Mastocytoma Cells Research Articles

Interfacing neural cells with typical microelectronics materials for future manufacturing

The biocompatibility of materials used in electronic devices is critical for the development of implantable devices like pacemakers and neuroprosthetics, as well as in future biomanufacturing. Biocompatibility refers to the ability of these materials to interact with living cells and tissues without causing an adverse response. Therefore, it is essential to evaluate the biocompatibility of metals and semiconductor materials used in electronic devices to ensure their safe use in medical applications. Here, we evaluated the biocompatibility of a collection of diced silicon chips coated with a variety of metal thin films, interfacing them with different cell types, including murine mastocytoma cells in suspension culture, adherent NIH 3T3 fibroblasts, and human induced pluripotent stem cell (iPSC)-derived neural progenitor cells (NPCs). All materials tested were biocompatible and showed the potential to support neural differentiation of iPSC-NPCs, creating an opportunity to use these materials in a scalable production of a range of biohybrid devices such as electronic devices to study neural behaviors and neuropathies.

O51 | Algal extracts as potential anticancer agents: Preliminary investigations in C2 canine mastocytoma cell line

Journal of Veterinary Pharmacology and TherapeuticsVolume 46, Issue S1 p. 52-53 ORAL PRESENTATIONS O51 | Algal extracts as potential anticancer agents: Preliminary investigations in C2 canine mastocytoma cell line First published: 11 June 2023 https://doi.org/10.1111/jvp.13217Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Volume46, IssueS1Special Issue: 15th International Congress of the European Association for Veterinary Pharmacology and Toxicology held Bruges, Belgium, July 2–5, 2023June 2023Pages 52-53 RelatedInformation

High Potency Vasoactive Intestinal Peptide Receptor Antagonists Induce Durable Antileukemia/Tumor T Cell Memory in Mice with Once Daily Dosing

Introduction: Allogeneic bone marrow transplantation (allo-BMT) is curative for patients with myeloid leukemia (AML) through the activity of cytotoxic effector donor T cells, but high morbidity and mortality of allo-BMT limits the use of this therapy. A long-standing goal is the development of strategies that induce an autologous immune response to leukemic blasts by the patient's T cells. Vasoactive intestinal peptide (VIP) is a neuropeptide with pleiotropic functions, including modulation of immune and inflammatory responses. Previous studies demonstrated that VIP hybrid (VIPhyb), a peptide antagonist of VIP-signaling, induced T cell-dependent anti-leukemic activity in murine allotransplant models and promoted activation of mouse and human T cells (Li et al., 2016, Cancer Res). We developed a series of novel peptide VIP antagonists (VIP-ANT) based upon predicted binding affinity in silico to human VIP receptors VPAC1 and VPAC2. We tested the anti-cancer potential of these new VIP-ANT peptides in murine models of myeloid leukemia and mastocytoma, investigating the optimal dose and schedule of administration, and explored mechanisms underlying anti-tumor memory induced by VIP-ANT peptides. Methods: B6 (CD45.1, or albino) mice were injected intravenously with 1 x 106 C1498 cells (AML), and DBA/2j mice were injected subcutaneously with 5 x 104 P815 cells (myeloid mastocytoma). Leukemia-bearing mice were treated with subcutaneous injections of VIP-ANT or control scrambled peptides. Treatment started six days after injection of cells when C1498 leukemia cells were detectable in the blood, and luciferase+ P815 cells as tumors were palpable. A range of VIP-ANT doses was administered s.c. at 10, 30, or 100 μg. Treatment schedules tested included twice daily for 14 doses, once daily, once every other day, once every three days, and once weekly for 7 doses. Some mice received a single dose at day +6 following leukemia cell injection. Lymphocyte kinetics and leukemia cell burden were analyzed weekly through submandibular peripheral blood collections. Mice without evidence of AML/mastocytoma >60 days post-inoculation received a second injection of a two-fold higher dose of C1498 (2 × 106 cells) or P815 (1 × 105 cells). Results: We tested over 13 new VIP-ANT peptides. Daily or every other day (qod) administration of the novel VIP-ANT peptides to leukemia/tumor-bearing mice led to clearance of C1498 cells from blood or complete regression of P815 in 40 % of mice, leading to significantly improved survival over 60 days. Daily administration of 10 μg of novel VIP-ANT peptides for 7 days to leukemic mice prolonged survival(p<0.0001 VIP-ANT vs scramble, Fig 1A), with the fraction of mice that remained leukemia-free proportional to the predicted binding affinity of the VIP-ANT to human VPAC1 and VPAC2. With increased dose intensity and dose-density of ANT308, the most potent peptide, 40%-80% of mice survived to 70 days (median survival days (MSD) of 60 days) after ANT308 treatment compared with the survival of <20% in mice receiving scrambled peptide (MSD 36 days). Increasing the dose and schedule of ANT308 administration to 100 μg twice-daily led to 65% survival (MSD not reached) versus 40% with daily dosing, 30% with every-other-day dosing, and 0% survival with scrambled-sequence control peptide (MSD 33 days) (p<0.001, Fig 1B). Notably, the affinity of different VIP-ANT peptides to VPAC1 and VPAC2 VIP receptors significantly correlated with the survival of C1498-leukemic mice following prior treatment with the corresponding peptide. Prior treatment of leukemic mice with VIP-ANT induced protective immunological memory, rendering mice resistant to re-challenge with C1498 acute myeloid leukemia (80% survival) and P815 mastocytoma (60% survival) cells, compared with 0% survival (MSD 21 days) among immunologically naïve mice. Conclusion: Blocking VIP-signaling with high-affinity VIP-R peptide antagonists represents a novel pharmacological approach to enhance adaptive T cell responses to leukemia/myeloid sarcoma-associated antigens in murine leukemia/tumor models. We are continuing PK and toxicology studies with the lead VIP-ANT peptides to support the development of phase 1 clinical trials for patients with relapsed AML. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Glutamine increases stability of TPH1 mRNA via p38 mitogen-activated kinase in mouse mastocytoma cells

Expression changes for tryptophan hydroxylase 1 (TPH1), the rate-limiting enzyme in serotonin synthesis, by environmental glutamine (GLN) were examined in mouse mastocytoma-derived P815-HTR cells. GLN-treated cells exhibited a robust increase in TPH1 mRNA after a 6 h exposure to GLN. 6-Diazo-5-oxo-L-norleucine (DON), a glutamine-utilizing glutaminase inhibitor, significantly inhibited the GLN-induction of TPH1 mRNA. Nuclear run-on assays and mRNA decay experiments demonstrated that the primary mechanism leading to increased TPH1 mRNA levels was not due to transcriptional changes, but rather due to increased TPH1 RNA stability induced by GLN. Treatment with GLN also led to activation of p38 MAP kinase, but not p42/44 MAPK. In addition, SB203580, a p38 MAP kinase specific inhibitor, completely abolished the GLN-mediated increase of TPH1 mRNA levels, suggesting the pathway stabilizing TPH1 mRNA might be mediated by the activated p38 MAP kinase pathway. Additionally, SB203580 significantly reduced the stability of TPH1 mRNA, and this reduction of the stability was not affected by GLN in the culture medium, implying a sequential signaling from GLN being mediated by p38 MAP kinase, resulting in alteration of TPH1 mRNA stability. TPH1 mRNA stability loss was also dependent on de novo protein synthesis as shown by treatment of cells with a transcriptional/translational blocker. We provide evidence that TPH1 mRNA levels are increased in response to increased exogenous GLN in mouse mastocytoma cells via a stabilization of TPH1 mRNA due to the activity of the p38 MAP kinase.

Hemangiosarcoma of the Third Eyelid in an American Pit Bull Terrier

Background: Hemangiosarcoma (HSA) is a malignant neoplasm arising from the endothelial cells of blood vessels. It has fast growth, and severe local infiltration and metastasis power, in addition to risk of hemorrhage due to the fragility of its vessels. HSA develops in dogs aged 8 to 13 years but can affect younger animals too. Ocular involvement in HSA is rare, but when identified, the third eyelid and bulbar conjunctiva close to the limbus are the most affected sites by this neoplasm. This study aimed to report the clinicopathological aspects of a case of HSA in the third eyelid of an American Pit Bull Terrier breed. Case: A 10-year-old male American Pit Bull Terrier with a history of a red hemorrhagic mass on the third eyelid of the left eye was examined at a veterinary clinic. On physical examination, the animal showed signs of ocular discomfort and bleeding. On ophthalmologic examination, a raised red mass, approximately 2 cm in diameter, was identified on the anterior surface of the third eyelid. The mass was surgically excised. The excised tissue fragment was fixed in 10% buffered formalin solution for 24 h and sent for histopathological examination. Macroscopically, the fragment was irregular, soft, and brownish and measured 2.0 × 1.0 × 0.5 cm. Histologically, proliferation of non-delimited and non-encapsulated atypical endothelial cells, which were organized in vascular arrangements forming small lakes filled with red blood cells, was observed. The cells exhibited elongated and basophilic cytoplasm, oval nuclei with coarse chromatin, and evident nucleoli. Moderate anisocytosis and anisocariosis were observed, with no mitotic figures. Epithelial hyperplasia with mild mixed inflammatory infiltrate was noted. Surgical margins were compromised. Sections of neoplastic tissue were processed for immunohistochemical evaluation with anti-CD31, anti-factor VIII, and anti-Ki-67 antibodies. Neoplastic cells exhibited marked immunostaining for CD31 and factor VIII, and only 8% of these cells were immunostained for Ki-67. Discussion: The diagnosis of HSA in the third eyelid was based on histological features and positive immunostaining for CD31 and factor VIII. The Ki 67 protein is a marker of cell proliferation, being highly expressed in malignant cells, and has been applied as a prognostic marker for different types of neoplasms. Hemangiosarcoma of the third eyelid is a rare malignant neoplasm in small animals. Dogs are the species most affected by this tumor, with the incidence age varying from 8 to 13 years; however, it can also affect younger animals. Animals with thin, light hair and glabrous regions, especially on the face and periocular region, may be more predisposed to this neoplasm. Surgical excision with a wide margin of safety is the recommended treatment for HSA. In addition, chemotherapy may be indicated as a complement to the surgical procedure, especially if the margins are compromised. The main chemotherapy protocols used for this neoplasm include VAC I and VAC II, which are associated with the drugs, doxorubicin, vincristine, and cyclophosphamide. Another alternative to conventional protocols is the use of metronomic chemotherapy, which involves intensifying an anti-tumor immune response and decreasing tumor vascular density. Differential diagnoses for hemangiosarcoma (HSA) of the third eyelid in dogs include other neoplasms with ocular-conjunctival involvement, such as third eyelid gland adenocarcinoma, conjunctival melanoma, mastocytoma, and squamous cell carcinoma. Keywords: angiosarcoma, HSA, malignant neoplasm, immunohistochemistry, eye, ocular, dog.

Synergistic Effect of Toceranib and Nanohydroxyapatite as a Drug Delivery Platform-Physicochemical Properties and In Vitro Studies on Mastocytoma Cells.

A new combination of Toceranib (Toc; 5-[(5Z)-(5-Fluoro-2-oxo-1,2-dihydro-3H-indol-3-ylidene)methyl]-2,4-dimethyl-N-[2-(pyrrolidin-1-yl)ethyl]-1H-pyrrole-3-carboxamide) with nanohydroxyapatite (nHAp) was proposed as an antineoplastic drug delivery system. Its physicochemical properties were determined as crystallinity, grain size, morphology, zeta potential and hydrodynamic diameter as well as Toceranib release. The crystalline nanorods of nHAp were synthesised by the co-precipitation method, while the amorphous Toceranib was obtained by its conversion from the crystalline form during nHAp–Toc preparation. The surface interaction between both compounds was confirmed using Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV–Vis) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS). The nHAp–Toc showed a slower and prolonged release of Toceranib. The release behaviour was affected by hydrodynamic size, surface interaction and the medium used (pH). The effectiveness of the proposed platform was tested by comparing the cytotoxicity of the drug combined with nHAp against the drug itself. The compounds were tested on NI-1 mastocytoma cells using the Alamar blue colorimetric technique. The obtained results suggest that the proposed platform shows high efficiency (the calculated IC50 is 4.29 nM), while maintaining the specificity of the drug alone. Performed analyses confirmed that nanohydroxyapatite is a prospective drug carrier and, when Toceranib-loaded, may be an idea worth developing with further research into therapeutic application in the treatment of canine mast cell tumour.

Multiplex genome editing of mammalian cells for producing recombinant heparin

Heparin is an essential anticoagulant used for treating and preventing thrombosis. However, the complexity of heparin has hindered the development of a recombinant source, making its supply dependent on a vulnerable animal population. In nature, heparin is produced exclusively in mast cells, which are not suitable for commercial production, but mastocytoma cells are readily grown in culture and make heparan sulfate, a closely related glycosaminoglycan that lacks anticoagulant activity. Using gene expression profiling of mast cells as a guide, a multiplex genome engineering strategy was devised to produce heparan sulfate with high anticoagulant potency and to eliminate contaminating chondroitin sulfate from mastocytoma cells. The heparan sulfate purified from engineered cells grown in chemically defined medium has anticoagulant potency that exceeds porcine-derived heparin and confers anticoagulant activity to the blood of healthy mice. This work demonstrates the feasibility of producing recombinant heparin from mammalian cell culture as an alternative to animal sources.

Peripheral Nerve Sheath Tumor in the Upper Eyelid in a Dog

Background: Schwannomas are benign neurogenic tumours of peripheral nerves. They originate from Schwann cells, which form the neural sheath.Peripheral nerve sheath tumors are most commonly found on the head and neck regions of both dogs and people. Schwannomas are rarely observed in ophthalmic areas. When they occur, ocular Schwannomas are usually located in the orbit, uveal tract and conjunctiva. The occurrence of uveal schwannoma, a subset of PNST has been well documented in the veterinary literature. This is the first report of a palpebral PNST in the dog. The lip-to-lid flap is a feasible technique to reconstruct the upper eyelid following wide surgical removal of a tumor in the dog.Case: A 9-year-old, spayed female mixed-breed dog was referred for evaluation of a large mass involving the right upper eyelid for a duration of approximately one month. The inspection revealed sero-sanguinolent discharge and an oval-shaped mass occupying more than 70% of the right upper eyelid. The dog was alert and the ophthalmic and general physical examination did not revealed abnormalities. Ocular ultrasonography did not show significant findings. A fine-needle aspirate of the palpebral tumor was not elucidative, even so, a presumptive diagnosis of eyelid neoplasia was considered most likely. Excision of the entire mass with a 2 cm margin was performed. The third eyelid and dorso-medial bulbar conjunctiva were also removed. Upper eyelid reconstruction was performed based on a similar technique previously described in cats (lip-to-lid flap). As a result, neoplastic spindle cells exhibited immunoreactivity for S100 and intense cytoplasmic staining for vimentin, supporting the diagnosis of schwannoma. Fifteen days later, the margins of the subdermal pattern flap were healed and skin sutures were removed. On the last follow-up, 9 months post-surgery, the dog was visual, and the flap was well incorporated and covered the ocular surface. Ten months later, another large mass arising from the right inferior palpebral conjunctiva was observed. Once ultrasound revealed orbital invasion exenteration combined with orbitectomy were performed, and the defect was covered with an auricular axial pattern flap. Although the second tumor had the same histological and immunohistochemical characteristics of the first mass additional staining for Ki67 was used to investigate the biological behavior of both masses.Discussion: Reported eyelid neoplasms in dogs include adenomas and adenocarcinomas of the meibomian glands, melanomas, fibroma, fibrosarcoma, histiocytoma, mastocytoma, lipomas, papillomas, and squamous cell carcinomas. To the author´s knowledge, however, this is the first case description of a PNST affecting the eyelid in a dog. The histologic distinction between PNSTs and other spindle cell tumors, including myxosarcoma, fibrosarcoma, leiomyosarcoma, hemangiopericytoma, and melanoma can be challenging and requires immunohistochemical stainin. S100 is an acidic protein that identifies various nervous tissue cells, including Schwann cells, and the majority of canine PNSTs diffusely express this molecule. As in the case presented here, neoplastic cells of different ocular and adnexal structures were also positive for S100 and vimentin in all PNSTs previously reported in the veterinary literature. This is the first report of PNST affecting the eyelid in a dog. The lip-to-lid flap is a feasible technique to reconstruct the upper eyelid following wide surgical removal of a tumor in dogs. However, the authors suggest radical surgery combining orbitectomy, exenteration and a miocutaneous flap if PNST is diagnosed in the eyelids of dogs. They also caution once recurrence is possible and can be more aggressive.Keywords: lip-to-lid transposition, S100, vimentin, desmin, Ki67, dog.

Phytochemical screening, antioxidant and in vitro anticancer activities of Bombax buonopozense stem bark extracts

In recent decades, extensive research has been focused on the screening and investigating the antioxidant and anticancer activities of medicinal plants extracts or isolated natural product-based drugs. Therefore, the present study aimed to evaluate the phytochemical, antioxidant and in vitro anticancer activities of Bombax buonopozense extracts. Standard methods were used for the identification of alkaloids, tannins, flavonoids, coumarins, saponins, sterol, triterpenes and reducing compounds. Free-radical–scavenging activity was measured by the 2,2’-diphenyl-1-picrylhydrazyl (DPPH) free radical assay, and the cytotoxic potential was evaluated in the P815 murin lymphoblast-like mastocytoma cell line using the MTT assay. Regarding the antioxidant activity, our results showed a powerful in vitro free-radical scavenging activity of the ethanolic extract compared to the aqueous extracts, with IC50 values of 10 and 220 µg/mL, respectively. In the MTT assay, the ethanolic extract showed a moderate and dose-dependent association growth inhibition of P815 cells in a dose above of 200 µg/mL with IC50 of 74 µg/mL compared to cisplatin (IC50= 4 µg/mL). Our findings demonstrate that Bombax buonopozense ethanolic extract could be an effective antioxidant and promising antiproliferative agent.

Safety, Immunogenicity, and Effectiveness of Defective Viral Particles Arising in Mast Cells Against Influenza in Mice.

Mast cells play pivotal roles in the pathogenesis of influenza A virus (IAV) infections. Defective viral particles (DPs) often arise during IAV replication, which can interfere with the replication of infectious viruses and stimulate the antiviral response of host cells. Therefore, DPs are expected to have immune-protective functions in clinic. However, the potent immunogenicity and effectiveness of DPs arising in mast cells during IAV replication have not been reported. In the present study, we showed that DPs generated in the human mastocytoma cell line HMC-1 following H1N1 infection were safe to mice after vaccination. Compared with lung adenocarcinoma cells, A549, DPs generated in infected mast cells had much better immunostimulatory activity, enhancing both humoral and cellular immunity of hosts. Notably, they could significantly increase the expression of immune-associated cytokines, especially the IFN-γ. Due to the robust immunogenicity, thus DPs generated in infected mast cells could stimulate the robust protective immune reaction effectively to fight against lethal IAV re-challenge after vaccination, which result in the high survival, decreased lung injury as well as inhibition of viral replication and inflammatory response in lungs. This study is the first to illustrate and explore the safety, immunogenicity, and effectiveness of DPs arising in mast cells against influenza as favorable potential vaccination. The results provide insight into the advances of new prophylactic strategies to fight influenza by focusing on DPs generated in mast cells.

Defective Viral Particles Produced in Mast Cells Can Effectively Fight Against Lethal Influenza A Virus.

Mast cells play an important role in the pathogenesis of highly pathogenic H5N1 avian influenza virus (H5N1-HPAIV) infection. Defective viral particles (DPs) can interfere with the replication of infectious viruses and stimulate the innate immune response of host cells. However, DPs arising from mast cells during HPAIV replication and their potent antiviral actions has not been reported. Here, we showed that the human mastocytoma cell line, HMC-1, allowed for the productive replication of the H5N1-HPAIV. Compared with alveolar cell line A549, DPs were propagated preferentially and abundantly in mast cells following IAV infection, which can be attributed to the wide existence of Argonaute 2 (AGO2) in HMC-1 cells. In addition, DPs generated in H5N1-infected cells could provide great therapeutic protection on mice to fight against various influenza A viruses, which included not only homologous H5N1-HPAIV, but also heterologous H1N1, H3N2, H7N2, and H9N2. Importantly, DPs generated in H5N1-infected HMC-1 cells could diminish viral virulence in vivo and in vitro by triggering a robust antiviral response through type II interferon signaling pathways. This study is the first to illustrate the arising of DPs in H5N1-HPAIV infected mast cells and explore their favorable ability to protect mice from influenza A viruses infection, which provides a novel insight and valuable information for the progress of new strategies to fight influenza A viruses infection, especially highly pathogenic avian influenza virus infection by focusing on the DPs generated in mast cells.

Characterization of WWOX expression and function in canine mast cell tumors and malignant mast cell lines

BackgroundThe WW domain-containing oxidoreductase (WWOX) tumor suppressor gene is frequently lost in a variety of solid and hematopoietic malignancies in humans. Dysregulation of WWOX has been implicated as playing a key role in tumor cell survival, DNA damage repair, and genomic stability. The purpose of this study was to characterize WWOX expression in spontaneous canine mast cell tumors (MCTs) and malignant cell lines and investigate the potential contribution of WWOX loss on malignant mast cell behavior.Methods/resultsWWOX expression is decreased in primary canine MCTs and malignant mast cell lines compared to normal canine bone marrow-cultured mast cells. In transformed canine mastocytoma cell lines, overexpression of WWOX or WWOX knockdown had no effect on mast cell viability. Inhibition of WWOX enhanced clonogenic survival following treatment with ionizing radiation in the C2 mast cell line. Lastly, immunohistochemistry for WWOX was performed using a canine MCT tissue microarray, demonstrating that WWOX staining intensity and percent of cells staining for WWOX is decreased in high-grade MCTs compared to low-grade MCTs.ConclusionsThese data suggest that WWOX expression is attenuated or lost in primary canine MCTs and malignant mast cell lines. Given the observed increase in clonogenic survival in WWOX-deficient C2 mast cells treated with ionizing radiation, further investigation of WWOX and its role in mediating the DNA damage response in malignant mast cells is warranted.

Characterization of canine mastocytoma cell response to cryoablation

Introduction: Mastocytoma Tumors (MCT) represent 16%-21% of all skin cancers in dogs, making it the most common form of cutaneous cancer. Solitary MCT are typically treated with wide surgical excision margins. While effective, MCT excision can cause the release of a large amount of histamine and other cytokines resulting in complications such as systemic shock or anaphylaxis. Treatments such as chemotherapy and radiotherapy have been considered to achieve complete remission. Cryoablation also represents a potential treatment option for MCT. While studies have shown cryoablation to be beneficial for the treatment of numerous cancers in animals and humans, few studies have described the use of cryoablation to treat MCT’s. The limited use of cryoablation is due to a number of factors including a lack of basic information pertaining to dosing (minimal lethal temperature) necessary to destroy MCT cancer. As such, in this study we conducted a series of in vitro studies using the C2 cell line and a pilot ex vivo fine needle aspirate tissue sample in an effort to detail the effects of freezing of canine MCT.

Role of Zinc Sulphate in Immune Regulation in Artemisia annua Pollen-challenged P815 Mastocytoma Cells

ABSTRACT Objective This study aimed to investigate the role of zinc sulphate in immune regulation in Artemisia annua pollen-challenged P815 mastocytoma cells. Methods P815 mastocytoma cells were treated with various concentrations of zinc sulphate and Artemisia annua pollen. Cell proliferation was measured using the Cell Counting Kit-8. The amount of ST2 and p38 in the cells were measured using Western blotting. The level of interleukins (IL)-33 in the supernatant was determined using the enzyme-linked immunosorbent assay. The levels of IL-2, IL-4, IL-5, interferon-γ, and tumor necrosis factor were measured using the cytometric bead array. Results Artemisia annua pollen at a concentration >0.001 µg/mL induced allergic response in the P815 mastocytoma cells. Expressions of IL-33, IL-4, ST2, and p38 increased along with higher concentrations of Artemisia annua pollen. Zinc sulphate of 50–200 µmol/L promoted the proliferation of P815 mastocytoma cells. Zinc sulphate attenuated the upregulation of IL-33, IL-4, ST2, and p38 caused by Artemisia annua pollen. Conclusion Zinc sulphate can promote the proliferation of P815 mastocytoma cells. It can also attenuate allergic response in the P815 mastocytoma cells induced by Artemisia annua pollen, which might provide a new treatment method for allergic diseases.

Reactive Oxygen Species-Mediated Apoptosis and Cytotoxicity of Newly Synthesized Pyridazin-3-Ones In P815 (Murin Mastocytoma) Cell Line.

In cancer cells, the intracellular antioxidant capacity and the redox homeostasis are mainly maintained by the glutathione- and thioredoxin-dependent systems which are considered as promising targets for anticancer drugs. Pyridazinones constitute an interesting source of heterocyclic compounds for drug discovery. The present investigation focused on studying the in-vitro antitumor activity of newly synthesized Pyridazin-3(2h)-ones derivatives against P815 (Murin mastocytoma) cell line. The in-vitro cytotoxic activities were investigated toward the P815 cell line using tetrazolium-based MTT assay. Lipid peroxidation and the specific activities of antioxidant enzymes were also determined. The newly compounds had a selective dose-dependent cytotoxic effect without affecting normal cells (PBMCs). Apoptosis was further confirmed through the characteristic apoptotic morphological changes and DNA fragmentation. Two compounds (6F: and 7H: ) were highly cytotoxic and were submitted to extend biological testing to determine the likely mechanisms of their cytotoxicity. Results showed that these molecules may induce cytotoxicity via disturbing the redox homeostasis. Importantly, the anticancer activity of 6F: and 7H: could be due to the intracellular reactive oxygen species hypergeneration through significant loss of glutathione reductase and thioredoxin reductase activities. This eventually leads to oxidative stress-mediated P815 cell apoptosis. Furthermore, the co-administration of 6F: or 7H: with Methotrexate exhibited a synergistic cytotoxic effect. considering their significant anticancer activity and chemosensitivity, 6F: and 7H: may improve the therapeutic efficacy of the current treatment for cancer.

The HMGCR Inhibitor Fluvastatin Induces Apoptosis and Autophagy in Primary and Neoplastic Mast Cells

Abstract Mast cell hyperplasia is noted in many inflammatory and allergic diseases. Mast cells can also generate a subtype of acute myelogenous leukemia. Understanding and treating mast cell hyperplasia and leukemia could be beneficial to both inflammatory and malignant diseases. Recently the family of statin drugs, widely employed as HMG CoA Reductase (HMGCR) inhibitors to lower serum cholesterol, have been found to be immunosuppressive. However, statin effects on mast cell survival are not known. We report that fluvastatin induces apoptosis in mouse bone marrow-derived mast cells (BMMC) and mastocytoma cells. Apoptosis was suppressed in p53 KO and Bcl-2 Tg BMMC, consistent with detectable mitochondrial damage and Caspase-9 activation. Because apoptosis induction could be mimicked by suppressing geranylgeranyl transferase (GGT), and fluvastatin effects were reversed by adding the product of the GGT reaction, loss of GGT-mediated protein lipidation is the likely mechanism of cell death. In addition to apoptosis, fluvastatin also induced autophagy. Chemical blockade of autophagy enhanced fluvastatin-mediated apoptosis in primary mast cells, but reduced it in mastocytomas. These data suggest that the FDA-approved statin drugs may be useful in suppressing mast cell hyperplasia and leukemia.

Incorporation, intracellular trafficking and processing of extracellular heparanase by mast cells: Involvement of syndecan-4-dependent pathway

We investigated the fate of proheparanase added to the culture media of mast cells. A recombinant protein mimicking proheparanase was continuously internalized into mastocytoma cells as well as bone marrow- and peritoneal cell-derived mast cells. Internalized heparanase molecules were accumulated in granules and a significant portion was released by stimulation with ionomycin, indicating that the internalized heparanase was sorted into secretory granules. The pro-form heparanase was processed into a mature and an active form inside the cells, in which intracellular heparin was fragmented by the mature enzyme. The internalization was substantially inhibited by addition of heparin and heparan sulfate to the culture medium, suggesting that glycosaminoglycan is involved in the uptake pathway. Out of four syndecans, expression of syndecan-3 and syndecan-4, especially cell surface syndecan-4, was detected in the mastocytoma cells. Two knockdown clones transfected with a shRNA expression vector targeting the syndecan-4 gene took up significantly lower amounts of heparanase than mock cells. We propose that some exogenous substances like proheparanase can be incorporated into mast cell granules via a glycosaminoglycan-mediated, especially syndecan-4-dependent, uptake pathway.

Increased IL-27/IL-27R expression in association with the immunopathology of murine ocular toxoplasmosis.

Interleukin 27 (IL-27) is a member of the IL-6/IL-12 family, and IL-27 receptor (IL-27R) consists of WSX-1 (the IL-27Rα subunit) and the signal-transducing subunit gp130. Human and mouse mast cells (MCs) express the IL-27R. To explore the expressions of IL-27/IL-27R subunits (WSX-1 and gp130) during acute ocular toxoplasmosis (OT), we established mouse model by intraocular injection of 500 Toxoplasma gondii RH strain tachyzoites. Histopathological changes were analyzed, MCs were counted by toluidine blue staining, and tryptase+/IL-27+ MCs were examined by immunofluorescence double-staining in the eyes and cervical lymph nodes (CLNs) of T. gondii-infected mice. The mRNA expressions of IL-27p28, WSX-1, gp130, and tachyzoite specific surface antigen 1 (SAG1) in the eyes and CLNs of T. gondii-infected mice, and the expressions of WSX-1 and gp130 in the murine mastocytoma cell line P815 infected with T. gondii tachyzoites in vitro were examined by using quantitative real-time reverse transcription-polymerase chain reaction. Our results showed that, after T. gondii infection, severe histopathological changes, increased numbers of total MCs and degranulated MCs, elevated expressions of IL-27p28, WSX-1, and gp130 were found in the eyes and CLNs, and significant correlations between the levels of IL-27 and SAG1 existed in the eyes and CLNs of T. gondii-infected mice. In addition, increased levels of WSX-1 and gp130 were examined in T. gondii-infected P815 cells. Our data suggested that IL-27/IL-27R expression induced by T. gondii infection may regulate MC-mediated immune response during acute OT in mouse model.

Biotin conjugated organic molecules and proteins for cancer therapy: A review

The main transporter for biotin is sodium dependent multivitamin transporter (SMVT), which is overexpressed in various aggressive cancer cell lines such as ovarian (OV 2008, ID8), leukemia (L1210FR), mastocytoma (P815), colon (Colo-26), breast (4T1, JC, MMT06056), renal (RENCA, RD0995), and lung (M109) cancer cell lines. Furthermore, its overexpression was found higher to that of folate receptor. Therefore, biotin demand in the rapidly growing tumors is higher than normal tissues. Several biotin conjugated organic molecules has been reported here for selective delivery of the drug in cancer cell. Biotin conjugated molecules are showing higher fold of cytotoxicity in biotin positive cancer cell lines than the normal cell. Nanoparticles and polymer surface modified drugs and biotin mediated cancer theranostic strategy was highlighted in this review. The cytotoxicity and selectivity of the drug in cancer cells has enhanced after biotin conjugation.

In Vitro Antitumor Activity of Newly Synthesized Pyridazin-3(2H)-One Derivatives via Apoptosis Induction

Systemic toxicity associated with drug resistance continues to be the major obstacle to curative therapy of cancer. Tumor cell resistance to chemotherapeutic drugs often results in coordinate resistance to other structurally and functionally unrelated drugs and the subsequent development of cross resistance phenotype. Therefore, it seems necessary to identify new molecules as anticancer agents. In this process, we synthesized a series of new pyridazin-3(2H)-one derivatives and evaluated their antitumor potential. These cyclic molecules were synthesized and designed as a combination of benzofuran with pyridazinones. All final compounds have been characterized by spectral and elemental analyses to confirm successful synthesis reactions. To evaluate their anticancer activity, all derivatives were assessed against the human breast adenocarcinoma cell line (MCF-7) and the murine mastocytoma cell line (P815) using the methyl tetrazolium Test (MTT assay). The cytotoxic activity was found to be dose-dependent and the IC50 values of the synthesized compounds ranged from 14.5 to 40 μM against MCF-7 and from 35 to 82.5 μM against P815. At the same time, no cytotoxic activity was observed against normal cells. In order to investigate the molecular mechanism of the most cytotoxic product (6f), apoptosis induction was measured against MCF-7 cells. Using the annexin-V FITC staining technique, we showed that the cytotoxic effect of this product is associated with apoptosis induction.