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Published on: August 23, 2019
MAPK and SHH pathways modulate type 3 deiodinase expression in papillary thyroid carcinoma
Mírian Romitti1, Simone Magagnin Wajner1, Lucieli Ceolin1
1Thyroid SectionEndocrine Division, Serviço de Endocrinologia, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2350, CEP 90035-003 Porto Alegre, RS, BrazilExperimental Research CenterHospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, BrazilDepartment of Cell and Developmental BiologyInstitute of Biomedical Sciences, Universidade de São Paulo, São Paulo, SP, Brazil.
Type 3 deiodinase (DIO3) upregulation in papillary thyroid carcinoma (PTC) is linked to MAPK and sonic hedgehog pathways. Inhibiting DIO3 reduces PTC cell proliferation, suggesting its role in tumor growth.
Area of Science:
- Endocrinology
- Oncology
- Molecular Biology
Background:
- Type 3 deiodinase (DIO3) is reactivated in human cancers.
- Elevated DIO3 levels correlate with tumor size and metastasis in papillary thyroid carcinoma (PTC).
Purpose of the Study:
- To investigate signaling pathways driving DIO3 upregulation in PTC.
- To explore the role of DIO3 in PTC cell proliferation.
Main Methods:
- Analysis of DIO3 mRNA, protein, and activity in PTC cell lines (K1, TPC-1) and tumor samples.
- Gene silencing using siRNA.
- Pharmacological inhibition of BRAF, MEK, p38 MAPK, and sonic hedgehog (SHH) pathways.
Main Results:
- DIO3 expression was higher in BRAF(V600E)-mutated PTC and K1 cells compared to RET/PTC1-rearranged PTC and TPC-1 cells.
- Inhibition of BRAF, MEK, p38, and SHH pathways decreased DIO3 expression.
- DIO3 silencing reduced cyclin D1 expression and induced G1 cell cycle arrest, decreasing proliferation.
Conclusions:
- MAPK and SHH pathways sustain DIO3 expression in PTC.
- DIO3 plays a role in PTC tumor growth and aggressiveness by promoting cell proliferation.
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