EXPRESSION OF MENIN IN THE HUMAN THYROID GLAND.

Area of Science:

• Endocrinology
• Oncology
• Molecular Biology

Background:

• Menin expression in the thyroid gland is debated, with conflicting human and animal study results.
• Inactivation of menin in animal models suggests a role in aggressive thyroid cancer progression.
• Human studies show mixed findings regarding MEN1 gene mutations and thyroid cancer prevalence.

Purpose of the Study:

• To investigate the immunohistochemical expression patterns of menin across various human thyroid carcinoma subtypes.
• To clarify the role of menin in thyroid tumorigenesis by analyzing its expression levels.

Main Methods:

• Immunohistochemical analysis of nuclear menin expression using an anti-menin antibody.
• Tested 48 thyroid tumors including papillary, anaplastic, poorly differentiated, medullary, and oncocytic carcinomas, plus adenomas and goiters.
• Categorized menin expression as positive, negative, or decreased.

Main Results:

• Menin expression was positive and similar to normal tissue in 81.25% (39/48) of thyroid tumors.
• Decreased or absent menin expression was observed in 18.75% (9/48) of tumors.
• Notably, 42% of poorly differentiated thyroid carcinomas and 40% of oncocytic carcinomas showed reduced or absent menin.

Conclusions:

• Menin expression is predominantly preserved in human thyroid carcinomas.
• A subset of thyroid cancers, particularly poorly differentiated and oncocytic types, exhibit decreased or absent menin.
• Further molecular investigations are warranted to elucidate the functional significance of menin in thyroid cancer development.