A therapeutic HBV vaccine containing a checkpoint modifier enhances CD8+ T cell and antiviral responses.

In patients who progress from acute hepatitis B virus (HBV) infection to a chronic HBV (CHB) infection, CD8+ T cells fail to eliminate the virus and become impaired. A functional cure of CHB likely requires new and highly functional CD8+ T cell responses different from those induced by the infection. Here we report preclinical immunogenicity and efficacy of an HBV therapeutic vaccine that includes herpes simplex virus (HSV) glycoprotein D (gD), a checkpoint modifier of early T cell activation, that enhances, broadens, and prolongs CD8+ T cell responses. We developed a therapeutic HBV vaccine based on a chimpanzee adenovirus serotype 6 (AdC6) vector, called AdC6-gDHBV2, that targets conserved and highly immunogenic regions of the viral polymerase (pol) and core antigens fused into HSV gD. The vaccine was tested with, and without gD, in mice for immunogenicity and in an adeno-associated virus (AAV)8-1.3HBV vector model for antiviral efficacy. The vaccine encoding the HBV antigens within gD stimulates potent and broad CD8+ T cell responses. In a surrogate model of HBV infection, a single intramuscular (i.m.) injection of AdC6-gDHBV2 achieved significant and sustained declines of circulating HBV DNA copies (cps) and HBV surface antigen (HBsAg); both inversely correlated with HBV specific CD8+ T cell frequencies in spleens and livers. AdC6-gDHBV2 is the first therapeutic vaccine to show significant reductions in levels of HBV genome copies and HBsAg when used alone, even when vaccination was delayed for months from infection.

Preclinical Immunogenicity and Efficacy Studies for Therapeutic Vaccines for Human Papillomavirus-Type-16-Associated Cancer.

The objective of this study was to conduct preclinical immunogenicity and efficacy studies with several therapeutic vaccines for human papillomavirus (HPV)-16-associated cancers expressing the early antigens E5, E6, and E7 with or without E2. The viral oncoproteins were either expressed by themselves as fusion proteins or the fusion proteins were inserted genetically into herpes simplex virus (HSV)-1 glycoprotein D (gD) which, upon binding to the herpes virus entry mediator (HVEM), inhibits an early T cell checkpoint mediated by the B and T cell mediator (BTLA). This, in turn, lowers the threshold for T cell activation and augments and broadens CD8+ T cell responses to the antigens. The fusion antigens were expressed by chimpanzee adenovirus (AdC) vectors. Expression of the HPV antigens within gD was essential for vaccine immunogenicity and efficacy against challenge with TC-1 cells, which express E7 and E6 of HPV-16 but neither E5 nor E2. Unexpectedly, inclusion of E2 increased both CD8+ T cell responses to the other oncoproteins of HPV-16 and the effectiveness of the vaccines to cause the regression of sizable TC-1 tumors.

Treatment with the PPARα agonist fenofibrate improves the efficacy of CD8+ T cell therapy for melanoma.

Adoptive transfer of tumor antigen-specific CD8+ T cells can limit tumor progression but is hampered by the T cells' rapid functional impairment within the tumor microenvironment (TME). This is in part caused by metabolic stress due to lack of oxygen and glucose. Here, we report that fenofibrate treatment of human ex vivo expanded tumor-infiltrating lymphocytes (TILs) improves their ability to limit melanoma progression in a patient-derived xenograft (PDX) mouse model. TILs treated with fenofibrate, a peroxisome proliferator receptor alpha (PPARα) agonist, switch from glycolysis to fatty acid oxidation (FAO) and increase the ability to slow the progression of autologous melanomas in mice with freshly transplanted human tumor fragments or injected with tumor cell lines established from the patients' melanomas and ex vivo expanded TILs.

Heterologous chimpanzee adenovirus vector immunizations for SARS-CoV-2 spike and nucleocapsid protect hamsters against COVID-19.

Available COVID-19 vaccine only provide protection for a limited time due in part to the rapid emergence of viral variants with spike protein mutations, necessitating the generation of new vaccines to combat SARS-CoV-2. Two serologically distinct replication-defective chimpanzee-origin adenovirus (Ad) vectors (AdC) called AdC6 and AdC7 expressing early SARS-CoV-2 isolate spike (S) or nucleocapsid (N) proteins, the latter expressed as a fusion protein within herpes simplex virus glycoprotein D (gD), were tested individually or as a mixture in a hamster COVID-19 SARS-CoV-2 challenge model. The S protein expressing AdC (AdC-S) vectors induced antibodies including those with neutralizing activity that in part cross-reacted with viral variants. Hamsters vaccinated with the AdC-S vectors were protected against serious disease and showed accelerated recovery upon SARS-CoV-2 challenge. Protection was enhanced if AdC-S vectors were given together with the AdC vaccines that expressed the gD N fusion protein (AdC-gDN). In contrast hamsters that just received the AdC-gDN vaccines showed only marginal lessening of symptoms compared to control animals. These results indicate that immune response to the N protein that is less variable than the S protein may potentiate and prolong protection achieved by the currently used S protein based genetic COVID-19 vaccines.

Caffeic Acid Phenethyl Ester Attenuates Dextran Sulfate Sodium-Induced Ulcerative Colitis Through Modulation of NF-κB and Cell Adhesion Molecules.

Ulcerative colitis (UC) is a serious health condition and defined as inflammation in the colon. Untreated, UC can develop into colitis-associated cancer (CAC), for which effective medicines are not available. Natural products are a better choice to treat UC by alleviating the inflammation. Caffeic acid phenethyl ester (CAPE) is a phenolic compound and known for its beneficial effects, including antibacterial, anti-inflammatory, anti-diabetic, and anticancer. We aimed to study the effect of CAPE on dextran sulfate sodium (DSS)-induced UC in mouse model. Administration of CAPE to DSS-induced mice protected against colon damage by improving body weight of mice, reducing the weight of spleen, and increased colon length. In addition, administration of CAPE resulted reduced the activity of myeloperoxidase (MPO) and CD68+ positive cells. Furthermore, a significant decrease in the production of key cytokines and the expression of nuclear factor (p65-NF)-κB. Moreover, p65-NF-κB activation was reduced in lipopolysaccharide (LPS)-treated RAW 264.7 macrophage cells from mouse origin. CAPE treatment leads to the reduced expressions of intercellular adhesion molecules (ICAM)-1 and vascular cell adhesion molecules (VCAM), both are key cell adhesion molecules. The results of this study clearly indicate that CAPE can potentially control inflammation in the colon and can be used as a therapy for UC.

Hepatitis B virus polymerase-specific T cell epitopes shift in a mouse model of chronic infection.

BACKGROUND: Chronic hepatitis B virus (HBV) infection (CHB) is a significant public health problem that could benefit from treatment with immunomodulators. Here we describe a set of therapeutic HBV vaccines that target the internal viral proteins. METHODS: Vaccines are delivered by chimpanzee adenovirus vectors (AdC) of serotype 6 (AdC6) and 7 (AdC7) used in prime only or prime-boost regimens. The HBV antigens are fused into an early T cell checkpoint inhibitor, herpes simplex virus (HSV) glycoprotein D (gD), which enhances and broadens vaccine-induced cluster of differentiation (CD8)+ T cell responses. RESULTS: Our results show that the vaccines are immunogenic in mice. They induce potent CD8+ T cell responses that recognize multiple epitopes. CD8+ T cell responses increase after a boost, although the breadth remains similar. In mice, which carry high sustained loads of HBV particles due to a hepatic infection with an adeno-associated virus (AAV)8 vector expressing the 1.3HBV genome, CD8+ T cell responses to the vaccines are attenuated with a marked shift in the CD8+ T cells' epitope recognition profile. CONCLUSIONS: Our data show that in different stains of mice including those that carry a human major histocompatibility complex (MHC) class I antigen HBV vaccines adjuvanted with a checkpoint inhibitor induce potent and broad HBV-specific CD8+ T cell responses and lower but still detectable CD4+ T cell responses. CD8+ T cell responses are reduced and their epitope specificity changes in mice that are chronically exposed to HBV antigens. Implications for the design of therapeutic HBV vaccines are discussed.

T cell responses to adenoviral vectors expressing the SARS-CoV-2 nucleoprotein.

SARS-CoV-2 vaccines aim to protect against COVID-19 through neutralizing antibodies against the viral spike protein. Mutations within the spike's receptor-binding domain may eventually reduce vaccine efficacy, necessitating periodic updates. Vaccine-induced immunity could be broadened by adding T cell-inducing antigens such as SARS-CoV-2's nucleoprotein (N). Here we describe two replication-defective chimpanzee adenovirus (AdC) vectors from different serotypes expressing SARS-CoV-2 N either in its wild-type form or fused into herpes simplex virus glycoprotein D (gD), an inhibitor of an early T cell checkpoint. The vaccines induce potent and sustained CD8+ T cell responses that are broadened upon inclusion of gD. Depending on the vaccine regimen booster immunizations increase magnitude and breadth of T cell responses. Epitopes that are recognized by the vaccine-induced T cells are highly conserved among global SARS-CoV-2 isolates indicating that addition of N to COVID-19 vaccines may lessen the risk of loss of vaccine-induced protection due to variants.

The role of miRNAs 34a, 146a, 320a and 542 in the synergistic anticancer effects of methyl 2-(5-fluoro-2-hydroxyphenyl)-1H- benzo[d]imidazole-5-carboxylate (MBIC) with doxorubicin in breast cancer cells.

Combination Index (CI) analysis suggested that MBIC and doxorubicin synergistically inhibited up to 97% of cell proliferation in ER+/PR+MCF-7 and triple negative MDA-MB-231 breast cancer cell lines. Moreover, treatment of the breast cancer cells with the combined drugs resulted in lower IC50 values in contrast to the individual drug treatment. Small noncoding microRNAs (miRNA) may function as non-mutational gene regulators at post-transcriptional level of protein synthesis. In the present study, the effect of the combined treatment of MBIC and doxorubicin on the expression level of several miRNAs including miR-34a, miR-146a, miR-320a and miR-542 were evaluated in MCF-7 and MDA-MB-231 breast cancer cell lines. These miRNAs have the potential to alter the protein level of survivin, the anti-apoptotic protein and reduce the metastatic activity in human breast cancer cell lines by interfering with the nuclear accumulation of NF-κB. Our results demonstrated the several fold changes in expression of miRNAs, which is drug and cell line dependent. This finding demonstrated a functional synergistic network between miR-34a, miR-320a and miR-542 that are negatively involved in post-transcriptional regulation of survivin in MCF-7 cells. While in MDA-MB-231 cells, changes in expression level of miR-146a was correlated with inhibition of the nuclear translocation of NF-κB. The overall result suggested that alteration in protein level and location of survivin and NF-κB by miR-34a, miR-320a, miR-146a and miR-542, remarkably influenced the synergistic enhancement of combined MBIC and doxorubicin in treatment of aggressive and less aggressive human breast cancer cell lines.

Activation of autophagy by stress-activated signals as a cellular self-defense mechanism against the cytotoxic effects of MBIC in human breast cancer cells in vitro.

We recently reported that methyl 2-(-5-fluoro-2-hydroxyphenyl)-1H-benzo[d]imidazole-5-carboxylate (MBIC) is a microtubule targeting agent (MTA) with multiple mechanisms of action including apoptosis in two human breast cancer cell-lines MCF-7 and MDA-MB-231. In the present study, investigation of early molecular events following MBIC treatment demonstrated the induction of autophagy. This early (<24 h) response to MBIC was characterized by accumulation of autophagy markers; LC3-II, Beclin1, autophagic proteins (ATGs) and collection of autophagosomes but with different variations in the two cell-lines. MBIC-induced autophagy was associated with generation of reactive oxygen species (ROS). In parallel, an increased activation of SAPK/JNK pathway was detected, as an intersection of ROS production and induction of autophagy. The cytotoxic effect of MBIC was enhanced by inhibition of autophagy through blockage of SAPK/JNK signaling, suggesting that MBIC-induced autophagy, is a possible cellular self-defense mechanism against toxicity of this agent in both breast cancer cell-lines. The present findings suggest that inhibition of autophagy eliminates the cytoprotective activity of MDA-MB-231 and MCF-7 cells, and sensitizes both the aggressive and non-aggressive human breast cancer cell-lines to the cytotoxic effects of MBIC.

Modulation of oncogenic transcription factors by bioactive natural products in breast cancer.

Carcinogenesis, a multi-step phenomenon, characterized by alterations at genetic level and affecting the main intracellular pathways controlling cell growth and development. There are growing number of evidences linking oncogenes to the induction of malignancies, especially breast cancer. Modulations of oncogenes lead to gain-of-function signals in the cells and contribute to the tumorigenic phenotype. These signals yield a large number of proteins that cause cell growth and inhibit apoptosis. Transcription factors such as STAT, p53, NF-κB, c-JUN and FOXM1, are proteins that are conserved among species, accumulate in the nucleus, bind to DNA and regulate the specific genes targets. Oncogenic transcription factors resulting from the mutation or overexpression following aberrant gene expression relay the signals in the nucleus and disrupt the transcription pattern. Activation of oncogenic transcription factors is associated with control of cell cycle, apoptosis, migration and cell differentiation. Among different cancer types, breast cancer is one of top ten cancers worldwide. There are different subtypes of breast cancer cell-lines such as non-aggressive MCF-7 and aggressive and metastatic MDA-MB-231 cells, which are identified with distinct molecular profile and different levels of oncogenic transcription factor. For instance, MDA-MB-231 carries mutated and overexpressed p53 with its abnormal, uncontrolled downstream signalling pathway that account for resistance to several anticancer drugs compared to MCF-7 cells with wild-type p53. Appropriate enough, inhibition of oncogenic transcription factors has become a potential target in discovery and development of anti-tumour drugs against breast cancer. Plants produce diverse amount of organic metabolites. Universally, these metabolites with biological activities are known as "natural products". The chemical structure and function of natural products have been studied since 1850s. Investigating these properties leaded to recognition of their molecular effects as anticancer drugs. Numerous natural products extracted from plants, fruits, mushrooms and mycelia, show potential inhibitory effects against several oncogenic transcription factors in breast cancer. Natural compounds that target oncogenic transcription factors have increased the number of candidate therapeutic agents. This review summarizes the current findings of natural products in targeting specific oncogenic transcription factors in breast cancer.

Mechanisms of the anti-tumor activity of Methyl 2-(-5-fluoro-2-hydroxyphenyl)-1 H-benzo[d]imidazole-5-carboxylate against breast cancer in vitro and in vivo.

Microtubule Targeting Agents (MTAs) induce cell death through mitotic arrest, preferentially affecting rapidly dividing cancer cells over slowly proliferating normal cells. Previously, we showed that Methyl 2-(-5-fluoro-2-hydroxyphenyl)-1H-benzo[d]imidazole-5-carboxylate (MBIC) acts as a potential MTA. In this study, we demonstrated that MBIC exhibits greater toxicity towards non-aggressive breast cancer cell-line, MCF-7 (IC50 = 0.73 ± 0.0 µM) compared to normal fibroblast cell-line, L-cells (IC50 = 59.6 ± 2.5 µM). The IC50 of MBIC against the aggressive breast cancer cell-line, MDA-MB-231 was 20.4 ± 0.2 µM. We hypothesized that the relatively high resistance of MDA-MB-231 cells to MBIC is associated with p53 mutation. We investigated p53 and three of its downstream proteins: survivin, cyclin dependent kinase (Cdk1) and cyclin B1. Following treatment with MBIC, survivin co-immunoprecipitated with caspases with higher affinity in MDA-MB-231 compared to MCF-7 cells. Furthermore, silencing survivin caused a 4.5-fold increase in sensitivity of MDA-MB-231 cells to MBIC (IC50 = 4.4 ± 0.3). In addition, 4 weeks of MBIC administration in MDA-MB-231 cells inoculated BALB/c nude mice resulted in 79.7% reduction of tumor volume compared to the untreated group with no severe sign of toxicity. Our results demonstrated MBIC has multiple anti-tumor actions and could be a potential drug in breast cancer therapy.

Phytometabolites Targeting the Warburg Effect in Cancer Cells: A Mechanistic Review.

Phytometabolites are functional elements derived from plants and most of them exhibit therapeutic characteristics such as anti-cancer, anti-inflammatory and anti-oxidant effects. Phytometabolites exert their anti-cancer effect by targeting multiple signaling pathways. One of the remarkable phenomena targeted by phytometabolites is the Warburg effect. The Warburg effect describes the observation that cancer cells exhibit an increased rate of glycolysis and aberrant redox activity compared to normal cells. This phenomenon promotes further cancer development and progression. Recent observations revealed that some phytometabolites could target metabolic-related enzymes (e.g. Hexokinase, Pyruvate kinase M2, HIF-1) in cancer cells, with little or no harm to normal cells. Since hyper-proliferation of cancer cells is fueled by higher cellular metabolism, phytometabolites targeting these metabolic pathways can create synergistic crosstalk with induced apoptotic pathways and sensitize cancer cells to chemotherapeutic agents. In this review, we discuss phytometabolites that target the Warburg effect and the underlying molecular mechanism that leads to tumor growth suppression.

Targeting of tubulin polymerization and induction of mitotic blockage by Methyl 2-(5-fluoro-2-hydroxyphenyl)-1H-benzo[d]imidazole-5-carboxylate (MBIC) in human cervical cancer HeLa cell.

BACKGROUND: Microtubule Targeting Agents (MTAs) including paclitaxel, colchicine and vinca alkaloids are widely used in the treatment of various cancers. As with most chemotherapeutic agents, adverse effects and drug resistance are commonly associated with the clinical use of these agents. Methyl 2-(5-fluoro-2-hydroxyphenyl)-1H- benzo[d]imidazole-5-carboxylate (MBIC), a benzimidazole derivative displays greater toxicity against various cancer compared to normal human cell lines. The present study, focused on the cytotoxic effects of MBIC against HeLa cervical cancer cells and possible actions on the microtubule assembly. METHODS: Apoptosis detection and cell-cycle assays were performed to determine the type of cell death and the phase of cell cycle arrest in HeLa cells. Tubulin polymerization assay and live-cell imaging were performed to visualize effects on the microtubule assembly in the presence of MBIC. Mitotic kinases and mitochondrial-dependent apoptotic proteins were evaluated by Western blot analysis. In addition, the synergistic effect of MBIC with low doses of selected chemotherapeutic actions were examined against the cancer cells. RESULTS: Results from the present study showed that following treatment with MBIC, the HeLa cells went into mitotic arrest comprising of multi-nucleation and unsegregated chromosomes with a prolonged G2-M phase. In addition, the HeLa cells showed signs of mitochondrial-dependant apoptotic features such as the release of cytochrome c and activation of caspases. MBIC markedly interferes with tubulin polymerization. Western blotting results indicated that MBIC affects mitotic regulatory machinery by up-regulating BubR1, Cyclin B1, CDK1 and down-regulation of Aurora B. In addition, MBIC displayed synergistic effect when given in combination with colchicine, nocodazole, paclitaxel and doxorubicin. CONCLUSION: Taken together, our study demonstrated the distinctive microtubule destabilizing effects of MBIC against cervical cancer cells in vitro. Besides that, MBIC exhibited synergistic effects with low doses of selected anticancer drugs and thus, may potentially reduce the toxicity and drug resistance to these agents.

Boldine suppresses dextran sulfate sodium-induced mouse experimental colitis: NF-κB and IL-6/STAT3 as potential targets.

Ulcerative colitis (UC) is a nonspecific inflammatory disorder characterized by oxidative and nitrosative stress, leucocyte infiltration, and upregulation of inflammatory mediators. Boldine is an alkaloid compound found in Boldo tree, with multiple pharmacological actions, mainly anti-inflammatory, antioxidant, antitumor, and immunomodulatory activities. Hence, the effect of boldine for its anti-inflammatory properties against dextran sulfate sodium (DSS)-induced UC in BALB/c mice was studied. Administration of boldine to DSS-induced mice protects colon damage by reduced disease activity index, spleen weight, and increased colon length. Also administration of boldine showed a reduction in the activity of myeloperoxidase (MPO) and CD 68+ expression. Boldine reduced the colon damage, with significant reductions in both the extent and the severity of the inflammation as well as in crypt damage and leukocyte infiltration in the mucosa. Analysis in vivo showed clear decrease in the production of tumor necrosis factor (TNF)-α, Interleukin (IL)-6, IL-17, and signal transducer and activator of transcription-(p-STAT3)(Y705) with nuclear factor (p65-NF-κB) production being reduced significantly. Moreover, p65-NF-κB activation was reduced in mouse macrophage RAW 264.7 cells in vitro. The data demonstrated that boldine may be beneficial in colitis through selective immunomodulatory effects, which may be mediated, at least in part, by inhibition of p65-NF-κB and STAT3 signaling pathways. © 2016 BioFactors, 42(3):247-258, 2016.

The gastroprotective effects of hydroalcoholic extract of Monolluma quadrangula against ethanol-induced gastric mucosal injuries in Sprague Dawley rats.

Monolluma quadrangula (Forssk.) Plowes is used in Saudi traditional medicines to treat gastric ulcers. The hydroalcoholic extract of M. quadrangula (MHAE) was used in an in vivo model to investigate its gastroprotective effects against ethanol-induced acute gastric lesions in rats. Five groups of Sprague Dawley rats were used. The first group was treated with 10% Tween 20 as a control. The other four groups included rats treated with absolute ethanol (5 mL/kg) to induce an ulcer, rats treated with 20 mg/kg omeprazole as a reference drug, and rats treated with 150 or 300 mg/kg MHAE. One hour later, the rats were administered absolute ethanol (5 mL/kg) orally. Animals fed with MHAE exhibited a significantly increased pH, gastric wall mucus, and flattening of the gastric mucosa, as well as a decreased area of gastric mucosal damage. Histology confirmed the results; extensive destruction of the gastric mucosa was observed in the ulcer control group, and the lesions penetrated deep into the gastric mucosa with leukocyte infiltration of the submucosal layer and edema. However, gastric protection was observed in the rats pre-fed with plant extracts. Periodic acid-Schiff staining of the gastric wall revealed a remarkably intensive uptake of magenta color in the experimental rats pretreated with MHAE compared to the ulcer control group. Immunohistochemistry staining revealed an upregulation of the Hsp70 protein and a downregulation of the Bax protein in rats pretreated with MHAE compared with the control rats. Gastric homogenate showed significantly increased catalase and superoxide dismutase, and the level of malondialdehyde (MDA) was reduced in the rats pretreated with MHAE compared to the control group. In conclusion, MHAE exhibited a gastroprotective effect against ethanol-induced gastric mucosal injury in rats. The mechanism of this gastroprotection included an increase in pH and gastric wall mucus, an increase in endogenous enzymes, and a decrease in the level of MDA. Furthermore, protection was given through the upregulation of Hsp70 and the downregulation of Bax proteins.

Forkhead Box Transcription Factor (FOXO3a) mediates the cytotoxic effect of vernodalin in vitro and inhibits the breast tumor growth in vivo.

BACKGROUND: Natural compounds have been demonstrated to lower breast cancer risk and sensitize tumor cells to anticancer therapies. Recently, we demonstrated that vernodalin (the active constituent of the medicinal herb Centratherum anthelminticum seeds) induces apoptosis in breast cancer cell-lines. The aim of this work was to gain an insight into the underlying anticancer mechanism of vernodalin using in vitro and in vivo model. METHODS: Vernodalin was isolated through the bioassay guided fractionation from the seeds. The protein expression of p-Akt, PI3K, FOXO3a, Bim, p27kip1, cyclinD1, and cyclinE was examined by the Western blot analysis. Immunoprecipitation assays were performed to analyse Akt kinase activity. Small interfering RNA (siRNA) was used to study the role of FOXO3a upregulation and their targets during vernodalin treatment. Immunofluorescence, subcellular localisation of FOXO3a by Western blot was performed to analyse FOXO3a localisation in nucleus of breast cancer cells. Immunohistochemical analysis of PCNA, Ki67, p27kip1, FOXO3a and p-FOXO3a in the LA7-induced mammary gland tumor model was performed. RESULTS: Our results showed that vernodalin regulates cancer cell apoptosis through activation of FOXO transcription factors and its downstream targets (Bim, p27Kip1, p21Waf1/cip1, cyclin D1, cyclin E) as examined by Western blots. Furthermore, we showed that FOXO3a/PI3K-Akt played a significant role in vernodalin induced apoptosis in breast cancer cells. Immunoprecipitation assays showed Akt kinase activity was downregulated. Immunofluorescence, subcellular fractionation and Western blot showed FOXO3a accumulation in the nucleus of breast cancer cells after vernodalin treatment. Silencing of FOXO3a protected breast cancer cells against vernodalin induced apoptosis. The anti-tumor action of vernodalin was further confirmed by examining cell proliferative markers, PCNA and Ki67 in the LA7-induced mammary gland tumor model. We also corroborated our findings in vivo by showing upregulation of p27Kip1, FOXO3a and decrease in the p-FOXO3a level in vernodalin-treated breast tumor tissue. CONCLUSIONS: Our results suggest that PI3K-Akt/FOXOa pathway is a critical mediator of vernodalin-induced cytotoxicity and this compound could be further developed as a potential chemopreventive or chemotherapeutic agent for breast cancer therapy.

The chemopreventive potential of Curcuma purpurascens rhizome in reducing azoxymethane-induced aberrant crypt foci in rats.

Curcuma purpurascens BI. rhizome, a member of the Zingiberaceae family, is a popular spice in Indonesia that is traditionally used in assorted remedies. Dichloromethane extract of C. purpurascens BI. rhizome (DECPR) has previously been shown to have an apoptosis-inducing effect on colon cancer cells. In the present study, we examined the potential of DECPR to prevent colon cancer development in rats treated with azoxymethane (AOM) (15 mg/kg) by determining the percentage inhibition in incidence of aberrant crypt foci (ACF). Starting from the day immediately after AOM treatment, three groups of rats were orally administered once a day for 2 months either 10% Tween 20 (5 mL/kg, cancer control), DECPR (250 mg/kg, low dose), or DECPR (500 mg/kg, high dose). Meanwhile, the control group was intraperitoneally injected with 5-fluorouracil (35 mg/kg) for 5 consecutive days. After euthanizing the rats, the number of ACF was enumerated in colon tissues. Bax, Bcl-2, and proliferating cell nuclear antigen (PCNA) protein expressions were examined using immunohistochemical and Western blot analyses. Antioxidant enzymatic activity was measured in colon tissue homogenates and associated with malondialdehyde level. The percentage inhibition of ACF was 56.04% and 68.68% in the low- and high-dose DECPR-treated groups, respectively. The ACF inhibition in the treatment control group was 74.17%. Results revealed that DECPR exposure at both doses significantly decreased AOM-induced ACF formation, which was accompanied by reduced expression of PCNA. Upregulation of Bax and downregulation of Bcl-2 suggested the involvement of apoptosis in the chemopreventive effect of DECPR. In addition, the oxidative stress resulting from AOM treatment was significantly attenuated after administration of DECPR, which was shown by the elevated antioxidant enzymatic activity and reduced malondialdehyde level. Taken together, the present data clearly indicate that DECPR significantly inhibits ACF formation in AOM-treated rats and may offer protection against colon cancer development.

Synthesis, characterization and apoptotic activity of quinazolinone Schiff base derivatives toward MCF-7 cells via intrinsic and extrinsic apoptosis pathways.

The current study investigated the cytotoxic effect of 3-(5-chloro-2-hydroxybenzylideneamino)-2-(5-chloro-2-hydroxyphenyl)-2,3-dihydroquinazolin-41(H)-one (A) and 3-(5-nitro-2-hydroxybenzylideneamino)-2-(5-nitro-2-hydroxyphenyl)-2,3-dihydroquinazolin-4(1H)-one (B) on MCF-7, MDA-MB-231, MCF-10A and WRL-68 cells. The mechanism involved in apoptosis was assessed to evaluate the possible pathways induced by compound A and B. MTT assay results using A and B showed significant inhibition of MCF-7 cell viability, with IC50 values of 3. 27 ± 0.171 and 4.36 ± 0.219 µg/mL, respectively, after a 72 hour treatment period. Compound A and B did not demonstrate significant cytotoxic effects towards MDA-MB-231, WRL-68 and MCF-10A cells. Acute toxicity tests also revealed an absence of toxic effects on mice. Fluorescent microscopic studies confirmed distinct morphological changes (membrane blebbing and chromosome condensation) corresponding to typical apoptotic features in treated MCF-7 cells. Using Cellomics High Content Screening (HCS), we found that compound A and B could trigger the release of cytochrome c from mitochondria to the cytosol. The release of cytochrome c activated the expression of caspases-9 and then stimulated downstream executioner caspase-3/7. In addition, caspase-8 showed remarkable activity, followed by inhibition of NF-κB activation in A-and B-treated MCF-7 cells. The results indicated that A and B could induce apoptosis via a mechanism that involves either extrinsic or intrinsic pathways.

(6E,10E) Isopolycerasoidol and (6E,10E) Isopolycerasoidol Methyl Ester, Prenylated Benzopyran Derivatives from Pseuduvaria monticola Induce Mitochondrial-Mediated Apoptosis in Human Breast Adenocarcinoma Cells.

Phytochemicals from Pseuduvaria species have been reported to display a wide range of biological activities. In the present study, a known benzopyran derivative, (6E,10E) isopolycerasoidol (1), and a new benzopyran derivative, (6E,10E) isopolycerasoidol methyl ester (2), were isolated from a methanol extract of Pseuduvaria monticola leaves. The structures of the isolated compounds were elucidated by spectroscopic methods including 1D and 2D NMR, IR, UV, and LCMS-QTOF, and by comparison with previously published data. The anti-proliferative and cytotoxic effects of these compounds on human breast cancer cell-lines (MCF-7 and MDA-MB-231) and a human normal breast epithelial cell line (MCF-10A) were investigated. MTT results revealed both (1) and (2) were efficient in reducing cell viability of breast cancer cells. Flow cytometry analysis demonstrated that (1) and (2) induced cell death via apoptosis, as demonstrated by an increase in phosphotidylserine exposure. Both compounds elevated ROS production, leading to reduced mitochondrial membrane potential and increased plasma membrane permeability in breast cancer cells. These effects occurred concomitantly with a dose-dependent activation of caspase 3/7 and 9, a down-regulation of the anti-apoptotic gene BCL2 and the accumulation of p38 MAPK in the nucleus. Taken together, our data demonstrate that (1) and (2) induce intrinsic mitochondrial-mediated apoptosis in human breast cancer cells, which provides the first pharmacological evidence for their future development as anticancer agents.