Human Thyroid Carcinoma Cell Line Research Articles

Mechanisms of vemurafenib-induced anti-tumor effects in ATC FRO cells

BackgroundAnaplastic Thyroid Carcinoma (ATC) is a rare and deadly malignant tumor in humans. It is prone to developing resistance to radiotherapy and chemotherapy. Molecular targeted therapy offers a novel way to treat ATC. The BRAF mutation is closely associated with many cancers, including thyroid carcinoma. Vemurafenib, a small-molecule inhibitor, is specifically designed to target the mutant serine/threonine kinase BRAF. The objective of this study is to elucidate the regulatory mechanisms underlying the effects of vemurafenib on human anaplastic thyroid carcinoma cell line FRO and to assess its potential therapeutic role. MethodsThe effects of vemurafenib on the proliferation of FRO cells were assessed by the CCK-8 method and Colony-forming assay. Transwell chambers and scratch tests were employed to examine the impact of vemurafenib on the invasion and migration of FRO cells. Apoptosis and cycle distribution of FRO cells were analyzed by tunel assay and flow cytometry. The effects of vemurafenib on the expression of BRAF-activated non-protein coding RNA (BANCR), Bax, Bcl2, and E-cadherin were evaluated by qRT-PCR. Furthermore, the effects of vemurafenib on the expression of phosphoinositol-3-kinase (PI3K)/phosphoinositol-3-kinase (AKT) pathway-related proteins, BRAF, CyclinD1, Bcl-2, Bax, and E-cadherin proteins in FRO cells were investigated through the western-blot method. All experiments were conducted in three replicates. ResultsVemurafenib was observed to inhibit proliferation and induce apoptosis in a dose- and time-dependent manner (P < 0.05). The formation of FRO cell colonies, as well as migration and invasion, all showed a dose-dependent reduction (P < 0.05). Flow cytometric analysis indicated G0/G1 cell cycle arrest (P < 0.05). QRT-PCR revealed that vemurafenib could suppress the expression of BANCR and Bcl2 while increasing the expression of Bax and E-cadherin in a dose-dependent manner (P < 0.05). The protein expression levels of Bax and E-cadherin were up-regulated significantly, and the expression levels of BRAF, CyclinD1, Bcl-2, p-PI3K, p-AKT, and p-mTOR were markedly down-regulated with increasing concentrations of vemurafenib (P < 0.05). ConclusionsThe proliferation and metastasis of FRO cells can be suppressed by vemurafenib through the silencing of BRAF and BANCR expression, inhibition of PI3K/AKT signaling pathway activation, induction of apoptosis, and cell cycle arrest.

PRMT1 accelerates cell proliferation, migration, and tumor growth by upregulating ZEB1/H4R3me2as in thyroid carcinoma.

Thyroid carcinoma (TC) represents the most prevalent malignancy of the endocrine system. Protein arginine methyltransferase 1 (PRMT1) is a critical member of the protein arginine methyltransferase family in mammals and is involved in multiple biological processes. This study aimed to investigate the function of PRMT1 in TC. In the present study, human TC cell lines (8505C, CAL62, and BCPAP) and a normal human thyroid cell line Nthy‑ori 3‑1 were employed. Small interfering RNA targeting PRMT1 was used to knock down PRMT1 expression in 8505C cells, and PRMT1 overexpression plasmids were transfected into BCPAP cells. Cell viability was assessed using a CCK‑8 and colony formation assays. Apoptosis was measured using flow cytometry and TUNEL assays. Cell migration was assessed using wound healing and Transwell assays. Reverse transcription‑quantitative PCR was used to determine the mRNA expression levels of PRMT1. Western blotting was used to detect the protein expression levels of PRMT1, E‑cadherin, vimentin, H4R3me2as, and zinc‑finger E homeobox‑binding 1 (ZEB1). Notably, PRMT1 expression was elevated in TC (P<0.01). PRMT1 knockdown inhibited TC cell proliferation and migration and concurrently enhanced migration. Furthermore, PRMT1 knockdown suppressed tumor growth and metastasis in a mouse model of TC. PRMT1 downregulation increased E‑cadherin expression and decreased the expression of vimentin, H4R3me2as, and ZEB1 in the TC cells and the mouse model of TC. Conversely, PRMT1 overexpression had the opposite effect on TC malignant characteristics (P<0.05). These findings suggest that PRMT1 knockdown inhibited TC malignancy by downregulating H4R3me2as/ZEB1, thereby highlighting novel therapeutic targets and diagnostic markers for the management of TC.

P18INK4C and BRCA1 inhibit follicular cell proliferation and dedifferentiation in thyroid cancer

ABSTRACT Only 3% of thyroid cancers are medullary thyroid carcinomas (MTCs), the rest are follicular epithelial cell derived non-MTCs (NMTCs). A dysfunctional INK4-CDK4-RB pathway is detected in most of NMTCs. DNA repair defects and genome instability are associated with NMTC dedifferentiation and aggressiveness. Whether inactivation of the INK4-CDK4-RB pathway induces NMTCs and how differentiation of NMTC cells is controlled remain elusive. In this study, we generated p18Ink4c and Brca1 singly and doubly deficient mice as well as p16Ink4a and Brca1 singly and doubly deficient mice. By using these mice and human thyroid carcinoma cell lines, we discovered that loss of p18Ink4c, not p16Ink4a, in mice stimulated follicular cell proliferation and induced NMTCs. Depletion of Brca1 alone or both p16Ink4a and Brca1 did not induce thyroid tumor. Depletion of Brca1 in p18Ink4c null mice results in poorly differentiated and aggressive NMTCs with epithelial-mesenchymal transition (EMT) features and enhanced DNA damage. Knockdown of BRCA1 in thyroid carcinoma cells activated EMT and promoted tumorigenesis whereas overexpression of BRCA1 inhibited EMT. BRCA1 and EMT marker expression were inversely related in human thyroid cancers. Our finding, for the first time, demonstrates that inactivation of INK4-CDK4-RB pathway induces NMTCs and that Brca1 deficiency promotes dedifferentiation of NMTC cells. These results suggest that BRCA1 and p18INK4C collaboratively suppress thyroid tumorigenesis and progression and CDK4 inhibitors will be effective for treatment of INK4-inactivated or cyclin D-overexpressed thyroid carcinomas.

Rhodamine B-Quinoline based schiff base as fluorescent ‘turn on’ sensor of Al3+, Cr3+, HSO4− and its cytotoxicity and cell imaging application on TPC-1 and HtH-7 cell lines

A designed Rhodamine-B-quinoline based Schiff base chemosensor (RhBQ) has been synthesized and characterized using various spectroscopic techniques. It shows ‘turn on’ fluorescence emission and also colorimetric sensitivity and selectivity towards trivalent metal ions (Al3+ and Cr3+) and anion (HSO4−) present in aqueous medium. Stoichiometry of both metal (Al3+ & Cr3+) - RhBQ complexes are found to be 1:1 using Job’s plot. A notable enhancement in emission intensity for RhBQ-Al3+ (∼341 fold), RhBQ-Cr3+ (∼292 fold), and RhBQ-HSO4− (∼136 fold) complexes compare to RhBQ are observed. Sensing mechanism i.e. opening of spirolactam ring of RhBQ has been confirmed through various spectroscopic techniques such as; 1H NMR, 13C NMR, ESI-MS, TRPL, FT-IR, and DFT based computational study. The limit of detection (LOD) for Al3+, Cr3+, and HSO4− are found to be 2.2 × 10−8 M, 2.12 × 10−8 M and 8.63 × 10−7 M respectively. An advanced level 3 input OR–INHIBIT logic gate are constructed using chelating ligand EDTA. For onsite detection, TLC paper strip spot of the probe, RhBQ is prepared and the detection of Al3+ in few antacid drug are presented. In addition, cell-imaging analysis of Al3+, Cr3+, and HSO4− ions in the Human papillary thyroid carcinoma cell line (TPC-1) & Human anaplastic thyroid cancer cell lines (HtH-7) are presented and shows promising concentration and time-dependent detection results.

Growth inhibition by fusidic acid in cervical, thyroid, and breast carcinoma cell lines.

We investigated the effects of fusidic acid (FA) on human cervical, thyroid, and breast carcinoma cell lines to determine the potential usefulness of FA in cancer treatment. Six cancer cell lines (cervical cancer: Caski, HeLa; thyroid cancer: 8505C, TPC1; and breast cancer: MCF-7, MDA-MB-231) were treated with FA. Furthermore the changes in cell growth, cell cycle duration, and extent of apoptosis were analyzed. After FA treatment, the cancer cells showed a decrease in growth rate. In the cell death assay, the cell populations were similar in each cell type after treatment with FA, indicating that growth inhibition by FA was not related to the induction of apoptosis. FA induced cell cycle arrest at a dose that inhibited growth rate, which varied in different cell types. G0/G1 phase arrest occurs in breast cancer, S phase arrest in 8505C thyroid cancer, and G2/M phase arrest in cervical cancer. These results indicate that FA reduces growth rates by inducing cell cycle arrest. FA treatment can interfere with cell proliferation by inducing cell cycle arrest in human cervical, thyroid, and breast carcinoma cell lines. Thus, FA can be useful in treating human cervical, thyroid, and breast carcinomas.

Nuclear-targeted EGF receptor enhances proliferation and migration of human anaplastic thyroid cancer cells.

Epidermal growth factor (EGF) has various important physiological functions, which it exerts by binding to the epidermal growth factor receptor (EGFR). Reports show that EGF expression is strongly correlated with the occurrence and development of many types of tumour. To date, however, the relationship between EGF/EGFR and the occurrence and development of thyroid carcinoma remains unclear. In the current study, we investigated this phenomenon using human anaplastic thyroid carcinoma cell lines (SUN-80). The results indicated that EGF triggered the EGFR-mediated intracellular signalling pathway, including signal transducers and activators of transcription 1/3/5 (STAT1/3/5) and protein kinase B (AKT) in a time- and dose-dependent manner. In addition, results from EGF-induced EGFR internalization and co-localization analyses showed that clathrin, Rab5/7, and EEA1 play critical roles in the intracellular trafficking of EGF/EGFR. Interestingly, EGF triggered EGFR translocation into the nucleus, while nuclear-localized EGFR affected cell cycle distribution, thereby significantly promoting the ration of S phase. Overall, these findings indicated that nuclear EGFR exerts biological activity and physiological functions, including changing cell cycle, which in turn promotes proliferation and migration of SUN-80 cells. These findings lay a foundation for further explorations seeking to understand the biological effects of the EGF/EGFR system on the occurrence and development of thyroid cancer.

Inhibiting ERK dimerization ameliorates BRAF-driven anaplastic thyroid cancer

BackgroundRAS-to-ERK signaling is crucial for the onset and progression of advanced thyroid carcinoma, and blocking ERK dimerization provides a therapeutic benefit in several human carcinomas. Here we analyzed the effects of DEL-22379, a relatively specific ERK dimerization inhibitor, on the activation of the RAS-to-ERK signaling cascade and on tumor-related processes in vitro and in vivo.MethodsWe used a panel of four human anaplastic thyroid carcinoma (ATC) cell lines harboring BRAF or RAS mutations to analyze ERK dynamics and tumor-specific characteristics. We also assessed the impact of DEL-22379 on the transcriptional landscape of ATC cell lines using RNA-sequencing and evaluated its therapeutic efficacy in an orthotopic mouse model of ATC.ResultsDEL-22379 impaired upstream ERK activation in BRAF- but not RAS-mutant cells. Cell viability and metastasis-related processes were attenuated by DEL-22379 treatment, but mostly in BRAF-mutant cells, whereas in vivo tumor growth and dissemination were strongly reduced for BRAF-mutant cells and mildly reduced for RAS-mutant cells. Transcriptomics analyses indicated that DEL-22379 modulated the transcriptional landscape of BRAF- and RAS-mutant cells in opposite directions.ConclusionsOur findings establish that BRAF- and RAS-mutant thyroid cells respond differentially to DEL-22379, which cannot be explained by the previously described mechanism of action of the inhibitor. Nonetheless, DEL-22379 demonstrated significant anti-tumor effects against BRAF-mutant cells in vivo with an apparent lack of toxicity, making it an interesting candidate for the development of combinatorial treatments. Our data underscore the differences elicited by the specific driver mutation for thyroid cancer onset and progression, which should be considered for experimental and clinical approaches.

Design and synthesis of nano Cu/chitosan-starch bio-composite for the treatment of human thyroid carcinoma

In this study we report the green synthesis of nontoxic and stable Cu nanoparticles (NP) using chitosan/starch hydrogel with reducing/capping ability without using any harsh reducing agents. Starch was used as a reducing agent for the synthesis of Cu NPs that was further stabilized by chitosan polymers. The in situ prepared Cu NPs/CS-Starch bio-composite were characterized by advanced physicochemical techniques like Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX), X-ray Diffraction (XRD), UV–Vis, TGA and Inductively Coupled Plasma-Optical Emission Spectroscopic (ICP-OES) study. It has been established that Cu NPs/CS-Starch bio-composite have a spherical shape with a mean diameter from 5 to 7 nm. Cell viability of Cu NPs/CS-Starch bio-composite was very low against common human thyroid carcinoma cell lines i.e. TPC1, BCPAP and FTC133 without any cytotoxicity on normal cell line. The best anti-human thyroid carcinoma effects of Cu NPs/CS-Starch bio-composite was observed against the TPC1 cell line. For investigating the antioxidant properties of Cu NPs/CS-Starch bio-composite, the DPPH assay was used in the presence of butylated hydroxytoluene as the positive control. Cu NPs/CS-Starch bio-composite inhibited half of the DPPH molecules in the concentration of 207 µg/mL. The antioxidant activity of Cu NPs/CS-Starch bio-composite is significantly related to its anti-human thyroid carcinoma potentials. Based on to the above findings, the Cu NPs/CS-Starch bio-composite could be administrated for the treatment of several types of human thyroid carcinoma in humans.

NKX2-1 re-expression induces cell death through apoptosis and necrosis in dedifferentiated thyroid carcinoma cells.

NK2 homeobox 1 (NKX2-1) is a thyroid transcription factor essential for proper thyroid formation and maintaining its physiological function. In thyroid cancer, NKX2-1 expression decreases in parallel with declined differentiation. However, the molecular pathways and mechanisms connecting NKX2-1 to thyroid cancer phenotypes are largely unknown. This study aimed to examine the effects of NKX2-1 re-expression on dedifferentiated thyroid cancer cell death and explore the underlying mechanisms. A human papillary thyroid carcinoma cell line lacking NKX2-1 expression was infected with an adenoviral vector containing Nkx2-1. Cell viability decreased after Nkx2-1 transduction and apoptosis and necrosis were detected. Arginase 2 (ARG2), regulator of G protein signaling 4 (RGS4), and RGS5 mRNA expression was greatly increased in Nkx2-1-transducted cells. After suppressing these genes by siRNA, cell death, apoptosis, and necrosis decreased in RGS4 knockdown cells. These findings demonstrated that cell death was induced via apoptosis and necrosis by NKX2-1 re-expression and involves RGS4.

Tamoxifen triggers apoptosis of papillary thyroid cancer cells by two different mechanisms

Thyroid cancer occurs more frequently in women, implying the probable role of female sex hormones in this high incidence. Tamoxifen is an anticancer drug that binds to estrogen receptor and antagonizes estrogen biological effects. The main goal of the current investigation was to identify the impact of tamoxifen on apoptosis of human papillary thyroid carcinoma (PTC) cell line, BCPAP, and clarify underlying mechanisms. BCPAP cell line was incubated with the 2.5 μM tamoxifen for 48 h. The proliferation of these cells was assayed utilizing 3-(4, 5-dimethylthiazol-2-yl) -2, 5-diphenyltetrazolium bromide (MTT) method. Then, the mRNA expression of antiapoptotic factor Bcl-2, pro-apoptotic factor BAX, Caspase-3, proliferation marker MKI67, as well as the expression of long non-coding RNAs TUG1, NEAT1, and lincDUSP were analyzed via Real time-polymerase chain reaction (Real time-PCR) technique. The expression of the caspase-3 protein was semi-quantified using western blotting. Tamoxifen hindered the proliferation of BCPAP cells and reduced the expression of proliferation marker MKI67. Tamoxifen induced apoptosis and decreased the expression of Bcl-2, while upregulated Bax and caspase-3 in BCPAP cells. It was also identified that TUG1, NEAT1, and lincDUSP expressions were downregulated by tamoxifen treatment. Tamoxifen blocked proliferation and stimulated apoptosis in the BCPAP cell line. A potential molecular mechanism was the stimulation of mitochondrial apoptosis via effects on MKI67, Bcl-2, Bax, and Caspase-3 expression. The other mechanism might function through downregulating TUG1, NEAT1, and lincDUSP. Thus, tamoxifen may provide a candidate for the development of a prospective therapeutic strategy for thyroid cancer.

Cytotoxicity, Apoptosis induction and change of p53, PARP, p21 and Bcl-2 genes expression in the human anaplastic thyroid carcinoma cells line (SW-1736) with curcumin

Anaplastic thyroid carcinoma is highly invasive with a poor response to a treatment. In this study, curcumin bioavailability and its effects on apoptosis induction and selected genes expression of the human anaplastic thyroid carcinoma cell line (SW-1736) were examined. SW-1736 cells were incubated for 24 and 48 hours with different concentrations of curcumin 2.5, 5, 7.5 and 10 μM to examine bioavailability, and for 24, 48 and 72 hours with concentrations of 2.5, 5, 7.5, 10 μM and 2.5, 5 and 10 μM respectively to examine apoptosis and the expression of p53, PARP, p21 and Bcl-2 genes. Then, bioavailability was analyzed by MTS kit, apoptosis was analyzed by flow- cytometry using Annexin V-FITC/PI kit and the expression of p53, PARP, p21 and Bcl-2 genes were analyzed by Real Time PCR. ANOVA test and SPSS 16 software were used for statistical analysis. The results indicate that curcumin at the concentration of 7.5 μM has significantly decreased bioavailability in anaplastic thyroid cells in comparison with other treatments at both incubation periods. Induction of apoptosis with increasing concentration of curcumin in dose and time dependent manner increased in this cell line. Also, treatment with curcumin significantly decreased the expression of Bcl-2 gene and increased the expression of p53, PARP and p21 genes in some experimental groups compared to the control group. Curcumin inhibited the growth, proliferation and invasion of anaplastic thyroid cancer cells through altering the expression of the genes involved in the apoptosis process.

Anti-proliferative and apoptotic effects of hull-less pumpkin extract on human papillary thyroid carcinoma cell line.

Papillary thyroid carcinoma (PTC) is one of the most common cancers of the endocrine system. Previous studies have shown that the extract of hull-less pumpkin seed (HLPS) has a significant anti-cancer effect. The aim of this study was to evaluate the effect of this plant extract on the proliferation of PTC cells. In this study, an extract of this plant was prepared by soxhlet extraction method and analyzed by Gas Chromatography-Mass Spectrometry. The cytotoxicity of PTX and plant extract was investigated using the methylthiazol tetrazolium (MTT) method. For careful investigation of morphological alteration, we used hematoxylin and eosin and Giemsa stinging. Based on MTT assay test, the IC50 value of paclitaxel (PTX) was significantly less than the hydro-alcoholic extract of HLPS at all of the incubation time. Our results of histological staining showed that HLPS and PTX induced significant morphological alteration in the PTC cultured cell that consistent with cell death. Comparing the groups treated by PTX or HLPS with control group showed significant differences. It seems that HLPS extract has an apparent effect on treatment of PTC, at least in laboratory condition, albeit for realistic decision about the effect of HLPS on PTC, more molecular investigations are necessary.

Antineoplastic Activity of an Old Natural Antidiabetic Biguanide on the Human Thyroid Carcinoma Cell Line.

In the last decades, metformin (Met), an herbal anti-diabetic medicine, has been proposed as an anti-cancer agent. Thyroid cancers are the most common malignancy of the endocrine system. Therefore, the current study was performed to assess the effects of Met on cell proliferation and activation of the Phosphoinositide 3- Kinase (PI3K)/Protein kinase B (AKT)/Forkhead Box O1 (FOXO1) signaling pathway in the Medullary Thyroid Carcinoma (MTC) cells. The effects of Met on the expression of REarranged during Transfection (RET) proto-oncogene were also investigated. MTC cell line (TT) was treated with 0, 2.5, 5, 10, 20, 30, 40, 50, and 60 mM concentrations of Met for 24, 48, and 72h. The viability and apoptosis of the treated cells were measured by the 3-(4,5-Dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Annexin V- Propidium Iodide (PI) assays. The expression level of PI3K, AKT, FOXO1, and RET genes was investigated by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR), and phosphorylation of their proteins was determined by the Enzyme-Linked Immunosorbent Assay (ELISA). Results showed that Met significantly decreased the viability of the MTC cells. Met also reduced the expression level of PI3K, AKT, and FOXO1 genes (P<0.05), whereas it elevated the expression level of RET proto-oncogene (P<0.05). It seems that the Met has a cytostatic effect on the TT cells. Our results showed that anti-tumoral effects of Met may be cell type-specific, and according to the induction of RET (as a proto-oncogene) and inhibition of FOXO1 (as a tumor suppressor gene), Met could not be an appropriate agent in the treatment of MTC. The antineoplastic activity of Met has been confirmed against several malignancies in "in vitro" and "in vivo" studies. However, its molecular mechanisms in the treatment of different carcinomas particularly in thyroid cancers are not clearly understood and more studies are required to confirm its exact effect on the MTC.

Synergistic effect of 17-allylamino-17-demethoxygeldanamycin with dehydroxymethylepoxyquinomicin on the human anaplastic thyroid carcinoma cell line KTC2

The use of targeted inhibitors has shown promise as an effective approach in cancer therapy. However, targeted therapies based only on one drug, such as 17-allylamino-17-demethoxygeldanamycin (17-AAG), have limited success, partly because cancer cells engage alternate pathways for survival and proliferation. In the present study, we evaluated whether dehydroxymethylepoxyquinomicin (DHMEQ), a nuclear factor ?B (NF-?B) inhibitor, can enhance the antitumor activities of 17-AAG, a 90 kDa heat shock protein (Hsp90) inhibitor, in the anaplastic thyroid cancer cell line KTC2. We examined the effect of combined drug treatment vs single drug treatment on cell survival. Isobologram analysis was performed to distinguish the additive vs synergistic effects of the drug combination. Western blotting was performed to investigate apoptosis markers: caspase 3, poly(ADP-ribose) polymerase-one (PARP-1), B-cell lymphoma-extra large (Bcl-XL), X-linked inhibitor of apoptosis (XIAP) and cellular inhibitor of apoptosis 2 (cIAP-2). Compared to monotherapy, the combined treatment enhanced growth-inhibitory effects in a synergistic manner and strongly potentiated apoptosis. These results demonstrate the first in vitro evidence that a combination of Hsp90 and NF-?B inhibitors is a more effective modality for inhibiting cell proliferation and survival in anaplastic thyroid carcinoma cells than either agent alone, warranting further investigations.

MicroRNA-124-3p inhibits tumourigenesis by targeting mitogen-activated protein kinase 4 in papillary thyroid carcinoma.

The study aimed to investigate the role of miR-124-3p and its potential molecular mechanism in papillary thyroid cancer (PTC). The expression of miR-124-3p and mitogen-activated protein kinase 4 (MAP2K4) in human thyroid follicular epithelial cell line (NTHY-ORI3-1) and human papillary thyroid carcinoma cell lines (SW1736, BCPAP, TPC-1 and K1) was measured by RT-qPCR. Cell proliferation was measured by CCK-8, while cell cycle and apoptosis rate were measured by flow cytometry. Invasive ability and migrative ability were measured by transwell assay and wound healing assay, respectively. Western blot was used to detect the levels of relative proteins. In vivo, TPC-1 cells transfected with miR-124-3p mimic were subcutaneously injected into the flank of the mice to form tumour. After successful modelling, mice were divided into two groups (n = 10): Control group and miR-124-3p mimic group. The present study showed that miR-124-3p was lowly expressed, while MAP2K4 was highly expressed in PTC cell lines. Besides, miR-124-3p targeted MAP2K4 and negatively regulated MAP2K4 in TPC-1 cells. In addition, miR-124-3p inhibited the proliferation and motility, and induced apoptosis and cell cycle arrest of TPC-1 cells by inactivating MAP2K4/JNK/JunD pathway. Furthermore, miR-124-3p inhibited tumour formation by downregulating MAP2K4 level in vivo. In conclusion, the study provided a novel molecular mechanism of miR-124-3p in the progress of PTC. SIGNIFICANCE OF THE STUDY: Papillary thyroid cancer (PTC) is the most important pathological type of thyroid cancer, accounting for 80% of thyroid cancer. miR-124-3p exhibited significant inhibitory role in the transformation and development of malignant tumours. However, in PTC, the roles and its potential molecular mechanism are unclear. Here, the study investigated the roles of miR-124-3p in the progress of PTC and its potential molecular mechanism. We found that miR-124-3p inhibited the proliferation and motility, and induced apoptosis and cell cycle arrest in PTC cells. This study provided a novel molecular mechanism of miR-124-3p in the progress of PTC.

Down-Regulation of the Mammalian Target of Rapamycin (mTOR) Pathway Mediates the Effects of the Paeonol-Platinum(II) Complex in Human Thyroid Carcinoma Cells and Mouse SW1736 Tumor Xenografts.

BackgroundThis study aimed to investigate the effects of the paeonol-platinum(II) (PL-Pt[II]) complex on SW1736 human anaplastic thyroid carcinoma cell line and the BHP7-13 human thyroid papillary carcinoma cell line in vitro and on mouse SW1736 tumor xenografts in vivo.Material/MethodsThe cytotoxic effects of the PL-Pt(II) complex on SW1736 cells and BHP7-13 cells was measured using the MTT assay. Western blot measured the expression levels of cyclins, cell apoptotic proteins, and signaling proteins. DNA content and apoptosis were detected by flow cytometry. SW1736 cell thyroid tumor xenografts were established in mice followed by treatment with the PL-Pt(II) complex.ResultsTreatment of the SW1736 and BHP7-13 cells with the PL-Pt(II) complex reduced cell proliferation in a dose-dependent manner, with an IC50 of 1.25 μM and 1.0 μM, respectively, and increased the cell fraction in G0/G1phase, inhibited p53, cyclin D1, promoted p27 and p21 expression, and significantly increased the sub-G1 fraction. Treatment with the PL-Pt(II) complex increased caspase-3 degradation, reduced the expression of p-4EBP1, p-4E-BP1 and p-S6, and reduced the expression of p-ERK1/2 and p-AKT. Treatment with the PL-Pt(II) complex reduced the volume of the SW1736 mouse tumor xenografts on day 14 and day 21, and reduced AKT phosphorylation and S6 protein expression and increased degradation of caspase-3.ConclusionsThe cytotoxic effects of the PL-Pt(II) complex in human thyroid carcinoma cells, including activation of apoptosis and an increased sub-G1 cell fraction of the cell cycle, were mediated by down-regulation of the mTOR pathway.

Thyroid-related hormones as potential markers of hypoxia/ischemia

This study aimed to investigate the usefulness of the thyroid-related hormones as markers of acute systemic hypoxia/ischemia to identify deaths caused by asphyxiation due to neck compression in human autopsy cases. The following deaths from pathophysiological conditions were examined: mechanical asphyxia and acute/subacute blunt head injury; acute/subacute non-head blunt injury; sharp instrument injury as the hemorrhagic shock condition; drowning as alveolar injury; burn; and death due to cardiac dysfunction. Blood samples were collected from the left and right cardiac chambers and iliac veins, and serum triiodothyronine (T3), thyroxine (T4), thyroglobulin (Tg), and thyroid-stimulating hormone (TSH) levels were measured using electrochemiluminescence immunoassays. Two types of thyroid cell lines were used to confirm independent thyroid function under the condition of hypoxia (3% O2). The human thyroid carcinoma cell line (HOTHC) cell line derived from human anaplastic thyroid carcinoma and the UD-PTC (sample of the second resection papillary thyroid carcinoma) cell line derived from human thyroid papillary adenoma, which forms Tg retention follicles, were used to examine the secretion levels of T3, T4, and Tg hormones. The results showed a strong correlation between T3 and T4 levels in all blood sampling sites, while the TSH and Tg levels were not correlated with the other markers. Serum T3 and T4 levels were higher in cases of mechanical asphyxia and acute/subacute blunt head injury, representing hypoxic and ischemic conditions of the brain as compared to those in other causes of death. In the thyroid gland cell line, T4, T3, and Tg levels were stimulated after exposure to hypoxia for 10–30 min. These findings suggest that systemic advanced hypoxia/ischemia may cause a rapid and TSH-independent release of T3 and T4 thyroid hormones in autopsy cases. These findings demonstrate that increased thyroid-related hormone (T3 and T4) levels in the pathophysiological field may indicate systemic hypoxia/ischemia.

Effect of miR‑449a‑mediated Notch signaling pathway on the proliferation, apoptosis and invasion of papillary thyroid carcinoma cells.

The present study aimed to investigate the effect of miR-449a-mediated Notch signaling pathway on the proliferation, apoptosis and invasion of papillary thyroid carcinoma cells. Human papillary thyroid carcinoma cell line TPC-1 was selected, and cells were grouped and transfected: Control group (without any treatment), negative control (NC) group (transfection with NC plasmid), miR-449a mimic group (transfection with miR-449a mimic), miR-449a inhibitor group (transfection with miR-449a inhibitor), DAPT group (addition of γ-secretase inhibitor DAPT to inhibit the Notch signaling pathway), and miR-449a inhibitor + DAPT group (transfection with miR-449a inhibitor and addition of DAPT). The target relationship between miR-449a and Notch1 was detected by dual-luciferase reporter assay. qRT-PCR and western blotting were used to assess the expression of miR-449a, Notch1 and Jagged1 in cells. Cell proliferation was detected using EdU; the cell cycle and apoptosis were detected by flow cytometry; cell invasion ability was detected by Transwell assay. PCNA, MMP-2, MMP-9, Bcl-2 and Bax mRNA and protein expression were assessed by qRT-PCR and western blotting. The results revealed that miR-449a negatively regulated Notch1. Compared with the control group, there was significantly increased miR-449a expression in the miR-449a mimic group, and there was significantly decreased expression of Notch1, Jagged1, PCNA, MMP-2, MMP-9 and Bcl-2, increased Bax, reduced cell proliferation, increased G1-phase cell fraction, decreased S-phase cell fraction, an increased apoptosis rate, and decreased invasion ability in the miR-449a mimic group and DAPT group (all P<0.05). However, the results in the miR-449a inhibitor group were the opposite of those in miR-449a mimic group (all P<0.05). There was no significant difference in cell proliferation, apoptosis and invasion in the NC group and miR-449a inhibitor + DAPT group compared to the control group (all P>0.05). miR-449a overexpression can inhibit Notch signaling pathway, thereby inhibiting the proliferation and invasion of papillary thyroid carcinoma cells and promoting cell apoptosis.

MicroRNA-92b suppresses proliferation of papillary thyroid cancer cells by regulating ilent information regulator 1 gene expression

Objective To investigate the regulating effects of microRNA (miRNA, miR)-122 on the expression of ilent information regulator 1 (SIRT1), and the proliferation abilities of papillary thyroid cancer cells. Methods Real-time quantitative polymerase chain reaction (Real-time PCR) was used to observe the expression of miR-122 in papillary thyroid carcinoma and adjacent tissues and to analyze its correlation with SIRT1 expression. After transfecting miR-122 mimics into human papillary thyroid carcinoma cell line TPC-1, the dual luciferase reporter gene assay was used to observe the regulation of miR-122 on SIRT1 gene. The effect of miR-122 on the proliferation of thyroid cancer cells was observed by CCK-8 assay. At the same time, the overexpressed SIRT1 plasmid was co-transfected into TPC-1 cells, and then the effect of miR-122 and SIRT1 expression on the proliferation of papillary thyroid carcinoma cells was detected by CCK-8 assay. Analysis was performed using GraphPad Prism 7.0 statistical software. Correlation analysis was performed using Spearman rank correlation analysis. Student’s t test was used to compare the two sample means. Results Compared with adjacent tissues (1.20±0.15), the expression level of miR-122 (3.06±0.26) in papillary thyroid carcinoma was significantly down-regulated, and the difference was statistically significant (t=5.972, P<0.01). Correlation analysis showed that miR-122 was negatively correlated with SIRT1 mRNA expression (r=-0.621, P<0.01). The relative luciferase activity of SIRT1 in miR-122 mimics transfection group was significantly lower than that in the control group, and the difference was statistically significant (t=17.730, P<0.01). The cell proliferation ability of miR-122 mimics group was significantly lower than that of the control group, and the difference was statistically significant (t=3.991, P<0.01). After co-transfection of the SIRT1 overexpression plasmid, the inhibition of the proliferation of thyroid papillary carcinoma cells by miR-122 mimics was reversed. Conclusion miR-122 can inhibit the proliferation of papillary thyroid cancer cells, and its mechanism may be related to the targeted inhibition of SIRT1 expression. Key words: MicroRNA-122; Ilent information regulator 1; Papillary thyroid cancer; Proliferation

Exosomes Expressing Thyrotropin Receptor Attenuate Autoantibody-Mediated Stimulation of Cyclic Adenosine Monophosphate Production.

Background: Exosomes or small extracellular vesicles secreted from cells are nanovesicles with a diameter of 40-150 nm, which play a number of roles in both physiologic and pathologic processes. In Graves' disease (GD), autoantibodies bind to the thyrotropin receptor (TSHR) on the surface of thyroid follicular epithelial cells and stimulate thyroid growth and thyroid hormone synthesis and secretion via cyclic adenosine monophosphate (cAMP) production. The present study aimed to confirm the existence of TSHR in exosomes secreted from thyroid cells and to define the role of TSHR exosomes in GD. Methods: Exosomes were isolated by differential centrifugation from the culture medium of the human thyroid follicular epithelial cell line (NTHY-ori 3-1) and thyroid carcinoma cell lines (8305C, 8505C, and FTC-133). TSHR expression in cell lysates and exosomes was evaluated by Western blot analysis. In order to study the function of TSHR exosomes, human embryonic kidney (HEK) 293 cells stably expressing TSHR (HEK/TSHR) were established. Using exosomes isolated from both HEK and HEK/TSHR cells, the binding capacity of the M22 human monoclonal autoantibody to TSHR exosomes and their effect on M22-mediated stimulation of cAMP production in HEK/TSHR cells were evaluated. As a positive control for the functional assay, human recombinant TSHR chimera protein capable of binding to TSH was used. Results: TSHR was detected in exosomes from cancer cells as well as normal epithelial cells. An in vitro binding assay showed that alkaline phosphatase-labeled M22 bound to TSHR exosomes in a dose-dependent manner. M22 dose-dependently stimulated intracellular cAMP production in HEK/TSHR cells. The addition of exosomes from HEK/TSHR cells but not those from parental HEK cells significantly ameliorated cAMP production stimulated by treatment with M22 in HEK/TSHR cells. A decoy effect similar to TSHR exosomes was observed for human recombinant TSHR chimera. Conclusions: The results suggest that exosomes expressing TSHR may be secreted from normal and cancerous thyroid cells. In the thyroid gland of patients with GD, TSHR exosomes may exert a decoy effect by sequestering autoantibody, thereby ameliorating autoantibody-mediated activation of thyroid function.