancer effects of methanol extract of Flacourtia indica (FIM) aerial parts in human colon cancer (HCT116) cells. Treatment of cells with FIM at a concentration of 500 µg/ml for 24 hours significantly reduced cell viability and induced apoptosis, which was associated with the increased cytoplasmic expression of cytochrome c, activation of caspase-3, and the cleavage of poly-(ADP-ribose) polymerase. Incubation with FIM also inhibited the levels of Bcl-2, Bcl-xl and survivin, which are the markers of cell proliferation, whereas the expression of Bax remained unchanged. Treatment with FIM led to the generation of reactive oxygen species (ROS) in a concentration-dependent manner. Pharmacological inhibition of ROS generation by pretreatment of cells with N-acetyl cysteine abrogated FIM-induced apoptosis in HCT116 cells. Thus, these results demonstrate that FIM has anti-proliferative and pro-apoptotic effects in HCT116 cells and the effects are, at least in part, due to the ROS dependent activation of caspases.