Abstract
Objective Thyroid tumor progression is dependent on cellmotility, a highly complex process that involves the co-ordination of cell adhesion, actin dynamics and signal transduction. The proto-oncogene pituitary tumor-transforming gene (PTTG)-binding factor (PBF/PTTG1IP) is a transmembrane glycoprotein that is overexpressed in thyroid cancer and associated with a poorer prognosis. PBF significantly promotes thyroid cancer cell migration and invasion through phosphorylation at PBF-Y174 by Src kinase. The aim of this study was to identify downstream mediators of PBF-induced thyroid cancer cell motility.
Methods: A phosphoproteomic screen was performed in normal thyroid epithelial cells (Nthy-ori 3-1) with and without stable PBF overexpression. Selected significantly altered phosphoproteins were manipulated using siRNA-mediated knockdown or plasmid transfection in TPC-1 thyroid cancer cells. Changes in PBF-induced cell motility were appraised via scratch wound migration assays and Transwell invasion assays.
Results: Alterations in the phosphoproteome following PBF overexpression in Nthy-ori 3-1 cells revealed an enrichment of proteins involved in cytoskeletal arrangement, cell adhesion and small GTPase activity. The phosphorylation of FGD1 (FYVE, RhoGEF and PH domain-containing protein 1) and N-WASP (Neural Wiskott-Aldrich syndrome protein) was significantly altered with PBF upregulation. Given their involvement in small GTPase signaling and cell motility we investigated a role for FGD1 and N-WASP in PBF-induced motility of TPC-1 thyroid cancer cells. Notably, siRNA-mediated knockdown of either FGD1 or N-WASP significantly abrogated both PBF-induced cell migration and invasion. Co-expression of either FGD1 or N-WASP with PBF did not further stimulate cell invasion. However, PBF and N-WASP acted additively to induce cell migration.
Conclusion Taken together, our data suggest that both FGD1 and N-WASP mediate the induction of cellmotility by PBF in thyroid cancer cells, revealing novel signaling events in thyroid tumor progression.
Methods: A phosphoproteomic screen was performed in normal thyroid epithelial cells (Nthy-ori 3-1) with and without stable PBF overexpression. Selected significantly altered phosphoproteins were manipulated using siRNA-mediated knockdown or plasmid transfection in TPC-1 thyroid cancer cells. Changes in PBF-induced cell motility were appraised via scratch wound migration assays and Transwell invasion assays.
Results: Alterations in the phosphoproteome following PBF overexpression in Nthy-ori 3-1 cells revealed an enrichment of proteins involved in cytoskeletal arrangement, cell adhesion and small GTPase activity. The phosphorylation of FGD1 (FYVE, RhoGEF and PH domain-containing protein 1) and N-WASP (Neural Wiskott-Aldrich syndrome protein) was significantly altered with PBF upregulation. Given their involvement in small GTPase signaling and cell motility we investigated a role for FGD1 and N-WASP in PBF-induced motility of TPC-1 thyroid cancer cells. Notably, siRNA-mediated knockdown of either FGD1 or N-WASP significantly abrogated both PBF-induced cell migration and invasion. Co-expression of either FGD1 or N-WASP with PBF did not further stimulate cell invasion. However, PBF and N-WASP acted additively to induce cell migration.
Conclusion Taken together, our data suggest that both FGD1 and N-WASP mediate the induction of cellmotility by PBF in thyroid cancer cells, revealing novel signaling events in thyroid tumor progression.
| Original language | English |
|---|---|
| Article number | OC27 |
| Pages (from-to) | A91-A91 |
| Number of pages | 1 |
| Journal | Thyroid |
| Volume | 32 |
| Issue number | S1 |
| DOIs | |
| Publication status | Published - 11 Oct 2022 |
| Event | AMERICAN THYROID ASSOCIATION 2022 ANNUAL MEETING - Palais des Congrès de Montréal, Montreal, Canada Duration: 19 Oct 2022 → 23 Oct 2022 Conference number: 91 https://www.thyroid.org/91st-annual-meeting-ata/ |
