Autocrine phosphatase PDP2 inhibits ferroptosis by dephosphorylating ACSL4 in the Luminal A Breast Cancer

Phosphatases can dephosphorylate phosphorylated kinases, leading to their inactivation, and ferroptosis is a type of cell death. Therefore, our aim is to identify phosphatases associated with ferroptosis by analyzing the differentially expressed genes (DEGs) of the Luminal A Breast Cancer (LumABC) cohort from the Cancer Genome Atlas (TCGA). An analysis of 260 phosphatase genes from the GeneCard database revealed that out of the 28 DEGs with high expression, only the expression of pyruvate dehydrogenase phosphatase 2 (PDP2) had a significant correlation with patient survival. In addition, an analysis of DEGs using gene ontology, Kyoto Encyclopedia of Genes and Genomes and gene set enrichment analysis revealed a significant variation in the expression of ferroptosis-related genes. To further investigate this, we analyzed 34 ferroptosis-related genes from the TCGA-LumABC cohort. The expression of long-chain acyl-CoA synthetase 4 (ACSL4) was found to have the highest correlation with the expression of PDP2, and its expression was also inversely proportional to the survival rate of patients. Western blot experiments using the MCF-7 cell line showed that the phosphorylation level of ACSL4 was significantly lower in cells transfected with the HA-PDP2 plasmid, and ferroptosis was correspondingly reduced (p < 0.001), as indicated by data from flow cytometry detection of membrane-permeability cell death stained with 7-aminoactinomycin, lipid peroxidation, and Fe2+. Immunoprecipitation experiments further revealed that the phosphorylation level of ACSL4 was only significantly reduced in cells where PDP2 and ACSL4 co-precipitated. These findings suggest that PDP2 may act as a phosphatase to dephosphorylate and inhibit the activity of ACSL4, which had been phosphorylated and activated in LumABC cells. Further experiments are needed to confirm the molecular mechanism of PDP2 inhibiting ferroptosis.

Gankyrin inhibits ferroptosis through the p53/SLC7A11/GPX4 axis in triple-negative breast cancer cells

Gankyrin is found in high levels in triple-negative breast cancer (TNBC) and has been established to form a complex with the E3 ubiquitin ligase MDM2 and p53, resulting in the degradation of p53 in hepatocarcinoma cells. Therefore, this study sought to determine whether gankyrin could inhibit ferroptosis through this mechanism in TNBC cells. The expression of gankyrin was investigated in relation to the prognosis of TNBC using bioinformatics. Co-immunoprecipitation and GST pull-down assays were then conducted to determine the presence of a gankyrin and MDM2 complex. RT-qPCR and immunoblotting were used to examine molecules related to ferroptosis, such as gankyrin, p53, MDM2, SLC7A11, and GPX4. Additionally, cell death was evaluated using flow cytometry detection of 7-AAD and a lactate dehydrogenase release assay, as well as lipid peroxide C11-BODIPY. Results showed that the expression of gankyrin is significantly higher in TNBC tissues and cell lines, and is associated with a poor prognosis for patients. Subsequent studies revealed that inhibiting gankyrin activity triggered ferroptosis in TNBC cells. Additionally, silencing gankyrin caused an increase in the expression of the p53 protein, without altering its mRNA expression. Co-immunoprecipitation and GST pull-down experiments indicated that gankyrin and MDM2 form a complex. In mouse embryonic fibroblasts lacking both MDM2 and p53, this gankyrin/MDM2 complex was observed to ubiquitinate p53, thus raising the expression of molecules inhibited by ferroptosis, such as SLC7A11 and GPX4. Furthermore, silencing gankyrin in TNBC cells disrupted the formation of the gankyrin/MDM2 complex, hindered the degradation of p53, increased SLC7A11 expression, impeded cysteine uptake, and decreased GPX4 production. Our findings suggest that TNBC cells are able to prevent cell ferroptosis through the gankyrin/p53/SLC7A11/GPX4 signaling pathway, indicating that gankyrin may be a useful biomarker for predicting TNBC prognosis or a potential therapeutic target.

3'-epi-12β-hydroxyfroside-mediated autophagy degradation of RIPK1/RIPK3 necrosomes leads to anergy of immunogenic cell death in triple-negative breast cancer cells

Increasing studies have suggested that some cardiac glycosides, such as conventional digoxin (DIG) and digitoxin, can induce immunogenic cell death (ICD) in various tumors. We previously found that 3'-epi-12β-hydroxyfroside (HyFS), a novel cardenolide compound isolated by our group, could induce cytoprotective autophagy through inactivation of the Akt/mTOR pathway. However, whether HyFS can induce ICD remains unknown. In this study, we extend our work to further investigate whether HyFS could induce both autophagy and ICD, and we investigated the relationship between autophagy and ICD in three TNBC cell lines. Unexpectedly, compared to DIG, we found that HyFS could induce complete autophagy flux but not ICD in three human triple-negative breast cancer (TNBC) cell lines and one murine TNBC model. Inhibition of HyFS-induced autophagy resulted in the production of ICD in TNBC MDA-MB-231, MDA-MB-436, and HCC38 cells. A further mechanism study showed that formation of RIPK1/RIPK3 necrosomes was necessary for ICD induction in DIG-treated TNBC cells, while HyFS treatment led to receptor-interacting serine-threonine kinase (RIPK)1/3 necrosome degradation via an autophagy process. Additionally, inhibition of HyFS-induced autophagy by the autophagy inhibitor chloroquine resulted in the reoccurrence of ICD and reversion of the tumor microenvironment, leading to more significant antitumor effects in immunocompetent mice than in immunodeficient mice. These findings indicate that HyFS-mediated autophagic degradation of RIPK1/RIPK3 necrosomes leads to inactivation of ICD in TNBC cells. Moreover, combined treatment with HyFS and an autophagy inhibitor may enhance the antitumor activities, suggesting an alternative therapeutic for TNBC treatment.

Immunotherapy combining tumor and endothelium cell lysis with immune enforcement by recombinant MIP-3α Newcastle disease virus in a vessel-targeting liposome enhances antitumor immunity

Background

Several agents for oncolytic immunotherapy have been approved for clinical use, but monotherapy is modest for most oncolytic agents. The combination of several therapeutic strategies through recombinant and nanotechnology to engineer multifunctional oncolytic viruses for oncolytic immunotherapy is a promising strategy.

Methods

An endothelium-targeting iRGD-liposome encapsulating a recombinant Newcastle disease virus (NDV), which expresses the dendritic cell (DC) chemokine MIP-3α (iNDV3α-LP), and three control liposomes were constructed. MIP-3α, HMGB1, IgG, and ATP were detected by western blotting or ELISA. The chemotaxis of DCs was examined by Transwell chambers. The phenotypes of the immune cells were analyzed by flow cytometry. The antitumor efficiency was investigated in B16 and 4T1 tumor-bearing mice. Immunofluorescence and immunohistochemistry were used to observe the localization of liposomes, molecular expression and angiogenesis. Synergistic index was calculated using the data of tumor volume, tumor angiogenesis and tumor-infiltrating lymphocytes.

Results

Compared with NDV-LP, treatment with iNDV3α-LP and NDV3α-LP induced stronger virus replication and cell lysis in B16 and 4T1 tumor cells and human umbilical vein endothelial cells (HUVECs) with the best response observed following iNDV3α-LP treatment. B16 and 4T1 cells treated with iNDV3α-LP produced more damage-associated molecular pattern molecules, including secreted HMGB1, ATP, and calreticulin. Moreover, iNDV3α-LP specifically bound to αvβ3-expressing 4T1 cells and HUVECs and to tumor neovasculature. Tumor growth was significantly suppressed, and survival was longer in iNDV3α-LP-treated B16-bearing and 4T1-bearing mice. A mechanism study showed that iNDV3α-LP treatment initiated the strongest tumor-specific cellular and humoral immune response. Moreover, iNDV3α-LP treatment could significantly suppress tumor angiogenesis and reverse the tumor immune suppressive microenvironment in both B16-bearing and 4T1-bearing mice.

Conclusions

In this study, iNDV3α-LP had several functions, such as tumor and vessel lysis, MIP-3α immunotherapy, and binding to αvβ3-expressing tumor and its neovasculature. iNDV3α-LP treatment significantly suppressed tumor angiogenesis and reversed the tumor immunosuppressive microenvironment. These findings offer a strong rationale for further clinical investigation into a combination strategy for oncolytic immunotherapy, such as the formulation iNDV3α-LP in this study.

A recombinant oncolytic Newcastle virus expressing MIP-3α promotes systemic antitumor immunity

BACKGROUND

The oncolytic Newcastle disease virus (NDV) is inherently able to trigger the lysis of tumor cells and induce the immunogenic cell death (ICD) of tumor cells and is also an excellent gene-engineering vector. The macrophage inflammatory protein-3α (MIP-3α) is a specific chemokine for dendritic cells (DCs). Thus, we constructed a recombinant NDV expressing MIP-3α (NDV-MIP3α) as an in vivo DC vaccine for amplifying antitumor immunities.

METHODS

The recombinant NDV-MIP3α was constructed by the insertion of MIP-3α cDNA between the P and M genes. Western blotting assay and ELISA were used to detect MIP-3α, HMGB1, IgG, and ATP in the supernatant and sera. The chemotaxis of DCs was examined by Transwell chambers. The phenotypes of the immune cells (eg, DCs) were analyzed by flow cytometry. The antitumor efficiency of NDV-MIP3α was observed in B16 and CT26 tumor-bearing mice. Immunofluorescence and immunohistochemistry were applied to observe the ecto-calreticulin (CRT) and intratumoral attraction of DCs. Adoptive transfer of splenocytes and antibodies and depletion of T-cell subsets were used to evaluate the relationship between antitumor immunities and the role of the T-cell subtype.

RESULTS

The findings show that NDV-MIP3α has almost the same capabilities of tumor lysis and induction of ICD as the wild-type NDV (NDV-WT). MIP-3α secreted by NDV-MIP3α could successfully attract DCs in vitro and in vivo. Both B16 and CT26 cells infected with NDV-MIP3α could strongly promote DC maturation and activation. Compared with NDV-WT, intratumoral injection of NDV-MIP3α and the adoptive transfer of T lymphocytes from mice injected with NDV-MIP3α resulted in a significant suppression of B16 and CT26 tumor growth. The NDV-MIP3α-induced production of tumor-specific cellular and humoral immune responses was dependent on CD8⁺ T cells and partially on CD4⁺ T cells. A significant reversion of tumor microenvironments was found in the mice injected with NDV-MIP3α.

CONCLUSIONS

Compared with NDV-WT, the recombinant NDV-MIP3α as an in vivo DC vaccine demonstrates enhanced antitumor activities through the induction of stronger system immunities and modulation of the tumor microenvironment. This strategy may be a potential approach for the generation of an in vivo DC vaccine.

Toxicarioside O Inhibits Cell Proliferation and Epithelial-Mesenchymal Transition by Downregulation of Trop2 in Lung Cancer Cells

Toxicarioside O (TCO), a natural product derived from Antiaris toxicaria, has been identified to be a promising anticancer agent. In this study, we aimed to investigate the effect of TCO on the proliferation and epithelial-mesenchymal transition (EMT) of lung cancer cells and its molecular mechanisms. Here, we indicated that TCO inhibits the proliferation of lung cancer cells both in vitro and in vivo. Our results demonstrated that TCO induces apoptosis in lung cancer cells. Moreover, we found that TCO suppresses EMT program and inhibits cell migration in vitro. Mechanistically, TCO decreases the expression of trophoblast cell surface antigen 2 (Trop2), resulting in inhibition of the PI3K/Akt pathway and EMT program. Overexpression of Trop2 rescues TCO-induced inhibition of cell proliferation and EMT. Our findings demonstrate that TCO markedly inhibits cell proliferation and EMT in lung cancer cells and provides guidance for its drug development.

Association of PRKCA expression and polymorphisms with layer duck eggshell quality

1. Eggshell quality is important for the poultry industry. Calcium is deposited during eggshell formation, and protein kinase C alpha (PRKCA) is involved in transmembrane transport of calcium ions in cells. However, the biological function of PRKCA in poultry is still not understood. Therefore, the aim of this study was to explore the association of mRNA expression and single nucleotide polymorphisms (SNPs) of the PRKCA gene with eggshell quality in laying ducks. 2. The mRNA expression and SNPs of the PRKCA gene were detected by real-time fluorescence quantitative PCR (qRT-PCR) and sequencing of PCR products in 45-week-old female Sansui ducks, which is a high production layer duck breed in China. The association of mRNA expression and SNPs in the PRKCA gene with layer duck eggshell traits was analysed using SPSS (v18.0) software. 3. The results demonstrated that PRKCA mRNA was widely expressed in all examined tissues, and expression was highest in kidney and lowest in the gizzard. Furthermore, the PRKCA mRNA level in uterus was significantly positively correlated with eggshell strength and eggshell weight (P < 0.05). Three novel SNPs, the synonymous mutations of g.9571770 T > C in exon 5, g.9583222 C > T and g.9583227 G > A in exon 7, were found in the PRKCA gene, giving four haplotypes and 10 diplotypes, which affected the mRNA secondary structure and free energy. The g.9583222 C > T and g.9583227 G > A mutations were significantly associated with eggshell strength (P < 0.05). Diplotype H1H1 was advantageous for increasing the strength and thickness of an eggshell. 4. In conclusion, the study showed that the mRNA transcription and genetic variation in the PRKCA gene could significantly affect the strength of duck eggshell and that the PRKCA gene is an important candidate gene for improving eggshell quality in poultry.

Exopolysaccharide from Paecilomyces lilacinus modulates macrophage activities through the TLR4/NF‑κB/MAPK pathway

Multiple exopolysaccharides (EPSs) have been isolated from various organisms in extreme environments and have yielded a variety of activities. The present study evaluated the immunomodulatory capabilities of an EPS (termed PH‑EPS) derived from the fungus Paecilomyces lilacinus PH0016, which was isolated from a tropical and hyperhaline environment in southern China. The macrophage RAW 264.7 cell line was used to investigate the mechanism of PH‑EPS‑induced macrophage activation. The results indicated that RAW 264.7 macrophages were activated by PH‑EPS, in an effect slightly inferior to lipopolysaccharide (LPS), as evidenced by secretion of interleukin (IL)‑1β, tumor necrosis factor (TNF)‑α and nitric oxide (NO), and by significantly increased phagocytosis in the cells treated with PH‑EPS. Nuclear factor (NF)‑κB p65 was significantly translocated into the nucleus in the PH‑EPS‑treated cells. In addition, expression of inducible NO synthase (iNOS) and IκB‑α degradation were enhanced in PH‑EPS‑treated cells. The phosphorylation levels of p38, JNK and ERK were also significantly increased in the PH‑EPS‑treated cells. Furthermore, IL‑1β and TNF‑α production was markedly decreased in PH‑EPS‑treated cells when the mitogen‑activated protein kinase (MAPK) pathways were blocked by the inhibitor Dectin‑1 and by antibodies against Toll‑like receptor 4 (TLR4). The present results indicated that PH‑EPS from Paecilomyces lilacinus possessed the capability of activating RAW 264.7 cells via the TLR4/NF‑κB/MAPKs signaling pathway.

Impaired Autophagic Degradation of Transforming Growth Factor-β-Induced Protein by Macrophages in Lattice Corneal Dystrophy

Purpose

Lattice corneal dystrophy (LCD) is related to the denaturation of transforming growth factor-β-induced protein (TGFBIp). Autophagic degradation of the denatured proteins by macrophages is one pathway to remove the denatured proteins. Thus, we investigated the role of autophagy in the degradation of mutant (MU) TGFBIp in macrophages.

Methods

Corneas from participants were observed by slit-lamp photography and subjected to histopathologic and genetic analysis. Wild-type (WT) and MU TGFBIp were recombined and expressed. Macrophages from MU participants were isolated and cocultured with the recombinant TGFBIp. Colocalization of the two molecules was observed by immunofluorescent microscopy. Enzyme-linked immunosorbent assay, Western blotting, and flow cytometry were used to detect changes in molecule expression related to the phenotype and autophagy process.

Results

Fourteen members from a family of 25 were identified as LCD sufferers. Significant TGFBIp aggregates and macrophage infiltration were found only in the corneas of LCD sufferers. Marker accumulation of TGFBIp was found in macrophages exposed to MU TGFBIp even at 5 hours after MU TGFBIp was withdrawn. High expressions of CD68 and CD36 were found in macrophages exposed to WT TGFBIp, but not to MU TGFBIp. Impaired autophagic flux due to defective autophagosome fusion to lysosomes was found in macrophages exposed to MU TGFBIp. Blockage of the autophagic process suppressed the expression of CD68 and CD36 in macrophages exposed to WT TGFBIp to levels similar to those found in macrophages exposed to MU TGFBIp.

Conclusions

Our results suggested that reversion of the defective autophagic process in macrophages may be a therapeutic strategy for patients with LCD.

Intrinsic, Cancer Cell-Selective Toxicity of Organic Photothermal Nanoagent: A Simple Formulation for Combined Photothermal Chemotherapy of Cancer

Nano-agent-mediated photothermal therapy (PTT) combined with chemotherapy has been proposed as an effective strategy against cancer. However, chemotherapeutic agents often cause serious side effects. Herein, a novel PTT nanoagent (Cy5.5-MSA-G250) with unanticipated intrinsic tumor-selective cytotoxicity is developed. The Cy5.5-MSA-G250 nanoparticles (NPs) are created by mixing mouse serum albumin (MSA) and coomassie brilliant blue (G250) and then conjugated with cyanine 5.5 (Cy5.5). As expected, Cy5.5-MSA-G250 NPs can efficiently kill cancer cells in vitro and in vivo by PTT. Meanwhile, we accidentally discover that Cy5.5-MSA-G250 have intrinsic specific cytotoxicity against tumor cells but not against normal cells. Moreover, the tumor-specific cytotoxicity of Cy5.5-MSA-G250 is much stronger than that of cytarabine, an FDA-approved anticancer drug. In vivo experiments also prove that Cy5.5-MSA-G250 NPs can effectively eliminate residual tumor cells and prevent metastasis. Further study indicates that selective induction of G1 cell cycle arrest and inhibition of DNA duplication in tumor cells may be the possible mechanism of the tumor cell-selective cytotoxicity of Cy5.5-MSA-G250 NPs. In addition, direct visualization, low systematic toxicity, good biodegradation, and efficient body excretion further make Cy5.5-MSA-G250 NPs attractive for in vivo applications. Taken together, Cy5.5-MSA-G250 NPs are proven to be a promising platform for combined photothermal chemotherapy.

PEG-dBSA-RuS1.7 Nanoclusters as a NIR Light and pH Responsive Drug Delivery Nanoplatform for Chemo-Photothermal Synergistic Therapy

A combination of chemotherapy and photothermal therapy has emerged as a promising method of cancer treatment since it can enhance therapeutic efficacies and reduce side effects. Herein, we fabricated doxorubicin (DOX) loaded PEG-dBSA-RuS1.7 which could be used as a synergistic therapeutic nanoplatform. The PEG-dBSA-RuS1.7/DOX nanoparticles exhibit good monodispersity, physiological stability and biocompatibility. Moreover, the prepared PEG-dBSA-RuS1.7/DOX nanoparticles can intelligently release DOX by pH- and NIR-triggered therapy. In comparison with chemotherapy or photothermal treatment alone, the combined therapy shows a better therapeutic effect. We believe that the PEG-dBSA-RuS1.7/DOX can act as an efficient multifunctional nanoplatform for chemophotothermal synergistic cancer therapy.

Induction of enhanced immunogenic cell death through ultrasound-controlled release of doxorubicin by liposome-microbubble complexes

Immunogenic cell death (ICD) is a specific kind of cell death that stimulates the immune system to combat cancer cells. Ultrasound (US)-controlled targeted release of drugs by liposome-microbubble complexes is a promising approach due to its non-invasive nature and visibility through ultrasound imaging. However, it is not known whether this approach can enhance ICD induced by drugs, such as doxorubicin. Herein, we prepared a doxorubicin-liposome-microbubble complex (MbDox), and the resultant MbDox was then characterized and tested for US-controlled release of Dox (MbDox+US treatment) to enhance the induction of ICD in LL/2 and CT26 cancer cells and in syngeneic murine models. We found that MbDox+US treatment caused more cellular uptake and nuclear accumulation of Dox in tumor cells, and more accumulation of Dox in tumor tissues. Enhanced induction of ICD occurred both in vitro and in vivo. MbDox+US treatment induced more apoptosis, stronger membrane exposure and the release of ER stress proteins and DAMPs in tumor cells, and increased DC maturation in vitro. In addition, MbDox+US treatment also resulted in stronger therapeutic effects in immunocompetent mice than in immunodeficient mice. Moreover, MbDox+US enhancement of ICD was also evidenced by a higher proportion of activated CD8⁺ T-lymphocytes but lower Treg in tumor tissues. Taken together, our results demonstrate that US-controlled release of ICD inducers into nuclei using liposome-microbubble complexes may be an effective approach to enhance the induction of ICD for tumor treatment.

Coroglaucigenin induces senescence and autophagy in colorectal cancer cells

OBJECTIVES

Coroglaucigenin (CGN), a natural product isolated from Calotropis gigantean by our research group, has been identified as a potential anti-cancer agent. However, the molecular mechanisms involved remain poorly understood.

MATERIALS AND METHODS

Cell viability and cell proliferation were detected by MTT and BrdU assays. Flow cytometry, SA-β-gal assay, western blotting and immunofluorescence were performed to determine CGN-induced apoptosis, senescence and autophagy. Western blotting, siRNA transfection and coimmunoprecipitation were carried out to investigate the mechanisms of CGN-induced senescence and autophagy. The anti-tumour activities of combination therapy with CGN and chloroquine were observed in mice tumour models.

RESULTS

We demonstrated that CGN inhibits the proliferation of colorectal cancer cells both in vitro and in vivo. We showed that the inhibition of cell proliferation by CGN is independent of apoptosis, but is associated with cell-cycle arrest and senescence in colorectal cancer cells. Notably, CGN induces protective autophagy that attenuates CGN-mediated cell proliferation. Functional studies revealed that CGN disrupts the association of Hsp90 with both CDK4 and Akt, leading to CDK4 degradation and Akt dephosphorylation, eventually resulting in senescence and autophagy, respectively. Combination therapy with CGN and chloroquine resulted in enhanced anti-tumour effects in vivo.

CONCLUSIONS

Our results demonstrate that CGN induces senescence and autophagy in colorectal cancer cells and indicate that combining it with an autophagy inhibitor may be a novel strategy suitable for CGN-mediated anti-cancer therapy.

3'-epi-12β-hydroxyfroside, a new cardenolide, induces cytoprotective autophagy via blocking the Hsp90/Akt/mTOR axis in lung cancer cells

Rationale: Cardenolides have potential as anticancer drugs. 3′-epi-12β-hydroxyfroside (HyFS) is a new cardenolide structure isolated by our research group, but its molecular mechanisms remain poorly understood. This study investigates the relationship between its antitumor activities and autophagy in lung cancer cells.

Methods: Cell growth and proliferation were detected by MTT, lactate dehydrogenase (LDH) release, 5-ethynyl-20-deoxyuridine (EDU) and colony formation assays. Cell apoptosis was detected by flow cytometry. Autophagic and signal proteins were detected by Western blotting. Markers of autophagy and autophagy flux were also detected by immunofluorescence, transmission electron microscopy and acridine orange staining. Real time RT-PCR was used to analyze the gene expression of Hsp90. Hsp90 ubiquitination was detected by coimmunoprecipitation. The antitumore activities of HyFS were observed in nude mice.

Results: HyFS treatment inhibited cell proliferation and induced autophagy in A549 and H460 lung cancer cells, but stronger inhibition of cell proliferation and induction of cell apoptosis were shown when HyFS-mediated autophagy was blocked. The Hsp90/Akt/mTOR axis was found to be involved in the activation of HyFS-mediated autophagy. Evidence of direct interaction between Hsp90 and Akt was observed. HyFS treatment resulted in decreased levels of heat shock protein 90 (Hsp90) and phosphorylated Akt, overexpression of Hsp90 increased activation of autophagy, and inhibition of Hsp90 expression decreased autophagy. In addition, ubiquitin-mediated degradation of Hsp90 and subsequent dephosphorylation of its client protein Akt were also found in HyFS-treated lung cancer cells. Moreover, combination treatment with HyFS and chloroquine showed remarkably increased tumor inhibition in both A549- and H460-bearing mice.

Conclusion: Our results demonstrate that HyFS induced cytoprotective autophagy through ubiquitin-mediated degradation of Hsp90, which further blocked the Akt/mTOR pathway in lung cancer cells. Thus, a combination of a HyFS-like cardenolide and an autophagic inhibitor is a potential alternative approach for the treatment of lung cancer.

Toxicarioside O induces protective autophagy in a sirtuin-1-dependent manner in colorectal cancer cells

Colorectal cancer is the most common cancer. It has high morbidity and mortality worldwide, and more effective treatment strategies need to be developed. Toxicarioside O (TCO), a natural product derived from Antiaris toxicaria, has been shown to be a potential anticancer agent. However, the molecular mechanisms involved remain poorly understood. In this study, our results demonstrated that TCO can induce both apoptosis and autophagy in colorectal cancer cells. Moreover, TCO-induced autophagy was due to the increase of the expression and activity of the enzyme sirtuin-1 (SIRT1), and subsequent inhibition of the Akt/mTOR pathway. Inhibition of SIRT1 activity by its inhibitor, EX-527, attenuated TCO-induced autophagy. Of interest, inhibition of autophagy by chloroguine, an autophagy inhibitor, enhanced TCO-induced apoptotic cell death, suggesting that autophagy plays a protective role in TCO-induced apoptosis. Together, these findings suggest that combination of TCO and autophagy inhibitor may be a novel strategy suitable for potentiating the anticancer activity of TCO for treatment of colorectal cancer.

Penicilazaphilone C, a new antineoplastic and antibacterial azaphilone from the Marine Fungus Penicillium sclerotiorum

Two azaphilonidal derivatives [penicilazaphilones B (1) and C (2)], have been isolated from the fermented products of marine fungus strain Penicillium sclerotiorum M-22, penicilazaphilones C was a new compound. The compound's structures were identified by the analysis of spectroscopic data including 1D and 2D NMR techniques (¹H-NMR, ¹³C-NMR, COSY, HMQC, and HMBC). Biological evaluation revealed that penicilazaphilones B and C showed selective cytotoxicity against melanoma cells B-16 and human gastric cancer cells SGC-7901 with IC₅₀ values of 0.291, 0.449 and 0.065, 0.720 mM, respectively, while exhibiting no significant toxicity to normal mammary epithelial cells M10 at the same concentration. Moreover, penicilazaphilones C also exhibited strong antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia and Escherichia coli with MIC values 0.037-0.150 mM, while penicilazaphilones B's bacteriostatic action was weaker.

Breast Cancer Outcomes as Defined by the Estrogen Receptor, Progesterone Receptor, and Human Growth Factor Receptor-2 in a Multi-ethnic Asian Country

INTRODUCTION

Breast cancer can be divided into four subtypes based on the expressions of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor-2 (HER2). Each subtype has different clinicopathological features and outcomes.

OBJECTIVE

To compare the clinicopathological features and survival of ER and/or PR positive HER2 negative (ER+PR+HER2-, ER+PR-HER2- or ER-PR+HER2-), ER and/or PR positive HER2 positive (ER+PR+HER2+, ER+PR-HER2+ or ER-PR+HER2+), ER negative PR negative HER2 positive (ER-PR-HER2+), and ER negative PR negative HER2 negative (ER-PR-HER2-) subtypes.

METHODS

1957 patients with Stage 1-3 breast carcinoma diagnosed between Jan 2005 and Dec 2011 were categorized into the four subtypes. The clinicopathological features between the subtypes were compared using χ (2) test. Kaplan-Meier analysis was performed to estimate 5-year overall survival. Multivariate Cox regression was used to determine the association between subtypes and mortality adjusted for age, ethnicity, stage, pathological features, and treatment.

RESULTS

ER-PR-HER2+ and ER-PR-HER2- subtypes were associated with younger age, larger tumors, and higher grade. There was no difference in the 5-year survival of the ER-PR-HER2+ and ER-PR-HER2- subtypes (75.1 and 74.4 %, respectively) and survival was poorer than in the ER and/or PR positive HER2 negative and ER and/or PR positive HER2 positive subtypes (87.1 and 83.1 %, respectively). Only 9.5 % of women with HER2 positive breast cancer had access to trastuzumab.

CONCLUSION

In a low resource setting with limited access to trastuzumab, there is no difference in survival between the ER-PR-HER2+ and ER-PR-HER2- subtypes of breast cancer.

Abstract P5-08-39: Low risk of contralateral breast cancer rates in Asian women- A case for not recommending contralateral prophylactic mastectomy

Introduction

The rates of contralateral prophylactic mastectomy (CPM)appears to be higher in the west as compared to the east.1,2There is a suggestion of an improved survival benefit of CPM. 1The trends are increasing in the west and little is known in Asia. In western data a rate of 0.5 to 1% per year is often quoted. However, There is scarcity of epidemiological data on rates of contralateral breast cancer (CBC) in Asia.

Known predictors of CBC in the west include high stage at diagnosis, early age at diagnosis, presence of family history, genetic predisposition, time from first diagnosis and hormone receptor status. Little is known in Asia. Population based registries are not available in Malaysia as in many Southeast Asian countries. This study aims to provide CBC rates to provide evidence for informed decision making of CPM in Asians.

Method

A prospective database of newly diagnosed Stage I and II breastcancer patients diagnosed in University Malaya Medical Centre between 1993 to 2012 were analysed. Data on CBC were obtained from institutional database and medical records. Multivariate analysis used Cox regression was applied to observe for any associations with multiple variables such as age at diagnosis, time from diagnosis, presence of family history, menopausal status, ethnic groups, parity and hormone status.

Results

A total of 3060 Stage I and II patients were prospectively followed up. 127 (4.2%) women developed contralateral breast cancer.At 5 years, 57 (1.9%) and at 10 years, 100(3.4%) developed CBC. Using a multivariate model, the only independent predictor of developing contralateral breast cancer at 5 years was a positive family history OR 1.97(CI 1.02-3.80).

However, at 10 years we found the effect of positive family history diminished OR1.57 (CI 0.94-2.64) and younger women were more likely to develop cancer, those aged 51 to 64 years OR 0.29 (CI 0.11-0.73) , &gt;65 years OR 0.20 (CI 0.07-0.60)compared to those less than 35 years. The other factors in the model were not significant.

Discussion

There is an increasing rate of CPM at 22% from 9% in the west1. A study in Singapore showed a low CPM rate of 1.25%2 . Although uptake of CPM in Asia has not been reported extensively and appears low, the trends may rise and that evidence is needed to counsel patients on the benefits and harms of CPM if patients request for CPM. Given the lower incidence of breast cancer in Malaysia ie 5% average risk compared to 10% in the west, an urgent need to document the risk of contralateral breast cancer, and this data from a single institution is the first to report this rates in Southeast Asia.

Conclusion

The data shows that risk of contralateral breast cancer is low in this Southeast Asian country. Any recommendations or practice of CPM should be dealt with extreme caution.

References

1. Kauffmann R, Nelson R, Smith D, et al: Improved survival with contralateral prophylactic mastectomy. Abstract in 2014 Society of Surgical Oncology Cancer Symposium.

2. Sim Y, Tan VK, Ho GH, Wong CY, Madhukumar P, Tan BK, Yong WS, Ng YY, OngKW.Contralateral prophylactic mastectomy in an Asian population: a single institution review. Breast. 2014 Feb;23(1):56-62. doi: 10.1016/j.breast.2013.10.008. Epub 2013 Nov 23.

Citation Format: Taib NA, See MH, Bhoo Pathy N, Yahya A, Tan GH, Jamaris S, Yip CH. Low risk of contralateral breast cancer rates in Asian women- A case for not recommending contralateral prophylactic mastectomy. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-39.

Preferential Use of Carbon Sources in Culturable Aerobic Mesophilic Bacteria of Coptotermes curvignathus's (Isoptera: Rhinotermitidae) Gut and Its Foraging Area

The lower termite, Coptotermes curvignathus, is one of the most prominent plantation pests that feed upon, digest, and receive nourishment from exclusive lignocellulose diets. The objective of this study was to examine the utilization of sole carbon sources by isolated culturable aerobic bacteria among communities from the gut and foraging pathway of C. curvignathus. We study the bacteria occurrence from the gut of C. curvignathus and its surrounding feeding area by comparing the obtained phenotypic fingerprint with Biolog's extensive species library. A total of 24 bacteria have been identified mainly from the family Enterobacteriaceae from the identification of Biolog Gen III. Overall, the bacteria species in the termite gut differ from those of foraging pathway within a location, except Acintobacter baumannii, which was the only bacteria species found in both habitats. Although termites from a different study area do not have the same species of bacteria in the gut, they do have a bacterial community with similar role in degrading certain carbon sources. Sugars were preferential in termite gut isolates, while nitrogen carbon sources were preferential in foraging pathway isolates. The preferential use of specific carbon sources by these two bacterial communities reflects the role of bacteria for regulation of carbon metabolism in the termite gut and foraging pathway.

Prediction of lymph node involvement in patients with breast tumors measuring 3-5 cm in a middle-income setting: the role of CancerMath

BACKGROUND

In settings with limited resources, sentinel lymph node biopsy (SNB) is only offered to breast cancer patients with small tumors and a low a priori risk of axillary metastases.

OBJECTIVE

We investigated whether CancerMath, a free online prediction tool for axillary lymph node involvement, is able to identify women at low risk of axillary lymph node metastases in Malaysian women with 3-5 cm tumors, with the aim to offer SNB in a targeted, cost-effective way.

METHODS

Women with non-metastatic breast cancers, measuring 3-5 cm were identified within the University Malaya Medical Centre (UMMC) breast cancer registry. We compared CancerMath-predicted probabilities of lymph node involvement between women with versus without lymph node metastases. The discriminative performance of CancerMath was tested using receiver operating characteristic (ROC) analysis.

RESULTS

Out of 1,017 patients, 520 (51 %) had axillary involvement. Tumors of women with axillary involvement were more often estrogen-receptor positive, progesterone-receptor positive, and human epidermal growth factor receptor (HER)-2 positive. The mean CancerMath score was higher in women with axillary involvement than in those without (53.5 vs. 51.3, p = 0.001). In terms of discrimination, CancerMath performed poorly, with an area under the ROC curve of 0.553 (95 % confidence interval CI 0.518-0.588). Attempts to optimize the CancerMath model by adding ethnicity and HER2 to the model did not improve discriminatory performance.

CONCLUSION

For Malaysian women with tumors measuring 3-5 cm, CancerMath is unable to accurately predict lymph node involvement and is therefore not helpful in the identification of women at low risk of node-positive disease who could benefit from SNB.

Antigen 43/Fcε3 chimeric protein expressed by a novel bacterial surface expression system as an effective asthma vaccine

The IgE Fcε3 domain is an active immunotherapeutic target for asthma and other allergic diseases. However, previous methods for preparing IgE fusion protein vaccines are complex. Antigen 43 (Ag43) is a surface protein found in Escherichia coli that contains α and β subunits (the α subunit contains multiple T epitopes). Here we constructed a novel Ag43 surface display system (Ag43 system) to express Ag43 chimeric proteins to disrupt immune tolerance against IgE. The Ag43 system was constructed from the E. coli strain Tan109, in which the Ag43 gene was deleted and a recombinant plasmid (pETAg43) expressing a partial Ag43 gene was introduced. The Fcε3 domain of the IgE gene was then subcloned into plasmid pETAg43, resulting in a recombinant plasmid pETAg43/Fcε3, which was used to transform Tan109 for Ag43/Fcε3 surface expression. Thereafter, Ag43/Fcε3 was investigated as an asthma vaccine in a mouse model. Ag43/Fcε3 was expressed on and could be separated from the bacterial surface by heating to 60° while retaining activity. Ag43/Fcε3, as a protein vaccine, produced neutralizing autoantibodies to murine IgE, induced significant anti-asthma effects, and regulated IgE and T helper cytokines in a murine asthma model. Data show that Ag43/Fcε3 chimeric protein is a potential model vaccine for asthma treatment, and that the Ag43 system may be an effective tool for novel vaccine preparation to break immune tolerance to other self-molecules.

Abstract P6-06-11: The Will Rogers phenomenon in breast cancer - How does the change from AJCC 5th edition to AJCC 6th edition affect cancer survival?

Introduction: Staging of cancers are important to select appropriate treatment and to estimate prognosis. The most extensive and significant revisions that have ever been made in the breast cancer staging system occurred when the 5th Edition (AJCC5) was updated to the 6th Edition (AJCC6) in Jan 2003. The principal changes were related to the size, number, and location of metastases to the lymph nodes. AJCC6 takes into account the number of lymph nodes involved, and if 4 or more lymph nodes are involved, a Stage 2 breast cancer under AJCC5 is upstaged to Stage 3 under AJCC6. The presence of a supraclavicular lymph node in the absence of other metastases was considered a Stage 4 under AJCC5, but under AJCC6, patients with a supraclavicular lymph node is downstaged to Stage 3. The Will Rogers phenomenon to describe the effect of the “stage migration” has been described as one of the most important biases limiting the use of historical cohorts when comparing survival or treatment. In breast cancer, when we move the “poor prognosis” Stage 2’s, with 4 or more nodes involved, to Stage 3, the Stage 2's remaining will be a “better prognosis” Stage 2, and hence survival should improve. These “poor prognosis” Stage 2's will then be the “better prognosis” Stage 3's and hence the survival of Stage 3 should improve. The aim of this study is to investigate how the change from AJCC5 to AJCC6 affected stage-specific survival in a group of Asian breast cancer patients.

Patients and Methods: 3127 new cases of breast cancer cases presenting to the University Malaya Medical Centre between Jan 1993 and Dec 2007 were prospectively registered into the UMMC Breast Cancer Database. Non-epithelial cancers and ductal carcinoma in situ were excluded. All patients were restaged into AJCC5 and AJCC6

Results:

Comparison of Staging by AJCC5 and AJCC6StageAJCC5AJCC61706 (22.6%)706 (22.6%)21553 (49.7%)1230 (39.3%)3511 (16.3%)854 (27.3%)4357 (11.4%)337 (10.8%)Total31273127

Discussion: It is important to compare stage-specific survival in different time periods to determine whether survival has improved, usually due to timely and optimal treatment. Out of 1553 women classified into Stage 2 breast cancer, 323 or 20.8%, were moved to Stage 3 under AJCC6. The shift from Stage 4 to 3 is less significant because only 20 out of 357 women (5.6%) had supraclavicular lymph node metastases only. The survival of AJCC 5 Stage 2 breast cancer had a 5 year survival rate of 82.9% compared to a 86.1% with AJCC6 Stage 2. Similarly, the 5 year survival of AJCC5 Stage 3 was 50.6% compared to 59% with AJCC6 Stage 3.

Conclusion: Similar to other studies, the stage specific survival in women with Stage 2 and 3 breast cancer improves significantly when AJCC6 is used for staging in the same cohort of patients, again underlying the importance of standardizing the stage when comparing survival from two time periods.

Comparison of 5-year relative survival by AJCC5 and AJCC6StageAJCC5AJCC6196.996.9282.986.1350.659414.412.6

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-11.

Bacterial surface display of endoglin by antigen 43 induces antitumor effectiveness via bypassing immunotolerance and inhibition of angiogenesis

Various angiogenesis-related self-molecules have been considered to be therapeutic targets. However, the direct use of self-molecules as vaccines is not recommended because of the inherent ability of the host to develop immune tolerance. Antigen 43 (Ag43) is a surface protein found in E. coli and contains an α and a β subunits, which contains multiple T epitopes in α subunit. Here we construct a novel Ag43 surface display system (Ag43 system) to express Ag43 chimeric proteins to disrupt immune tolerance against self-molecules. The Ag43 system was constructed from an Escherichia coli strain Tan109, derived from JM109, in which the Ag43 gene was deleted and a recombinant plasmid (pETAg43') expressing a partial Ag43 gene was introduced. The extracellular domain of angiogenesis-related endoglin gene was then subcloned into plasmid pETAg43', resulting in a recombinant plasmid pETAg43'/END(e) which was then used to transform Tan109 for protein expression. We found that Ag43 and endoglin chimeric protein (Ag43'/END(e) ) was expressed on the bacterial surface. The chimeric protein could be separated from the bacterial surface by heating to 60°C and yet retain activity. We used Ag43'/END(e) as a protein vaccine and found that it could disrupt immune tolerance against endoglin by inducing significant antitumor activities and inhibit angiogenesis in several tumor models without significant side effects. These data suggest that Ag43'/END(e) chimeric protein is a potential model vaccine for active tumor immunotherapy, and that Ag43 system could be an effective tool for novel vaccine preparation to break immune tolerance to other angiogenesis-related self-molecules for cancer therapy.

Evaluation on the immune response induced by DNA vaccine encoding MIC8 co-immunized with IL-12 genetic adjuvant against Toxoplasma gondii infection

OBJECTIVE

To examine the immunoprotection effect induced by MIC8 DNA vaccine co-immunized with a plasmid encoding murine IL-12 (pcIL-12) as an adjuvant in mice against the challenge of Toxoplasma gondii.

METHODS

The gene sequence encoding MIC8 of T. gondii RH strain was inserted into eukaryotic expression vector pcDNA3.1 to construct the pcMIC8 expression plasmid. The recombinant plasmid was transfected into HeLa cells to test its expression and the recombinant protein was then characterized by Western blotting. Eighty Kunming mice were randomly divided into 5 groups (16 per group): 3 control groups (PBS, pcDNA3.1, and pcIL-12), pcMIC8 group, and pcMIC8 plus pcIL-12 group. Mice in the pcMIC8 plus pcIL-12 group were co-injected intramuscularly at a dosage of 100 microl each of pcMIC8 and pcIL-12 suspended in 100 microg sterile PBS. Mice in other groups were inoculated with PBS, pcDNA3.1, pcIL-12, and pcMIC8 respectively following the same protocol. All the mice received three immunizations at 2-week intervals. Serum samples were collected on day 0, 13, 27, 41, and 55 before each inoculation for determining antibody IgG, IgG subclass IgG2a. Four weeks after the final immunization, IFN-gamma and IL-4 levels in splenocytes cultures from immunized mice were detected by ELISA. The mice were challenged with 10(3) tachyzoites of the virulent T. gondii RH strain three weeks after the last immunization to observe the survival time.

RESULTS

Western blotting showed that the protein extracts in HeLa cells upon transfection with pcMIC8 were effectively expressed in cells. The levels of IgG (0.51 +/- 0.028) and IgG2a (0.261 +/- 0.04)(on day 55) in mice immunized with pcMIC8 plus pcIL-12 were higher than pcMIC8 group (497.65 +/- 98.15) and control groups (PBS 47.18 +/- 2.73, pcDNA3.1 50.08 +/- 4.62, pcIL-12 118.15 +/- 12.73) (P < 0.05). There was no significant difference in the level of IgG 1 and IL-4 among the five groups (P > 0.05). After a lethal challenge of T. gondii RH strain, the survival time in mice immunized with pcMIC8 plus pcIL-12 (15d) was prolonged in comparison to that of pcMIC8 (10d) and control groups (PBS 5 d, pcDNA3.1 6d, pcIL-12 8 d) (P < 0.05).

CONCLUSION

The immune responses induced by the combined use of the recombinant plasmid encoding MIC8 of T. gondii with murine IL-2 gene adjuvant can be enhanced.

Cytochalasin D promotes pulmonary metastasis of B16 melanoma through expression of tissue factor

Cytochalasin D (CytD) targets actin, a ubiquitous protein in eukaryotic cells. Previous studies have focused mainly on the antitumor effects of CytD. We previously found CytD to promote lung metastasis in B16 melanoma cells, which we had not anticipated, and, therefore, in the present study we investigated the possible underlying mechanisms. B16 melanoma cells were co-cultured with CytD and other agents and used to establish a lung metastatic model. In this B16 melanoma metastatic model, significantly increased lung metastasis and lung weight were found in CytD-treated mice, which was almost completely suppressed by tissue factor (TF) RNA interference expressed via lentivirus. The results of northern and western blot, and real-time RT-PCR analysis showed that the expression of TF was significantly upregulated in B16 cells treated with CytD but was significantly inhibited by TF RNA interference. In addition, upregulation and phosphorylation of mitogen-activated protein kinase p38 were also found in the metastatic lung tissues treated with CytD and in the B16 cells co-cultured with CytD and factor VIIa (FVIIa), but not in cells cultured with CytD, dimethyl sulfoxide or FVIIa alone. These results indicate that CytD stimulates the expression of TF in B16 melanoma cells, activating both coagulation-dependent and -independent pathways via binding to FVIIa, eventually promoting lung metastasis. TF interference is a potential approach to the prevention of B16 melanoma metastasis.

The non-coding RNA llme23 drives the malignant property of human melanoma cells

Several lines of evidence support the notion that increased RNA-binding ability of polypyrimidine tract-binding (PTB) protein-associated splicing factor (PSF) and aberrant expression of long non-coding RNAs (lncRNAs) are associated with mouse and human tumors. To identify the PSF-binding lncRNA involved in human oncogenesis, we screened a nuclear RNA repertoire of human melanoma cell line, YUSAC, through RNA-SELEX affinity chromatography. A previously unreported lncRNA, termed as Llme23, was found to bind immobilized PSF resin. The specific binding of Llme23 to both recombinant and native PSF protein was confirmed in vitro and in vivo. The expression of PSF-binding Llme23 is exclusively detected in human melanoma lines. Knocking down Llme23 remarkably suppressed the malignant property of YUSAC cells, accompanied by the repressed expression of proto-oncogene Rab23. These results may indicate that Llme23 can function as an oncogenic RNA and directly associate the PSF-binding lncRNA with human melanoma.

An unusual cause of a penetrating injury to the anterior urethra: a thorny situation

Concurrent penetrating injury to the male external genitalia and the anterior urethra is uncommon. This case illustrates an unusual cause of such an injury, and its subsequent management and outcome. A 69-year-old man had his scrotum and anterior urethra pierced by a long thorn when he fell in his farm. He presented with urine leakage from the scrotal wound each time he micturated. Cystoscopic examination confirmed the cause and extent of the injury, and also facilitated the extraction of the thorn. The injury was allowed time to heal by urinary diversion with a urinary catheter. There were no stricture or fistula formations and the patient remained symptom-free at 3 months follow-up. Careful cystoscopic examination was both diagnostic and therapeutic in this case. A conservative approach is a feasible option in the management of selected cases of penetrating anterior urethral injury.

[Immune response in mice induced by complex gene vaccine pcSAG1-ROP5 of Toxoplasma gondii]

OBJECTIVE

To observe the immune response induced by complex gene vaccine pcSAG1-ROP5 of Toxoplasma gondii in mice.

METHODS

The recombinant eukaryotic expression plasmids pcSAG1, pcROP5 and pcSAG1-ROP5 were constructed and identified by PCR, restriction enzyme digestion, and sequencing. The three recombinant plasmids were transfected into HeLa cells to express in vitro and identified by Western blotting analysis. Seventy Kunming mice were randomly divided into 5 groups with 14 each, i.e. pcSAG1 group, pcROP5 group, pcSAG1-ROP5 group, blank plasmid group and PBS control group. The mice were immunized intramuscularly with pcSAG1, pcROP5, pcSAG1-ROP5, pcDNA3.1, and PBS, respectively, every two weeks for three times. Sera were collected before each injection and 2 weeks after the last immunization. The titer of mice serum in pcSAG1-ROP5 group combined with recombinant protein SAG1, ROP5 and SAG1-ROP5 and the level of IgG against T. gondii in 5 groups were determined by ELISA. Three weeks after the last immunization, ten mice of each group were challenged with 10(3) tachyzoites of the virulent T. gondii RH strain to observe the survival time. One week later, the rest four mice in each group were sacrificed and the supernatant of cultured splenocytes was collected for the detection of IFN-gamma and IL-4.

RESULTS

Western blotting showed that the recombinant plasmids pcSAG1, pcROP5 and pcSAG1-ROP5 were expressed in HeLa cells with M(r) 31 000, 57 000, and 88 000, respectively. The serum titer in pcSAG1-ROP5 group combined with SAG1, ROP5 and SAG1-ROP5 was 1:320, 1:160, and 1:2560, respectively. The IgG level kept rising in pcSAG1, pcROP5 and pcSAG1-ROP5 groups. Two weeks after the last immunization, the IgG level in pcSAG1-ROP5 group was higher than those in other groups (P<0.05). After a lethal challenge of T. gondii RH strain, the survival time of the mice in pcSAG1-ROP5 group was (288 +/- 7) h, which was 48 h and 96h longer than the groups of pcSAG1 and pcROP5, respectively (P< 0.05). Four weeks after the last immunization, IFN-gamma in splenocyte culture of pcSAG1-ROP5 group [(908.52 +/- 6.31) pg/ml] was higher than other groups (P<0.05), with no significant difference in IL-4 (P>0.05).

CONCLUSION

Compared with the single gene vaccines pcSAG1 and pcROP5, higher levels of IgG and IFN-gamma and longer survival time are observed in mice immunized with pcSAG1-ROP5.

Ficolin-A Enhances Inhibition of the C-Terminal 19 kDa Region of Merozoite Surface Protein-1 of Plasmodium berghei Using Test In Vivo

BACKGROUND

Malaria remains a serious public health problem with significant morbidity and mortality. This study was conducted to identify whether ficolin-A could play an active role of against malaria infection.

METHODS

The function of ficolin-A was analyzed in mouse model. The open reading frame of ficolin-A was cloned from the liver of new born C57BL/6 mice by RT-PCR and then inserted into the expression vector of eukaryon to construct pVAX1-ficolin-A plasmid. Meanwhile, the open reading frame of the 19-kDa fragment of merozoite surface protein-1 of Plasmodium berghei (MSP119) was cloned and then the expression vector of eukaryon, pVAX1- MSP119 was constructed. Both recombinant vectors were used in the mouse model of infection by Plasmodium berghei.

RESULTS

pVAX1-ficolin-A alone could not significantly suppress parasite density and prolong survival time of infection mice; however, when injected pVAX1-ficolin-A and pVAX1-MSP119 together, the percent of invasion by Plasmodium was decreased (from 43.78% to 22.23% at 10 day after infection, compared to vector) and the survival time was prolonged significantly in the infection mouse model (P=0.01).

CONCLUSION

Ficolin-A can enhance the immunoprotection of MSP119, it implies ficolin-A may be used as immunoenhancer in the study of vaccine defending malaria.

Function of ssDNA aptamer and aptamer pool against Mycobacterium tuberculosis in a mouse model

Novel antibacterial agents against Mycobacterium tuberculosis (MTB) are crucial due to the high infection and mortality rates associated with the disease. Our previous study confirmed that aptamers from a whole bacterium obtained by the Systematic Evolution of Ligands by Exponential Enrichment method specifically bound to the MTB virulent strain (H37Rv). In the present study, the function of aptamers against MTB in a mouse model was further determined. It was demonstrated that the NK2 aptamer has marked inhibitory effects on the adhesion/invasion of H37Rv to macrophages in vitro and stimulates intracellular IFN-γ production in CD4+ T-cells. The aptamer pool exhibited the strongest inhibitory effect on H37Rv adhesion/invasion to CD8+ T-cells in vitro compared with all aptamers-treated and control groups. Histopathological examination of lung biopsy specimens revealed a correlation between aptamer presence and lower pulmonary alveoli fusion, swelling and more prominent air spaces. Acid-fast staining of biopsy specimens from the lungs of the mice demonstrated parallel treatment effects. Results of the present study indicate that the 10th pool aptamers and NK2 may play an active role against H37Rv, however, the effect was different in vivo and in vitro. The treatment effect of 10th pool aptamers was found to be better in comparison to NK2 in vivo. Additional target sites involved in pathogenicity of H37Rv were also revealed and the NK2 binding site and aptamers, including the 10th pool aptamers, may antagonize these sites. Further studies are required to screen for other valuable aptamers which may be used as therapeutic drugs in combination with NK2.

Toxicarioside A inhibits SGC-7901 proliferation, migration and invasion via NF-κB/bFGF signaling

AIM: To investigate the inhibitory role of toxicarioside A on the gastric cancer cell line human gastric cancer cell line (SGC-7901) and determine the underlying molecular mechanism.

METHODS: After SGC-7901 cells were treated with toxicarioside A at various concentrations (0.5, 1.5, 4.5, 9.0 μg/mL) for 24 h or 48 h, cell viability was determined by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay, and the motility and invasion of tumor cells were assessed by the Transwell chamber assay. Immunofluorescence staining, reverse transcription polymerase chain reaction and Western blotting were performed to detect the expression of basic fibroblast growth factor (bFGF) and fibroblast growth factor receptor-1 (FGFR1), and nuclear factor-kappa B (NF-κB) activation was examined by electrophoretic mobility shift assay.

RESULTS: The results showed that toxicarioside A was capable of reducing cell viability, inhibiting cell growth, and suppressing cell migration and invasion activities in a time- and dose-dependent manner in SGC-7901 cells. Further analysis revealed that not only the expression of bFGF and its high-affinity receptor FGFR1 but also the NF-κB-DNA binding activity were effectively blocked by toxicarioside A in a dose-dependent manner compared with the control group (P < 0.05 or P < 0.01). Interestingly, application of the NF-κB specific inhibitor, pyrrolidinedithiocarbamate (PDTC), to SGC-7901 cells significantly potentized the toxicarioside A-induced down-regulation of bFGF compared with the control group (P < 0.05).

CONCLUSION: These findings suggest that toxicarioside A has an anti-gastric cancer activity and this effect may be achieved partly through down-regulation of NF-κB and bFGF/FGFR1 signaling.

Toxicarioside A, isolated from tropical Antiaris toxicaria, blocks endoglin/TGF-β signaling in a bone marrow stromal cell line

OBJECTIVE

To investigate possible mechanism of toxicarioside A in HS-5 bone stromal cells.

METHODS

HS-5 bone stromal cells were cultured in media supplemented with various concentrations of toxicarioside A or control DMSO (not treatment). Endoglin and TGF-β were detected by Northern and Western blot analysis and quantified in a standard method. Downstream molecules of endoglin and TGF-β (Smad1, Smad2 and their active phosphorylated counterparts, pSmad1 and pSmad2) were also detected and quantified by Western blot analysis. In addition, cell proliferation assay and small interfering RNA (siRNA) against endoglin were used to certificate the function of endolgin in the HS-5 cells.

RESULTS

Compared with the not treated (0 μg/mL) or DMSO treated control HS-5 cells, HS-5 cells treated with toxicarioside A were found significant attenuation of endolgin and TGF-β expression. Significant inhibition of cell proliferation was also found in the HS-5 cells treated with toxicarioside A. ALK1-related Smad1 and ALK5-related Smad2 were decreased in HS-5 cells treated with toxicarioside A. In addition, phosphorylated Smad1 (pSmad1) and Smad2 (pSmad2) were also found attenuation in toxicarioside A-treated HS-5 cells. RNA interference showed that blockage of endoglin by siRNA also decreased Smad1 and Smad2 expression in HS-5 cells.

CONCLUSIONS

Our results indicate that toxicarioside A can influence bone marrow stromal HS-5's function and inhibit HS-5 cell proliferation by alteration of endoglin-related ALK1 (Smad1) and ALK5 (Smad2) signaling.

Evaluation of power Doppler ultrasonography for prostate biopsy in men with elevated serum prostate specific antigen levels

OBJECTIVES

To evaluate power doppler ultrasonography (PDU)-directed prostate biopsy in patients with elevated serum prostate specific antigen (PSA) levels.

MATERIALS AND METHODS

Men with serum total PSA levels of more than 4 ng/ml undergoing biopsy for the first time were included. Grey-scale transrectal ultrasound (TRUS) and PDU were performed. PDU signal on vascularity accumulation and perfusion characteristics were recorded and graded as normal or abnormal in the peripheral zone of the prostate. Abnormalities were defined on transverse image as radial or arc hypervascularities. A biopsy regime based on Vienna-normogram was performed in all patients.

RESULTS

Overall, prostate adenocarcinoma detection rate was 21.4% and abnormal accumulation on PDU signal was identified in 96.7% of those patients (p = 0.01). PDU directed prostate biopsies were positive in 66.7% of the patients with prostate cancer. The sensitivity, specificity, positive predictive value and negative predictive value of PDU signal alone for prostate cancer detection was 96.7%, 24.5% and 96.4% respectively, and PDU guided biopsies were 66.7%, 24.5%, 19.4% and 73% respectively.

CONCLUSIONS

The high sensitivity and negative predictive value of PDU makes it useful as an aid for TRUS biopsy in selected patient with previous negative biopsies at risk of harbouring prostate cancer.

Clinicopathological features and survival of testicular tumours in a Southeast Asian university hospital: a ten-year review

INTRODUCTION

Testicular cancer mainly affects young men worldwide. There is lack of published data on patients with this malignant condition from the Southeast Asian region. The aim of this study was therefore to determine the clinicopathologic features of testicular cancer patients treated in a Southeast Asian university hospital and their overall survival rate.

MATERIALS AND METHODS

This was a retrospective study of testicular cancer patients treated between January 2001 and February 2011. Their epidemiological data, clinical presentation, pathologic diagnosis, stage of disease and treatment were gathered and the overall survival rate of this cohort was analyzed.

RESULTS

Thirty-one patients were included in this study. The majority of them were of Malay ethnicity. The average age at presentation was 33.7 years. The commonest testicular cancer was non-seminomatous germ cell tumour, followed by seminoma, lymphoma and rhabdomyosarcoma. More than half of all testicular germ cell tumour (GCT) patients had some form of metastasis at diagnosis. All the patients were treated with radical orchidectomy. Adjuvant chemotherapy was given to those with metastatic disease. Four seminoma patients received radiotherapy to the para-aortic lymph nodes. The 5-year survival rate for all testicular cancers in this cohort was 83.9%. The survival rate was 88.9% in 5 years when GCT were analyzed separately.

CONCLUSION

GCT affects patients in their third and fourth decades of life while lymphoma patients are generally older. Most of the patients treated for GCT are of Malay ethnicity. The majority have late presentation for treatment. The survival rate of GCT patients treated here is comparable to other published series in other parts of the world.

Internal hernia through the mesosalpinx: a lesson to learn

An internal hernia through the mesosalpinx is a rare condition which is often overlooked. We report the case of a 65-year-old lady who presented with features of small bowel obstruction. At laparotomy, a gangrenous ileum was found to have herniated through a defect in the right mesosalpinx. We discuss this rare cause of a small bowel obstruction and its diagnostic dilemma.

Saxagliptin added to a submaximal dose of sulphonylurea improves glycaemic control compared with uptitration of sulphonylurea in patients with type 2 diabetes: a randomised controlled trial

AIMS

Assess the efficacy and safety of saxagliptin added to a submaximal sulphonylurea dose vs. uptitration of sulphonylurea monotherapy in patients with type 2 diabetes and inadequate glycaemic control with sulphonylurea monotherapy.

METHODS AND PATIENTS

A total of 768 patients (18-77 years; HbA(1c) screening >or= 7.5 to <or= 10.0%) were randomised and treated with saxagliptin 2.5 or 5 mg in combination with glyburide 7.5 mg vs. glyburide 10 mg for 24 weeks. Blinded uptitration glyburide was allowed in the glyburide-only arm to a maximum total daily dose of 15 mg. Efficacy analyses were performed using ANCOVA and last-observation-carried-forward methodology.

RESULTS

At week 24, 92% of glyburide-only patients were uptitrated to a total glyburide dose of 15 mg/day. Saxagliptin 2.5 and 5 mg provided statistically significant adjusted mean decreases from baseline to week 24 vs. uptitrated glyburide, respectively, in HbA(1c) (-0.54%, -0.64% vs. +0.08%; both p < 0.0001) and fasting plasma glucose (-7, -10 vs. +1 mg/dl; p = 0.0218 and p = 0.002). The proportion of patients achieving an HbA(1c) < 7% was greater for saxagliptin 2.5 and 5 mg vs. uptitrated glyburide (22.4% and 22.8% vs. 9.1%; both p < 0.0001). Postprandial glucose area under the curve was reduced for saxagliptin 2.5 and 5 mg vs. uptitrated glyburide (-4296 and -5000 vs. +1196 mg.min/dl; both p < 0.0001). Adverse event occurrence was similar across all groups. Reported hypoglycaemic events were not statistically significantly different for saxagliptin 2.5 (13.3%) and 5 mg (14.6%) vs. uptitrated glyburide (10.1%).

CONCLUSION

Saxagliptin added to submaximal glyburide therapy led to statistically significant improvements vs. uptitration of glyburide alone across key glycaemic parameters and was generally well tolerated.

Combination of Recombinant Xenogeneic Endoglin DNA and Protein Vaccination Enhances Anti-tumor Effects

The immunization approaches with DNA vaccine priming and subsequent protein or peptide boosting has been widely tested in various models of infectious diseases. However, these approaches are seldom reported in the areas of cancer immunotherapy. In this study we combined endoglin plasmid DNA and recombinant protein as vaccines and used them to prime and boost, simultaneously, as a vaccine strategy. Our results showed that combination of endoglin DNA and protein vaccines could enhance both protective and therapeutic anti-tumor efficacy in both colon carcinoma and Lewis lung carcinoma models. Significant inhibition of tumor angiogenesis was found in the tumor tissues. The titers of autoantibodies against murine endoglin were significantly increased and the antibody levels lasted longer in the mice with combined endoglin DNA and recombinant protein vaccination. CTL response against endoglin-positive HUVECs, but not against endoglin-negative tumor cells was found in the mice combined DNA with protein vaccination. In addition, combination of endoglin DNA and recombinant protein vaccination significantly induced IFN-gamma secreting cells. These observations suggested that a combination of endoglin DNA and recombinant protein immunization as a vaccine strategy was superior to those using endoglin DNA or recombinant protein alone as vaccines.

Clinical characteristics of triple-negative breast cancer: experience in an Asian developing country

INTRODUCTION

Triple negative (TN) breast cancers are defined by a lack of expression of oestrogen, progesterone, and HER2 receptors. They tend to have a higher grade, with a poorer outcome compared to non-TN breast cancers.

OBJECTIVE

The aim of this study is to determine the incidence of TN breast cancer in an Asian country consisting of Malays, Chinese and Indians, and to determine the factors associated with this type of breast cancer.

RESULTS

The incidence of TN breast cancer in the University Malaya Medical Center is 17.6%. There is no significant difference amongst the Malays, Chinese and Indians. In bivariate analysis, TN breast cancer was significantly associated with younger age and Grade 3. However, in multivariate analysis using logistic regression, TN breast cancer was only associated with Grade 3.

CONCLUSION

The incidence of TN breast cancer in our study is similar to other studies, and associated with a higher grade.

Differential osteogenic activity of osteoprogenitor cells on HA and TCP/HA scaffold of tissue engineered bone

Biomaterial, an essential component of tissue engineering, serves as a scaffold for cell attachment, proliferation, and differentiation; provides the three dimensional (3D) structure and, in some applications, the mechanical strength required for the engineered tissue. Both synthetic and naturally occurring calcium phosphate based biomaterial have been used as bone fillers or bone extenders in orthopedic and reconstructive surgeries. This study aims to evaluate two popular calcium phosphate based biomaterial i.e., hydroxyapatite (HA) and tricalcium phosphate/hydroxyapatite (TCP/HA) granules as scaffold materials in bone tissue engineering. In our strategy for constructing tissue engineered bone, human osteoprogenitor cells derived from periosteum were incorporated with human plasma-derived fibrin and seeded onto HA or TCP/HA forming 3D tissue constructs and further maintained in osteogenic medium for 4 weeks to induce osteogenic differentiation. Constructs were subsequently implanted intramuscularly in nude mice for 8 weeks after which mice were euthanized and constructs harvested for evaluation. The differential cell response to the biomaterial (HA or TCP/HA) adopted as scaffold was illustrated by the histology of undecalcified constructs and evaluation using SEM and TEM. Both HA and TCP/HA constructs showed evidence of cell proliferation, calcium deposition, and collagen bundle formation albeit lesser in the former. Our findings demonstrated that TCP/HA is superior between the two in early bone formation and hence is the scaffold material of choice in bone tissue engineering.

A recombinant DNA plasmid encoding the human interleukin-5 breaks immunological tolerance and inhibits airway inflammation in a murine model of asthma

BACKGROUND

Eosinophils play a pivotal role in the generation of asthma inflammation. Interleukin (IL)-5 is the major activator of eosinophils. We hypothesize that modulating IL-5 activity could be an effective strategy for asthma therapy. In this study, we tested whether the plasmid encoding human IL-5 as a xenogeneic DNA vaccine could induce the production of autoantibodies, and be used for asthma treatment.

METHODS

A eukaryotic plasmid encoding the human IL-5 was constructed, and used as a DNA vaccine. A mouse model of asthma was established to observe its antiasthma activities. Eosinophils in tissue, blood and the bronchoalveolar lavage were stained and counted. Airway hyperresponsiveness (AHR) was determined by whole body plethysmography. Antibody characters and cytokines were detected with immunological methods.

RESULTS

Immunization with a plasmid encoding the human IL-5 as DNA vaccine reduced airway inflammation, reversed Th2 cytokines, and decreased AHR in mice. In addition, this immunization induced the production of polyclonal antibodies that were cross-reactive with native murine IL-5, and IgG1 and IgG2a were the major subclasses. Adoptive transfer of the purified antibodies from the sera of mice immunized with the plasmid encoding the human IL-5 resulted in similar antiasthma effects.

CONCLUSIONS

Our results suggest that active vaccination against IL-5 may be a rational therapeutic approach for the treatment of asthma and potentially other eosinophilic disorders.

Active immunotherapy of allergic asthma with a recombinant human interleukin-5 protein as vaccine in a murine model

BACKGROUND

Eosinophils are highly related to allergic asthma inflammation. Interleukin (IL)-5 is the major chemokine of eosinophils, inhibition of the activity of IL-5 thus seems to be a potential approach to asthma therapy. The current study was performed to determine whether a recombinant human IL-5 protein as a xenogeneic vaccine has the capability of inducing anti-asthma activities.

METHODS

Recombinant human IL-5 was used as a protein vaccine. Mouse asthma model was established to observe the anti-asthma activities. Lung histology was observed; eosinophils in blood and bronchoalveolar lavage were stained and counted. Airway hyperresponsiveness was determined by whole body plethysmograph. Antibody characters and cytokines were detected with enzyme linked immunosorbent assay (ELISA) and Western blot assay.

RESULTS

Vaccination with recombinant human IL-5 protein as vaccine significantly reduced airway inflammation and airway hyperresponsiveness, and shifted the cytokine production from Th2 (IL-4) to Th1 (INF-gamma) in mice allergic-asthma model. Immunization with recombinant human IL-5 protein vaccine bypassed the immunological tolerance and induced production of polyclonal antibodies that were cross-reactive with murine IL-5.

CONCLUSIONS

Active immunization with xenogeneic homologous IL-5 may be a possible therapeutic approach to the treatment of asthma and potentially of other eosinophilic disorders.

Immunotherapy of hepatoma with a monoclonal antibody against murine endoglin

AIM: To explore the capability of a monoclonal antibody (mAb) against murine endoglin to inhibit tumor angiogenesis and suppression of hepatoma growth in murine models.

METHODS: A monoclonal antibody against murine endoglin was purified by affinity chromatography and passively transfused through tail veins in two murine hepatoma models. Tumor volume and survival time were observed at three-day intervals for 48 d. Microvessels in tumor tissues were detected by immunohistochemistry against CD31, and angiogenesis in vivo was determined by alginate encapsulated assay. In addition, tumor cell apoptosis was detected by TUNEL assay.

RESULTS: Passive immunotherapy with anti-endoglin mAb could effectively suppress tumor growth, and prolonged the survival time of hepatoma-bearing mice. Angiogenesis was apparently inhibited within the tumor tissues, and the vascularization of alginate beads was also reduced in the mice passively transfused with anti-endoglin mAb. In addition, increased apoptotic cells were observed within the tumor tissues from the mice passively transfused with anti-endoglin mAb.

CONCLUSION: Passive immunotherapy with anti-endoglin mAb effectively inhibits tumor growth via inhibiting tumor angiogenesis and increasing tumor cell apoptosis, which may be highly correlated with the blockage of endoglin-related signal pathway induced by anti-endoglin mAb.

Comparison of bioengineered human bone construct from four sources of osteogenic cells

Osteoprogenitor cells have been reported to be present in periosteum, cancellous and cortical bone, and bone marrow; but no attempt to identify the best cell source for bone tissue engineering has yet been reported. In this study, we aimed to investigate the growth and differentiation pattern of cells derived from these four sources in terms of cell doubling time and expression of osteoblast-specific markers in both monolayer cells and three-dimensional cell constructs in vitro. In parallel, human plasma derived-fibrin was evaluated for use as biomaterial when forming three-dimensional bone constructs. Our findings showed osteoprogenitor cells derived from periosteum to be most proliferative followed by cortical bone, cancellous bone, and then bone marrow aspirate. Bone-forming activity was observed in constructs formed with cells derived from periosteum, whereas calcium deposition was seen throughout the constructs formed with cells derived from cancellous and cortical bones. Although no mineralization activity was seen in constructs formed with osteoprogenitor cells derived from bone marrow, well-organized lacunae as would appear in the early phase of bone reconstruction were noted. Scanning electron microscopy evaluation showed cell proliferation throughout the fibrin matrix, suggesting the possible application of human fibrin as the bioengineered tissue scaffold at non-load-bearing sites.

Combination of low-dose gemcitabine and recombinant quail vascular endothelial growth factor receptor-2 as a vaccine induces synergistic antitumor activities

Vascular endothelial growth factor receptor-2 (VEGFR-2) has been shown to play a major role in inducing the full spectrum of VEGF biological response which is essential for tumor angiogenesis. We have demonstrated that immunotherapy of tumors with a vaccine based on quail homologous VEGFR-2 (qVEGFR) was effective in providing both protective and therapeutic antitumor immunity in several tumor models in mice. The purpose of this study was to determine whether the combination therapy of low-dose gemcitabine with qVEGFR as a vaccine could inhibit tumor growth to a greater extent. To test this concept, H22 hepatoma and Lewis lung carcinoma models were established in BALB/c mice and C57BL/6 mice, respectively. Mice were treated with either qVEGFR as a protein vaccine, gemcitabine, or both agents together. qVEGFR or low-dose chemotherapy treatment individually resulted in tumor inhibition to a certain extent.Remarkably, the combination therapy resulted in synergistic antitumor activity. Histological examination revealed that there was endothelial deposition of immunoglobulins within tumor tissues from mice treated with vaccine or combination therapy, especially intratumor angiogenesis was suppressed more significantly for the combination group. Also, ELISPOT analysis showed that mice treated with either qVEGFR alone or in combination with low-dose chemotherapy produced similar amount of anti-VEGFR antibody-producing B cells, which suggested that low-dose gemcitabine did not suppress the host's immune response, but potentiated the antitumor activity of the qVEGFR vaccine. Furthermore, TUNEL staining demonstrated a significant increase in the number of TUNEL-positive cells in the combination group compared with those of other groups. The observations may provide a new bio-chemotherapeutic approach for cancer.

Bone graft substitute using hydroxyapatite scaffold seeded with tissue engineered autologous osteoprogenitor cells in spinal fusion: early result in a sheep model

Spinal fusion using autologous bone graft is performed in an increasing rate for many spinal disorders. However, graft harvesting procedure is associated with prolonged operation time and potential donor site morbidity. We produced an engineered 'bone graft' substitute by using porous hydroxyapatite (HA) scaffold seeded with autologous bone marrow osteoprogenitor cells (OPCs) and fibrin. This obviates bone graft harvesting, thus eliminates donor site morbidity and shortens the operation time. The aim of this study is to evaluate Hydroxyapatite (HA) ceramics as scaffold for autologous tissue engineered bone construct for spinal fusion in a sheep model. The sheep's marrow was aspirated from iliac crest. The bone marrow mesenchymal stem cells (BMMSCs) were cultured for several passages in the presence of growth and differentiation factors to increase the number of OPCs. After the cultures reached confluence, they were trypsinized and seeded on Hydroxyapatite scaffold (HA). Approximately 5 million cells were generated after 3 weeks of culture. Microscopically, very tight Colony Forming Units (CFU-Fs) were seen on monolayer culture. The Von Kossa and Alizarin Red staining of monolayer culture showed positive mineralization areas; indicating the presence of OPCs. Sheep underwent a posterolateral spinal fusion in which scaffolds with or without OPCs seeded were implanted on both sides of the lumbar spine (L1-L2). Intended fusion segments were immobilized using wires. At the end of third month, the fusion constructs were harvested for histological examination. Fibrous tissue infiltration found in the inter-connecting pores of plain HA ceramics indicates inefficient new bone regeneration. New bone was found surrounding the HA ceramics seeded with autologous cells. The new bone is probably formed by the sheep BMMSCs that were initially encapsulating HA while it remained intact. The new bone is naturally fused with the vertebrae. In conclusion, the incorporation of autologous bone marrow cells improved the effectiveness of HA ceramics as 'bone graft' substitute for spinal fusion.

Progressive supra-axial cervical instability in Down syndrome: a case report emphasising the role of extended short-segment fusion

We report a case of upper cervical instability associated with Down syndrome to highlight its potential progression to inflict cord compression and the rationale for surgical decompression and extended short segment occipito-axial fusion.