IgG-Mediated Histamine Release from Canine Mastocytoma-Derived Cells

Abstract

Background: Recent data suggest that normal tissue mast cells can express functional receptors for IgG under certain conditions. However, little is known about IgG receptor expression and functional consequences in mast cell neoplasms. Methods: In this study, neoplastic mast cells were obtained from a dog with cutaneous mastocytoma (CM-MC) and from a dog with visceral mastocytoma (VI-MC). Both cell populations were characterized morphologically and functionally. Results: Most cells proliferated constantly in suspension without particular supplements. Doubling times of CM-MC and VI-MC were 52.2 and 27.5 h, respectively. Both cell types were sensitive to formalin fixation, did not contain heparin and were tryptase and chymase positive. Electron microscopy showed fine granules with electron-dense content in both cell populations. The total histamine content of CM-MC and VI-MC was 0.25 and 0.10 pg/cell, respectively. Calcium ionophore A23187 and substance P induced dose-dependent histamine release, whereas compound 48/80 had no effect. Most significantly, both cell types, when sensitized with monomeric dog IgG, released histamine upon stimulation by anti-dog IgG. Conclusions: Dog mastocytoma-derived cells may be useful to study the regulation of neoplastic mast cell growth and differentiation, as well as IgG receptor-mediated activation in neoplastic mast cells. Further research is required to clarify the pathophysiological significance of constitutive expression of IgG receptors in neoplastic (canine) mast cells.

Multi-center, Placebo-controlled, Double-blind, Randomized Study of Oral Toceranib Phosphate (SU11654), a Receptor Tyrosine Kinase Inhibitor, for the Treatment of Dogs with Recurrent (Either Local or Distant) Mast Cell Tumor Following Surgical Excision

“…MCTs release large quantities of inflammatory cytokines and other chemical mediators (histamine, leukotrienes, etc) that can directly influence tumor size (i.e., induce local tissue swelling; refs. [39][40][41][42][43], inducing waxing and waning of tumor size over time. Spontaneous complete responses have been reported in dogs with MCTs although these are more likely to occur in dogs with less-advanced disease than those enrolled in the current study.…”

Retinoids Induce Growth Inhibition and Apoptosis in Mast Cell Tumor Cell Lines

“…Cell culture: Three canine MCT cell lines (CoMS, CM-MC and VI-MC) were used in this study [9,21]. CoMS and VI-MC cells were cultured in RPMI-1640 medium (Nissui Pharmaceutical Co., Tokyo, Japan) supplemented with 10% heat-inactivated (56°C, 30 min) fetal bovine serum (FBS), 2 mM L-glutamine, 50 mg/L gentamycin sulfate and 1.5 mg/ L amphotericin B. CM-MC cells were cultured in RPMI-1640 medium supplemented with 10% heat-inactivated FBS, 2 mM L-glutamine, 10 U/ml penicillin G, 10 µg/ml streptomycin and 50 mM 2-mercaptoethanol.…”

Screening of Therapeutic Targets for Canine Mast Cell Tumors from a Variety of Kinase Molecules

“…HRMC and CMMC1 were originated from cutaneous MCT [25,31,33]. VIMC1 was derived from visceral MCT [31,33]. HRMC cells were cultured in serum-free AIM-V medium (Invitrogen, Carlsbad, CA, U.S.A.).…”

“…The mRNAs expressed in the cell lines were represented on Table 3 the inhibitors in the present study. The viability of the cells was assessed at 72 (HRMC and CMMC1) or 36 hr (VIMC1) depending on the doubling times of the cells [25,31]. As shown in Table 4, 10, 9 and 17 inhibitors suppressed more than 50% growth of HRMC, VIMC1 and CMMC1 cells, respectively.…”