Limits...
Elevated Src family kinase activity stabilizes E-cadherin-based junctions and collective movement of head and neck squamous cell carcinomas.

Veracini L, Grall D, Schaub S, Beghelli-de la Forest Divonne S, Etienne-Grimaldi MC, Milano G, Bozec A, Babin E, Sudaka A, Thariat J, Van Obberghen-Schilling E - Oncotarget (2015)

Bottom Line: EGF receptor (EGFR) overexpression is thought to drive head and neck carcinogenesis however clinical responses to EGFR-targeting agents have been modest and alternate targets are actively sought to improve results.Src family kinases (SFKs), reported to act downstream of EGFR are among the alternative targets for which increased expression or activity in epithelial tumors is commonly associated to the dissolution of E-cadherin-based junctions and acquisition of a mesenchymal-like phenotype.Selective inhibition of SFKs with SU6656 delocalized E-cadherin and disrupted cellular junctions without affecting E-cadherin expression and this effect was phenocopied by knockdown of Src or Yes.

View Article: PubMed Central - PubMed

Affiliation: University of Nice Sophia Antipolis, UFR Sciences, Nice, France.

ABSTRACT
EGF receptor (EGFR) overexpression is thought to drive head and neck carcinogenesis however clinical responses to EGFR-targeting agents have been modest and alternate targets are actively sought to improve results. Src family kinases (SFKs), reported to act downstream of EGFR are among the alternative targets for which increased expression or activity in epithelial tumors is commonly associated to the dissolution of E-cadherin-based junctions and acquisition of a mesenchymal-like phenotype. Robust expression of total and activated Src was observed in advanced stage head and neck tumors (N=60) and in head and neck squamous cell carcinoma lines. In cultured cancer cells Src co-localized with E-cadherin in cell-cell junctions and its phosphorylation on Y419 was both constitutive and independent of EGFR activation. Selective inhibition of SFKs with SU6656 delocalized E-cadherin and disrupted cellular junctions without affecting E-cadherin expression and this effect was phenocopied by knockdown of Src or Yes. These findings reveal an EGFR-independent role for SFKs in the maintenance of intercellular junctions, which likely contributes to the cohesive invasion E-cadherin-positive cells in advanced tumors. Further, they highlight the need for a deeper comprehension of molecular pathways that drive collective cell invasion, in absence of mesenchymal transition, in order to combat tumor spread.

No MeSH data available.


Related in: MedlinePlus

Regulation of cell cohesion and SFK on cell-derived matrix and in vivo(A) CAL33 cells were plated on non-coated culture plates (left) or cell-derived matrix (right). Phase contrast images (bar=150μm), and immunofluoresence staining of E-cadherin (bar=15μm) are shown. (B) Western blot of E-cadherin, SFK-pY419 and Src in CAL33 cells on non-coated culture plates (NC) or cell-derived matrix (CDM). ERK1/2 expression is shown as loading control. (C) Immunostaining of E-cadherin or β-catenin in CAL33 cells on cell-derived matrix treated for 12h with SU6656 (5μM) or DMSO control (bar=50μm). (D) Phase contrast images (bar=150μm) of CAL33 cells on cell-derived matrix treated or not with 5μM SU6656 are shown above tracings of cell migration after 12 hours of treatment. (E) Immunohistochemical staining of Src and E-cadherin in FFPE sections of CAL33-derived tumors isolated from mice (bar=200μm). An E-cadherin-positive tumor embolus in muscle tissue adjacent to the tumor mass is shown on the right panel (bar=100μm).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4480700&req=5

Figure 6: Regulation of cell cohesion and SFK on cell-derived matrix and in vivo(A) CAL33 cells were plated on non-coated culture plates (left) or cell-derived matrix (right). Phase contrast images (bar=150μm), and immunofluoresence staining of E-cadherin (bar=15μm) are shown. (B) Western blot of E-cadherin, SFK-pY419 and Src in CAL33 cells on non-coated culture plates (NC) or cell-derived matrix (CDM). ERK1/2 expression is shown as loading control. (C) Immunostaining of E-cadherin or β-catenin in CAL33 cells on cell-derived matrix treated for 12h with SU6656 (5μM) or DMSO control (bar=50μm). (D) Phase contrast images (bar=150μm) of CAL33 cells on cell-derived matrix treated or not with 5μM SU6656 are shown above tracings of cell migration after 12 hours of treatment. (E) Immunohistochemical staining of Src and E-cadherin in FFPE sections of CAL33-derived tumors isolated from mice (bar=200μm). An E-cadherin-positive tumor embolus in muscle tissue adjacent to the tumor mass is shown on the right panel (bar=100μm).

Mentions: In order to extend the in vivo relevance of our results obtained in a conventional culture system, we performed experiments with tumor cells on 3D cell-derived matrices. These fibrillar matrices, produced by human telomerase-immortalized fibroblasts (TIFs) recapitulate important features (composition, topology, physical properties) of the stromal matrix in human HNSCC. As shown in Figure 6A, we observed that adhesion of tumor cells to a cell-derived matrix, as compared to tissue culture plastic, enhanced spreading. Enhanced spreading was accompanied by decrease in SFK activity (Figure 6B) and a reduction in inter-cellular cohesion, as seen in phase contrast images and immunofluorescence staining of E-cadherin. Similar to the response of cells plated on non-coated plastic, pharmacological inhibition of Src in cells plated on cell-derived matrices de-localized junctional E-cadherin, disrupted cell-cell adhesions and abrogated collective migration (Figure 6C, D).


Elevated Src family kinase activity stabilizes E-cadherin-based junctions and collective movement of head and neck squamous cell carcinomas.

Veracini L, Grall D, Schaub S, Beghelli-de la Forest Divonne S, Etienne-Grimaldi MC, Milano G, Bozec A, Babin E, Sudaka A, Thariat J, Van Obberghen-Schilling E - Oncotarget (2015)

Regulation of cell cohesion and SFK on cell-derived matrix and in vivo(A) CAL33 cells were plated on non-coated culture plates (left) or cell-derived matrix (right). Phase contrast images (bar=150μm), and immunofluoresence staining of E-cadherin (bar=15μm) are shown. (B) Western blot of E-cadherin, SFK-pY419 and Src in CAL33 cells on non-coated culture plates (NC) or cell-derived matrix (CDM). ERK1/2 expression is shown as loading control. (C) Immunostaining of E-cadherin or β-catenin in CAL33 cells on cell-derived matrix treated for 12h with SU6656 (5μM) or DMSO control (bar=50μm). (D) Phase contrast images (bar=150μm) of CAL33 cells on cell-derived matrix treated or not with 5μM SU6656 are shown above tracings of cell migration after 12 hours of treatment. (E) Immunohistochemical staining of Src and E-cadherin in FFPE sections of CAL33-derived tumors isolated from mice (bar=200μm). An E-cadherin-positive tumor embolus in muscle tissue adjacent to the tumor mass is shown on the right panel (bar=100μm).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4480700&req=5

Figure 6: Regulation of cell cohesion and SFK on cell-derived matrix and in vivo(A) CAL33 cells were plated on non-coated culture plates (left) or cell-derived matrix (right). Phase contrast images (bar=150μm), and immunofluoresence staining of E-cadherin (bar=15μm) are shown. (B) Western blot of E-cadherin, SFK-pY419 and Src in CAL33 cells on non-coated culture plates (NC) or cell-derived matrix (CDM). ERK1/2 expression is shown as loading control. (C) Immunostaining of E-cadherin or β-catenin in CAL33 cells on cell-derived matrix treated for 12h with SU6656 (5μM) or DMSO control (bar=50μm). (D) Phase contrast images (bar=150μm) of CAL33 cells on cell-derived matrix treated or not with 5μM SU6656 are shown above tracings of cell migration after 12 hours of treatment. (E) Immunohistochemical staining of Src and E-cadherin in FFPE sections of CAL33-derived tumors isolated from mice (bar=200μm). An E-cadherin-positive tumor embolus in muscle tissue adjacent to the tumor mass is shown on the right panel (bar=100μm).
Mentions: In order to extend the in vivo relevance of our results obtained in a conventional culture system, we performed experiments with tumor cells on 3D cell-derived matrices. These fibrillar matrices, produced by human telomerase-immortalized fibroblasts (TIFs) recapitulate important features (composition, topology, physical properties) of the stromal matrix in human HNSCC. As shown in Figure 6A, we observed that adhesion of tumor cells to a cell-derived matrix, as compared to tissue culture plastic, enhanced spreading. Enhanced spreading was accompanied by decrease in SFK activity (Figure 6B) and a reduction in inter-cellular cohesion, as seen in phase contrast images and immunofluorescence staining of E-cadherin. Similar to the response of cells plated on non-coated plastic, pharmacological inhibition of Src in cells plated on cell-derived matrices de-localized junctional E-cadherin, disrupted cell-cell adhesions and abrogated collective migration (Figure 6C, D).

Bottom Line: EGF receptor (EGFR) overexpression is thought to drive head and neck carcinogenesis however clinical responses to EGFR-targeting agents have been modest and alternate targets are actively sought to improve results.Src family kinases (SFKs), reported to act downstream of EGFR are among the alternative targets for which increased expression or activity in epithelial tumors is commonly associated to the dissolution of E-cadherin-based junctions and acquisition of a mesenchymal-like phenotype.Selective inhibition of SFKs with SU6656 delocalized E-cadherin and disrupted cellular junctions without affecting E-cadherin expression and this effect was phenocopied by knockdown of Src or Yes.

View Article: PubMed Central - PubMed

Affiliation: University of Nice Sophia Antipolis, UFR Sciences, Nice, France.

ABSTRACT
EGF receptor (EGFR) overexpression is thought to drive head and neck carcinogenesis however clinical responses to EGFR-targeting agents have been modest and alternate targets are actively sought to improve results. Src family kinases (SFKs), reported to act downstream of EGFR are among the alternative targets for which increased expression or activity in epithelial tumors is commonly associated to the dissolution of E-cadherin-based junctions and acquisition of a mesenchymal-like phenotype. Robust expression of total and activated Src was observed in advanced stage head and neck tumors (N=60) and in head and neck squamous cell carcinoma lines. In cultured cancer cells Src co-localized with E-cadherin in cell-cell junctions and its phosphorylation on Y419 was both constitutive and independent of EGFR activation. Selective inhibition of SFKs with SU6656 delocalized E-cadherin and disrupted cellular junctions without affecting E-cadherin expression and this effect was phenocopied by knockdown of Src or Yes. These findings reveal an EGFR-independent role for SFKs in the maintenance of intercellular junctions, which likely contributes to the cohesive invasion E-cadherin-positive cells in advanced tumors. Further, they highlight the need for a deeper comprehension of molecular pathways that drive collective cell invasion, in absence of mesenchymal transition, in order to combat tumor spread.

No MeSH data available.


Related in: MedlinePlus