Expression of Mast Cell Major Basic Protein in Oral Squamous Cell Carcinoma

Role of mast cells and eosinophils in oral tumours is not yet well define. Good and poor outcomes have been associated with eosinophils and mast cell abundant oral tumours. Major basic protein is one of the principal and specific proteins present in eosinophils. It is implicated in many pathological conditions including allergic reactions, parasitic infections and activation and stimulation of cells to produce cytokines. The protein was thought to be exclusively present in the eosinophil granules. However, a recent study revealed its presence in mast cells as well. In this brief article, the authors confirm the presence of major basic protein in mast cells associated with oral squamous cell carcinoma. This finding may doubts the validity of using anti-major basic protein as eosinophil specific. Furthermore, labelling eosinophils using anti-major basic protein antibodies as a marker would mistake mast cells as eosinophils. More importantly, the finding will better aid in understanding some of the mysterious function of MC in tumours