A self-assembling peptide inhibits the growth and function of fungi via a wrapping strategy.

Fungal infections contribute substantially to human morbidity and mortality. A particular concern is the high rate of mortality associated with invasive fungal infections, which often exceeds 50.0% despite the availability of several antifungal drugs. Herein, we show a self-assembling antifungal peptide (AFP), which is able to bind to chitin on the fungal cell wall and in situ form AFP nanofibers, wrapping fungi. As a result, AFP limits the proliferation of fungi, slows down the morphological transformation of biphasic fungi, and inhibits the adhesion of fungi to host cells and the formation of biofilms. Compared to the broad-spectrum antifungal fluconazole, AFP achieved a comparable inhibitory effect (MIC50 = 3.5 µM) on fungal proliferation. In addition, AFP significantly inhibited the formation of fungal biofilms with the inhibition rate of 69.6% at 1 µM, better than fluconazole (17.2% at 1 µM). In a skin infection model of mice, it was demonstrated that AFP showed significantly superior efficacy to fluconazole. In the systemic candidiasis mouse model, AFP showed similar efficacy to first-line antifungal amphotericin B (AmpB) and anidulafungin (AFG). This study provides a promising wrapping strategy for anti-fungal infection.

LncRNA SNHG12 promotes proliferation and migration of hepatic progenitor cells via the Wnt/ß-catenin pathway.

BACKGROUND: Hepatic progenitor cells (HPCs) play an important role in the treatment of chronic liver disease. OBJECTIVES: To investigate the effect and mechanism of long noncoding RNAs/small nucleolar RNA host gene 12 (lncRNA SNHG12) on the proliferation and migration of the HPC cell line WB-F344. MATERIAL AND METHODS: Hepatic progenitor cells were divided into a no-treatment group (sham), empty vector transfection of plasmid pcDNA3.1 (NC vector), pcDNA3.1-SNHG12 (SNHG12), negative short hairpin RNA (sh-NC), SNHG12 shRNA (sh-SNHG12), and pcDNA3.1-SNHG12+salinomycin intervention (SNHG12+salinomycin) groups. Cell proliferation, cell cycle and migration ability, as well as albumin (ALB), alpha-fetoprotein (AFP), â-catenin, cyclin D1, and c-Myc protein expression in each group were determined using Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, transwell migration assays, enzyme-linked immunosorbent assay (ELISA), and western blot. RESULTS: The overexpression of lncRNA SNHG12 significantly upregulated proliferation, migration and cell cycle progression of WB-F344 cells. Furthermore, the overexpression of lncRNA SNHG12 increased the level of ALB, and the protein expression of â-catenin, cyclin D1 and c-Myc in the cell line, while decreasing the level of AFP. Conversely, the knockdown of lncRNA SNHG12 displayed the opposite effects. The inhibition of the Wnt/â-catenin signaling pathway with salinomycin significantly downregulated the â-catenin, cyclin D1 and c-Myc protein expression in WB-F344 cells. CONCLUSIONS: The lncRNA SNHG12 promotes the proliferation and migration of WB-F344 cells via activating the Wnt/â-catenin pathway.

Submilligram Level of Beetle Antifreeze Proteins Minimize Cold-Induced Cell Swelling and Promote Cell Survival.

Hypothermic (cold) preservation is a limiting factor for successful cell and tissue transplantation where cell swelling (edema) usually develops, impairing cell function. University of Wisconsin (UW) solution, a standard cold preservation solution, contains effective components to suppress hypothermia-induced cell swelling. Antifreeze proteins (AFPs) found in many cold-adapted organisms can prevent cold injury of the organisms. Here, the effects of a beetle AFP from Dendroides canadensis (DAFP-1) on pancreatic ß-cells preservation were first investigated. As low as 500 µg/mL, DAFP-1 significantly minimized INS-1 cell swelling and subsequent cell death during 4 °C preservation in UW solution for up to three days. However, such significant cytoprotection was not observed by an AFP from Tenebrio molitor (TmAFP), a structural homologue to DAFP-1 but lacking arginine, at the same levels. The cytoprotective effect of DAFP-1 was further validated with the primary ß-cells in the isolated rat pancreatic islets in UW solution. The submilligram level supplement of DAFP-1 to UW solution significantly increased the islet mass recovery after three days of cold preservation followed by rewarming. The protective effects of DAFP-1 in UW solution were discussed at a molecular level. The results indicate the potential of DAFP-1 to enhance cell survival during extended cold preservation.

Chemoprotective Effect of Decalactone on Hepatic Cancer via Diminishing the Inflammatory Response and Oxidative Stress.

Hepatocellular Carcinoma (HCC) is the 5th most common type of cancer in all types of cancers, globally. It is well known that the frequency of inflammatory reaction and oxidative stress increases during the HCC. The goal of this study was to see if decalactone could prevent rats against HCC caused by diethylnitrosamine (DEN). Single intraperitoneal administration of DEN (200 mg/kg) used as inducer and weekly intraperitoneal injection of phenobarbital (8 mg/kg) was used as promotor for induction the HCC in rats. Serum alpha fetoprotein (AFP) was used for the confirmation of HCC. Different doses of decalactone (5, 10 and 15 mg/kg) were orally administered to the rats. The body weight was determined at regular time. The hepatic, non-hepatic, antioxidant markers and inflammatory mediators were scrutinized. All groups of animals were scarified and macroscopically examination of the liver tissue was performed and the weight of organ (hepatic tissue) were estimated. Decalactone increased body weight while also suppressing hepatic nodules and tissue weight. Decalactone treatment reduced AFP, total bilirubin, and direct bilirubin levels while increasing albumin and total protein levels in a dose-dependent manner. Decalactone reduced lipid peroxidation (LPO) and increased catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), and superoxide dismutase (SOD) levels significantly (p < 0.001) (SOD). Decalactone lowered the levels of significantly (p < 0.001) inflammatory cytokines and inflammatory markers in the liver. Based on the findings, we may conclude that decalactone inhibited HCC in DEN-induced HCC animals via reducing oxidative stress and inflammatory mediators.

Fungal Infections as an Uprising Threat to Human Health: Chemosensitization of Fungal Pathogens With AFP From Aspergillus giganteus.

Occurrence and intensity of systemic invasive fungal infections have significantly risen in recent decades with large amount of mortality and morbidity rates at global level. Treatment therapy lies on the current antifungal interventions and are often limited due to the emergence of resistance to antifungal agents. Chemosensitization of fungal strains to the conventional antimycotic drugs are of growing concern. Current antifungal drugs often have been reported with poor activity and side effects to the host and have a few number of targets to manifest their efficacy on the pathogens. Indiscriminately, the aforementioned issues have been easily resolved by the development of new intervention strategies. One such approach is to employ combinational therapy that has exhibited a great level of inhibitions than that of a single compound. Chemosensitization of pathogenic mycoses to commercial antifungal drugs could be drastically enhanced by co-application of chemosensitizers along with the conventional drugs. Chemosensitizers could address the resistance mechanisms evolved in the pathogenic fungi and targeting the system to make the organism susceptible to commercially and clinically proven antifungal drugs. However, this strategy has not been overreached to the greater level, but it needs much attention to fight against not only with the pathogen but combat the resistance mechanisms of pathogens to drugs. Natural compounds including plant compounds and microbial proteins act as potential chemosensitizers to break the resistance in mycoses. Aspergillus giganteus, a filamentous fungus, is known to produce a cysteine rich extracellular protein called as antifungal protein (AFP). AFP has shown enhanced efficacy against several filamentous and non-filamentous fungal pathogens. On the basis of the reported studies on its targeted potential against pathogenic mycoses, AFP would be fabricated as a good chemosensitizer to augment the fungicidal efficacy of commercial antimycotic drugs. This paper reviews on breakthrough in the discovery of antifungal drugs along with the resistance patterns of mycoses to commercial drugs followed by the current intervention strategies applied to augment the fungicidal potential of drugs.

Cryoprotective effect of antifreeze protein III on the rabbit ovary.

CONTEXT: Ovarian tissue cryopreservation is effective in preserving fertility in cancer patients who have concerns about fertility loss due to cancer treatment. However, ischemia reduces the lifespan of grafts. Microvascular transplantation of cryopreserved whole ovary may allow immediate revascularisation, but the damage incurred during the cryopreservation procedure may cause follicular depletion; hence, preventing chilling injury would help maintain ovarian function. AIM: This study was designed to investigate the beneficial effects of antifreeze protein III (AFP III) on rabbit ovary cryopreservation. METHODS: Ovaries (n =25) obtained from 5-month-old female rabbits (n =13) were frozen by slow freezing and vitrification. Cryoprotectant media were supplemented with and without 1mg/mL of AFP III. The experiment was divided into five groups: fresh control group (F), slow freezing group (S), slow freezing group with AFP III (AFP III-S), vitrification group (V) and vitrification group with AFP III (AFP III-V). All groups of ovaries were examined by histological characteristics analysis, ultrastructural analysis, apoptosis detection and follicle viability test. KEY RESULTS: With slow freezing, the normal rate of change in follicle morphology, density of stromal cells and the survival rate of follicles in the AFP III supplemented group were significantly higher than those in the non-supplemented group, and a lower oocyte apoptotic rate was shown in the AFP III supplemented group. In the vitrification groups, the normal rate of change in follicle morphology and density of stromal cells in the AFP III supplemented group were significantly higher than those in the non-supplemented group, and a lower oocyte apoptotic rate was found in the AFP III supplemented group. But there was no obvious difference in the survival rate of follicles between the two groups. There was also no significant difference in the normal rate of change in follicle morphology, the survival rate of follicles and the apoptotic rate of oocytes between the vitrification and slow freezing groups (P >0.05), but the density of stromal cells in the vitrification groups was statistically higher than that of the slow freezing group (P <0.05). CONCLUSIONS: The addition of AFP III in slow freezing and vitrification could improve the cryoprotective effect of ovaries, which was more evident in slow freezing. IMPLICATIONS: The findings of this study provide a foundation for further research on the effects of AFP III in human ovarian tissue.

Protective Effect of Nerium oleander Distillate and Tarantula cubensis Alcoholic Extract on Cancer Biomarkers in Colon and Liver Tissues of Rats with Experimental Colon Cancer.

BACKGROUND: Colon cancers are among the top three causes of cancer-related deaths. This study is a continuation of previous research aiming to identify effective treatments. OBJECTIVE: This study investigated the effects of Tarantula cubensis alcoholic extract (TCAE) and Nerium oleander (NO) distillate on the levels of midkine, transforming growth factor (TGF)-ß, vascular endothelial growth factor (VEGF), alpha-fetoprotein (AFP), cyclooxygenase (COX)-2, insulin-like growth factor (IGF) and caspase-3 in the liver and colon tissues of rats with experimentally induced colon cancer. METHODS: The liver and colon tissues of rats were homogeneously divided into control, colon cancer (azoxymethane, AZM), AZM + TCAE, and AZM + NO distillate groups. The levels of midkine, TGF-ß, VEGF, AFP, COX-2, IGF, and caspase-3 in the colon and liver tissues were measured by ELISA. RESULTS: The levels of all parameters in colon and liver tissues in the AZM group were higher (p<0.05) than those in the control group. TCAE and NO distillate prevented (p < 0.05) increases in midkine, TGF-ß, VEGF, AFP, COX-2, IGF, and caspase-3 levels in the colon. NO distillate prevented the increase in all parameters except IGF, whereas TCAE prevented the increase in all values apart from COX-2 and IGF levels in the liver (p<0.05). CONCLUSION: NO distillate and TCAE may prevent the studied markers from reaching specified levels observed in the colon in AZM-induced colon cancer. The increases in the levels of the parameters in the liver were not as severe as those in the colon; however, an 18-week study period may not be sufficient for liver metastasis formation. Future molecular studies should investigate the mechanisms and pathways of these treatments in greater detail.

AFP peptide (AFPep) as a potential growth factor for prostate cancer.

Prostate cancer is the most common cancer among men in the USA. A peptide derived from the active site of alpha-fetoprotein (AFP), known as AFPep, has been shown to be efficacious in inhibiting breast cancer growth. The role of this derived peptide AFPep in the development of prostate cancer has yet to be studied. To investigate the role of AFPep on prostate cancer, we used the PC-3 and DU-145 cell lines. We found that through key anti-apoptosis and pro-proliferation molecules, AFPep enhances the proliferation of DU-145 prostate cancer cells. The anti-proliferative molecules p18, p21, and p27, along with the pro-apoptotic molecules Fas and Bax, were all down-regulated in DU-145 cell lines treated with AFPep. Conversely, AFPep was not found to have a proliferative effect on the PC-3 prostate cancer cell line. This finding suggests the effects of AFPep to be cell line-specific in prostate cancer. Further investigation into the effects of AFPep could lead to new areas of treating prostate cancer.

Efficacy and tolerability of AFPep, a cyclic peptide with anti-breast cancer properties.

PURPOSE: The purpose of this study is to assess the efficacy and safety profile of AFPep, a 9-amino acid cyclic peptide prior to its entry into pre-clinical toxicology analyses en route to clinical trials. METHODS: AFPep was assessed for anti-estrogenic activity in a mouse uterine growth assay and for breast cancer therapeutic efficacy in a human tumor xenograft model in mice. AFPep was assessed for tolerability in a variety of in vivo models, notably including assessment for effects on rat liver and human hepatocellular carcinoma cell lines and xenografts. RESULTS: AFPep arrests the growth of human MCF-7 breast cancer xenografts, inhibits the estrogen-induced growth of mouse uteri, and does not affect liver growth nor stimulate growth of human hepatocellular carcinoma cell lines when growing in vitro or as xenografts in vivo. AFPep is well tolerated in mice, rats, dogs, and primates. CONCLUSIONS: AFPep is effective for the treatment of ER-positive breast cancer and exhibits a therapeutic index that is substantially wider than that for drugs currently in clinical use. The data emphasize the importance of pursuing pre-clinical toxicology studies with the intent to enter clinical trials.

Binding characterization of the targeting drug AIMPILA to AFP receptors in human tumor xenografts.

The main objective of this study was the characterization of preclinical tumor models based on their expression of alpha-fetoprotein receptor (RECAF) for targeting cancer cells with a new non-covalent complex (AIMPILA) containing alpha-fetoprotein as the carrier and Atractyloside as an apoptosis-inducing agent. For that purpose, we measured the amount of RECAF in the homogenates of the grafted tumors T47D and SW620 and in HepG2 cell extracts. We also determined the alpha-fetoprotein binding specificity of the targeting drug AIMPILA using a solid-phase chemiluminescent assay with AIMPILA-Acrdidinium. We found that RECAF is practically absent from healthy mice tissues (100 Units/mg) where in malignant cells, the amount of alpha-fetoprotein receptors follows this order: T47D (9152 Units/mg) > HepG2 (4865 Units/mg) > SW620 (2839 Units/mg). This agrees with our findings regarding AIMPILA-induced tumor growth inhibition (T47D (T/C = 22%) > HepG2 (T/C = 51%) > SW620 (T/C = 70%), where T/C is the ratio of tumor volume in treated vs control animals). Our results demonstrate that the therapeutic response to the targeting drug AIMPILA strongly depends on the RECAF expression by human tumors and confirms the choice of the tumor models used for an AIMPILA preclinical study.

Purification and characterization of a bioactive alpha-fetoprotein produced by HEK-293 cells.

Alpha-fetoprotein (AFP) is a biomarker that is used to diagnose hepatocellular carcinoma (HCC) and can promote malignancy in HCC. AFP is an important target in the treatment of liver cancer. To obtain enough AFP to screen for AFP inhibitors, we expressed and purified AFP in HEK-293 cells. In the present study, we produced AFP in the cells and harvested highly pure rAFP (or recombinant expression AFP in HEK-293 cells). We also analysed the bioactivity of rAFP and found that rAFP promoted growth of the human HCC cells, antagonize paclitaxel inhibition of HCC cell proliferation, suppress expression of active caspase-3, and promote expression of Ras and survivin. This study provides a method to produce significant amounts of AFP for use in biochemical assays and functional studies and to screen AFP inhibitors for use in HCC therapy.

Decorin-loaded poly lactic-co-glycolic acid nanoparticles modified by anti-alpha fetoprotein antibody: preparation, proliferation inhibition and induced apoptosis effects on HepG2 cells in vitro.

OBJECTIVES: Decorin (DCN) is a negative regulatory factor for the growth of cancer cells and can inhibit the proliferation, metastasis of cancer cells and angiogenesis in cancer tissues. The aims of this study were to prepare the nanoparticles consisting of DCN and poly lactic-co-glycolic acid (PLGA) modified by anti-alpha fetoprotein (AFP) monoclonal antibody (mAb) and to examine the conventional physical properties, the in-vitro release of DCN and the targeting effect of these nanoparticles on HepG2 cells. KEY FINDINGS: The encapsulated plasmid was slowly and steadily released from the nanoparticles. The targeted PLGA nanoparticles were initiatively taken in HepG2 cells high-efficiently. According to the results of RT-PCR, DCN gene in AFPmAb-PLGA-rhDCN nanoparticles can be expressed in HepG2 cells successfully. These nanoparticles significantly inhibited the proliferation of HepG2 cells and induced apoptosis. The mRNA expression of Bcl-2 gene in the AFPmAb-PLGA-rhDCN-treated groups appeared significantly to decrease and the caspase-3 gene had the opposite trend as compared with that of control group (P < 0.01). CONCLUSION: These studies revealed that these nanoparticles were capable of specifically targeting the HepG2 cells and inhibiting the proliferation and they induce apoptosis of HepG2 cells in vitro, which was in a dose- and time-dependent manner.

Expression and bioactivity of human α-fetoprotein in a Bac-to-Bac system.

α-fetoprotein (AFP) is an early serum growth factor in foetal embryonic development and hepatic oncogenesis. A growing number of investigations of AFP as a tumour-specific biomarker have concluded that AFP is an important target for cancer treatment. AFP also plays an immunomodulatory role in the treatment of several autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis, myasthenia gravis and thyroiditis. In an effort to support biochemical screening and drug design and discovery, we attempted to express and purify human AFP in a Bac-to-Bac system. Two key factors affecting the expression of recombinant human AFP (R-AFP), namely the infectious baculovirus inoculum volume and the culturing time post-infection, were optimized to maximize the yield. We achieved a high yield of approximately 1.5 mg/l of harvested medium with a 72-96 h incubation period after infection and an inoculum volume ratio of 1:100. We also assessed the role of R-AFP in the proliferation of the human liver cancer cell line Bel 7402, and the results indicated that R-AFP promoted the growth of hepatoma cells. We concluded that this method can produce high yields of R-AFP, which can be used for studies related to AFP.

Alpha fetoprotein antagonises benzyl isothiocyanate inhibition of the malignant behaviors of hepatocellular carcinoma cells.

Benzyl isothiocyanate (BITC) is a dietary isothiocyanate derived from cruciferous vegetables. Recent studies showed that BITC inhibited the growth of many cancer cells, including hepatocellular carcinoma (HCC) cells. Alpha-fetoprotein (AFP) is a important molecule for promoting progression of HCC, in the present investigation, we explore the influence of AFP on the role of BITC in the malignant behaviours of HCC cells, and the potential underlying mechanisms. We found thatBITC inhibited viability, migration, invasion and induced apoptosis of human liver cancer cell lines, Bel 7402(AFP producer) and HLE(non-AFP producer) cells in vitro. The role of BITC involve in promoting actived-caspase-3 and PARP-1 expression, and enhancing caspase-3 activity but decreasing MMP-2/9, survivin and CXCR4 expression. AFP antagonized the effect of BITC. This study suggests that BITC induced significant reductions in the viability of HCC cell lines. BITC may activate caspase-3 signal and inhibit the expression of growth- and metastasis-related proteins; AFP is an pivotal molecule for the HCC chemo-resistance of BITC.

[Accumulation of doxorubicin conjugates with dendritic polymer and vector protein in normal and tumor cells in vitro].

Accumulation of doxorubicin (Dox), its conjugates with the second generation dendritic polymer (G2-Dox) and vector pro- tein (recombinant third domain of alpha-fetoprotein - 3D-G2- Dox) in normal and tumor cells was studied in vitro within the framework of the development of selective transport system of anticancer drugs to the target cells. The objects of the study were cells of peripheral blood mononuclear fraction of healthy donors and cells of breast adenocarcinoma lines MCF-7 and MCF-7/MDR1, differing in chemosensitivity. G2-Dox and 3D-G2-Dox accumulated in tumor cells of the both lines better than free Dox (p<0,05). However removal of these drugs out of cells MCF-7 and MCF-7/MDR1 was significantly different: in the latter case all free Dox was excluded from the cells for 24 hours while Dox, accumulated in composition with dendrimers, still remained in the cells. It was important that 3D-G2-Dox (unlike the G2-Dox) accumulated in normal cells worse than free Dox (p<0.01). Thus, the results indicate that the use of 3D-G2-Dox is the most promising because it accumulates in tumor cells better and in normal cells worse than free Dox. Furthermore it can be assumed that the use of 3D-G2-Dox would be especially useful in cases of multi-drug resistance associated with the high expression of P-glycoprotein.

Recombinant human alpha fetoprotein synergistically potentiates the anti-cancer effects of 1'-S-1'-acetoxychavicol acetate when used as a complex against human tumours harbouring AFP-receptors.

PURPOSE: Previous in vitro and in vivo studies have reported that 1'-S-1'-acetoxychavicol acetate (ACA) isolated from rhizomes of the Malaysian ethno-medicinal plant Alpinia conchigera Griff (Zingiberaceae) induces apoptosis-mediated cell death in tumour cells via dysregulation of the NF-κB pathway. However there were some clinical development drawbacks such as poor in vivo solubility, depreciation of biological activity upon exposure to an aqueous environment and non-specific targeting of tumour cells. In the present study, all the problems above were addressed using the novel drug complex formulation involving recombinant human alpha fetoprotein (rhAFP) and ACA. EXPERIMENTAL DESIGN: To study the synergistic effect of both agents on human cancer xenografts, athymic nude (Nu/Nu) mice were used and treated with various combination regimes intraperitoneally. Serum levels of tumour markers for carcinoembryonic antigen (CEA) and prostate specific antigen (PSA) were assessed using sandwich ELISA. IHC and Western blotting were also conducted on in vivo tumour biopsies to investigate the involvement of NF-κB regulated genes and inflammatory biomarkers. Quantification and correlation between drug efficacies and AFP-receptors were done using IF-IC and Pearson's correlation analysis. RESULTS: Mice exposed to combined treatments displayed higher reductions in tumour volume compared to stand alone agents, consistent with in vitro cytotoxicity assays. Milder signs of systemic toxicity, such as loss in body weight and inflammation of vital organs were also demonstrated compared to stand alone treatments. Tumour marker levels were consistent within all rhAFP/ACA treatment groups where levels of CEA and PSA were initially elevated upon commencement of treatment, and consecutively reduced corresponding to a decrease in tumour bulk volume. Both IHC and Western blotting results indicated that the combined action of rhAFP/ACA was not only able to down-regulate NF-κB activation, but also reduce the expression of NF-κB regulated genes and inflammatory biomarkers. The efficacy of rhAFP/ACA complex was also found to be weakly negatively correlated to the level of surface AFP-receptors between tumour types. CONCLUSIONS: This drug complex formulation shows great therapeutic potential against AFP-receptor positive tumours, and serves as a basis to overcome insoluble and non-specific anti-neoplastic molecules.

Analysis of Y-P30/Dermcidin expression and properties of the Y-P30 peptide.

BACKGROUND: The survival promoting peptide Y-P30 has a variety of neuritogenic and neuroprotective effects in vitro and in vivo. In previous work we reported the expression of Y-P30/dermcidin in maternal peripheral blood mononuclear cells (PBMCs) and the transport of the protein to the fetal brain. In this study we analyzed hormonal regulation of Y-P30 in human immune cells and expression of Y-P30 in the placenta. We further studied the stability and secretion of the Y-P30 peptide. RESULTS: We found indications that Y-P30 might be produced in human placenta. The Y-P30 mRNA was rarely found in isolated human PBMCs and alpha-feto-protein, human chorionic gonadotropin as well as estradiol combined with progesterone could not induce Y-P30 expression. Y-P30 was found to be extraordinarily stable; therefore, contamination with the peptide and the Y-P30/Dermcidin precursor mRNA is a serious concern in experiments looking at the expression of Y-P30/Dermcidin. In cultured cell lines and primary neurons we found that Y-P30 could be released, but neuronal uptake of Y-P30 was not observed. CONCLUSIONS: Our data suggest that a source of Y-P30 apart from eccrine glands might be the placenta. The peptide can be secreted together with the signaling peptide and it might reach the fetal brain where it can exert its neuritogenic functions by binding to neuronal membranes.

Cancer targeting gene-viro-therapy specific for liver cancer by α-fetoprotein-controlled oncolytic adenovirus expression of SOCS3 and IL-24.

The combination of gene therapy and virotherapy for cancer treatment has received close attention and has become a trend in the field of cancer biotherapy. A strategy called 'Cancer Targeting Gene-Viro-Therapy' (CTGVT) or 'Gene Armed Oncolytic Viral Therapy' (GAOVT) has been proposed, in which an antitumor gene is inserted into an oncolytic viral vector. In our previous study, a dual-regulated oncolytic adenovirus with enhanced safety for normal cells and strict liver cancer-targeting ability, designated Ad•enAFP•E1A•E1B (Δ55) (briefly Ad•enAFP•D55), was successfully constructed. In the current work, interleukin-24 (IL-24) and suppressor of cytokine signaling 3 (SOCS3) genes were packaged into Ad•enAFP•D55. The new constructs, Ad•enAFP•D55-(IL-24) and Ad•enAFP•D55-(SOCS3), showed improved tumoricidal activity in hepatoma cell lines compared with the oncolytic viral vector Ad•enAFP•D55. The co-administration of Ad•enAFP•D55-(IL-24) and Ad•enAFP•D55-(SOCS3) showed much better antitumor effect than Ad•enAFP•D55-(IL-24) or Ad•enAFP•D55-(SOCS3) alone both in vitro and in a nude mouse xenograft model. Moreover, our results also showed that blockade of the Jak/Stat3 pathway by Ad•enAFP•D55-(SOCS3) infection in HuH-7 cells could down-regulate some anti-apoptosis proteins, such as XIAP, Bcl-xL, and survivin, which might sensitize the cells to Ad•enAFP•D55-(IL-24)-induced apoptosis. These results indicate that co-administration of Ad•enAFP•D55-(IL-24) and Ad•enAFP•D55-(SOCS3) may serve as a candidate therapeutic approach for the treatment of liver cancer.

α-Fetoprotein impairs activation of natural killer cells by inhibiting the function of dendritic cells.

α-Fetoprotein (AFP) is a tumour-associated antigen in hepatocellular carcinoma (HCC). The biological properties of AFP have been identified in its regulatory effects on immune responses of T cells and B cells. However, AFP effects on natural killer (NK) cells are still unclear. In this study, we examined the immunoregulation of AFP on NK activity. The cytolytic activity against K562 cells and Huh7 cells of NK cells co-cultured with AFP-treated dendritic cells (DCs) (AFP-DCs) was lower than that with albumin-treated DCs (Alb-DCs). Direct addition of AFP to NK cells did not alter the cytolytic activity of NK cells. Adding AFP inhibited the interleukin (IL)-12 production of DCs after stimulation with lipopolysaccharide (LPS) [Toll-like receptor (TLR)-4 ligand], or Poly(I:C) (TLR-3 ligand), but not IL-18 production. The mRNAs of IL-12p35 and IL-12p40 were significantly inhibited in AFP-DCs compared with Alb-DCs, but those of TLR-4 or TLR-3 were not. Transwell experiments revealed that soluble factors derived from DCs played roles in inhibition of the ability of activating NK cells by AFP-DCs. Adding the neutralizing antibody of IL-12 to NK cells co-cultured with Alb-DCs resulted in a decrease of cytolytic activity to the levels of NK cells co-cultured with AFP-DCs. Adding IL-12 to NK cells co-cultured with AFP-DCs resulted in an increase of cytolytic activity to the levels of NK cells co-cultured with Alb-DCs. These demonstrated that the impairment of IL-12 production from AFP-DCs resulted in inhibition of the ability of the activation of NK cells by DCs, and thus suggests a role of AFP in HCC development.

Immunoregulatory effects of AFP domains on monocyte-derived dendritic cell function.

BACKGROUND: Alpha-fetoprotein (AFP) is a tumor-associated glycoprotein that functions in regulation of both ontogenic and oncogenic growth. Recent study showed that AFP can induce apoptosis or impair monocyte-derived dendritic cell (MDDC) function. However, it is still unclear which AFP domain (D-AFP) plays major role in this function. RESULTS: As expected monocytes cultured in the presence of Granulocyte Macrophage-Colony Stimulating Factor (GM-CSF) and Interleukin-4 (IL-4) developed into MDDC. Up-regulation of HLA-DR and CD11c as well as loss of CD14 molecules could be observed. Full length AFP (FL-AFP), domain 2 AFP (D2-AFP) and D3-AFP, but not D1-AFP, significantly inhibited the expression of HLA-DR high/CD11c high and CD80+/CD86 high molecules. In contrast, CD83 expression was substantially down-regulated in all samples. Expression of CD40 was significantly suppressed by FL-AFP but not by any D-AFPs. Finally, both FL-AFP and D-AFP impaired the MDDC ability to secrete IL-12 (p70). CONCLUSIONS: D2- and D3- but not D1-AFP extensively suppresses the MDDC function. All the recombinant AFP proteins impaired the ability of MDDC to secrete IL-12.