Improved short- and long-term XTT-based colorimetric cellular cytotoxicity assay for melanoma and other tumor cells

Preparation and characterization of amidated pectin-gelatin-oxidized tannic acid hydrogel films supplemented with in-situ reduced silver nanoparticles for wound-dressing applications

Wound dressings play a crucial role in protecting injured tissues and promoting the healing process. Traditional fabrication of antibacterial wound dressings can be complex and may involve toxic components. In this study, we developed an innovative hydrogel film (AP:GE@OTA/Ag) composed of amidated pectin (AP), gelatin (GE), oxidized tannic acid (OTA) at varying concentrations, and in-situ reduced silver nanoparticles (AgNPs). FTIR and XRD analyses confirmed that crosslinking occurs via interactions between OTA quinone groups and free amino groups in AP and GE. TEM imaging demonstrated the well-dispersed AgNPs with an average particle size of 58.64 nm, while the TG measurements indicated the enhancement of the thermal stability compared to AP:GE films. The AP:GE@OTA/Ag films exhibited superior fluid uptake ability (90.96 % at 2 h), water retention capacity (91.69 % at 2 h), and water vapor transmission rate (1903.29 g/m2/day), alongside improved tensile strength (38 MPa). Additionally, these films showed excellent cytocompatibility and sustained potent antimicrobial activity against S. aureus and E. coli with low AgNPs loadings of 1.02 ± 0.13 μg/cm2. NIT-1 mouse insulinoma cells demonstrated robust proliferation when cultured with the prepared dressings. These films significantly accelerated wound repair in a skin excision model, indicating their potential clinical applications for wound healing.

Encapsulated probiotic Lactiplantibacillus strains with promising applications as feed additives for broiler chickens

Lactic acid bacteria (LAB), particularly Lactobacilli strains, represent a widely studied and promising group of probiotics with numerous potential health benefits. In this study, we isolated LAB strains from fecal samples of healthy broiler chickens and characterized their probiotic properties. Out of 62 initial isolates, five strains were selected for further investigations based on their antibacterial activity against pathogenic bacteria. These selected strains were identified as Lactiplantibacillus species. They exhibited desirable probiotic traits, including non-hemolyis, non-cytotoxicity, lack of antibiotic resistance, acid tolerance, auto-aggregation, and antioxidative potential. Encapsulation of these strains in alginate beads enhanced their survival compared to free cells, in stomach (69-87 % vs. 34-47 %) and intestinal (72-100 % vs. 27-51 %) juices, after 120 min exposure. These findings suggest that encapsulated Lactiplantibacillus strains could be used as feed additives for broiler chickens. Nevertheless, further studies are needed to set on their probiotic potential in vivo.

TSPO acts as an immune resistance gene involved in the T cell mediated immune control of glioblastoma

Glioblastoma (GB) IDH-wildtype is the most malignant primary brain tumor. It is particularly resistant to current immunotherapies. Translocator protein 18 kDa (TSPO) is upregulated in GB and correlates with malignancy and poor prognosis, but also with increased immune infiltration. Here, we studied the role of TSPO in the regulation of immune resistance of human GB cells. The role of TSPO in tumor immune resistance was experimentally determined in primary brain tumor initiating cells (BTICs) and cell lines through genetic manipulation of TSPO expression and subsequent cocultures with antigen specific cytotoxic T cells and autologous tumor-infiltrating T cells. Death inducing intrinsic and extrinsic apoptotic pathways affected by TSPO were investigated. TSPO-regulated genes mediating apoptosis resistance in BTICs were identified through gene expression analysis and subsequent functional analyses. TSPO transcription in primary GB cells correlated with CD8⁺ T cell infiltration, cytotoxic activity of T cell infiltrate, expression of TNFR and IFNGR and with the activity of their downstream signalling pathways, as well as with the expression of TRAIL receptors. Coculture of BTICs with tumor reactive cytotoxic T cells or with T cell-derived factors induced TSPO up-regulation through T cell derived TNFα and IFNγ. Silencing of TSPO sensitized BTICs against T cell-mediated cytotoxicity. TSPO selectively protected BTICs against TRAIL-induced apoptosis by regulating apoptosis pathways. TSPO also regulated the expression of multiple genes associated with resistance against apoptosis. We conclude that TSPO expression in GB is induced through T cell-derived cytokines TNFα and IFNγ and that TSPO expression protects GB cells against cytotoxic T cell attack through TRAIL. Our data thereby provide an indication that therapeutic targeting of TSPO may be a suitable approach to sensitize GB to immune cell-mediated cytotoxicity by circumventing tumor intrinsic TRAIL resistance.

CAR and TCR form individual signaling synapses and do not cross-activate, however, can co-operate in T cell activation

In engineered T cells the CAR is co-expressed along with the physiological TCR/CD3 complex, both utilizing the same downstream signaling machinery for T cell activation. It is unresolved whether CAR-mediated T cell activation depends on the presence of the TCR and whether CAR and TCR mutually cross-activate upon engaging their respective antigen. Here we demonstrate that the CD3ζ CAR level was independent of the TCR associated CD3ζ and could not replace CD3ζ to rescue the TCR complex in CD3ζ KO T cells. Upon activation, the CAR did not induce phosphorylation of TCR associated CD3ζ and, vice versa, TCR activation did not induce CAR CD3ζ phosphorylation. Consequently, CAR and TCR did not cross-signal to trigger T cell effector functions. On the membrane level, TCR and CAR formed separate synapses upon antigen engagement as revealed by total internal reflection fluorescence (TIRF) and fast AiryScan microscopy. Upon engaging their respective antigen, however, CAR and TCR could co-operate in triggering effector functions through combinatorial signaling allowing logic "AND" gating in target recognition. Data also imply that tonic TCR signaling can support CAR-mediated T cell activation emphasizing the potential relevance of the endogenous TCR for maintaining T cell capacities in the long-term.

A CD19-Anti-ErbB2 scFv Engager Protein Enables CD19-Specific CAR T Cells to Eradicate ErbB2+ Solid Cancer

The efficacy of CD19-specific CAR T cells in the treatment of leukemia/lymphoma relies, at least in part, on the unique properties of the particular CAR and the presence of healthy B cells that enhance the target cell lysis and cytokine secretion through repetitive stimulation. Here, we report to apply the same CAR to target solid tumors, such as ErbB2⁺ carcinoma. CD19 CAR T cells are redirected towards the ErbB2⁺ cells by a fusion protein that is composed of the herceptin-derived anti-ErbB2 scFv 4D5 linked to the CD19 exodomain. The CD19-4D5scFv engager enabled CD19 CAR T cells to recognize the ErbB2⁺ cancer cells and to suppress the ErbB2⁺ tumor growth. The primary killing capacity by the ErbB2-redirected CD19 CAR T cells was as efficient as by the ErbB2 CAR T cells, however, adding CD19⁺ B cells furthermore reinforced the activation of the CD19 CAR T cells, thereby improving the anti-tumor activities. The ErbB2-redirected CD19 CAR T cells, moreover, showed a 100-fold superior selectivity in targeting cancer cells versus healthy fibroblasts, which was not the case for the ErbB2 CAR T cells. The data demonstrate that the CD19 CAR T cells can be high-jacked by a CD19-scFv engager protein to attack specifically solid cancer, thereby expanding their application beyond the B cell malignancies.

IL12 integrated into the CAR exodomain converts CD8+ T cells to poly-functional NK-like cells with superior killing of antigen-loss tumors

Chimeric antigen receptor (CAR)-redirected T cell therapy often fails to control tumors in the long term due to selecting cancer cells that downregulated or lost CAR targeted antigen. To reprogram the functional capacities specifically of engineered CAR T cells, we inserted IL12 into the extracellular moiety of a CD28-ζ CAR; both the CAR endodomain and IL12 were functionally active, as indicated by antigen-redirected effector functions and STAT4 phosphorylation, respectively. The IL12-CAR reprogrammed CD8⁺ T cells toward a so far not recognized natural killer (NK) cell-like signature and a CD94⁺CD56⁺CD62L^high phenotype closely similar, but not identical, to NK and cytokine induced killer (CIK) cells. In contrast to conventional CAR T cells, IL12-CAR T cells acquired antigen-independent, human leukocyte antigen E (HLA-E) restricted cytotoxic capacities eliminating antigen-negative cancer cells in addition to eliminating cancer cells with CAR cognate antigen. Simultaneous signaling through both the CAR endodomain and IL12 were required for inducing maximal NK-like cytotoxicity; adding IL12 to conventional CAR T cells was not sufficient. Antigen-negative tumors were attacked by IL12-CAR T cells, but not by conventional CAR T cells. Overall, we present a prototype of a new family of CARs that augments tumor recognition and elimination through expanded functional capacities by an appropriate cytokine integrated into the CAR exodomain.

Synthesis and biological in vitro evaluation of the effect of hydroxyimino steroidal derivatives on breast cancer cells

Breast cancer is the most common cause of cancer death in women, according to Global Cancer Observatory. This fact forces scientists to continue in the search for effective treatments against this aggressive type of cancer. Breast cancer frequently metastasizes to other organs, most often the bones, lungs, and liver. Breast cancer is normally associated with estrogen and progestogen levels and can be hormone or non-hormone dependent. In current experiments herein reported, some hydroxyimino spirostan derivatives showed great potential against MCF-7 breast cancer, a Luminal-A cancer. On the other hand, a set of synthesized 6-hydroxyimino-22-oxocholestane compounds had excellent activity against the MDA-MB-231 breast cancer cell line. The synthesis of hydroxyamino derivatives from spirostan and 22-oxocholestane compounds was improved. The hydroxyimino compounds enhanced the bioactivity when compared with their parent carbonyl skeletons.

Toxicity and Cell Density Monitoring in Monolayer and Three-dimensional Cultures with the XTT Assay

The application of viability criteria (MTT and XTT tests) to monolayer cultures and immobilised cells in three-dimensional systems was investigated in order to assess cell viability and cell proliferation. The suitability and accuracy of these tests were compared with the conventional criteria (cellular protein and DNA content) used in monolayer cultures for the same purpose. The colorimetric assay based on the metabolic reduction of the tetrazolium salt XTT to a water-soluble formazan proved to be very useful, rapid and sensitive. This automated spectrophotometric enzymatic method, due to its lack of toxicity, also permits repeated nondestructive assays on a single cellular culture for the long-term monitoring of cytotoxicity, cell survival and cell proliferation, and can be performed in 96-well plates with minimal handling. This method could offer a solution for cellular density evaluation in complex cell cultures that do not permit visual examination; it is also the best choice for protein-based, three-dimensional systems such as collagen gels.

IL7-IL12 Engineered Mesenchymal Stem Cells (MSCs) Improve A CAR T Cell Attack Against Colorectal Cancer Cells

Chimeric antigen receptor (CAR) redirected T cells are efficacious in the treatment of leukemia/lymphoma, however, showed less capacities in eliminating solid tumors which is thought to be partly due to the lack of cytokine support in the tumor lesion. In order to deliver supportive cytokines, we took advantage of the inherent ability of mesenchymal stem cells (MSCs) to actively migrate to tumor sites and engineered MSCs to release both IL7 and IL12 to promote homeostatic expansion and Th1 polarization. There is a mutual interaction between engineered MSCs and CAR T cells; in presence of CAR T cell released IFN-γ and TNF-α, chronic inflammatory Th2 MSCs shifted towards a Th17/Th1 pattern with IL2 and IL15 release that mutually activated CAR T cells with extended persistence, amplification, killing and protection from activation induced cell death. MSCs releasing IL7 and IL12 were superior over non-modified MSCs in supporting the CAR T cell response and improved the anti-tumor attack in a transplant tumor model. Data demonstrate the first use of genetically modified MSCs as vehicles to deliver immuno-modulatory proteins to the tumor tissue in order to improve the efficacy of CAR T cells in the treatment of solid malignancies.

Faecal Proteases from Pouchitis Patients Activate Protease Activating Receptor-2 to Disrupt the Epithelial Barrier

BACKGROUND AND AIMS

The pathogenesis of pouch inflammation may involve epithelial barrier disruption. We investigated whether faecal proteolytic activity is increased during pouchitis and results in epithelial barrier dysfunction through protease activating receptor [PAR] activation, and assessed whether the intestinal microbiome may be the source of the proteases.

METHODS

Faecal samples were measured for protease activity using a fluorescein isothiocyanate [FITC]-casein florescence assay. Caco-2 cell monolayers were exposed to faecal supernatants to assess permeability to FITC-dextran. Tight junction protein integrity and PAR activation were assessed by immunoblot and immunofluorescence. A truncated PAR2 protein in Caco-2 cells was achieved by stable transfection using CRISPR/Cas9 plasmid. PAR2 activation in pouch biopsies was examined using antibodies directed to the N-terminus of the protein. Microbial composition was analysed based on 16S rRNA gene sequence analysis.

RESULTS

Ten pouchitis patients, six normal pouch [NP] patients and nine healthy controls [HC] were recruited. The pouchitis patients exhibited a 5.19- and 5.35-fold higher faecal protease [FP] activity [p ≤ 0.05] compared to the NP and HC participants, respectively. The genus Haemophilus was positively associated with FP activity [R = 0.718, false discovery rate < 0.1]. Faecal supernatants from pouchitis patients activated PAR2 on Caco-2 monolayers, disrupted tight junction proteins and increased epithelial permeability. PAR2 truncation in Caco-2 abrogated faecal protease-mediated permeability. Pouch biopsies obtained from pouchitis patients, but not from NP patients, displayed PAR2 activation.

CONCLUSIONS

Protease-producing bacteria may increase faecal proteolytic activity that results in pouch inflammation through disruption of tight junction proteins and increased epithelial permeability in a PAR2-dependent manner. This mechanism may initiate or propagate pouch inflammation.

Engineered Jurkat Cells for Targeting Prostate-Specific Membrane Antigen on Prostate Cancer Cells by Nanobody-Based Chimeric Antigen Receptor

Background:

Recently, modification of T cells with CAR has been an attractive approach for adoptive immunotherapy of cancers. Typically, CARs contain a scFv. Most often, scfvs are derived from a monoclonal antibody of murine origin and may be a trigger for host immune system that leads to the T-cell clearance. Nanobody is a specific antigen-binding fragment derived from camelid that has great homology to human VH and low immunogenic potential. Therefore, in this study, nanobody was employed instead of scFv in CAR construct.

Methods:

In this study, a CAR was constructed based on a nanobody against PSMA (NBPII-CAR). At first, Jurkat cells were electroporated with NBPII-CAR, and then flow cytometry was performed for NBPII-CAR expression. For functional analysis, CAR T cells were co-cultured with prostate cancer cells and analyzed for IL-2 secretion, CD25 expression, and cell proliferation.

Results:

Flow cytometry results confirmed the expression of NBPII-CAR on the transfected Jurkat cells. Our data showed the specificity of engineered Jurkat cells against prostate cancer cells by not only increasing the IL-2 cytokine (about 370 pg/ml) but also expressing the T-cell activation marker CD25 (about 30%). In addition, proliferation of engineered Jurkat cells increased nearly 60% when co-cultured with LNCaP (PSMA⁺), as compared with DU145 (PSMA^-).

Conclusion:

Here, we describe the ability of nanobody-based CAR to recognize PSMA that leads to the activation of Jurkat cells. This construct might be used as a promising candidate for clinical applications in prostate cancer therapy.

Blocking CD30 on T Cells by a Dual Specific CAR for CD30 and Colon Cancer Antigens Improves the CAR T Cell Response against CD30- Tumors

Chimeric antigen receptor (CAR)-engineered T cells are efficacious in controlling advanced leukemia and lymphoma, however, they fail in the treatment of solid cancer, which is thought to be due to insufficient T cell activation. We revealed that the immune response of CAR T cells with specificity for carcinoembryonic antigen (CEA) was more efficacious against CEA⁺ cancer cells when simultaneously incubated with an anti-CD30 immunotoxin or anti-CD30 CAR T cells, although the targeted cancer cells lack CD30. The same effect was achieved when the anti-CD30 single-chain variable fragment (scFv) was integrated into the extracellular domain of the anti-CEA CAR. Improvement in T cell activation was due to interfering with the T cell CD30-CD30L interaction by the antagonistic anti-CD30 scFv HRS3; an agonistic anti-CD30 scFv or targeting the high-affinity interleukin-2 (IL-2) receptor was not effective. T cells with the anti-CD30/CEA CAR showed superior immunity against established CEA⁺ CD30^- tumors in a mouse model. The concept is broadly applicable since anti-CD30/TAG72 CAR T cells also showed improved elimination of TAG72⁺ CD30^- cancer cells. Taken together, targeting CD30 on CAR T cells by the HRS3 scFv within the anti-tumor CAR improves the redirected immune response against solid tumors.

Functionality and Cell Senescence of CD4/ CD8-Selected CD20 CAR T Cells Manufactured Using the Automated CliniMACS Prodigy® Platform

Clinical studies using autologous CAR T cells have achieved spectacular remissions in refractory CD19+ B cell leukaemia, however some of the patient treatments with CAR T cells failed. Beside the heterogeneity of leukaemia, the distribution and senescence of the autologous cells from heavily pretreated patients might be further reasons for this. We performed six consecutive large-scale manufacturing processes for CD20 CAR T cells from healthy donor leukapheresis using the automated CliniMACS Prodigy® platform. Starting with a CD4/CD8-positive selection, a high purity of a median of 97% T cells with a median 65-fold cell expansion was achieved. Interestingly, the transduction rate was significantly higher for CD4+ compared to CD8+ T cells and reached in a median of 23%. CD20 CAR T cells showed a good specific IFN-γ secretion after cocultivation with CD20+ target cells which correlated with good cytotoxic activity. Most importantly, 3 out of 5 CAR T cell products showed an increase in telomere length during the manufacturing process, while telomere length remained consistent in one and decreased in another process. In conclusion, this shows for the first time that beside heterogeneity among healthy donors, CAR T cell products also differ regarding cell senescence, even for cells manufactured in a standardised automated process.

Construction of a chimeric antigen receptor bearing a nanobody against prostate a specific membrane antigen in prostate cancer

Adoptive transfer of T cells expressing chimeric antigen receptors (CARs) is considered to be a novel anticancer therapy. To date, in most cases, single-chain variable fragments (scFvs) of murine origin have been used in CARs. However, this structure has limitations relating to the potential immunogenicity of mouse antigens in humans and the relatively large size of scFvs. For the first time, we used camelid nanobody (VHH) to construct CAR T cells against prostate specific membrane antigen (PSMA). The nanobody against PSMA (NBP) was used to show the feasibility of CAR T cells against prostate cancer cells. T cells were transfected, and then the surface expression of the CAR T cells was confirmed. Then, the functions of VHH-CAR T cell were evaluated upon coculture with prostate cancer cells. At the end, the cytotoxicity potential of NBPII-CAR in T cells was approximated by determining the cell surface expression of CD107a after encountering PSMA. Our data show the specificity of VHH-CAR T cells against PSMA⁺ cells (LNCaP), not only by increasing the interleukin 2 (IL-2) cytokine (about 400 pg/mL), but also the expression of CD69 by almost 38%. In addition, VHH-CAR T cells were proliferated by nearly 60% when cocultured with LNCaP, as compared with PSMA negative prostate cancer cell (DU-145), which led to the upregulation of CD107a in T cells upto 31%. These results clearly show the possibility of using VHH-based CAR T cells for targeted immunotherapy, which may be developed to target virtually any tumor-associated antigen for adoptive T-cell immunotherapy of solid tumors.

Synthesis, Spectroscopic Analysis and Assessment of the Biological Activity of New Hydrazine and Hydrazide Derivatives of 3-Formylchromone

The hydrazine and hydrazide derivatives of benzo-γ-pyrones with fluorine substituents remain an unexplored group of chemical compounds. This preliminary study reports the synthesis, structural assessment, initial microbiological screening and biological testing of the synthesized compounds on cell lines using the XTT-assay. A series of 10 novel hydrazine and hydrazide derivatives of 3-formylchromone were synthesized and their structures determined. Structural assessment consisted of elemental analysis, IR, ¹H-NMR, 13C-NMR, MS and crystallographic studies. Antimicrobial activity was tested on standard strains representing different groups of microorganisms. The tested compounds were found to inhibit microbial growth. Concentrations of 0.01⁻1250 µmol/L were found to influence cell proliferation, demonstrating antiproliferative and stimulation of proliferation against two cell lines: the L929 cell line (mouse fibroblast cell line) and the EA.hy926 cell line (the human umbilical vein, somatic cell hybrid).

Cytostatic resistance profile of the sulfur mustard resistant keratinocyte cell line HaCaT/SM

BACKGROUND

The cell line HaCaT/SM was developed as a sulfur mustard (SM) resistant cell line from the human keratinocyte cell line HaCaT. This cell line was established to learn more about the effect of SM and possible therapeutic approaches to counteract the cytotoxic effects of SM. The aim of this study was to clarify whether the SM-resistant cell line HaCaT/SM exhibit also resistance to other alkylating agents or cytotoxic drugs with different mechanism of action.

MATERIAL AND METHOD

The chemosensitivity of SM-resistant human keratinocyte cell line HaCaT/SM and the original cell line HaCaT were tested using the XTT assay. Nine cytotoxic drugs from five different substance groups were investigated.

RESULTS

HaCaT/SM showed a significant increase in resistance against all tested drugs. From the substance class of the alkylating agents, HaCaT/SM showed the strongest resistance increase against chlorambucil (1.7 fold increase). Whereas over all substances strongest increase was observed against cisplatin (5.1 fold increase).

DISCUSSION

The highest resistance was observed for cisplatin. The SM resistant cells revealed changes in the miRNA profile as described before. The resistance to cisplatin is also connected to a specific miRNA profile. Interestingly, changes of miRNA-203 and miRNA-21 levels were found in HaCaT/SM as well as in cisplatin resistant cells. It is therefore conceivable that the same resistance pathways are involved for both substances.

Most Do, but Some Do Not: CD4⁺CD25- T Cells, but Not CD4⁺CD25⁺ Treg Cells, Are Cytolytic When Redirected by a Chimeric Antigen Receptor (CAR)

Evidences are accumulating that CD4⁺ T cells can physiologically mediate antigen specific target cell lysis. By circumventing major histocompatibility complex (MHC)-restrictions through an engineered chimeric antigen receptor (CAR), CD4⁺ T cells lyse defined target cells as efficiently as do CD8⁺ T cells. However, the cytolytic capacity of redirected CD4⁺CD25^- T cells, in comparison with CD4⁺CD25⁺ regulatory T (Treg) cells was so far not thoroughly defined. Treg cells require a strong CD28 signal together with CD3ζ for activation. We consequently used a CAR with combined CD28-CD3ζ signalling for redirecting CD4⁺CD25^- T cells and CD4⁺CD25⁺ Treg cells from the same donor. CAR redirected activation of these T cell subsets and induced a distinct cytokine pattern with high IL-10 and a lack of IL-2 release by Treg cells. Despite strong antigen-specific activation, CAR Treg cells produced only weak target cell lysis, whereas CD4⁺CD25^- CAR T cells were potent killers. Cytolysis did not correlate with the target cell sensitivity to Fas/FasL mediated killing; CD4⁺CD25^- T cells upregulated perforin and granzyme B upon CAR activation, whereas Treg cells did less. The different cytolytic capacities of CAR redirected conventional CD4⁺ cells and Treg cells imply their use for different purposes in cell therapy.

Pixuna virus modifies host cell cytoskeleton to secure infection

Pixuna virus (PIXV) is an enzootic member of the Venezuelan Equine Encephalitis Virus complex and belongs to the New World cluster of alphaviruses. Herein we explore the role of the cellular cytoskeleton during PIXV replication. We first identified that PIXV undergoes an eclipse phase consisting of 4 h followed by 20 h of an exponential phase in Vero cells. The infected cells showed morphological changes due to structural modifications in actin microfilaments (MFs) and microtubules (MTs). Cytoskeleton-binding agents, that alter the architecture and dynamics of MFs and MTs, were used to study the role of cytoskeleton on PIXV replication. The virus production was significantly affected (p < 0.05) after treatment with paclitaxel or nocodazole due to changes in the MTs network. Interestingly, disassembly of MFs with cytochalasin D, at early stage of PIXV replication cycle, significantly increased the virus yields in the extracellular medium (p < 0.005). Furthermore, the stabilization of actin network with jasplakinolide had no effect on virus yields. Our results demonstrate that PIXV relies not only on intact MTs for the efficient production of virus, but also on a dynamic actin network during the early steps of viral replication.

Triterpenoid saponins from the roots of Spergularia marginata

Phytochemical investigations of the roots of Spergularia marginata had led to the isolation of four previously undescribed triterpenoid saponins, a known one and one spinasterol glycoside. Their structures were established by extensive NMR and mass spectroscopic techniques as 3-O-β-D-glucuronopyranosyl echinocystic acid 28-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-α-L- arabinopyranosyl ester, 3-O-β-D-glucopyranosyl-(1 → 3)-β-D-glucuronopyranosyl echinocystic acid 28-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)- α-L-arabinopyranosyl ester, 3-O-β-D-glucopyranosyl-(1 → 4)-3-O-sulfate-β-D-glucuronopyranosyl echinocystic acid 28-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl ester, and 3-O-β-D-glucopyranosyl-(1 → 4)-β-D-glucuronopyranosyl 21-O-acetyl acacic acid. Their cytotoxicity was evaluated against two human cancer cell lines SW480 and MCF-7. The most active compound showed a cytotoxicity with IC₅₀ 14.2 ± 0.8 μM (SW480), and 18.7 ± 0.8 μM (MCF-7), respectively.

Transplantation of Retinal Pigment Epithelium Using Viable Cryopreserved Cells

Transplantation of retinal pigment epithelium (RPE) may have potential clinical application for the surgical treatment of RPE-specific retinal degeneration, including age-related macular degeneration. The feasibility of an RPE storage bank has been investigated by experimenting with transplantation using viable, cryopreserved RPE cells. Fresh and cultured fetal human and bovine RPE cells were cryopreserved in 90% fetal bovine serum containing 10% dimethyl sulfoxide. The viability of the cells before and after cryopreservation was evaluated by trypan blue dye exclusion test, microculture tetrazolium assay (MTA), tissue culture, and transplantation after cryopreservation. The origin of RPE cells before and after cryopreservation was assessed by immunocytochemistry, immunoblotting, and indirect ELISA of RPE-marker protein using cytokeratin for cultured fetal human RPE cells and by immunocytochemistry of cellular retinaldehyde-binding protein (CR-ALBP) for cultured bovine RPE cells. Freshly isolated and cryopreserved uncultured bovine RPE cells were transplanted by posterior transscleral approach into the subretinal spaces of adult albino rabbits and 23-day-old Royal College of Surgeons (RCS) rats with a 33 gauge Hamilton syringe. Following surgery, artificial retinal blebs were confirmed by fundus examination. Morphologic examination was performed postoperatively by light and electron microscopy in albino rabbits and by light microscopy in RCS rats up to 3 mo. Control subretinal injections using vehicle solution also were performed in RCS rats. Cultured fetal human and bovine RPE cells after cryopreservation were found to be viable, based on the results of trypan blue dye exclusion test, MTA, tissue culture, and transplantation. Expression and reexpression of cytokeratin intermediate filaments in cultured fetal human RPE were demonstrated by immunocytochemistry, immunoblotting, and indirect ELISA before and after cryopreservation. Immunocytochemistry of CRALBP before and after cryopreservation in uncultured bovine RPE cells disclosed expression and reexpression of RPE cell marker protein. No uncultured fetal human RPE cells showed proliferation in tissue culture after cryopreservation. In rabbits, light and electron microscopy disclosed xenografted RPE cells residing on Bruch's membrane of the host retina. No sign of graft vs. host reaction was observed. No morphologic difference was noted between the fresh and 10-day-old cryopreserved RPE cells in situ following transplantation at day 25. In RCS rats, subretinal injection of 3-wk-old cryopreserved bovine RPE cells partially rescued photoreceptor cells locally at the transplanted area observed at 3 mo postoperatively. The retinal photoreceptors at the inferior hemisphere of the transplanted eye and the eye injected with vehicle solution showed no rescue effect. We found that cryopreserved cultured fetal human RPE cells and uncultured and cultured bovine RPE cells can be used for RPE transplantation studies. The ability to create an RPE storage bank as a source of donor cells may result in several clinical advantages.

Targeted delivery system for cancer cells consist of multiple ligands conjugated genetically modified CCMV capsid on doxorubicin GNPs complex

Targeted nano-delivery vehicles were developed from genetically modified Cowpea chlorotic mottle virus (CCMV) capsid by ligands bioconjugation for efficient drug delivery in cancer cells. RNA binding (N 1-25aa) and β-hexamer forming (N 27-41aa) domain of capsid was selectively deleted by genetic engineering to achieve the efficient in vitro assembly without natural cargo. Two variants of capsids were generated by truncating 41 and 26 amino acid from N terminus (NΔ41 and NΔ26) designated as F₁ and F₂ respectively. These capsid were optimally self-assembled in 1:2 molar ratio (F₁:F₂) to form a monodisperse nano-scaffold of size 28 nm along with chemically conjugated modalities for visualization (fluorescent dye), targeting (folic acid, FA) and anticancer drug (doxorubicin). The cavity of the nano-scaffold was packed with doxorubicin conjugated gold nanoparticles (10 nm) to enhance the stability, drug loading and sustained release of drug. The chimeric system was stable at pH range of 4–8. This chimeric nano-scaffold system showed highly specific receptor mediated internalization (targeting) and ~300% more cytotoxicity (with respect to FA⁻ delivery system) to folate receptor positive Michigan Cancer Foundation-7 (MCF7) cell lines. The present system may offer a programmable nano-scaffold based platform for developing chemotherapeutics for cancer.

Chemotherapeutic potentials of the stem bark of Balanite aegyptiaca (L.) Delile: an antiangiogenic, antitumor and antioxidant agent

Background

Balanite aegyptiaca (L.) Delile, is a plant with extensive medicinal properties. Its stem bark is traditionally known for its spasmolytic and antiepileptic properties and used to treat yellow fever, jaundice and syphilis. Angiogenesis (sprouting of new blood vessels) is crucial for tumor growth and metastasis. The goal of this study is investigate the antiangiogenic, cytotoxicity and antioxidant activity as well as antitumor in vivo properties of B. aegyptiaca stem bark extracts.

Method

The dried powder of stem bark was extracted sequentially with n-hexane, chloroform, methanol and water. Rat aorta ring assay (RARA) was used as a platform to screen for antiangiogenic affect. The most active extract was subjected to further confirmatory antiangiogenic tests i.e. cell migration, tube formation and VEGF inhibition and finally evaluated for its in vivo antitumor efficacy in nude mice. The cytotoxicity of extracts on four cancer cell lines (HCT-116, K562, U937 and MCF-7) and one normal cells line (HUVEC) was evaluated. To assess the antioxidant activity screening, four methods were used, (DPPH•) and ABTS radical scavenging activity, as well as total flavonoids and phenolic contents.

Results

Methanol extract of B. aegyptiaca stem bark (MBA) showed the highest antiangiogenic, antioxidant and anticancer properties. It was found selectively cytotoxic to leukemia cell lines as well as breast cancer cell line MCF-7. (MBA) thus exhibited antiangiogenic in ex-vivo rat aorta ring model; it was found to excel its antiangiogenic effect via inhibition of the key growth factor (VEGF) as well as to halt HUVEC cell migration and tube formation, furthermore animals bearing colon cancer treated with (MBA) showed significant reduction in tumor growth.

Conclusion

Different extracts of B. aegyptiaca stem bark showed various anticancer and antiangiogenic properties. MBA demonstrated potent antiangiogenic, antioxidant and antitumor in vivo. The outcome of this study suggests the potential of stem bark of the B. aegyptiaca for developing chemotherapeutic agent against solid tumor as well as leukemia.

Immunotoxicity Evaluation of Resorcinol Bis-Diphenylphosphate (Fyrolflex RDP) in B6C3F1 Mice

RDP was administered daily to groups of female B6C3F1 mice by oral gavage for 28 days at dose levels of 500, 1500, or 5000 mg/kg/day body weight (BW). Control animals were sham dosed. Animals were euthanized 1 day following final exposure or following a 60-day recovery period. End point observations included necropsy and histopathology, spleen and thymus weights and cellularity, peritoneal cell numbers and differential cell analysis, splenic natural killer (NK) cell activity, lymphocyte blastogenesis, antibody-forming cell (AFC) response, peritoneal macrophage phagocytic activity, and host susceptibility to Listeria monocytogenes infection. In-life observations included weekly clinical examinations and body weights. No adverse clinical signs were noted and the only significant finding was an increase in body weight in high dose mice on week 4 as compared to sham controls. Small changes in body weight gain were seen in all dose groups as compared to sham controls after completion of dosing on weeks 5 and 6 and in mid-dose mice on weeks 7 and 12. No significant differences were found in spleen and thymus weights or in cellularity. No changes were found in peritoneal cell numbers or cell types, peritoneal macrophage phagocytic activity, or host susceptibility to infection. Likewise, splenic NK cell activity, lymphocyte blastogenesis, and AFC function were also unaffected. No histopathologic changes were observed. All animals that received positive-control substances demonstrated a significant effect in the respective tests. In conclusion, a standardized and validated battery of immune function tests demonstrated no immunotoxicity following daily oral exposure to up to 5000 mg/kg BW of RDP for 28 days.

Steroidal saponins from Chlorophytum deistelianum

Phytochemical investigation of the aerial parts of Chlorophytum deistelianum led to the isolation of four previously undescribed steroidal saponins called chlorodeistelianosides A-D with five known ones. Their structures were established mainly by extensive 1D and 2D NMR spectroscopic techniques and mass spectrometry as (25R)-3β-[(β-D-glucopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→4)]-β-D-xylopyranosyl-(1→3)-[β-D-glucopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-β-D-galactopyranosyl)oxy]-5α-spirostan-12-one, (24S,25S)-24-[(β-D-glucopyranosyl)oxy]-3β-[(β-d-glucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyranosyl-(1→4)-β-D-galactopyranosyl)oxy]-5α-spirostan-12-one, (25R)-26-[(β-D-glucopyranosyl)oxy]-2α-hydroxy-22α-methoxy-5α-furostan-3β-yl β-D-glucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside, and (25R)-26-[(β-D-glucopyranosyl)oxy]-3β-[(β-D-glucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyranosyl-(1→4)-β-D-galactopyranosyl)oxy]-5α-furost-20(22)-en-12-one. Cytotoxicity of most compounds was evaluated against one human cancer cell line (SW480) and one rat cardiomyoblast cell line (H9c2). Among them, three known spirostane-type glycosides exhibited cytotoxicity on both cell lines with IC50 ranging from 8 to 10 μM.

Superior Therapeutic Index in Lymphoma Therapy: CD30(+) CD34(+) Hematopoietic Stem Cells Resist a Chimeric Antigen Receptor T-cell Attack

Recent clinical trials with chimeric antigen receptor (CAR) redirected T cells targeting CD19 revealed particular efficacy in the treatment of leukemia/lymphoma, however, were accompanied by a lasting depletion of healthy B cells. We here explored CD30 as an alternative target, which is validated in lymphoma therapy and expressed by a broad variety of Hodgkin's and non-Hodgkin's lymphomas. As a safty concern, however, CD30 is also expressed by lymphocytes and hematopoietic stem and progenitor cells (HSPCs) during activation. We revealed that HRS3scFv-derived CAR T cells are superior since they were not blocked by soluble CD30 and did not attack CD30(+) HSPCs while eliminating CD30(+) lymphoma cells. Consequently, normal hemato- and lymphopoiesis was not affected in the long-term in the humanized mouse; the number of blood B and T cells remained unchanged. We provide evidence that the CD30(+) HSPCs are protected against a CAR T-cell attack by substantially lower CD30 levels than lymphoma cells and higher levels of the granzyme B inactivating SP6/PI9 serine protease, which furthermore increased upon activation. Taken together, adoptive cell therapy with anti-CD30 CAR T cells displays a superior therapeutic index in the treatment of CD30(+) malignancies leaving healthy activated lymphocytes and HSPCs unaffected.

Oleanolic acid and hederagenin glycosides from Weigela stelzneri

Four previously undescribed and one known oleanolic acid glycosides were isolated from the roots of Weigela stelzneri, and one previously undescribed and three known hederagenin glycosides were isolated from the leaves. Their structures were elucidated mainly by 2D NMR spectroscopic analysis and mass spectrometry as 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyloleanolic acid, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyloleanolic acid, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid 28-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl ester, and 3-O-β-D-glucopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin 28-O-β-D-xylopyranosyl-(1 → 6)-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-glucopyranosyl ester. The majority of the isolated compounds were evaluated for their cytotoxicity against two tumor cell lines (SW480 and EMT-6), and for their anti-inflammatory activity. The compounds 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid and 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyloleanolic acid exhibited the strongest cytotoxicity on both cancer cell lines. They revealed a 50% significant inhibitory effect of the IL-1β production by PBMCs stimulated with LPS at a concentration inducing a very low toxicity of 23% and 28%, respectively.

In search of the optimal processing technique for fat grafting

OBJECTIVE

Unpredictability in graft retention remains a significant drawback of fat grafting. Processing of fat grafts has been the focus of several studies to improve graft survival. The objective of this study was to systematically review the outcomes of different fat graft processing techniques with the goal of (1) deriving clinically oriented insights and (2) identifying gaps in knowledge to stimulate future research.

METHODS

PubMed, EMBASE, and Cochrane Databases were searched to identify studies that compared different fat graft processing techniques. Outcome measures of interest were any subjective or objective measures of fat graft survival or reports of adverse events.

RESULTS

A total of 2056 abstracts were generated from the literature searches; 13 studies met the criteria for data extraction and analysis. Processing methods assessed included decantation, washing, gauze filtration, and centrifugation. Each processing method was found to be better than other methods, depending on the outcome measure used to study graft survival. As well, several studies found statistical equipoise in the outcome measures when analyzing the results of the different techniques. Adverse events were rarely reported and did not correlate with any processing method in particular.

CONCLUSIONS

No firm concluding recommendation can be made to deem 1 processing technique superior to the others. However, it would seem that techniques, which use a combination of gentle washing and centrifugation, strike the optimal balance of preserving adipocyte viability while removing bulk of the contaminants.

Elevated caspase 3 activity and cytosolic cytochrome c in NT2 cybrids containing amyotrophic lateral sclerosis subject mtDNA

Apoptosis of motor neurons is an important feature in amyotrophic lateral sclerosis (ALS). A vital role of mitochondria in apoptosis and cell survival is well documented. Eventually mitochondria have shown to be an early target in the pathogenesis of ALS. On account of these facts, we investigated the involvement of mitochondrial-dependent apoptosis in ALS and control (CTR) cybrids, generated fusing human platelets with mitochondrial DNA-depleted NT2-neuroteratocarcinoma cells. After a 6 week selection process during which transferred subject mtDNA repopulated the NT2 cells and restored mitochondrial oxygen consumption, we assessed cell viability and two programmed cell death parameters, caspase 3 activity and cytosolic cytochrome c levels. Compared to the control cybrid lines (n = 5), the ALS cybrid lines (n = 10) showed 45% less XTT reduction and higher caspase 3 activity ( p < 0.05, two-way Student's t test) exhibiting lesser cell viability and execution of apoptosis. Elevated cytosolic cytochrome c levels in ALS cybrid lines (n = 8) than in CTR (n = 4) ( p < 0.05, two-way Student's t-test) indicating its mitochondrial release and initiation of apoptosis. This indicates apoptosis as one of the possible mechanisms of cell death in ALS. Our findings support the view that in ALS, subject's mitochondria are altered in non-degenerating tissues in such a way that intrinsic apoptotic pathway activity is relatively increased.

A New Aromatic Compound from the Stem Bark of Terminalia catappa

A new aromatic compound 3,4,5-trimethoxyphenyl-1- O-(4-sulfo)-β-D-glucopyranoside (1), in addition to two triterpenoid saponins (chebuloside II, arjunoglucoside II), two triterpenes (arjunolic acid and 3-betulinic acid) and sitosterol-3- O-β-D-glucopyranoside have been isolated from the barks of Terminalia catappa. Their structures have been established on the basis of spectroscopic techniques (1D/2D NMR) and MS. Their cytotoxicity and anti-inflammatory activity, together with the antioxidant capacity of compound 1 were also evaluated.

The chemistry and bioactivity of Southern African flora I: a bioactivity versus ethnobotanical survey of alkaloid and terpenoid classes

As a whole, the African continent is highly endowed with a huge floral biodiversity.

Novel synthesis of fluorochrome-coupled zoledronate with preserved functional activity on gamma/delta T cells and tumor cells

A novel fluorescent derivative of bisphosphonate zoledronate was synthesized and shown to have comparable functional activity as native zoledronate.

Oligonucleotides conjugated with short chemically defined polyethylene glycol chains are efficient antisense agents

Ligand conjugation is an attractive approach to rationally modify the poor pharmacokinetic behavior and cellular uptake properties of antisense oligonucleotides. Polyethylene glycol (PEG) attachment is a method to increase solubility of oligonucleotides and prevent the rapid elimination, thus increasing tissue distribution. On the other hand, the attachment of long PEG chains negatively influences the pharmacodynamic effect by reducing the hybridization efficiency. We examined the use of short PEG ligands on the in vitro effect of antisense agents. Circular dichroism showed that the tethering of PEG12-chains to phosphodiester and phosphorothioate oligonucleotides had no influence on their secondary structure and did not reduce the affinity to the counter strand. In an in vitro tumor model, a luciferase reporter assay indicated unchanged gene silencing activity compared to unmodified compounds, and even slightly superior target down regulation was found after treatment with a phosphorothioate modified conjugate.

π-π Stacking induced enhanced molecular solubilization, singlet oxygen production, and retention of a photosensitizer loaded in thermosensitive polymeric micelles

Cancer photodynamic therapy (PDT) by photosensitizers (PS)-loaded polymeric micelles (PM) is hampered by the tendency of PS to aggregate in PM and/or by premature release of PS in the blood circulation. In the present study, aromatic thermosensitive PM, characterized by π-π stacking interaction, are used to encapsulate an axially solketal-substituted silicon phthalocyanine (Si(sol)2 Pc) with enhanced loading capacity, smaller size, and significantly improved retention of Si(sol)2 Pc compared with systems based on thermosensitive PM lacking aromatic groups. Interestingly, Si(sol)2 Pc is much less prone to aggregation in the aromatic PM, i.e., the amount of Si(sol)2 Pc that could be encapsulated without aggregation is 330 times higher in the aromatic PM than in the nonaromatic PM. Furthermore, Si(sol)2 Pc in the aromatic PM in a molecularly dissolved (non-aggregated) form displays three times more efficient singlet oxygen production than Si(sol)2 Pc aggregated in the non-aromatic PM. As a result, the photocytotoxicity of Si(sol)2 Pc-loaded aromatic PM to B16F10 cells is increased, compared with that of the non-aromatic PM, while no significant cytotoxicity is observed in the dark. Fluorescence-activated cell sorting (FACS) and confocal laser scanning microscopy (CLSM) analysis shows cell uptake of Si(sol)2 Pc loaded in the aromatic PM, and the Si(sol)2 Pc is taken up by the cells together with the micelles. The efficient singlet oxygen production of Si(sol)2 Pc dissolved in the aromatic PM makes it an interesting formulation for cancer PDT.

Dendritic cells enhance the activity of human MUC1-stimulated mononuclear cells against breast cancer

Dendritic cells (DCs) are among the most potent antigen-presenting cells (APCs), stimulating peripheral blood mononuclear cells (PBMCs) to generate antigen-specific cytotoxic T lymphocytes (CTLs). The objectives of this study were to determine if interleukin (IL)-4 is beneficial or detrimental for the generation of human DCs in vitro and to understand whether DCs generated in vitro in the presence or absence of IL-4 stimulate the killing of adenocarcinoma cells by CTLs in vivo. Mucin 1 (MUC1), a glycoprotein found on the surface of adenocarcinoma cells was used to load DCs. MUC1-loaded DCs generated in the absence of IL-4 were superior to their counterparts produced with IL-4 in stimulating PBMCs to kill human breast cancer MCF-7 cells in vitro. A corollary in vivo protection experiment was performed by injecting immunodeficient NOD-SCID mice with MCF-7 cells s.c. and MUC1-loaded CTLs, PBMCs, or DCs generated in the absence of IL-4, i.p. Mice that received CTLs and MUC1-loaded DCs on days 0, 2, 4, 9, 14 and 19 were completely protected against the development of MCF-7-derived tumors, while other schedules conferred lower protection. Therefore, tumor antigen-loaded DCs enhance the efficacy of adoptive CTL transfer, and should thus be considered for combinatorial immunotherapeutic regimens.

Triterpenoid saponins from the roots of two Gypsophila species

Two triterpenoid saponins with two known ones have been isolated from the roots of Gypsophila arrostii var. nebulosa, and two new ones from the roots of Gypsophila bicolor. Their structures were established by extensive NMR and mass spectroscopic techniques as 3-O-β-d-galactopyranosyl-(1→2)-[β-d-xylopyranosyl-(1→3)]-β-d-glucuronopyranosylquillaic acid 28-O-β-d-xylopyranosyl-(1→4)-[β-d-glucopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)]-β-d-fucopyranosyl ester (1), 3-O-β-d-galactopyranosyl-(1→2)-[β-d-xylopyranosyl-(1→3)]-β-d-glucuronopyranosylgypsogenin 28-O-β-d-xylopyranosyl-(1→4)-[β-d-glucopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)]-β-d-fucopyranosyl ester (2), 3-O-β-d-galactopyranosyl-(1→2)-[β-d-xylopyranosyl-(1→3)]-β-d-glucuronopyranosylgypsogenin 28-O-β-d-xylopyranosyl-(1→3)-β-d-xylopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→2)-[(4-O-acetyl)-β-d-quinovopyranosyl-(1→4)]-β-d-fucopyranosyl ester (3), gypsogenic acid 28-O-β-d-glucopyranosyl-(1→3)-{6-O-[3-hydroxy-3-methylglutaryl]-β-d-glucopyranosyl-(1→6)}-β-d-galactopyranosyl ester (4). Three compounds were evaluated against one human colon cancer cell line SW480 and one rat cardiomyoblast cell line H9c2.

Triterpenoid saponins from Polycarpaea corymbosa Lamk. var. eriantha Hochst

Four triterpenoid saponins (1-4) were isolated from Polycarpaea corymbosa Lamk. var. eriantha Hochst along with the known apoanagallosaponin IV (5). Their structures were elucidated by spectroscopic data analysis. Among the compounds 1, 3-5 which were evaluated for their cytotoxicity against three tumor cell lines (SW480, DU145 and EMT6), compound 1 exhibited cytotoxicity with IC50 values ranging from 4.61 to 22.61 μM, which was greater than that of etoposide. Compound 2 was tested only against SW480 and a cardiomyoblast cell line (H9c2), and was inactive.

TGFα-PE38 enhances cytotoxic T-lymphocyte killing of breast cancer cells

The aim of the present study was to determine whether the combination of two modalities of immunotherapy, targeting two different tumor antigens, may be feasible and non-toxic, yet enhance the killing of a human breast cancer cell line. The first modality was tumor growth factor α-Pseudomonas exotoxin 38 (TGFα-PE38), which specifically targets and kills tumor cells that express the epidermal growth factor receptor. The second modality was mucin-1 (MUC1)-specific cytotoxic T lymphocytes (CTLs), generated by MUC1 stimulation of peripheral blood mononuclear cells, to target the human breast cancer cell line, MCF7. TGFα-PE38 exhibited specific lysis of the MCF7 cells in a concentration- and time-dependent manner. TGFα-PE38 did not kill the normal hematopoietic stem cells or CTLs. Furthermore, TGFα-PE38 was not inhibitory for the growth or differentiation of the normal human hematopoietic stem cells into erythroid and myeloid colonies. In addition, TGFα-PE38 did not inhibit the killing function of CTLs, either when preincubated or co-incubated with CTLs. Finally, therapeutic enhancement was observed, in that TGFα-PE38 and CTLs were additive in the specific lysis of the MCF7 cells. These two modalities of immunotherapy may be beneficial for humans with breast cancer with or without other therapies, including autologous hematopoietic stem cell transplantation, specifically for purging cancer cells from hematopoietic stem cells prior to transplantation.

Acylated oleanane-type saponins from Ganophyllum giganteum

Five oleanane-type saponins, 3-O-β-D-glucuronopyranosylzanhic acid 28-O-β-D-xylopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-(4-O-acetyl)-β-D-fucopyranosyl ester (1), 3-O-β-D-glucopyranosylzanhic acid 28-O-β-D-xylopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-(4-O-acetyl)-β-D-fucopyranosyl ester (2), zanhic acid 28-O-β-D-xylopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-(4-O-acetyl)-β-D-fucopyranosyl ester (3), zanhic acid 28-O-α-L-rhamnopyranosyl-(1→2)-4-O-[(3'-hydroxy-2'-methyl-butyroyloxy)-3-hydroxy-2-methyl-butyroyloxy]-β-D-fucopyranosyl ester (4), medicagenic acid 28-O-α-L-rhamnopyranosyl-(1→2)-4-O-[(3'-hydroxy-2'-methyl-butyroyloxy)-3-hydroxy-2-methyl-butyroyloxy]-β-D-fucopyranosyl ester (5), were isolated from the root barks of Ganophyllum giganteum. Compounds 4 and 5 possessed an unusual substitution of the C-4 position of the β-D-fucopyranosyl moiety by a C10 ester group formed by two symmetrical C5 nilic acid. From a chemotaxonomic point of view, their structures are in accordance with the previous saponins isolated from the Doratoxyleae tribe of the Sapindaceae family. Their cytotoxicity and anti-inflammatory activity were also evaluated.

Cytotoxic steroidal glycosides from Allium flavum

Three new spirostane-type glycosides (1-3) were isolated from the whole plant of Allium flavum. Their structures were elucidated mainly by 2D NMR spectroscopic analysis and mass spectrometry as (20S,25R)-2α-hydroxyspirost-5-en-3β-yl O-β-D-xylopyranosyl-(1→3)-[β-D-galactopyranosyl-(1→2)]-β-D-galactopyranosyl-(1→4)-β-D-galactopyranoside (1), (20S,25R)-2α-hydroxyspirost-5-en-3β-yl O-β-D-xylopyranosyl-(1→3)-[β-D-glucopyranosyl-(1→2)]-β-D-galactopyranosyl-(1→4)-β-D-galactopyranoside (2), and (20S,25R)-spirost-5-en-3β-yl O-α-L-rhamnopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)]-β-D-glucopyranoside (3). The three saponins were evaluated for cytotoxicity against a human cancer cell line (colorectal SW480).

Arming cytokine-induced killer cells with chimeric antigen receptors: CD28 outperforms combined CD28-OX40 "super-stimulation"

Cytokine-induced killer (CIK) cells raised interest for use in cellular antitumor therapy due to their capability to recognize and destroy autologous tumor cells in a HLA-independent fashion. The antitumor attack of CIK cells, predominantly consisting of terminally differentiated CD8(+)CD56(+) cells, can be improved by redirecting by a chimeric antigen receptor (CAR) that recognizes the tumor cell and triggers CIK cell activation. The requirements for CIK cell activation were, however, so far less explored and are likely to be different from those of "younger" T cells. We revealed that CD28 and OX40 CARs produced higher interferon- secretion as compared with the first-generation ζ-CAR; CD28-ζ and the third-generation CD28-ζ-OX40 CAR, however, performed similar in modulating most CIK cell effector functions. Compared with the CD28-ζ CAR, however, the CD28-ζ-OX40 CAR accelerated terminal maturation of CD56(+) CIK cells producing high frequencies in activation-induced cell death (AICD) and reduced antitumor efficiency in vivo. Consequently, CD28-ζ CAR CIK cells of CD56(-) phenotype were superior in redirected tumor cell elimination. CAR-mediated CIK cell activation also increased antigen-independent target cell lysis; the CD28-ζ CAR was more efficient than the CD28-ζ-OX40 CAR. Translated into therapeutic strategies, CAR-redirected CIK cells benefit from CD28 costimulation; "super-costimulation" by the CD28-ζ-OX40 CAR, however, performed less in antitumor efficacy due to increased AICD.

Neutral sphingomyelinase 2 modulates cytotoxic effects of protopanaxadiol on different human cancer cells

Background

Some of ginsenosides, root extracts from Panax ginseng, exert cytotoxicity against cancer cells through disruption of membrane subdomains called lipid rafts. Protopanaxadiol (PPD) exhibits the highest cytotoxic effect among 8 ginsenosides which we evaluated for anti-cancer activity. We investigated if PPD disrupts lipid rafts in its cytotoxic effects and also the possible mechanisms.

Methods

Eight ginsenosides were evaluated using different cancer cells and cell viability assays. The potent ginsenoside, PPD was investigated for its roles in lipid raft disruption and downstream pathways to apoptosis of cancer cells. Anti-cancer effects of PPD was also investigated in vivo using mouse xenograft model.

Results

PPD consistently exerts its potent cytotoxicity in 2 cell survival assays using 5 different cancer cell lines. PPD disrupts lipid rafts in different ways from methyl-β-cyclodextrin (MβCD) depleting cholesterol out of the subdomains, since lipid raft proteins were differentially modulated by the saponin. During disruption of lipid rafts, PPD activated neutral sphingomyelinase 2 (nSMase 2) hydrolyzing membrane sphingomyelins into pro-apoptotic intracellular ceramides. Furthermore, PPD demonstrated its anti-cancer activities against K562 tumor cells in mouse xenograft model, confirming its potential as an adjunct or chemotherapeutic agent by itself in vivo.

Conclusions

This study demonstrates that neutral sphingomyelinase 2 is responsible for the cytotoxicity of PPD through production of apoptotic ceramides from membrane sphingomyelins. Thus neutral sphingomyelinase 2 and its relevant mechanisms may potentially be employed in cancer chemotherapies.

Syzygium campanulatum korth methanolic extract inhibits angiogenesis and tumor growth in nude mice

BACKGROUND

Syzygium campanulatum Korth (Myrtaceae) is an evergreen shrub rich in phenolics, flavonoid antioxidants, and betulinic acid. This study sought to investigate antiangiogenic and anti-colon cancer effects of S.C. standardized methanolic extract.

METHODS

Betulinic acid was isolated from methanolic extract by crystallization and chromatography techniques. S.C. methanolic extract was analyzed by UV-Vis spectrophotometry, FTIR, LC-MS, and HPLC. Antiangiogenic effect was studied on rat aortic rings, matrigel tube formation, cell proliferation and migration, and expression of vascular endothelial growth factor (VEGF). Antitumor effect was studied using a subcutaneous tumor model of HCT 116 colorectal carcinoma cells established in nude mice.

RESULTS

Analysis by HPLC, LC-MS and FTIR confirm presence of betulinic acid in S.C. methanolic extract. Quantitative analysis by HPLC indicates presence of betulinic acid in S.C. extract at 5.42 ± 0.09% (w/w). Antiangiogenesis study showed potent inhibition of microvessels outgrowth in rat aortic rings, and studies on normal and cancer cells did not show any significant cytotoxic effect. Antiangiogenic effect was further confirmed by inhibition of tube formation on matrigel matrix that involves human endothelial cells (IC50 = 17.6 ± 2.9 μg/ml). S.C. extract also inhibited migration of endothelial cells and suppressed expression of VEGF. In vivo antiangiogenic study showed inhibition of new blood vessels in chicken embryo chorioallantoic membrane (CAM), and in vivo antitumor study showed significant inhibition of tumor growth due to reduction of intratumor blood vessels and induction of cell death.

CONCLUSION

Collectively, our results indicate S. campanulatum as antiangiogenic and antitumor candidate, and a new source of betulinic acid.

Second mitochondria-derived activator of caspase (SMAC) mimetic potentiates tumor susceptibility toward natural killer cell-mediated killing

Resistance to apoptosis is a hallmark of cancer, and represents an important mechanism of how tumor cells resist immune cell destruction. Mitochondria are the central regulators of the apoptotic machinery by releasing pro-apoptotic factors including cytochrome c and second mitochondria-derived activator of caspase (SMAC) upon mitochondrial outer membrane permeabilization (MOMP). Small molecules activating MOMP such as BH3 mimetics or antagonizers of the inhibitor of apoptosis proteins (IAPs) such as SMAC mimetics have recently engendered new optimism for a more individualized and effective cancer therapy. Here we show that a SMAC mimetic potentiates cancer cell killing by natural killer (NK) cells through reactivation of tumor cell apoptosis. Specifically, the SMAC mimetic enhances the susceptibility of tumor cells toward NK cell-mediated effector mechanisms involving death receptors and cytolytic granules containing perforin and granzymes by relieving caspase activity. Our data highlight for the first time the specific use of SMAC mimetics for boosting immune cell-mediated immunotherapy, representing a novel and promising approach in the treatment of cancer.