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Updated: Feb 5, 2026
Transoral Robotic Total Thyroidectomy and Bilateral Central Regional Lymph Node Dissection for Papillary Thyroid Carcinoma
Published on: September 15, 2023
miR-718 is involved in malignancy of papillary thyroid cancer through repression of PDPK1
1Department of General Surgery, the First Hospital of Harbin, Harbin 150010, China.
Background:
MicroRNAs bind the 3' untranslated regions (3'-UTRs) of mRNAs and thereby regulate gene expression post-transcriptionally and play an important role in cancer delvelopment. In the present study, we have explored the role of miR-718 in papillary thyroid cancer cell malignancy.
Materials/Methods:
Here we examined the miRNA expression in human papillary thyroid cancer by RT-PCR. Luciferase activity, RT-PCR and western blot assays were used to confirmed the target of miRNA. MTT, colony formation, transwell, glucose consumption and lactate production assays were performed to analyze papillary thyroid cancer cell function. Western blot for signaling proteins was used to reveal the mechanism.
Results:
We first determined that miR-718 mRNA expression levels in PTC samples were reduced. The 3'-UTR of 3-Phosphoinositide Dependent Protein Kinase 1 (PDPK1) was then identified as a target of miR-718. Luciferase assays showed that miR-718 does in fact bind the wild-type PDPK1 3'-UTR. We assessed the effects of miR-718 on p-Akt, Akt, p-mTOR and mTOR expression. We determined that miR-718 negatively regulates their levels, respectively, of Akt-mTOR pathway components. We then assessed the effects of miR-718 on PTC cell behavior. The results revealed that miR-718 negatively regulates PTC cell proliferation, migration, and invasion. In addition, miR-718 was found to inhibit cell glucose metabolism, likely through the Akt-mTOR pathway. Finally, PDPK1 could rescue PTC cell inhibition induced by miR-718.
Conclusions:
The present study strongly suggests that miR-718 inhibits PTC cell proliferation, metastasis, and glucose metabolism by negatively regulating the Akt-mTOR signaling pathway.
Insights
MicroRNA-718 (miR-718) suppresses papillary thyroid cancer (PTC) by inhibiting cell growth and metabolism. It targets PDPK1, downregulating the Akt-mTOR pathway, thus reducing malignancy.
Area of Science:
- Molecular Biology
- Oncology
- Gene Regulation
Background:
- MicroRNAs (miRNAs) are key post-transcriptional regulators of gene expression.
- Dysregulated miRNA expression is implicated in various cancers, including thyroid cancer.
- The specific role of miR-718 in papillary thyroid cancer (PTC) malignancy was underexplored.
Purpose of the Study:
- To investigate the function of miR-718 in papillary thyroid cancer progression.
- To identify the molecular targets and signaling pathways regulated by miR-718 in PTC.
- To determine the potential of miR-718 as a therapeutic agent in thyroid cancer.
Main Methods:
- Quantitative reverse transcription-polymerase chain reaction (RT-PCR) to assess miRNA and mRNA expression.
- Luciferase reporter assays to confirm direct binding of miR-718 to its target.
- Cellular assays (MTT, colony formation, Transwell) to evaluate PTC cell proliferation, migration, and invasion.
- Western blotting to analyze protein expression and pathway activation (Akt-mTOR).
Main Results:
- miR-718 expression was significantly reduced in PTC tissues compared to normal tissues.
- 3-Phosphoinositide Dependent Protein Kinase 1 (PDPK1) was identified as a direct target of miR-718.
- miR-718 suppressed PTC cell proliferation, migration, and invasion.
- miR-718 inhibited glucose metabolism in PTC cells, likely via the Akt-mTOR pathway.
- Overexpression of PDPK1 could rescue the inhibitory effects of miR-718 on PTC cells.
Conclusions:
- miR-718 functions as a tumor suppressor in papillary thyroid cancer.
- The miR-718/PDPK1 axis negatively regulates the Akt-mTOR signaling pathway.
- miR-718 inhibits PTC cell proliferation, metastasis, and glucose metabolism, offering potential therapeutic strategies.
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