New Insights from the Expression of the Mismatch Repair System in Pituitary Neuroendocrine Tumors.

ABSTRACT: Although defects in the mismatch repair (MMR) system have been occasionally reported in aggressive/metastatic pituitary neuroendocrine tumors (PitNETs), the potential role of MMR dysregulation in pituitary tumorigenesis is largely unknown. This study aimed to evaluate the expression of the four key MMR components in a large series of PitNETs. MMR gene expression was studied by RT-qPCR in 127 tumors (54 PIT1, 51 SF1, 22 TPIT), and semi-quantitative immunohistochemistry (score 0-12) in selected cases (n=46). MSH2/6 and MLH1 promoters methylation was studied in 96 tumors. Except for MLH1, tumor lineage of origin was the most significant factor influencing MMR transcripts (P=0.005, <0.001 and 0.039 for MSH2/6 and PMS2, respectively), the highest levels being observed in SF1 tumors. Within subg

SUBMITTER: Carbonara F 

PROVIDER: S-EPMC12764676 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature