Divergent clinical outcomes in a phase 2B trial of the TLPLDC vaccine in preventing melanoma recurrence and the impact of dendritic cell collection methodology: a randomized clinical trial.

BACKGROUND: A randomized, double-blind, placebo-controlled phase 2b trial of the tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine was conducted in patients with resected stage III/IV melanoma. Dendritic cells (DCs) were harvested with and without granulocyte-colony stimulating factor (G-CSF). This analysis investigates differences in clinical outcomes and RNA gene expression between DC harvest methods. METHODS: The TLPLDC vaccine is created by loading autologous tumor lysate into yeast cell wall particles (YCWPs) and exposing them to phagocytosis by DCs. For DC harvest, patients had a direct blood draw or were pretreated with G-CSF before blood draw. Patients were randomized 2:1 to receive TLPLDC or placebo. Differences in disease-free survival (DFS) and overall survival (OS) were evaluated. RNA-seq analysis was performed on the total RNA of TLPLDC + G and TLPLDC vaccines to compare gene expression between groups. RESULTS: 144 patients were randomized: 103 TLPLDC (47 TLPLDC/56 TLPLDC + G) and 41 placebo (19 placebo/22 placebo + G). Median follow-up was 27.0 months. Both 36-month DFS (55.8% vs. 24.4% vs. 30.0%, p = 0.010) and OS (94.2% vs. 69.8% vs. 70.9%, p = 0.024) were improved in TLPLDC compared to TLPLDC + G or placebo, respectively. When compared to TLPLDC + G vaccine, RNA-seq from TLPLDC vaccine showed upregulation of genes associated with DC maturation and downregulation of genes associated with DC suppression or immaturity. CONCLUSIONS: Patients receiving TLPLDC vaccine without G-CSF had improved OS and DFS. Outcomes remained similar between patients receiving TLPLDC + G and placebo. Direct DC harvest without G-CSF had higher expression of genes linked to DC maturation, likely improving clinical efficacy.

A phase I/IIa clinical trial in stage IV melanoma of an autologous tumor-dendritic cell fusion (dendritoma) vaccine with low dose interleukin-2.

BACKGROUND: Stage IV melanoma has high mortality, largely unaffected by traditional therapies. Immunotherapy including cytokine therapies and checkpoint inhibitors improves outcomes, but has significant toxicities. In this phase I/IIa trial, we investigated safety and efficacy of a dendritoma vaccine, an active, specific immunotherapy, in stage IV melanoma patients. METHODS: Autologous tumor lysate and dendritic cells were fused creating dendritoma vaccines for each patient. Phase I patients were vaccinated every 3 months with IL-2 given for 5 days after initial inoculation. Phase IIa patients were vaccinated every 6 weeks with IL-2 given on days 1, 3 and 5 after initial inoculation. Toxicity and clinical outcomes were assessed. RESULTS: Twenty-five patients were enrolled and inoculated. All dendritoma and IL-2 toxicities were

Prospective, randomized, double-blind phase 2B trial of the TLPO and TLPLDC vaccines to prevent recurrence of resected stage III/IV melanoma: a prespecified 36-month analysis.

BACKGROUND: The tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine is made by ex vivo priming matured autologous dendritic cells (DCs) with yeast cell wall particles (YCWPs) loaded with autologous tumor lysate (TL). The tumor lysate, particle only (TLPO) vaccine uses autologous TL-loaded YCWPs coated with silicate for in vivo DC loading. Here we report the 36-month prespecified analyses of this prospective, randomized, double-blind trial investigating the ability of the TLPO and TLPLDC (±granulocyte-colony stimulating factor (G-CSF)) vaccines to prevent melanoma recurrence in high-risk patients. METHODS: Patients with clinically disease-free stage III/IV melanoma were randomized 2:1 initially to TLPLDC versus placebo (n=124) and subsequently TLPO versus TLPLDC (n=63). All patients were randomized and blinded; however, the placebo control arm was replaced in the second randomization scheme with another novel vaccine; some analyses in this paper therefore reflect a combination of the two randomization schemes. Patients receiving the TLPLDC vaccine were further divided by their method of DC harvest (with or without G-CSF pretreatment); this was not randomized. The use of standard of care checkpoint inhibitors was not stratified between groups. Safety was assessed and Kaplan-Meier and log-rank analyses compared disease-free (DFS) and overall survival (OS). RESULTS: After combining the two randomization processes, a total of 187 patients were allocated between treatment arms: placebo (n=41), TLPLDC (n=103), or TLPO (n=43). The allocation among arms created by the addition of patients from the two separate randomization schemes does not reflect concurrent randomization among all treatment arms. TLPLDC was further divided by use of G-CSF in DC harvest: no G-CSF (TLPLDC) (n=47) and with G-CSF (TLPLDC+G) (n=56). Median follow-up was 35.8 months. Only two patients experienced a related adverse event ≥grade 3, one each in the TLPLDC+G and placebo arms. DFS was 27.2% (placebo), 55.4% (TLPLDC), 22.9% (TLPLDC+G), and 60.9% (TLPO) (p<0.001). OS was 62.5% (placebo), 93.6% (TLPLDC), 57.7% (TLPLDC+G), and 94.6% (TLPO) (p=0.002). CONCLUSIONS: The TLPO and TLPLDC (without G-CSF) vaccines were associated with improved DFS and OS in this clinical trial. Given production and manufacturing advantages, the efficacy of the TLPO vaccine will be confirmed in a phase 3 trial. TRIAL REGISTRATION NUMBER: NCT02301611.

Effects of cardiac overexpression of type 6 adenylyl cyclase affects on the response to chronic pressure overload.

Adenylyl cyclase (AC) type 5 (AC5) and AC type 6 (AC6) are the two major AC isoforms in the heart. Cardiac overexpression of AC6 has been shown to be protective in response to several interventions. In this investigation, we examined the effects of chronic pressure overload in AC6 transgenic (TG) mice. In the absence of any stress, AC6 TG mice exhibited enhanced contractile function compared with their wild-type (WT) littermates, i.e., increased (P < 0.05) left ventricular (LV) ejection fraction (EF) (75 +/- 0.9 vs. 71 +/- 0.5%) and LV dP/dt (7,850 +/- 526 vs. 6,374 +/- 315 mmHg/s). Forskolin (25 microg x kg(-1) x min(-1) for 5 min) increased LVEF more (P < 0.05) in AC6 TG mice (14.8 +/- 1.0%) than in WT mice (7.7 +/- 1.0%). Also, isoproterenol (0.04 microg x kg(-1) x min(-1) for 5 min) increased LVEF more (P < 0.05) in AC6 TG mice (18.0 +/- 1.2%) than in WT mice (11.6 +/- 2.1%). Pressure overload, induced by 4 wk of transverse aortic constriction (TAC), increased the LV weight-to-body weight ratio and myocyte cross-sectional area similarly in both groups, but reduced LVEF more in AC6 TG mice (22%) compared with WT mice (9%), despite the higher starting level of LVEF in AC6 TG mice. LV systolic wall stress increased more in AC6 TG mice than in WT mice, which could be responsible for the reduced LVEF in AC6 TG mice with chronic pressure overload. In addition, LV dP/dt was no longer elevated in AC6 TG mice after TAC compared with WT mice. LV end-diastolic diameter was also greater (P < 0.05) in AC6 TG mice (3.8 +/- 0.07 mm) than in WT mice (3.6 +/- 0.05 mm) after TAC. Thus, in contrast to other interventions previously reported to be salutary with cardiac AC6 overpression, the response to chronic pressure overload was not; actually, AC6 TG mice fared worse than WT mice. The mechanism may be due to the increased LV systolic wall stress in AC6 TG mice with chronic pressure overload.

Fermented Noni Exudate-treated dendritic cells directly stimulate B lymphocyte proliferation and differentiation.

Noni juice as a folk medicine has been used for over two thousand years. Recently, some active ingredients of Noni juice have been successfully isolated and intensively studied. Because dendritic cells (DCs) are central regulators both in priming innate and adaptive immune responses and in maintaining self tolerance, in the current study we treated DCs with fermented Noni Exudate (fNE) in order to explore their function in regulating other immune cells. It was shown that fNE-treated DCs stimulate proliferation of splenocytes, among which, B cells are the major responsive cell group. The proliferative response of B cells to fNE-treated DCs is cell contact-dependent, CD40L-independent; and the adhesion feature of DCs was enhanced to form large DC-B conjugation cluster. Moreover, it was demonstrated that fNE-treated DCs promote B cell differentiation and Ig class switching. These results lay a foundation for the further exploration of fNE as a biological response modifier in the immune system.

Fermented Noni exudate (fNE): a mediator between immune system and anti-tumor activity.

The anti-tumor activity of Morinda citrifolia fruit juice (Noni) has been previously reported. However, the mechanism behind this activity remains unknown. In the present study, we studied the anti-tumor activity of fermented Noni exudate (fNE) and demonstrated that intraperitoneal injection of this material significantly increased the percentages of granulocytes and NK cells in the peripheral blood, peritoneum, and spleen. Furthermore, in preventive and treatment settings, fNE injection induced complete tumor rejection in normal C57BL/6J mice, partial tumor rejection in C57 nude mice lacking functional lymphocytes, and no tumor rejection in NK cell deficient beige mice. Over 85% of the C57BL/6J mice that received fNE survived the first tumor injection and rejected up to 5 x 10(6) tumor cells when re-challenged. The anti-tumor activity remains in the heat-inactivated and filtrated supernatant of fNE. These data demonstrate that fNE appears to be able to stimulate the innate immune system and the adaptive immune system to reject tumor cells. NK cells respond quickly and appear to be among the major players of the innate immune system, while the adaptive immune system reacts later with a retained memory.

Tumor lysate particle loaded dendritic cell vaccine: preclinical testing of a novel personalized cancer vaccine.

AIM: We developed a novel approach to efficiently deliver autologous tumor antigens to the cytoplasm of dendritic cells (DC) using yeast cell wall particles (YCWP). MATERIALS AND METHODS: Loading of YCWP, leakage of protein from loaded YCWP and cytoplasmic delivery of YCWP content was assessed using fluorescent-tagged experiments. Spectrophotometric analysis compared the epitope-specific T-cell responses following antigen presentation via YCWP versus exogenous loading. The in vivo effectiveness of tumor lysate (TL) particle loaded DC (TLPLDC) vaccine was assessed using murine melanoma models. RESULTS: In fluorescence-tagged experiments, YCWP efficiently delivered antigen to the cytoplasm of DC. TLPLDC loading was more effective than conventional exogenous loading of DC. Finally, in murine melanoma models, TLPLDC outperformed an analogous dendritoma vaccine. CONCLUSION: The TLPLDC vaccine is commercially scalable and holds the potential of producing personalized vaccines.

Initial phase I/IIa trial results of an autologous tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine in patients with solid tumors.

INTRODUCTION: Tumor vaccines use various strategies to generate immune responses, commonly targeting generic tumor-associated antigens. The tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine is produced from DC loaded with autologous tumor antigens, creating a patient-specific vaccine. Here, we describe initial phase I/IIa trial results. METHODS: This trial includes patients with any stage solid tumors, ECOG ≤1, and >4 months life-expectancy. A personalized vaccine is created using 1 mg of tumor and 120 ml blood (to isolate DC). Primary vaccination series (PVS) is four monthly inoculations. Patients are followed per standard of care (SOC). Endpoints include safety and tumor response (RECIST v1.1). RESULTS: 44 patients were enrolled and vaccinated consisting of 31 late stage patients with residual/measurable disease, and 13 disease-free patients after SOC therapies. While 4 patients progressed before completing the PVS, 12/31 (39%) demonstrated clinical benefit (2 complete responses, 4 partial responses, 6 stable disease). In the adjuvant setting, 46% of late stage patients remain disease free at a median of 22.5 months. CONCLUSIONS: The TLPLDC vaccine is scalable, generates a personalized DC vaccine, and requires little autologous tumor tissue and few DC. The vaccine is safe, with primarily grade 0-2 toxicities, and nearly 40% clinical benefit rate in varied tumors, warranting further study. TRIAL REGISTRATION: ISRCTN81339386, Registered 2/17/2016.

Transfer of in vitro expanded T lymphocytes after activation with dendritomas prolonged survival of mice challenged with EL4 tumor cells.

Adoptive T cell transfer after in vitro expansion represents an attractive cancer immunotherapy. The majority of studies so far have been focusing on the expansion of tumor infiltrated lymphocytes (TIL) and some have shown very encouraging results. Recently, we have developed a unique tumor immune response activator, dendritomas, by fusion of dendritic cells and tumor cells. Animal studies and early clinical trials have shown that dendritomas are able to activate tumor specific immune responses. In this study, we hypothesized that naïve T cells can be primed with dendritomas and expanded in vitro to develop an adoptive transfer therapy for patients who do not have solid tumors, such as leukemia. T cells were isolated and purified from lymph nodes of mice. The cells were then incubated with dendritomas made from syngeneic DCs and tumor cells and expanded in vitro using Dynabeads mouse CD3/CD28 T cell expander for approximately three weeks. The in vitro primed and expanded T cells showed tumor cell specific CTL activity and increased secretion of IFN-gamma. Tumor bearing mice receiving the in vitro expanded T cells survived significantly longer than control mice. Furthermore, the depletion of regulator T cells enhanced the survival of the mice that received the adoptive transfer therapy.

Combined treatment of dendritoma vaccine and low-dose interleukin-2 in stage IV renal cell carcinoma patients induced clinical response: A pilot study.

Vaccination using dendritic/tumor cell hybrids represents a novel and promising cancer immunotherapy. We have developed a technology that can instantly purify the hybrids (dendritomas) from the fusion mixture of dendritic cells (DCs) and tumor cells. Our animal studies and a phase I study of stage IV melanoma patients demonstrated that dendritoma vaccination could be conducted without major toxicity and induced tumor cell-specific immunological and clinical responses. In this pilot study, ten stage IV renal cell carcinoma patients were studied. Dendritomas were made from autologous DCs and tumor cells and administered by subcutaneous injection. After initial vaccination, three escalating doses of IL-2 (3, 6, and 9 million units each) were followed within five days. This treatment regimen was tolerated well without severe adverse events directly related to the dendritoma vaccine. Most adverse events were related to IL-2 administration or pre-existing disease. Patient-specific immune responses were evaluated by flow cytometric measurement of interferon-gamma-producing T-cells before and after vaccination in response to stimulation with tumor antigens. Nine out of nine patients eligible for the analysis showed an increase of IFN-gamma-expressing CD4+ T cells after vaccination(s); while five out of eight patients eligible for the analysis showed an increase of IFN-gamma-expressing CD8+ T cells. Clinical responses were documented in 40% of the patients, three with stabilization of disease and one with a partial response documented by a reduction in tumor size. This pilot study demonstrated that dendritoma vaccines could be administered safely to patients with metastatic renal cell carcinoma, while producing both clinical and immunologic evidence of response.

Dendritoma vaccination combined with low dose interleukin-2 in metastatic melanoma patients induced immunological and clinical responses.

A pilot clinical trial using dendritomas, purified hybrids from the fusion of dendritic/tumor cells combined with a low dose of IL-2, in metastatic melanoma patients was conducted in order to determine its safety and potential immunological and clinical responses. Ten metastatic melanoma patients were enrolled into this study. Dendritoma vaccines were created by fusing dendritic cells stained with green fluorescent dye with irradiated autologous tumor cells stained with red fluorescent dye and purifying the hybrids using immediate fluorescent-activated cell sorting. Initial vaccine was given subcutaneously and followed by IL-2 in serially elevated doses from 3-9 million units/m2 for 5 days. Repeated vaccinations were administered without IL-2, at 3-month intervals for a maximum of 5 times. Immune reactions were measured by the increase of interferon-gamma (IFN-gamma) expressing T cells. Vaccine doses ranged from 250,000 to 1,000,000 dendritomas. There was no grade 2 or higher toxicity directly attributable to the vaccine. All patients experienced toxicity due to IL-2 administration (9-grade 2, 3-grade 3, 1-grade 4). Eight of nine evaluable patients demonstrated immunologic reactions by increased IFN-gamma expressing T cells. One patient developed partial response at 12 weeks after the first vaccine. Nine months later, this patient achieved a complete response. In addition, two patients had stable disease for 9 and 4 months, respectively; one patient had a mixed response. Our findings demonstrated that dendritoma vaccines with a low dose of IL-2 can be safely administered to patients with metastatic melanoma and induce immunological and clinical responses.

Glycoinositol phospholipid-anchored interleukin 2 but not secreted interleukin 2 inhibits melanoma tumor growth in mice.

Whereas cancer immunotherapy with interleukin (IL) 2 and/or other cytokines has proved effective in activating immune responses against tumor cells, the major obstacle with the use of these cytokines in cancer patients is their severe side effects when delivered systemically at high doses. In an effort to overcome this problem, in the present study, a fusion protein containing human IL-2 and a glycoinositol phospholipid (GPI) anchor sequence of decay accelerating factor was generated. When expressed by transfected cells, these fusion proteins were presented on the cell surface in the GPI-anchored form as demonstrated by fluorescence-activated cell sorter and ELISA analyses. This GPI-anchored IL-2 is highly functional as indicated by significantly increased T-cell infiltration in tumor masses. Immunohistochemical analysis of tumor cells isolated from experimental tumors indicated that a local high level of IL-2 was achieved by GPI-anchored IL-2. More importantly, when injected into mice i.v., the growth of these B16F0 melanoma cells that were engineered to express this fusion protein was significantly inhibited. In contrast, the inhibition of secreted IL-2 on tumor growth was not observable in this study. These studies may provide a novel approach to locally deliver high doses of cytokines for cancer immunotherapy.

Fusion protein from RGD peptide and Fc fragment of mouse immunoglobulin G inhibits angiogenesis in tumor.

Targeting tumor vasculature represents an interesting approach for the treatment of solid tumors. The alpha v beta 3 integrins have been found to be specifically associated with angiogenesis in tumors. By using bacteriophage display technology, Ruoslahti et al found that a group of peptides containing the RGD (Arg-Gly-Asp) motif have high-binding affinity to the alpha v beta 3 integrins in tumors. In this study, we designed a fusion protein containing the RGD sequence and the Fc fragment of mouse IgG in order to target the Fc portion of IgG to the tumor vasculature to elicit an antiangiogenesis immune response. In vivo angiogenesis and tumor studies demonstrated that the fusion protein (RGD/mFc) inhibited tumor angiogenesis and tumor growth and improved overall survival. This approach may generate new therapeutic agents for solid tumor treatment.

Targeting foreign major histocompatibility complex molecules to tumors by tumor cell specific single chain antibody (scFv).

Down-regulation of the major histocompatibility complex (MHC) is one of the major mechanisms that tumor cells adopted to escape immunosurveillance. Therefore, specifically coating tumor cells with foreign MHC may make tumor cells a better target for immune recognition and surveillance. In this study, we designed and generated a fusion protein, H2Kd/scPSMA, consisting of a single chain antibody against human prostate specific membrane antigen (PSMA) and the extracellular domain of mouse H-2Kd. The expression of this fusion protein in B16F0 mouse melanoma cells was confirmed by RT-PCR and fluorescent activated cell sorting (FACS). Our animal study showed that the expression of H2Kd/scPSMA in B16F0/PSMA5, a B16F0 cell line expressing human PSMA, significantly inhibited tumor growth as demonstrated in the pulmonary metastasis assay and tumor growth study and improved overall survival.

Inhibition or promotion of tumor growth by granulocyte-macrophage colony stimulating factor derived from engineered tumor cells is dose-dependent.

BACKGROUND: Granulocyte-macrophage colony stimulating factor (GM-CSF) has been widely investigated as an adjuvant factor for tumor immunotherapy. However, the results are controversial with antitumor effects in some studies and a tumor growth promotion effect in others. MATERIALS AND METHODS: In order to determine whether there is a dose-dependent effect of GM-CSF on tumor growth, murine GM-CSF-expressing vector was constructed and transfected into TC-1 tumor cells and various clones stably expressing different levels of GM-CSF were obtained. The growth of these clones in vivo was studied. RESULTS: Although these clones grow at a similar rate in vitro, their growth in vivo is dramatically different. Clones expressing high levels (>10,000 pg/ml) of GM-CSF grow significantly faster than the control (p <0.001); clones expressing low levels (<100 pg/ml) of GM-CSF grow significantly slower than the control (p<0.001); while clones expressing intermediate levels (1000-2000 pg/ml) of GM-SCF grow at a similar rate as the control (p >0. 05). The high levels of GM-CSF secreted by tumor cells induced granulocytosis and lymphopenia. The antitumor growth effect induced by low levels of GM-CSF is not due to the function of lymphocytes. CONCLUSION: The inhibition or promotion of tumor growth by GM-CSF secreted from tumor cells is dose-dependent.

A biotin-streptavidin-biotin bridge dramatically enhances cell fusion.

Although the generation of hybrid cells by cell fusion plays a significant role in biotechnology and biomedicine, the low cell-fusion rates and the limitation of large-scale cell fusion for clinical applications of the two widely used approaches, polyethylene-glycol (PEG)-mediated cell fusion and electrofusion, hinder the application of this critical technology in certain key areas, including cancer immunotherapy. In the present study, a simple procedure that can not only significantly increase the heterologous cell fusion but is also capable of producing fused cells on a large scale is reported. A biotin-streptavidin-biotin (BSB) bridge was created by coating one to-be-fused cell with biotin and the other with biotin-streptavidin. The BSB bridge enhances cell-fusion rates induced with PEG fusion or electrofusion by 10-30% depending on the cell types when compared with cell fusions without the bridge. The procedure described increases heterologous cell pairing and eliminates the alignment step required for the majority of electrofusions. Notably, it can be used to make large-scale cell fusions for clinical applications.

'Reduced malignancy as a mechanism for longevity in mice with adenylyl cyclase type 5 disruption'.

Disruption of adenylyl cyclase type 5 (AC5) knockout (KO) is a novel model for longevity. Because malignancy is a major cause of death and reduced lifespan in mice, the goal of this investigation was to examine the role of AC5KO in protecting against cancer. There have been numerous discoveries in genetically engineered mice over the past several decades, but few have been translated to the bedside. One major reason is that it is difficult to alter a gene in patients, but rather a pharmacological approach is more appropriate. The current investigation employs a parallel construction to examine the extent to which inhibiting AC5, either in a genetic knockout (KO) or by a specific pharmacological inhibitor protects against cancer. This study is unique, not only because a combined genetic and pharmacological approach is rare, but also there are no prior studies on the extent to which AC5 affects cancer. We found that AC5KO delayed age-related tumor incidence significantly, as well as protecting against mammary tumor development in AC5KO × MMTV-HER-2 neu mice, and B16F10 melanoma tumor growth, which can explain why AC5KO is a model of longevity. In addition, a Food and Drug Administration approved antiviral agent, adenine 9-ß-D-arabinofuranoside (Vidarabine or AraAde), which specifically inhibits AC5, reduces LP07 lung and B16F10 melanoma tumor growth in syngeneic mice. Thus, inhibition of AC5 is a previously unreported mechanism for prevention of cancers associated with aging and that can be targeted by an available pharmacologic inhibitor, with potential consequent extension of lifespan.

An IL-12/Shh-C domain fusion protein-based IL-12 autocrine loop for sustained natural killer cell activation.

The dependency of activated natural killer (NK) cells on the continuous support of exogenous interleukin (IL)-2 for their in vivo survival, tumor localization and consequently, their antitumor effect, is a major obstacle for NK cell-mediated tumor therapy. In the present study, a fusion gene between IL-12 and mouse sonic hedgehog C-terminal domain (Shh-C) was constructed. The fusion protein was autocatalytically processed to form cholesterol-modified IL-12 molecules and an autocrine loop of IL-12 was established for the sustained activation of NK cells. The transduced NK cells matured more rapidly in vitro with the enhanced expression of granule-related proteins. NKIL-12/Shh-C cells reached the same proliferation rate as NK cells transduced with enhanced green fluorescent protein (EGFP)/Shh-C (NKEGFP/Shh-C) with <10-fold IL-2 supplementation, suggesting that the fusion protein reduced the dependency of NK cells on IL-2. The amount of interferon­Î³ (IFN-γ) in the supernatants of NKIL-12/Shh-C cells 5 and 7 days after transduction was significantly higher than that in the supernatants of NKIL-12 cells. Immunofluorescent staining of lung tissues from B16-bearing mice which had received an intravenous injection of lentivirus-transduced NK cells without exogenous IL-2 confirmed that donor NK cells successfully infiltrated into the lung tissues. The survival time of the mice which had received NKIL-12/Shh-C cells was significantly prolonged compared to the mice which had received NKEGFP/Shh-C cells.

Antitumor and anti-angiogenic activities of Scutellaria barbata extracts in vitro are partially mediated by inhibition of Akt/protein kinase B.

The Akt pathway is considered a pivotal player in regulating cell survival, growth, migration and angiogenesis. Disruption of normal Akt/PKB/PTEN signaling frequently occurs in numerous types of human cancers. Therefore, this signaling pathway is regarded as an important target for effective cancer therapeutic strategies. In the present study, methanol extracts from Scutellaria barbata (S. barbata) were determined to be Akt/protein kinase B inhibitory, after screening a panel of 40 traditional Chinese herbs with the Fast Activated Cell-based ELISA (FACE) assay. S. barbata extracts were found to suppress the phosphorylation levels of Akt. This inhibition was Akt kinase-specific as it had no effect on PI3K, the upstream kinase of Akt, whereas the levels of phosphorylated Bad and FHKR, the two downstream targets of Akt, changed as the levels of Akt changed. S. barbata extracts also exhibited cytotoxicity against LoVo and human umbilical vein endothelial cells (HUVECs). Furthermore, this extract inhibited the process of in vitro angiogenesis of HUVECs on Matrigel. S. barbata may be a suitable alternative source with which to isolate small molecules for use as Akt kinase inhibitors.

Fusion induced reversal of dendritic cell maturation: an altered expression of inflammatory chemokine and chemokine receptors in dendritomas.

Dendritic cell-mediated cancer immunotherapy employs several ways to engage tumor antigens. We have demonstrated in both pre-clinical animal studies and early clinical trials that dendritomas, highly purified hybrids between dendritic cells (DC) and tumor cells, are superior activators of anti-tumor immunity. It has been argued, however, that DC vaccines may be dysfunctional in lymph node migration. In the present study we examined inflammatory chemokine and chemokine receptor expression as well as other maturation induced genes in dendritomas produced from either immature or mature DCs in order to shed light on their capacity to migrate from injection sites to draining lymph nodes and elicit an appropriate immune response. RNA microarray analysis was used to identify gene expression profiles for inflammatory chemokines and receptors and other maturation induced genes within dendritomas, lysate-pulsed dendritic cells, immature DCs and mature DCs. Gene regulation was confirmed with relative quantification, real-time RT-PCR in a separate experiment. We found that fusion of immature DCs to tumor cells initiates maturation with respect to inflammatory chemokines, chemokine receptors and other maturation induced genes in a similar pattern as LPS matured DCs. Interestingly, we saw a reversed gene profile when mature DCs were fused to tumor cells. LPS matured DCs displayed the chemokine repertoire expected with DC maturation; however, once fused to tumor cells, these chemokines and other maturation induced genes reverted to levels comparable to immature DCs. It appears that mature DCs used for dendritoma production result in a de-mature genotype. Our results indicate that dendritomas from immature DC/tumor cell fusions may be more effective in migration from injection site to draining lymph nodes and, therefore, would be more effective in stimulating anti-tumor immunity.