Abstract
Metastasis is a multistep process responsible for the vast majority of
endocrine cancer cell deaths. The initial stage of metastasis involves
the invasion of tumour cells into the adjacent tissue. We have previously identified PBF to be upregulated in differentiated thyroid cancer, and recently PBF expression has been correlated with distant
thyroid cancer metastasis at diagnosis. Further, PBF potently induces
breast cancer cell invasion in vitro and our recent in vivo data demonstrate that colorectal tumours with higher PBF protein expression
demonstrate increased vascular invasion.
Boyden chamber invasion assays were used to determine if PBF
regulates thyroid cell invasion. To gain insight into the pathway in
which PBF induces cell invasion we used two different approaches. 1)
IP-MS was employed to discover PBF binding partners. 2) As epithelial cells undergo an epithelial to mesenchymal transition (EMT) to
facilitate invasion we performed focused SABiosciences cDNA arrays
housing 84 genes of central importance to EMT.
We now show that PBF significantly promotes thyroid cell invasion in vitro in SW1736 cells (1.3-fold compared to vector only (VO),
P < 0.01). Further, our IP-MS approach identified the cortical actin
binding protein, cortactin, as an interacting partner of PBF. This interaction was confirmed using co-immunoprecipitation assays, which
also found that mutation of residue F at position 177 to A within the Cterminal sorting signal of PBF disrupts this interaction. Cortactin has a
central role in invasion as it promotes cell migration; we therefore
examined whether the interaction between cortactin and PBF controls
cell migration. Wound healing assays in MDA-MB-231 cells revealed
that GFP-tagged PBF cells migrated significantly further than GFPVO cells (VO = 115.3 lm, PBF = 143.0 lm, P < 0.01). Finally, cDNA
arrays revealed that PBF significantly regulates four genes (DSP,
JAG1, PDGFRB and TCF3) of central importance to EMT in SW1736
thyroid cancer cells (P < 0.05).
Taken together these data suggest that PBF may promote thyroid
cell invasion by 2 independent mechanisms; 1) PBF binds to cortactin
and regulates migration, and 2) PBF regulates the expression of genes
involved in EMT.
endocrine cancer cell deaths. The initial stage of metastasis involves
the invasion of tumour cells into the adjacent tissue. We have previously identified PBF to be upregulated in differentiated thyroid cancer, and recently PBF expression has been correlated with distant
thyroid cancer metastasis at diagnosis. Further, PBF potently induces
breast cancer cell invasion in vitro and our recent in vivo data demonstrate that colorectal tumours with higher PBF protein expression
demonstrate increased vascular invasion.
Boyden chamber invasion assays were used to determine if PBF
regulates thyroid cell invasion. To gain insight into the pathway in
which PBF induces cell invasion we used two different approaches. 1)
IP-MS was employed to discover PBF binding partners. 2) As epithelial cells undergo an epithelial to mesenchymal transition (EMT) to
facilitate invasion we performed focused SABiosciences cDNA arrays
housing 84 genes of central importance to EMT.
We now show that PBF significantly promotes thyroid cell invasion in vitro in SW1736 cells (1.3-fold compared to vector only (VO),
P < 0.01). Further, our IP-MS approach identified the cortical actin
binding protein, cortactin, as an interacting partner of PBF. This interaction was confirmed using co-immunoprecipitation assays, which
also found that mutation of residue F at position 177 to A within the Cterminal sorting signal of PBF disrupts this interaction. Cortactin has a
central role in invasion as it promotes cell migration; we therefore
examined whether the interaction between cortactin and PBF controls
cell migration. Wound healing assays in MDA-MB-231 cells revealed
that GFP-tagged PBF cells migrated significantly further than GFPVO cells (VO = 115.3 lm, PBF = 143.0 lm, P < 0.01). Finally, cDNA
arrays revealed that PBF significantly regulates four genes (DSP,
JAG1, PDGFRB and TCF3) of central importance to EMT in SW1736
thyroid cancer cells (P < 0.05).
Taken together these data suggest that PBF may promote thyroid
cell invasion by 2 independent mechanisms; 1) PBF binds to cortactin
and regulates migration, and 2) PBF regulates the expression of genes
involved in EMT.
| Original language | English |
|---|---|
| Article number | P34 |
| Journal | Thyroid |
| Volume | 23(1_Suppl) |
| Publication status | Published - 2013 |
| Event | 83rd Annual Meeting of the American Thyroid Association - San Juan, Puerto Rico Duration: 16 Oct 2013 → 20 Oct 2013 |
