Related Experiment Video
Updated: May 28, 2026
HOX Loci Focused CRISPR/sgRNA Library Screening Identifying Critical CTCF Boundaries
Published on: March 31, 2019
Identification of novel Pax8 targets in FRTL-5 thyroid cells by gene silencing and expression microarray analysis
Tina Di Palma1, Anna Conti, Tiziana de Cristofaro
1Institute of Experimental Endocrinology and Oncology G. Salvatore (IEOS), National Research Council, Naples, Italy.
Background:
The differentiation program of thyroid follicular cells (TFCs), by far the most abundant cell population of the thyroid gland, relies on the interplay between sequence-specific transcription factors and transcriptional coregulators with the basal transcriptional machinery of the cell. However, the molecular mechanisms leading to the fully differentiated thyrocyte are still the object of intense study. The transcription factor Pax8, a member of the Paired-box gene family, has been demonstrated to be a critical regulator required for proper development and differentiation of thyroid follicular cells. Despite being Pax8 well-characterized with respect to its role in regulating genes involved in thyroid differentiation, genomics approaches aiming at the identification of additional Pax8 targets are lacking and the biological pathways controlled by this transcription factor are largely unknown.
Methodology/Principal Findings:
To identify unique downstream targets of Pax8, we investigated the genome-wide effect of Pax8 silencing comparing the transcriptome of silenced versus normal differentiated FRTL-5 thyroid cells. In total, 2815 genes were found modulated 72 h after Pax8 RNAi, induced or repressed. Genes previously reported to be regulated by Pax8 in FRTL-5 cells were confirmed. In addition, novel targets genes involved in functional processes such as DNA replication, anion transport, kinase activity, apoptosis and cellular processes were newly identified. Transcriptome analysis highlighted that Pax8 is a key molecule for thyroid morphogenesis and differentiation.
Conclusions/Significance:
This is the first large-scale study aimed at the identification of new genes regulated by Pax8, a master regulator of thyroid development and differentiation. The biological pathways and target genes controlled by Pax8 will have considerable importance to understand thyroid disease progression as well as to set up novel therapeutic strategies.
Insights
This study identifies novel genes regulated by the transcription factor Pax8, crucial for thyroid follicular cell development. Understanding these Pax8 targets advances knowledge of thyroid differentiation and disease mechanisms.
Area of Science:
- Endocrinology
- Molecular Biology
- Genetics
Background:
- Thyroid follicular cells (TFCs) differentiation depends on transcription factors and coregulators.
- Pax8 is a critical transcription factor for thyroid development and TFC differentiation.
- The full spectrum of Pax8-controlled pathways remains largely unknown.
Purpose of the Study:
- To identify novel downstream targets of the transcription factor Pax8.
- To elucidate the genome-wide transcriptional effects of Pax8 in thyroid cells.
- To explore biological pathways regulated by Pax8.
Main Methods:
- Genome-wide transcriptome analysis using RNA interference (RNAi) to silence Pax8 in FRTL-5 thyroid cells.
- Comparison of gene expression profiles between Pax8-silenced and control cells.
- Identification of modulated genes, including both previously known and novel targets.
Main Results:
- Silencing Pax8 modulated 2815 genes after 72 hours, confirming known targets and identifying novel ones.
- Newly identified Pax8 targets are involved in DNA replication, anion transport, kinase activity, apoptosis, and cellular processes.
- Transcriptome analysis confirms Pax8 as a key regulator of thyroid morphogenesis and differentiation.
Conclusions:
- This is the first large-scale study to identify new Pax8-regulated genes.
- Understanding Pax8's target genes and pathways is vital for comprehending thyroid disease progression.
- These findings pave the way for novel therapeutic strategies in thyroid disorders.
