Thyroid Cancer Research Laboratory

Lexington, KY, United States

Thyroid Cancer Research Laboratory

Lexington, KY, United States
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Nucera C.,Thyroid Cancer Research Laboratory | Nucera C.,Beth Israel Deaconess Medical Center | Nehs M.A.,Thyroid Cancer Research Laboratory | Nagarkatti S.S.,Thyroid Cancer Research Laboratory | And 8 more authors.
Oncologist | Year: 2011

Purpose. B-RafV600E may play a role in the progression from papillary thyroid cancer to anaplastic thyroid cancer (ATC). We tested the effects of a highly selective B-RafV600E inhibitor, PLX4720, on proliferation, migration, and invasion both in human thyroid cancer cell lines (8505cB-RafV600E and TPC-1RET/PTC-1 and wild-type B-Raf) and in primary human normal thyroid (NT) follicular cells engineered with or without B-RafV600E. Experimental Design. Large-scale genotyping analysis by mass spectrometry was performed in order to analyze >900 gene mutations. Cell proliferation and migration/invasion were performed upon PLX4720 treatment in 8505c, TPC-1, and NT cells. Orthotopic implantation of either 8505c or TPC-1 cells into the thyroid of severe combined immunodeficient mice was performed. Gene validations were performed by quantitative polymerase chain reaction and immunohistochemistry. Results. We found that PLX4720 reduced in vitro cell proliferation and migration and invasion of 8505c cells, causing early downregulation of genes involved in tumor progression. PLX4720-treated NT cells overexpressing B-RafV600E (heterozygous wild-type B-Raf/B-RafV600E) showed significantly lower cell proliferation, migration, and invasion. PLX4720 treatment did not block cell invasion in TPC-1 cells with wild-type BRaf, which showed very low and delayed in vivo tumor growth. In vivo, PLX4720 treatment of 8505c orthotopic thyroid tumors inhibited tumor aggressiveness and significantly upregulated the thyroid differentiation markers thyroid transcription factor 1 and paired box gene 8. Conclusions. Here, we have shown that PLX4720 preferentially inhibits migration and invasion of B-RafV600E thyroid cancer cells and tumor aggressiveness. Normal thyroid cells were generated to be heterozygous for wild-type B-Raf/B-RafV600E, mimicking the condition found in most human thyroid cancers. PLX4720 was effective in reducing cell proliferation, migration, and invasion in this heterozygous model. PLX4720 therapy should be tested and considered for a phase I study for the treatment of patients with B-RafV600E ATC. © AlphaMed Press.

Alapat D.V.,University of Kentucky | Ain K.B.,Thyroid Cancer Research Laboratory | Ain K.B.,University of Kentucky | Sloan D.A.,University of Kentucky | And 2 more authors.
Endocrine | Year: 2011

Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor of parafollicular or C-cells of thyroid that comprises 5-10% of all thyroid cancers [1, 2]. The neoplastic cells secrete calcitonin, carcinoembryonic antigen (CEA), and chromogranin A. Typically, increased serum levels of these tumor markers permit them to be used for initial diagnosis and long-term disease status surveillance. This article reports a case of sporadic MTC (pT2N0M0) in a young patient with normal serum tumor markers. A 16-year-old woman presented with MTC without evidence for this to be a familial case due to the absence of germline mutations in the RET proto-oncogene and negative family history. Surprisingly, there were normal preoperative serum levels of calcitonin, CEA, and chromogranin A, despite the immunohistochemistry showing strong and diffuse positive staining for these markers. This disparity between serum levels and tumor expression of calcitonin and CEA in MTC is quite rare. The relevant features of this case are discussed in consideration of the published experiences. This case may represent an unique subgroup of MTC with abnormal secretory capacity that requires reliance upon radiological evaluation for evidence of recurrent or disseminated disease, without the diagnostic benefit of serum tumor markers. © 2011 Springer Science+Business Media, LLC.

Li W.,Thyroid Cancer Research Laboratory | Li W.,University of Kentucky | Ain K.B.,Thyroid Cancer Research Laboratory | Ain K.B.,University of Kentucky
Endocrine-Related Cancer | Year: 2010

Radioiodine remains the only tumoricidal therapy for disseminated thyroid carcinomas; however, dedifferentiated tumors lose the expression of human sodium-iodide symporter (hNIS) gene, and cannot respond to this treatment. Previous studies suggested that a trans-active protein factor (NIS-repressor) represses endogenous hNIS transcription, likely contributing to the loss of radioiodine uptake, and defined the NIS-repressor binding site (NRBS) in the proximal hNIS promoter. Using electrophoretic mobility shift assay (EMSA), we found evidence of NIS-repressor in the nuclear extract from KAK-1 cells, and confirmed this result using nuclear extracts prepared from multiple verified thyroid cell lines. Luciferase reporter assays of hNIS promoter constructs and EMSA were used to define two core sequences, NRBS-P and NRBS-D, in the hNIS promoter as the binding sites for NIS-repressor. Electrophoretic analysis of KAK-1 nuclear extract proteins cross-linked with NRBS-P suggests that NIS-repressor is a protein complex. Analysis of KAK-1 nuclear extract proteins bound to NRBS-P, via liquid chromatography coupled with tandem mass spectroscopy, demonstrated poly(ADP-ribose) polymerase-1 (PARP-1) as a NIS-repressor component. Pharmacological inhibition of PARP-1 enzymatic activity using PJ34 stimulated both the luciferase reporter activity driven by hNIS promoter and the endogenous hNIS mRNA level. Supershift studies suggest that thyroid transcription factor 2 (TTF-2) is also associated with the NIS-repressor complex. NIS-repressor, including its PARP-1 component, presents a potential therapeutic target to restore radioiodine uptake in dedifferentiated thyroid carcinomas. © 2010 Society for Endocrinology.

Gal T.J.,University of Kentucky | Streeter M.,University of Kentucky | Burris J.,University of Kentucky | Kudrimoti M.,University of Kentucky | And 3 more authors.
Thyroid | Year: 2013

Background: External beam radiotherapy (XRT) has an established role in the management of recurrent or advanced well-differentiated thyroid carcinoma (WDTC). The goal of this study was to investigate the impact of this additional intervention on the quality of life (QOL) compared with total thyroidectomy (TT), with or without adjuvant radioactive iodine (RAI). Methods: A cross-sectional analysis using validated QOL instruments was performed. Patients receiving XRT between 1992 and 2008 for WDTC were identified and offered study participation. The Quality of Life Radiation Therapy Instrument and the Head and Neck Companion Module were administered retrospectively (N=13). For a comparison, patients previously treated with TT (N=11) alone as well as TT with postoperative RAI (N=11) for WDTC were also evaluated. Results: Thirty-four patients were included in the analysis. The XRT group reported significant decreases in chewing, swallowing, and appetite, and significant increase in pain, compared with both the RAI group and the TT group. Significant differences were reported for questions with regard to peace of mind, feeling discouraged, saliva, taste, ability to eat regular food, and concerns for the appearance of the neck in both RAI and XRT groups compared with TT patients. Subscale analysis of head and neck specific questions demonstrated significant overall differences for both RAI and XRT groups compared with thyroidectomy alone, with no differences observed between RAI and XRT groups in a direct comparison. Conclusions: RAI therapy results in a measurable decrease in head and neck specific QOL measures compared with TT alone. The addition of XRT results in additional measurable morbidity secondary to pain and dysphagia. © Copyright 2013, Mary Ann Liebert, Inc.

Ain K.B.,University of Kentucky | Ain K.B.,Thyroid Cancer Research Laboratory
Endocrine | Year: 2015

Differentiated thyroid carcinomas are typically treated with total thyroidectomy as initial therapy. Subsequent radioactive iodine (RAI) ablation destroys post-surgical thyroid remnants, can additionally provide adjuvant therapy of residual and metastatic thyroid cancers, and enhances the sensitivity and specificity of further diagnostic studies. There is current controversy regarding whether a large number of patients, broadly considered to have “low-risk” disease, should be provided RAI ablation. This is consequent to over-reliance on short-term studies, under-appreciation of the value of RAI remnant ablation, and inflation of the side effects of RAI therapy. A balanced assessment of all of these issues provides justification to utilize post-surgical radioiodine ablation, even in cases that are considered low risk on the basis of surgical findings. © 2015, Springer Science+Business Media New York (outside the USA).

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