<b>Conclusions</b>: Our data demonstrate that vitamin C kills thyroid cancer cells by inhibiting MAPK/ERK and PI3K/AKT pathways via a ROS-dependent mechanism and suggest that pharmaceutical concentration of vitamin C has potential clinical use in thyroid cancer therapy.
In conclusion, the data of this study suggested that naringin presented anti-tumor effects in TC cells through inhibiting TC cell proliferation and inducing cell apoptosis via regulating the expression of cell proliferation and apoptosis related genes and PI3K/AKT pathway activation.
Under the influence of transcriptional regulators (such as Nuclear Factor-kappa B, mitogen-activated protein kinases, or Phosphoinositide-3 kinase/protein kinase-B), oncogenes connected to the different subtypes of TC promote their farthermost proliferative effect on the tumor microenvironment.
Consistently, AXL stimulation with its ligand growth arrest-specific gene 6 (GAS6) increased AKT1- and p65 NF-kB-phosphorylation and promoted survival of thyroid cancer cell lines in culture.
As phosphoinositide 3-kinase/protein kinase-B (PI3K/AKT) signaling is a fundamental oncogenic driver in many thyroid cancers, we explored a potential role for miR-146b and its target genes in PI3K/AKT activation.
PPFP thyroid cancers have increased activation of AKT, and mice with thyroid-specific expression of PPFP combined with thyroid-specific loss of PTEN (a negative regulator of AKT) develop thyroid cancer.
Substantial improvement in the understanding of the oncogenic pathways in thyroid cancer has led to identification of specific molecular alterations, including mutations of BRAF and RET in papillary thyroid cancer, mutation of RAS and rearrangement of PPARG in follicular thyroid cancer, mutation of RET in medullary thyroid cancer, and mutations of TP53 and in the phosphatidylinositol 3'-kinase (PI3K)/AKT1 pathway in anaplastic thyroid cancer.
We also deplete AKT from multiple thyroid cancer cell lines, including putative cancer stem cell lines, and measure the effect on proliferation and invasion in vitro.
Our aim was to determine the therapeutic efficacy of simultaneously targeting these pathways in thyroid cancer with a single agent and to evaluate biomarkers of treatment response.<b>Experimental Design:</b> CUDC-907 is a first-in-class compound, functioning as a dual inhibitor of HDACs and the PI3K/AKT pathway.
In this review article, the role of different signaling pathways of PI3K/AKT in thyroid cancers, with the emphasis on the PI3K/AKT/mammalian target of rapamycin (mTOR), PI3K/AKT/forkhead box O (FOXO) and PI3K/AKT/phosphatase and tensin homolog deleted on chromosome ten (PTEN) pathways, and various therapeutic strategies targeting these pathways have been summarized.
The aim of this study is to identify its expression, function, and molecular mechanism in thyroid cancer. microRNA-137 (miR-137) downregulation was observed in thyroid cancer tissues compared with normal thyroid tissues. miR-137 mimics downregulated B-CPAP cell proliferation, colony formation ability, and invasion, with suppressed expression of cyclin E, MMP2, p-ERK, and p-AKT. miR-137 inhibitor transfection in TPC-1 cell line showed the opposite effects.
In vitro results suggest that the inhibition of either RAS-MAPK-ERK or PI3K-AKT-mTOR components may confer sensitivity of thyroid cancer cells to classic chemotherapeutics.
Thyroid cancer cells lose TSH/cAMP dependency of mTOR signaling and cell growth. mTOR activity is not decreased by the MEK or AKT inhibitors in the RAS or BRAF human thyroid cancer cell lines.
In addition, expression of Sin1 and activation of AKT kinase were analyzed in fresh-frozen tissue samples (normal/tumor), primary cell cultures (papillary thyroid carcinoma [PTC]), and an established thyroid cancer cell line (medullary thyroid carcinoma) by Western blotting.
The genes, coding the signaling cascade proteins (e.g., RET, RAS, BRAF, PI3K, PTEN, AKT), are mutated or aberrantly expressed in thyroid cancer derived from follicular thyroid cell.
Recent novel and promising findings include additional abnormalities in key pathways associated with thyroid tumorigenesis (RET-Ras-BRAF-MEK; RET-beta-cateinin; TRK-PI3K-AKT; and MDM-p53-PTEN), single-nucleotide polymorphisms associated with thyroid cancer susceptibility, epigenetic silencing, alternative splicing, and gene expression abnormalities.