scholarly journals Protein Kinase A-Independent Inhibition of Proliferation and Induction of Apoptosis in Human Thyroid Cancer Cells by 8-Cl-Adenosine

2008 ◽  
Vol 93 (3) ◽  
pp. 1020-1029 ◽  
Author(s):  
Audrey J. Robinson-White ◽  
Hui-Pin Hsiao ◽  
Wolfgang W. Leitner ◽  
Elizabeth Greene ◽  
Andrew Bauer ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Thyroid Cancer ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Cancer Cells ◽  
Human Thyroid ◽  
Inhibition Of Proliferation ◽  
Thyroid Cancer Cells ◽  
Kinase A

Abstract Purpose: Protein kinase A (PKA) affects cell proliferation in many cell types and is a potential target for cancer treatment. PKA activity is stimulated by cAMP and cAMP analogs. One such substance, 8-Cl-cAMP, and its metabolite 8-Cl-adenosine (8-Cl-ADO) are known inhibitors of cancer cell proliferation; however, their mechanism of action is controversial. We have investigated the antiproliferative effects of 8-Cl-cAMP and 8-CL-ADO on human thyroid cancer cells and determined PKA’s involvement. Experimental Design: We employed proliferation and apoptosis assays and PKA activity and cell cycle analysis to understand the effect of 8-Cl-ADO and 8-Cl-cAMP on human thyroid cancer and HeLa cell lines. Results: 8-Cl-ADO inhibited proliferation of all cells, an effect that lasted for at least 4 d. Proliferation was also inhibited by 8-Cl-cAMP, but this inhibition was reduced by 3-isobutyl-1-methylxanthine; both drugs stimulated apoptosis, and 3-isobutyl-1-methylxanthine drastically reduced 8-Cl-cAMP-induced cell death. 8-Cl-ADO induced cell accumulation in G1/S or G2/M cell cycle phases and differentially altered PKA activity and subunit levels. PKA stimulation or inhibition and adenosine receptor agonists or antagonists did not significantly affect proliferation. Conclusions: 8-Cl-ADO and 8-Cl-cAMP inhibit proliferation, induce cell cycle phase accumulation, and stimulate apoptosis in thyroid cancer cells. The effect of 8-Cl-cAMP is likely due to its metabolite 8-Cl-ADO, and PKA does not appear to have direct involvement in the inhibition of proliferation by 8-Cl-ADO. 8-Cl-ADO may be a useful therapeutic agent to be explored in aggressive thyroid cancer.

scholarly journals ZIC1 Is a Putative Tumor Suppressor in Thyroid Cancer by Modulating Major Signaling Pathways and Transcription Factor FOXO3a

2014 ◽  
Vol 99 (7) ◽  
pp. E1163-E1172 ◽  
Author(s):  
Wei Qiang ◽  
Yuan Zhao ◽  
Qi Yang ◽  
Wei Liu ◽  
Haixia Guan ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Transcription Factor ◽  
Thyroid Cancer ◽  
Tumor Suppressor ◽  
Cancer Cells ◽  
Colony Formation ◽  
Promoter Hypermethylation ◽  
Migration And Invasion ◽  
Thyroid Cancer Cells

Context: ZIC1 has been reported to be overexpressed and plays an oncogenic role in some brain tumors, whereas it is inactivated by promoter hypermethylation and acts as a tumor suppressor in gastric and colorectal cancers. However, until now, its biological role in thyroid cancer remains totally unknown. Objectives: The aim of this study is to explore the biological functions and related molecular mechanism of ZIC1 in thyroid carcinogenesis. Setting and Design: Quantitative RT-PCR (qRT-PCR) was performed to evaluate mRNA expression of investigated genes. Methylation-specific PCR was used to analyze promoter methylation of the ZIC1 gene. The functions of ectopic ZIC1 expression in thyroid cancer cells were determined by cell proliferation and colony formation, cell cycle and apoptosis, as well as cell migration and invasion assays. Results: ZIC1 was frequently down-regulated by promoter hypermethylation in both primary thyroid cancer tissues and thyroid cancer cell lines. Moreover, our data showed that ZIC1 hypermethylation was significantly associated with lymph node metastasis in patients with papillary thyroid cancer. Notably, restoration of ZIC1 expression in thyroid cancer cells dramatically inhibited cell proliferation, colony formation, migration and invasion, and induced cell cycle arrest and apoptosis by blocking the activities of the phosphatidylinositol-3-kinase (PI3K)/Akt and RAS/RAF/MEK/ERK (MAPK) pathways, and enhancing FOXO3a transcriptional activity. Conclusions: Our data demonstrate that ZIC1 is frequently inactivated by promoter hypermethyaltion and functions as a tumor suppressor in thyroid cancer through modulating PI3K/Akt and MAPK signaling pathways and transcription factor FOXO3a.

scholarly journals Expression of p27Kip1 in Osteoblast-Like Cells during Differentiation with Parathyroid Hormone*

Endocrinology ◽  
1997 ◽  
Vol 138 (5) ◽  
pp. 1995-2004 ◽  
Author(s):  
Takehisa Onishi ◽  
Keith Hruska
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Osteogenic Sarcoma ◽  
S Phase ◽  
G1 Phase ◽  
Osteoblastic Cell ◽  
Cyclin Dependent Kinases ◽  
Kinase A

Abstract PTH is a major systemic regulator of bone metabolism and plays an important role in both bone formation and resorption. PTH either inhibits or stimulates osteoblastic cell proliferation depending on the model that is studied. We analyzed the cell cycle of the UMR-106 cell line, a relatively differentiated osteoblastic osteogenic sarcoma line in which PTH is known to inhibit proliferation but the mechanism of action is unknown. PTH decreased the proportion of cells in S phase and increased the number of G1 phase cells. We examined the effect of PTH on the regulators of the G1 phase cyclin-dependent kinases and found that PTH increased p27Kip1, but not p21Cip1, levels. This effect was mimicked by 8-bromo-cAMP, but not by phorbol 12-myristate 13-acetate. The protein kinase A inhibitor KT5720 abolished the effect of PTH on the increase in p27Kip1 expression. PTH increased CDK2-associated p27Kip1 without affecting the levels of CDK2. CDK2 activity was down-regulated by both PTH and 8-bromo-cAMP treatment. These data suggest that PTH blocks entry of cells into S phase and inhibits cell proliferation as the consequence of an increase in p27Kip1, which is mediated through the protein kinase A pathway. The inhibition of G1 cyclin-dependent kinases by p27Kip1 could cause a reduction of phosphorylation of key substrates and inactivation of transcription factors essential for entry into S phase. The inhibition of cell cycle progression through PKA-mediated p27Kip1 induction might play an important role in PTH-induced differentiation of osteoblasts.

scholarly journals Local Anesthetics Induce Apoptosis in Human Thyroid Cancer Cells through the Mitogen-Activated Protein Kinase Pathway

PLoS ONE ◽  
2014 ◽  
Vol 9 (2) ◽  
pp. e89563 ◽  
Author(s):  
Yuan-Ching Chang ◽  
Yi-Chiung Hsu ◽  
Chien-Liang Liu ◽  
Shih-Yuan Huang ◽  
Meng-Chun Hu ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Protein Kinase ◽  
Cancer Cells ◽  
Local Anesthetics ◽  
Mitogen Activated Protein Kinase ◽  
Human Thyroid ◽  
Mitogen Activated Protein ◽  
Thyroid Cancer Cells ◽  
Kinase Pathway

scholarly journals Identification of microRNAs that Mediate Thyroid Cell Growth Induced by TSH

2012 ◽  
Vol 26 (3) ◽  
pp. 493-501 ◽  
Author(s):  
Takeshi Akama ◽  
Mariko Sue ◽  
Akira Kawashima ◽  
Huhehasi Wu ◽  
Kazunari Tanigawa ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Protein Kinase ◽  
Cell Growth ◽  
Protein Kinase A ◽  
Target Genes ◽  
Endocrine Function ◽  
Thyroid Cell ◽  
Thyroid Cells ◽  
Kinase A

Abstract TSH is a major regulator of thyroid cell growth and endocrine function. It is known that cAMP and phosphatidylinositol 3-kinase (PI3K) are responsible for mediating the action of TSH. Activation of these signals results in the induction of a series of transcription factors and cell cycle regulating proteins, which induce cell proliferation. In addition to such canonical transcriptional regulation, it was recently shown that microRNA (miRNA or miR) constitutes another key mechanism for the regulation of gene expression. However, whether TSH action is mediated by miRNA in the thyroid is unknown. In this study, we have performed miRNA microarray analysis and demonstrated that TSH significantly decreases expression of 47 miRNA in thyroid cells. Among these, we have shown, using their specific agonists, that overexpression of miR-16 and miR-195 suppressed cell cycle progression and DNA synthesis that was induced by TSH. In silico analysis predicted that Mapk8, Ccne1, and Cdc6, the expression of which was up-regulated by TSH, are potential target genes for these miRNA, and overexpression of miR-16 and miR-195 suppressed expression of these target genes. The decrease of miR-16 and miR-195 expression by TSH was reproduced by forskolin and N6,2′-O-dibutyryladenosine cAMP and reversed by the protein kinase A inhibitor H89 and the PI3K inhibitor LY294002. These results suggest that TSH activates cAMP/protein kinase A and PI3K cascades to decrease miR-16 and miR-195, which induce Mapk8, Ccne1, and Cdc6 to activate cell proliferation.

Anti-proliferative effects of evodiamine on human thyroid cancer cells

2014 ◽  
Author(s):  
Ying-Ray Lee ◽  
Chieh-Hsiang Lu ◽  
Yi-Sheng Chang ◽  
Yi-Wen Liu
Keyword(s):  
Thyroid Cancer ◽  
Cancer Cells ◽  
Human Thyroid ◽  
Thyroid Cancer Cells
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