p53 and p21(WAF1) expression in lymphocytic thyroiditis and thyroid tumors

Area of Science:

• Endocrinology
• Oncology
• Cell Biology

Background:

• Chronic autoimmune lymphocytic thyroiditis involves complex cellular processes.
• Thyroid tumorigenesis is influenced by apoptosis and cell proliferation.
• The roles of p53 and p21(WAF1) in these conditions require clarification.

Purpose of the Study:

• To investigate the expression and distribution of p53 and p21(WAF1) proteins.
• To correlate protein expression with thyroiditis severity and tumor cell dedifferentiation.
• To examine the relationship between apoptosis, cell proliferation, and these protein expressions.

Main Methods:

• Immunohistochemistry was used to detect p53 and p21(WAF1) protein expression in 158 thyroid tissue samples.
• Cellular quantification and distribution scoring of positive cells were performed.
• In situ DNA nick-end labeling and Ki-67/Bcl-2 immunohistochemistry were employed.

Main Results:

• Increased p53 and p21(WAF1) expression correlated with thyroiditis severity and tumor cell dedifferentiation.
• Expression of both proteins showed a significant correlation.
• Enhanced apoptosis, decreased Bcl-2, and increased Ki-67 labeling were observed.

Conclusions:

• Elevated p53 and/or p21(WAF1) suggest DNA damage and increased apoptosis in autoimmune thyroiditis.
• Protein overexpression is linked to thyroid tumor cell dedifferentiation.
• These findings clarify the roles of apoptosis and proliferation in thyroid disease progression.