Expression, function, and regulation of the embryonic transcription factor TBX1 in parathyroid tumors
Articolo
Data di Pubblicazione:
2017
Citazione:
Expression, function, and regulation of the embryonic transcription factor TBX1 in parathyroid tumors / C. Verdelli, L. Avagliano, V. Guarnieri, F. Cetani, S. Ferrero, L. Vicentini, E. Beretta, A. Scillitani, P. Creo, G. Bulfamante, V. Vaira, S. Corbetta. - In: LABORATORY INVESTIGATION. - ISSN 0023-6837. - (2017 Sep 18). [Epub ahead of print]
Abstract:
Transcription factors active in embryonic parathyroid cells can be maintained in adult parathyroids and be involved in
tumorigenesis. TBX1, the candidate gene of 22q11.2-DiGeorge syndrome, which includes congenital hypoparathyroidism,
is involved in parathyroid embryogenesis. The study aimed to investigate expression, function, and regulation of the
parathyroid embryonic transcription factor TBX1 in human parathyroid adult normal and tumor tissues. TBX1 transcripts
were detected in normal parathyroids and were deregulated in parathyroid tumors. Using immunohistochemistry, TBX1
protein was detected, mainly at the nuclear level, in a consistent proportion of cells in normal adult parathyroids, whereas
TBX1 immunoreactivity was absent in fetal parathyroids. TBX1-expressing cells were markedly reduced in about a half of
adenomas (PAds) and two-thirds of carcinomas and the proportion of TBX1-expressing cells negatively correlated with the
serum albumin-corrected calcium levels in the analyzed tumors. Moreover, a subset of TBX1-expressing tumor cells
coexpressed PTH. TBX1 silencing in HEK293 cells, expressing endogenous TBX1, increased the proportion of cells in the G0/
G1 phase of cell cycle; concomitantly, CDKN1A/p21 and CDKN2A/p16 transcripts increased and ID1 mRNA levels decreased.
TBX1 silencing exerted similar effects in PAd-derived cells, suggesting cell cycle arrest. Moreover, in PAd-derived cells GCM2
and PTH mRNA levels were unaffected by TBX1 deficiency, whereas it was associated with reduction of WNT5A, an
antagonist of canonical WNT/β-catenin pathway. WNT/β-catenin activation by lithium chloride inhibited TBX1 expression
levels both in HEK293 and PAd-derived cells. In conclusion, TBX1 is expressed in adult parathyroid cells and deregulated in
parathyroid tumors, where TBX1 deficiency may potentially contribute to the low proliferative nature of parathyroid tumors.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
C. Verdelli, L. Avagliano, V. Guarnieri, F. Cetani, S. Ferrero, L. Vicentini, E. Beretta, A. Scillitani, P. Creo, G. Bulfamante, V. Vaira, S. Corbetta
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