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The tetraspanins CD151 and Tspan8 are essential exosome components for the crosstalk between cancer initiating cells and their surrounding.

Yue S, Mu W, Erb U, Zöller M - Oncotarget (2015)

Bottom Line: Approaching to elaborate the underlying mechanism, we compared ASMLwt, -CD151kd and/or Tspan8kd clones.These effects are not seen or are weakened using ASML-CD151kd or -Tspan8kd exosomes, which is at least partly due to reduced binding/uptake of CD151- and/or Tspan8-deficient exosomes.Thus, CD151- and Tspan8-competent tumor exosomes support matrix degradation, reprogram stroma and hematopoietic cells and drive non-metastatic ASML-CD151/Tspan8kd cells towards a motile phenotype.

View Article: PubMed Central - PubMed

Affiliation: Department of Tumor Cell Biology, University Hospital of Surgery, Heidelberg, Germany.

ABSTRACT
Tspan8 and CD151 are metastasis-promoting tetraspanins and a knockdown (kd) of Tspan8 or CD151 and most pronounced of both tetraspanins affects the metastatic potential of the rat pancreatic adenocarcinoma line ASML. Approaching to elaborate the underlying mechanism, we compared ASMLwt, -CD151kd and/or Tspan8kd clones. We focused on tumor exosomes, as exosomes play a major role in tumor progression and tetraspanins are suggested to be engaged in exosome targeting. ASML-CD151/Tspan8kd cells poorly metastasize, but regain metastatic capacity, when rats are pretreated with ASMLwt, but not ASML-CD151kd and/or -Tspan8kd exosomes. Both exosomal CD151 and Tspan8 contribute to host matrix remodelling due to exosomal tetraspanin-integrin and tetraspanin-protease associations. ASMLwt exosomes also support stroma cell activation with upregulation of cytokines, cytokine receptors and proteases and promote inflammatory cytokine expression in hematopoietic cells. Finally, CD151-/Tspan8-competent exosomes support EMT gene expression in poorly-metastatic ASML-CD151/Tspan8kd cells. These effects are not seen or are weakened using ASML-CD151kd or -Tspan8kd exosomes, which is at least partly due to reduced binding/uptake of CD151- and/or Tspan8-deficient exosomes. Thus, CD151- and Tspan8-competent tumor exosomes support matrix degradation, reprogram stroma and hematopoietic cells and drive non-metastatic ASML-CD151/Tspan8kd cells towards a motile phenotype.

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Metastasis-supporting exosomes and EMT: ASML-CD151/Tspan8kd cells were cocultured for 48h with ASMLwt, -CD151kd or -Tspan8kd exosomes(A,B) ASMLwt, -CD151kd and/or -Tspan8kd cells and exosomes stained for the indicated EMT markers; mean percent±SD of stained cells / exosome-coated latex beads; significant differences to ASMLwt cells / exosomes: *. (C-E) EMT gene expression evaluated by flow cytometry (mean percent stained cells, 3 assays); significant differences to ASML-CD151/Tspan8kd cells cultured in the absence of exosomes: *, confocal microscopy (scale bar: 10μm) and WB. Expression of the EMT related vimentin protein as well as of the transcription factors Slug, Snail, Twist and, particularly, Notch, becomes upregulated, upregulation of vimentin and Snail predominantly depending on Tspan8 and of Notch on CD151 and Tspan8.
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Figure 8: Metastasis-supporting exosomes and EMT: ASML-CD151/Tspan8kd cells were cocultured for 48h with ASMLwt, -CD151kd or -Tspan8kd exosomes(A,B) ASMLwt, -CD151kd and/or -Tspan8kd cells and exosomes stained for the indicated EMT markers; mean percent±SD of stained cells / exosome-coated latex beads; significant differences to ASMLwt cells / exosomes: *. (C-E) EMT gene expression evaluated by flow cytometry (mean percent stained cells, 3 assays); significant differences to ASML-CD151/Tspan8kd cells cultured in the absence of exosomes: *, confocal microscopy (scale bar: 10μm) and WB. Expression of the EMT related vimentin protein as well as of the transcription factors Slug, Snail, Twist and, particularly, Notch, becomes upregulated, upregulation of vimentin and Snail predominantly depending on Tspan8 and of Notch on CD151 and Tspan8.

Mentions: In concern of EMT-related factors including EMT-associated transcription factors, only FN, vimentin, Notch and, borderline, Snail were downregulated in ASML-CD151kd and/or ASML-Tspan8kd cells. In exosomes, only expression of Slug and, slightly of Notch was reduced by the CD151kd and/or the Tspan8kd (Fig.8A,8B). Instead, after coculture of ASML-CD151/Tspan8kd cells with exosomes, expression of vimentin, Slug, Twist and, most strikingly, Notch became upregulated. While vimentin, Snail and Slug appeared to depend mostly on Tspan8, the strong upregulation of Notch required CD151- and Tspan8-competent exosomes (Fig.8C-8E).


The tetraspanins CD151 and Tspan8 are essential exosome components for the crosstalk between cancer initiating cells and their surrounding.

Yue S, Mu W, Erb U, Zöller M - Oncotarget (2015)

Metastasis-supporting exosomes and EMT: ASML-CD151/Tspan8kd cells were cocultured for 48h with ASMLwt, -CD151kd or -Tspan8kd exosomes(A,B) ASMLwt, -CD151kd and/or -Tspan8kd cells and exosomes stained for the indicated EMT markers; mean percent±SD of stained cells / exosome-coated latex beads; significant differences to ASMLwt cells / exosomes: *. (C-E) EMT gene expression evaluated by flow cytometry (mean percent stained cells, 3 assays); significant differences to ASML-CD151/Tspan8kd cells cultured in the absence of exosomes: *, confocal microscopy (scale bar: 10μm) and WB. Expression of the EMT related vimentin protein as well as of the transcription factors Slug, Snail, Twist and, particularly, Notch, becomes upregulated, upregulation of vimentin and Snail predominantly depending on Tspan8 and of Notch on CD151 and Tspan8.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385857&req=5

Figure 8: Metastasis-supporting exosomes and EMT: ASML-CD151/Tspan8kd cells were cocultured for 48h with ASMLwt, -CD151kd or -Tspan8kd exosomes(A,B) ASMLwt, -CD151kd and/or -Tspan8kd cells and exosomes stained for the indicated EMT markers; mean percent±SD of stained cells / exosome-coated latex beads; significant differences to ASMLwt cells / exosomes: *. (C-E) EMT gene expression evaluated by flow cytometry (mean percent stained cells, 3 assays); significant differences to ASML-CD151/Tspan8kd cells cultured in the absence of exosomes: *, confocal microscopy (scale bar: 10μm) and WB. Expression of the EMT related vimentin protein as well as of the transcription factors Slug, Snail, Twist and, particularly, Notch, becomes upregulated, upregulation of vimentin and Snail predominantly depending on Tspan8 and of Notch on CD151 and Tspan8.
Mentions: In concern of EMT-related factors including EMT-associated transcription factors, only FN, vimentin, Notch and, borderline, Snail were downregulated in ASML-CD151kd and/or ASML-Tspan8kd cells. In exosomes, only expression of Slug and, slightly of Notch was reduced by the CD151kd and/or the Tspan8kd (Fig.8A,8B). Instead, after coculture of ASML-CD151/Tspan8kd cells with exosomes, expression of vimentin, Slug, Twist and, most strikingly, Notch became upregulated. While vimentin, Snail and Slug appeared to depend mostly on Tspan8, the strong upregulation of Notch required CD151- and Tspan8-competent exosomes (Fig.8C-8E).

Bottom Line: Approaching to elaborate the underlying mechanism, we compared ASMLwt, -CD151kd and/or Tspan8kd clones.These effects are not seen or are weakened using ASML-CD151kd or -Tspan8kd exosomes, which is at least partly due to reduced binding/uptake of CD151- and/or Tspan8-deficient exosomes.Thus, CD151- and Tspan8-competent tumor exosomes support matrix degradation, reprogram stroma and hematopoietic cells and drive non-metastatic ASML-CD151/Tspan8kd cells towards a motile phenotype.

View Article: PubMed Central - PubMed

Affiliation: Department of Tumor Cell Biology, University Hospital of Surgery, Heidelberg, Germany.

ABSTRACT
Tspan8 and CD151 are metastasis-promoting tetraspanins and a knockdown (kd) of Tspan8 or CD151 and most pronounced of both tetraspanins affects the metastatic potential of the rat pancreatic adenocarcinoma line ASML. Approaching to elaborate the underlying mechanism, we compared ASMLwt, -CD151kd and/or Tspan8kd clones. We focused on tumor exosomes, as exosomes play a major role in tumor progression and tetraspanins are suggested to be engaged in exosome targeting. ASML-CD151/Tspan8kd cells poorly metastasize, but regain metastatic capacity, when rats are pretreated with ASMLwt, but not ASML-CD151kd and/or -Tspan8kd exosomes. Both exosomal CD151 and Tspan8 contribute to host matrix remodelling due to exosomal tetraspanin-integrin and tetraspanin-protease associations. ASMLwt exosomes also support stroma cell activation with upregulation of cytokines, cytokine receptors and proteases and promote inflammatory cytokine expression in hematopoietic cells. Finally, CD151-/Tspan8-competent exosomes support EMT gene expression in poorly-metastatic ASML-CD151/Tspan8kd cells. These effects are not seen or are weakened using ASML-CD151kd or -Tspan8kd exosomes, which is at least partly due to reduced binding/uptake of CD151- and/or Tspan8-deficient exosomes. Thus, CD151- and Tspan8-competent tumor exosomes support matrix degradation, reprogram stroma and hematopoietic cells and drive non-metastatic ASML-CD151/Tspan8kd cells towards a motile phenotype.

Show MeSH
Related in: MedlinePlus