The Comparative Effects of Gene Modulators on Thyroid-Specific Genes and Radioiodine Uptake

Tuncel, Murat; Aydin, Didem; Yaman, Elif; Tazebay, Uygar Halis; Güç, Dicle; Dogan, A. Lale; Taşbasan, Burçin; Uğur, Ömer

doi:10.1089/cbr.2006.319

Cited by 17 publications

(15 citation statements)

References 22 publications

(25 reference statements)

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“…For long-term storage, cell lysates were kept at -80°C. Relative TPO gene expression in the Nthy-ori 3-1 cell line has been previously quantified by others (Tuncel et al, 2007). In our experiments, TPO activity in cell extracts, which is proportional to relative fluorescence (for Ampliflu Red) or relative luminescence (for luminol) obtained from cell lysates containing 0.1-0.2 mg/ml total protein, was consistently above the limit of quantitation (LOQ) assessed as the mean of the blank + 10 times the standard deviation.…”

Section: Tpo Preparationmentioning

confidence: 99%

Simple and rapid in vitro assay for detecting human thyroid peroxidase disruption

Jomaa

Haan

Peijnenburg

et al. 2015

ALTEX

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SummaryA simple and rapid luminometric assay for the detection of chemical inhibitors of human thyroid peroxidase (hTPO) activity was developed and validated with 10 model compounds. hTPO was derived from the human thyroid follicular cell line Nthy-ori 3-1 and its activity was quantified by measuring the oxidation of luminol in the presence of hydrogen peroxide (H 2 O 2 ), which results in emission of light at 428 nm. In this assay, hTPO activity was shown to be inhibited by 5 known TPO inhibitors and not inhibited by 5 non-inhibitors. Similar results were obtained with porcine TPO (pTPO). The inhibition of hTPO by the model compounds was also tested with guaiacol and Ampliflu Red as alternative indicator substrates. While all substrates allowed the detection of pTPO activity and its inhibition, only the Ampliflu Red and luminol-based methods were sensitive enough to allow the quantification of hTPO activity from Nthy-ori 3-1 cell lysates. Moreover, luminol gave results with a narrower 95% confidence interval and therefore more reliable data. Whole extracts of fast-growing Nthy-ori 3-1 cells circumvent the need for animal-derived thyroid organs, thereby reducing costs, eliminating potential contamination and providing the possibility to study human instead of porcine TPO. Overall, the application of luminol and Nthy-ori 3-1 cell lysate for the detection of the disruption of hTPO activity was found to represent a valuable in vitro alternative and a possible candidate for inclusion within a high throughput integrated testing strategy for the detection of compounds that potentially interfere with normal thyroid function in vivo.

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Section: Tpo Preparationmentioning

confidence: 99%

Simple and rapid in vitro assay for detecting human thyroid peroxidase disruption

Jomaa

Haan

Peijnenburg

et al. 2015

ALTEX

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“…Suppression of signaling through the MAPK pathway (by knockdown of mutant BRAF or pharmacological inhibition of MEK) restores the expression of iodide-metabolizing genes in human thyroid carcinoma cells, highlighting this pathway as a critical target in re-differentiation strategies (Liu et al 2007, Hou et al 2010. On the epigenetic front, NIS and TSHR expression has been restored in human thyroid carcinoma cell lines with demethylating agents (Venkataraman et al 1999, Xing et al 2003, Tuncel et al 2007. In poorly differentiated and undifferentiated thyroid carcinoma cells, HDACi can also reactivate the expression of NIS, TPO and thyroglobulin.…”

Section: Epigenetic Control Of Differentiationmentioning

confidence: 99%

Epigenetics of thyroid cancer and novel therapeutic targets

Russo¹,

Damante²,

Puxeddu³

et al. 2011

Journal of Molecular Endocrinology

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An increasing body of evidence suggests that epigenetic changes (DNA methylation, remodeling and post-translational modification of chromatin) play important roles in thyroid tumorigenesis, as a result of their effects on tumor-cell differentiation and proliferation. Epigenetic silencing of various thyroid-specific genes has been detected in thyroid tumors. These changes can diminish the tumor's ability to concentrate radioiodine, which dramatically reduces treatment options. Epigenetic changes in tumor-promoting and tumor-suppressor genes also contribute to the dysregulation of thyrocyte growth and other aspects of tumorigenesis, such as apoptosis, motility and invasiveness. We provide a brief overview of the mechanisms underlying epigenetic regulation of gene expression and the current methods used to investigate it. This is followed by a review of the principal epigenetic alterations detected in thyroid cancer cells, epigenetic strategies for treating thyroid cancers and data from preclinical and clinical studies (some still underway) on the use in this setting of demethylating agents and histone deacetylase inhibitors.

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“…Limb, UCL Institute of Ophthalmology, London, England [39]. Human thyroid follicular epithelial cell line Nthy-ori 3-1 was gifted from Dr.Omer Ugur, Hacettepe Institute of Oncology [40], [41]. MIO-M1, MDA-MB-453, MCF-7 were cultured in Dulbecco’s modification of Eagle’s media (DMEM) containing glutamine, supplemented with 10% heat-inactivated fetal bovine serum (FBS), penicillin (100 IU/ml) and streptomycin (100 IU/ml).…”

Section: Methodsmentioning

confidence: 99%

Targeted Expression of Suicide Gene by Tissue-Specific Promoter and MicroRNA Regulation for Cancer Gene Therapy

et al. 2013

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In order to realise the full potential of cancer suicide gene therapy that allows the precise expression of suicide gene in cancer cells, we used a tissue specific Epithelial cell adhesion molecule (EpCAM) promoter (EGP-2) that directs transgene Herpes simplex virus–thymidine kinase (HSV-TK) expression preferentially in EpCAM over expressing cancer cells. EpCAM levels are considerably higher in retinoblastoma (RB), a childhood eye cancer with limited expression in normal cells. Use of miRNA regulation, adjacent to the use of the tissue-specific promoter, would provide the second layer of control to the transgene expression only in the tumor cells while sparing the normal cells. To test this hypothesis we cloned let-7b miRNA targets in the 3’UTR region of HSV-TK suicide gene driven by EpCAM promoter because let-7 family miRNAs, including let-7b, were found to be down regulated in the RB tumors and cell lines. We used EpCAM over expressing and let-7 down regulated RB cell lines Y79, WERI-Rb1 (EpCAM +ve/let-7bdown-regulated), EpCAM down regulated, let-7 over expressing normal retinal Müller glial cell line MIO-M1(EpCAM −ve/let-7bup-regulated), and EpCAM up regulated, let-7b up-regulated normal thyroid cell line N-Thy-Ori-3.1(EpCAM +ve/let-7bup-regulated) in the study. The cell proliferation was measured by MTT assay, apoptosis was measured by probing cleaved Caspase3, EpCAM and TK expression were quantified by Western blot. Our results showed that the EGP2-promoter HSV-TK (EGP2-TK) construct with 2 or 4 copies of let-7b miRNA targets expressed TK gene only in Y79, WERI-Rb-1, while the TK gene did not express in MIO-M1. In summary, we have developed a tissue-specific, miRNA-regulated dual control vector, which selectively expresses the suicide gene in EpCAM over expressing cells.

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The Comparative Effects of Gene Modulators on Thyroid-Specific Genes and Radioiodine Uptake

Cited by 17 publications

References 22 publications

Simple and rapid in vitro assay for detecting human thyroid peroxidase disruption

Simple and rapid in vitro assay for detecting human thyroid peroxidase disruption

Epigenetics of thyroid cancer and novel therapeutic targets

Targeted Expression of Suicide Gene by Tissue-Specific Promoter and MicroRNA Regulation for Cancer Gene Therapy

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