-
The Journal of clinical endocrinology and metabolism 08/2011; 96(10):3062-4. · 6.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Papillary thyroid carcinoma (PTC) is the most common endocrine and thyroid malignancy. The urokinase plasminogen activator receptor (uPAR) plays an important role in cancer pathogenesis, including breakdown of the extracellular matrix, invasion, and metastasis. Additionally, there is increasing evidence that uPAR also promotes tumorigenesis via the modulation of multiple signaling pathways. BRAFV600E, the most common initial genetic mutation in PTC, leads to ERK1/2 hyperphosphorylation, which has been shown in numerous cancers to induce uPAR. Treatment of the BRAFV600E-positive PTC cell line, BCPAP, with the MEK/ERK inhibitor U0126 reduced uPAR RNA levels by 90%. siRNA-mediated down-regulation of uPAR in BCPAP cells resulted in greatly decreased activity in the focal adhesion kinase (FAK)/phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. This phenomenon was concurrent with drastically reduced proliferation rates and decreased clonigenic survival, as well as demonstrated senescence-associated nuclear morphology and induction of b-galactosidase activity. uPAR-knockdown BCPAP cells also displayed greatly reduced migration and invasion rates, as well as a complete loss of the cells' ability to augment their invasiveness following plasminogen supplementation. Taken together, these data provide new evidence of a novel role for uPAR induction (as a consequence of constitutive ERK1/2 activation) as a central component in PTC pathogenesis, and highlight the potential of uPAR as a therapeutic target.
Cell cycle (Georgetown, Tex.) 01/2011; 10(1):100-7. · 5.36 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We analyzed the expression of urokinase plasminogen activator (uPA) and its receptor (uPAR) in papillary thyroid carcinoma (PTC) and normal thyroid tissue and examined in vitro how uPA and uPAR contribute to an invasive/metastatic phenotype, and the functional consequences of inhibiting this system.
Retrospective chart review of PTC patients, followed by prospective study using previously obtained patient tissue and PTC cellular models.
uPA and uPAR RNA and protein levels were analyzed in PTC patient tissue samples, PTC and normal thyroid tissue culture cells, and conditioned media (CM) using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and/or Western blotting. The plasminogen-activating ability of CM was examined using dark-quenched casein fluorimetry and casein-plasminogen gel zymography. The invasive potentials of the PTC and normal thyroid epithelial cell lines were assessed using an in vitro cellular invasion/migration system.
uPA and uPAR RNA and protein levels were increased in PTC patient samples and PTC cells relative to controls. uPA and uPAR RNA were also significantly higher in patients with metastatic disease. Casein-plasminogen zymography and Western blotting demonstrated increased active uPA secreted by PTC cells compared with normal thyroid cells. Fluorimetric assays revealed that the PTC cells' CM was able to activate plasminogen, resulting in measurable casein hydrolysis. This casein hydrolysis was prevented by the addition of several specific uPA inhibitors. Finally, the in vitro invasion phenotypes of PTC cells were augmented by the addition of plasminogen, and this augmentation was reversed by inhibitory anti-uPA and anti-uPAR antibodies.
These data provide new functional evidence of the uPA/uPAR system's role in PTC invasion/metastasis and demonstrate the attractiveness of uPA and uPAR as molecular biomarkers and therapeutic targets.
The Laryngoscope 07/2010; 120(7):1383-90. · 1.75 Impact Factor
-
Theodore S. Nowicki BS,
Nicolas T. Kummer PhD,
Codrin Iacob MD,
Nina Suslina BS,
Steven Schaefer MD,
Stimson Schantz MD,
Edward Shin MD,
Augustine L. Moscatello MD,
Raj K. Tiwari PhD,
Jan Geliebter PhD,
Theodore S. Nowicki,
Nicolas T. Kummer,
Codrin Iacob,
Nina Suslina,
Steven Schaefer,
Stimson Schantz, Edward Shin,
Augustine L. Moscatello,
Raj K. Tiwari,
Jan Geliebter
[show abstract]
[hide abstract]
ABSTRACT: Objectives/Hypothesis:We analyzed the expression of urokinase plasminogen activator (uPA) and its receptor (uPAR) in papillary thyroid carcinoma (PTC) and normal thyroid tissue and examined in vitro how uPA and uPAR contribute to an invasive/metastatic phenotype, and the functional consequences of inhibiting this system.Study Design:Retrospective chart review of PTC patients, followed by prospective study using previously obtained patient tissue and PTC cellular models.Methods:uPA and uPAR RNA and protein levels were analyzed in PTC patient tissue samples, PTC and normal thyroid tissue culture cells, and conditioned media (CM) using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and/or Western blotting. The plasminogen-activating ability of CM was examined using dark-quenched casein fluorimetry and casein-plasminogen gel zymography. The invasive potentials of the PTC and normal thyroid epithelial cell lines were assessed using an in vitro cellular invasion/migration system.Results:uPA and uPAR RNA and protein levels were increased in PTC patient samples and PTC cells relative to controls. uPA and uPAR RNA were also significantly higher in patients with metastatic disease. Casein-plasminogen zymography and Western blotting demonstrated increased active uPA secreted by PTC cells compared with normal thyroid cells. Fluorimetric assays revealed that the PTC cells' CM was able to activate plasminogen, resulting in measurable casein hydrolysis. This casein hydrolysis was prevented by the addition of several specific uPA inhibitors. Finally, the in vitro invasion phenotypes of PTC cells were augmented by the addition of plasminogen, and this augmentation was reversed by inhibitory anti-uPA and anti-uPAR antibodies.Conclusions:These data provide new functional evidence of the uPA/uPAR system's role in PTC invasion/metastasis and demonstrate the attractiveness of uPA and uPAR as molecular biomarkers and therapeutic targets.
The Laryngoscope 06/2010; 120(7):1383 - 1390. · 1.75 Impact Factor
