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Updated: Feb 12, 2026
Transoral Robotic Total Thyroidectomy and Bilateral Central Regional Lymph Node Dissection for Papillary Thyroid Carcinoma
Published on: September 15, 2023
The mTOR Kinase Inhibitor CZ415 Inhibits Human Papillary Thyroid Carcinoma Cell Growth
Background/Aim:
Mammalian target of rapamycin (mTOR) plays an important role in papillary thyroid carcinoma (PTC) cell progression. CZ415 is a novel, highly-efficient and specific mTOR kinase inhibitor. The current study tested the potential anti-tumor activity of CZ415 in human PTC cells.
Methods:
The established (TPC-1 cell line) and primary human PTC cells were treated with CZ415. Cell survival and growth were tested by Cell Counting Kit-8 assay and BrdU ELISA assay, respectively. Cell apoptosis was tested by caspase-3/-9 activity assay, Hoechst-33342 staining assay and single-stranded DNA ELISA assay. Cell cycle progression was tested by propidium iodide-FACS assay. The mTOR signaling was tested by Western blotting assay and co-immunoprecipitation assay. The mouse xenograft tumor model was applied to study the effect of CZ415 in vivo.
Results:
In cultured human PTC cells, treatment with CZ415 at nM concentrations significantly inhibited cell survival and growth. CZ415 induced apoptosis activation and cell cycle arrest in human PTC cells. CZ415 disrupted assembling of mTORC1 (mTOR-Raptor association) and mTORC2 (mTOR-Rictor-GβL association) in TPC-1 cells, which led to de-phosphorylation of the mTORC1 substrates (S6K1 and 4E-BP1) and the mTORC2 substrate AKT (Ser-473). Further studies show that the autophagy inhibitor 3-methyladenine (3-MA) or Beclin-1 shRNA aggravated CZ415-induced cytotoxicity against PTC cells. In vivo, CZ415 oral administration inhibited TPC-1 xenograft tumor growth in mice.
Conclusion:
Our results show that mTOR blockage by CZ415 inhibits PTC cell growth in vitro and in vivo.
Insights
CZ415, an mTOR kinase inhibitor, effectively reduced papillary thyroid carcinoma (PTC) cell growth and survival. This novel agent demonstrated anti-tumor activity by inducing apoptosis and cell cycle arrest in both in vitro and in vivo models.
Area of Science:
- Oncology
- Molecular Biology
- Pharmacology
Background:
- Mammalian target of rapamycin (mTOR) signaling is crucial for papillary thyroid carcinoma (PTC) cell progression.
- CZ415 is a novel, potent, and specific inhibitor of mTOR kinase.
Purpose of the Study:
- To evaluate the anti-tumor potential of CZ415 in human PTC cells.
- To investigate the mechanisms underlying CZ415's effects on PTC cells.
Main Methods:
- Human PTC cell lines (TPC-1) and primary cells were treated with CZ415.
- Assays included cell survival, growth, apoptosis, cell cycle, Western blotting, co-immunoprecipitation, and a mouse xenograft model.
Main Results:
- CZ415 significantly inhibited PTC cell survival and growth at nanomolar concentrations.
- CZ415 induced apoptosis, cell cycle arrest, and disrupted mTORC1/mTORC2 complex assembly.
- In vivo, CZ415 administration suppressed TPC-1 xenograft tumor growth in mice.
Conclusions:
- mTOR inhibition by CZ415 effectively suppresses PTC cell growth both in vitro and in vivo.
- CZ415 represents a promising therapeutic candidate for papillary thyroid carcinoma treatment.
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