Mast Cells: Key Players in the Shadow in Oral Inflammation and in Squamous Cell Carcinoma of the Oral Cavity

Abstract

Although mast cells (MCs) have been discovered over 130 years ago, their function was almost exclusively linked to allergic affections. At the time being, it is well known that MCs possess a great variety of roles, in both physiologic and pathologic conditions. In the oral tissues, MCs release different proinflammatory cytokines, tumor necrosis factor alpha (TNF-α), that promote leukocyte infiltration in various inflammatory states of the oral cavity. These cells play a key role in the inflammatory process and, as a consequence, their number changes in different pathologic conditions of the oral cavity, like gingivitis, periodontitis, and so on. MCs also represent a rich source of proteases, especially of mast cell tryptase and chymase, which directly degrade the extracellular matrix through their proteolytic activity and thus indirectly stimulate angiogenesis and facilitate invasion and metastasis. It may be stated that mast cells could have an impact on primary tumor development, progression, and metastases in oral squamous cell carcinoma. By understanding the role of mast cells in the pathogenesis of different inflammatory and tumor diseases of the oral cavity, these cells may become therapeutic targets that could possibly improve the prognosis and survival of these patients.

Correlation of elevated mast cell and micro-vessel densities with lymph node metastasis in oral squamous cell carcinoma

“…MCs accumulate around the tumor margins and release pro-angiogenic and angiogenic factors which favor tumor progression [17] . MCs in tissues can be identified using histochemical stains like toluidine blue, alcian blue and immunohistochemistry using tryptase, heparin, chymase and, carboxypeptidase [8] . In the present study, 1% toluidine blue stain was used for the identification and enumeration of MCs.…”

“…MCs can secrete angiogenic factors that enhance the angiogenesis of a tumor [8] . A previous study has shown that increased MCD and MVD in OSCC when compared to the normal oral mucosa, however, they could not demonstrate a statistically significant correlation between MCD and MVD in OSCC [18] .…”

“…MCs are a good source of proteases (tryptase and chymase) which directly degrade the extracellular matrix through their proteolytic activity and indirectly stimulate angiogenesis and facilitate invasion and metastasis through extracellular matrix remodeling. Hence MCs have an impact both on the development of the primary tumor and tumor progression and metastasis in OSCC [8] . The role of the MCs in OSCC has been investigated in many studies.…”

“…The total number of MCs have been found to be statistically significantly increased in OSCC when compared to normal controls [7,9] . According to experimental models, there is a gradual increase in MC counts in the transition from dysplasia to OSCC [8] .…”

Phenethyl isothiocyanate decreases thymic stromal lymphopoietin-induced inflammatory reactions in mast cells

“…Mast cells proliferation by inflammatory cytokines induces an increase of mast cell density in inflammatory tissues (Mierke et al, ). An increase in the number of mast cells is observed in reactive inflammatory conditions (Gaje et al, ). The increased number of mast cells is also observed in allergic inflammation with local recruitment and activation of T helper 2 (Th2) lymphocytes (Hart, ).…”