Telomere length and TERT abnormalities in pituitary adenomas

Area of Science:

• Endocrinology
• Oncology
• Molecular Biology

Background:

• Pituitary adenomas (PAs) are common intracranial tumors.
• Abnormal telomerase activity and telomere lengthening are hallmarks of cancer cells, potentially arising from TERT promoter mutations, gene amplification, or DNA methylation changes.
• These alterations have been observed in various brain tumors.

Purpose of the Study:

• To determine the frequency of TERT abnormalities in pituitary adenomas.
• To assess the role of TERT abnormalities in telomere lengthening within PAs.

Main Methods:

• Quantitative PCR (qPCR) was used to measure telomere length, TERT mRNA levels, and TERT gene amplification in 101 PA patients.
• Sanger sequencing analyzed TERT promoter mutations.
• Genome-wide DNA methylation profiling (HumanMethylation 450K) examined the TERT locus.

Main Results:

• Variable telomere length was observed, but not correlated with clinicopathological features.
• A single TERT promoter missense variant was found; increased TERT copy number occurred in 5.6% of patients, with no link to telomere length or TERT expression.
• No significant changes in DNA methylation at the TERT locus were detected between adenoma and normal tissues.

Conclusions:

• The findings suggest that telomerase abnormalities do not play a significant role in the pathogenesis of pituitary tumors.
• TERT alterations are unlikely drivers of pituitary adenoma development.