Mdm2 and the p53 pathway in human pituitary adenomas

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Updated: Oct 8, 2026

Yeast As a Chassis for Developing Functional Assays to Study Human P53
14:57

Yeast As a Chassis for Developing Functional Assays to Study Human P53

Published on: August 4, 2019

M Suliman1, J Royds, D Cullen

  • 1Department of Endocrinology, Royal Hallamshire Hospital, Sheffield, UK.

Clinical Endocrinology
|April 12, 2001
PubMed
Abstract

Insights

This study found that p53, p21(WAF--1), and Mdm2 proteins are present in pituitary tumors, indicating wild-type p53. p53 expression correlates with higher tumor proliferation, but the downstream pathway may be dysfunctional.

Area of Science:

  • Endocrinology
  • Oncology
  • Molecular Biology

Background:

  • Pituitary tumors often express wild-type p53, a tumor suppressor gene.
  • p21(WAF--1) and Mdm2 are downstream effectors of p53 involved in cell cycle regulation.
  • The role of these proteins in pituitary tumor behavior is not fully understood.

Purpose of the Study:

  • To investigate the expression of p53, p21(WAF--1), and Mdm2 in pituitary tumors.
  • To correlate their expression with tumor invasiveness and proliferative potential (Ki-67).

Main Methods:

  • Immunocytochemistry was used to detect p53, p21(WAF--1), Mdm2, and Ki-67 (MIB-1) in 69 pituitary tumors.
  • Tumor invasiveness was assessed using preoperative CT/MRI scans.

Main Results:

  • p53 was expressed in 61% of pituitary adenomas, correlating with higher proliferation (MIB-1 index) but not invasiveness.
  • Invasive tumors exhibited a higher growth fraction.
  • p21(WAF--1) and Mdm2 expression correlated with p53 expression, suggesting wild-type p53 activity.

Conclusions:

  • p53, p21(WAF--1), and Mdm2 are expressed in pituitary tumors, likely as wild-type.
  • p53 expression is linked to increased tumor proliferation.
  • The downstream p53 pathway involving p21(WAF--1) and Mdm2 may be dysfunctional in these tumors.

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