In these cell lines, both active ERK and active AKT kinase proteins were found in BRAF V600E mutated thyroid carcinoma cells by immunofluorescent staining and Western blots experiments.
Here, we identify Janus kinase/signal transducers and activators of transcription (STAT) and phosphatidyl inositol 3-kinase (PI3K)/AKT as the down-stream pathways through which these cytokines confer resistance to cell death in thyroid cancer.
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.
Interestingly, the exposure of thyroid carcinoma cells to PLX4032 resulted in a rapid feedback activation of EGFR signaling with parallel activation of AKT phosphorylation.
MicroRNA-126 suppresses proliferation of undifferentiated (BRAF(V600E) and BRAF(WT)) thyroid carcinoma through targeting PIK3R2 gene and repressing PI3K-AKT proliferation-survival signalling pathway.
Taken together, these results suggest that knockdown of HPIP inhibits the proliferation, migration and EMT by suppressing the PI3K/AKT pathway, and HPIP may be a potential therapeutic target for the treatment of thyroid carcinoma.
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.
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.
<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.
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.
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.
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.
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.
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.
Our review of the literature strongly supports this notion in that a polymorphism in one microRNAs (miR-146a) predisposes to thyroid carcinoma, whereas numerous other microRNAs are involved in signaling (mainly PTEN/PI3K/AKT and T3/THRB) that is central to thyroid carcinogenesis.