DOG1

DOG1 (Discovered on GIST-1) is a protein found on the surface of certain cells. It is commonly used in pathology to identify specific types of tumours. DOG1 was first identified in gastrointestinal stromal tumours (GISTs), but it can also be found in other normal tissues and tumours.

What is the function of DOG1?

Although DOG1’s exact function is not fully understood, it is believed to regulate ion channels within cells. Ion channels control the movement of electrically charged particles (ions) in and out of cells, which is important for maintaining normal cell function. In pathology, DOG1 is valuable as a marker to help identify tumours with specific cellular origins.

What types of normal cells and tissues express DOG1?

DOG1 is normally expressed in certain cells of the gastrointestinal tract, particularly the interstitial cells of Cajal. These cells coordinate the movement of the digestive system. DOG1 is also found in other normal tissues, such as the salivary glands and kidneys.

How do pathologists test for DOG1?

Pathologists test for DOG1 using immunohistochemistry. This test uses special antibodies that attach to DOG1 if it is present in the cells being examined. When the antibody binds to DOG1, it produces a colour change that can be seen under a microscope. This test helps pathologists confirm whether a tumour expresses DOG1, which can provide clues about the tumour’s type and origin.

What types of benign tumours express DOG1?

Benign (non-cancerous) tumours that may express DOG1 include:

• Breast fibroadenoma: A common benign tumour of the breast.
• Chondroblastoma: A rare benign bone tumour.
• Cylindroma: A benign skin tumour often found on the scalp or face.
• Hidradenoma papilliferum: A benign tumour of the sweat glands.
• Hidrocystadenoma: A cystic tumour of the sweat glands.
• Mixed tumour of the skin: A benign tumour with both epithelial and mesenchymal components.
• Pilomatrixoma: A benign tumour arising from hair follicle cells.
• Renal oncocytoma: A benign kidney tumour.
• Steatocystoma: A cystic tumour of sebaceous (oil-producing) glands.

DOG1 testing can help differentiate these tumours from malignant ones with similar features.

What types of malignant tumours express DOG1?

Malignant (cancerous) tumours that may express DOG1 include:

• Gastrointestinal stromal tumour (GIST): A type of cancer that arises in the digestive tract. DOG1 is one of the most reliable markers for this tumour.
• Acinic cell carcinoma: A salivary gland cancer.
• Adenoid cystic carcinoma: A slow-growing cancer often found in the salivary glands or other glands.
• Chromophobe renal cell carcinoma: A kidney cancer subtype.
• Epithelial myoepithelial carcinoma: A rare salivary gland cancer.
• Esophageal squamous cell carcinoma: A cancer of the lining of the esophagus.
• Extramammary Paget disease: A rare skin cancer found outside the breast.
• Mucoepidermoid carcinoma: A common salivary gland cancer.
• Polymorphous adenocarcinoma: A slow-growing cancer of the salivary glands.

DOG1 testing is especially helpful in diagnosing GIST but provides valuable information for other types of tumours.