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Expression and functions of galectin-7 in ovarian cancer.

Labrie M, Vladoiu MC, Grosset AA, Gaboury L, St-Pierre Y - Oncotarget (2014)

Bottom Line: Gal-7 expression correlated with a significant difference in the overall survival of patients with ovarian serous cystadenocarcinoma.Furthermore, using human EOC cell lines, we found that gal-7 expression was induced by mutant p53.Recombinant human gal-7 kills Jurkat T cells and human peripheral T cells, suggesting that gal-7 also has immunosuppressive properties.

View Article: PubMed Central - PubMed

Affiliation: INRS-Institut Armand-Frappier, Laval, Québec, Canada.

ABSTRACT
There is a critical need to develop effective new strategies for diagnosis and treatment of ovarian cancer. In the present work, we investigated the expression of galectin-7 (gal-7) in epithelial ovarian cancer (EOC) cells and studied its functional relevance. Immunohistochemical analysis of gal-7 expression in tissue microarrays showed that while gal-7 was not detected in normal ovarian tissues, positive cytoplasmic staining of gal-7 was detected in epithelial cells in all EOC histological subtypes but was more frequent in high grade tumors and metastatic samples. Gal-7 expression correlated with a significant difference in the overall survival of patients with ovarian serous cystadenocarcinoma. Furthermore, using human EOC cell lines, we found that gal-7 expression was induced by mutant p53. Mechanistically, Matrigel invasion assays and live cell imaging showed that gal-7 increased the invasive behavior of ovarian cancer cells by inducing MMP-9 and increasing cell motility. EOC cells can also secrete gal-7. Recombinant human gal-7 kills Jurkat T cells and human peripheral T cells, suggesting that gal-7 also has immunosuppressive properties. Taken together, our study validates the clinical significance of gal-7 overexpression in ovarian cancer and provides a rationale for targeting gal-7 to improve the outcome of patients with this disease.

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Gal-7 increases the invasive behavior of ovarian cancer cells(A) Migration of A2780 cells through Matrigel in absence and presence of increasing concentrations of recombinant gal-7. (B) RT-PCR and zymography showing expression of MMP-9 by A2780 cells with or without 5 μM recombinant gal-7. (C) Effect of GM6001 on gal-7-induced Matrigel invasion of A2780 cells. (D) Migration of OVCAR-3 cells through Matrigel following suppression of gal-7. (E) Western blot analysis showing specific gal-7 suppression by the siRNA. (F) Effect of gal-7 suppression on MMP-9 mRNA expression and (G) in vitro cell motility. Velocity, accumulated distance, Euclidean distance and directionality were measured on individual OVCAR-3 cells (n = 60) tracked by live cell imaging using a scratch wound healing test. Images were captured every 10 min for 2 h. Error bars represent SEM. (H) Intracellular distribution of gal-7 inside OVCAR-3 cells. Gal-7 (green) and F-actin (red) were detected by immunofluorescence and visualized by confocal imagery. Nuclei were stained with DAPI (blue). Bar represents 10 μm. Results are representative of three independent experiments. Error bars represent SD except for (G) which are SEM.
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Figure 4: Gal-7 increases the invasive behavior of ovarian cancer cells(A) Migration of A2780 cells through Matrigel in absence and presence of increasing concentrations of recombinant gal-7. (B) RT-PCR and zymography showing expression of MMP-9 by A2780 cells with or without 5 μM recombinant gal-7. (C) Effect of GM6001 on gal-7-induced Matrigel invasion of A2780 cells. (D) Migration of OVCAR-3 cells through Matrigel following suppression of gal-7. (E) Western blot analysis showing specific gal-7 suppression by the siRNA. (F) Effect of gal-7 suppression on MMP-9 mRNA expression and (G) in vitro cell motility. Velocity, accumulated distance, Euclidean distance and directionality were measured on individual OVCAR-3 cells (n = 60) tracked by live cell imaging using a scratch wound healing test. Images were captured every 10 min for 2 h. Error bars represent SEM. (H) Intracellular distribution of gal-7 inside OVCAR-3 cells. Gal-7 (green) and F-actin (red) were detected by immunofluorescence and visualized by confocal imagery. Nuclei were stained with DAPI (blue). Bar represents 10 μm. Results are representative of three independent experiments. Error bars represent SD except for (G) which are SEM.

Mentions: Release of galectins in the tumor microenvironment has been shown to play a central role in cancer progression, most notably by increasing the invasive properties of cancer cells through lectin-dependent interactions (As Reviewed in [14]). To test whether this was the case for gal-7 in ovarian cancer cells, A2780 cells were treated with increasing concentrations of recombinant human gal-7 and tested for their invasive properties using a standard Matrigel invasion assay. We found that addition of gal-7 to A2780 cells induced a dose-dependent and significant increase in their invasive behavior (P<0.001) (Fig. 4A). Interestingly, this increase correlated with higher expression of MMP-9 (Fig. 4B). The use of GM6001, a broad range MMP inhibitor, significantly reduced the invasive behavior that was observed after treatment with recombinant gal-7 (P<0.005) (Fig. 4C). Inhibition of endogenous gal-7 expression by siRNA also induced a significant reduction in their invasive properties (P<0.001) (Fig. 4D-E). However, suppression of gal-7 did not correlate with reduced levels of MMP-9 (Fig. 4F), suggesting that gal-7 may also function independently of MMPs, or that other MMPs are involved.


Expression and functions of galectin-7 in ovarian cancer.

Labrie M, Vladoiu MC, Grosset AA, Gaboury L, St-Pierre Y - Oncotarget (2014)

Gal-7 increases the invasive behavior of ovarian cancer cells(A) Migration of A2780 cells through Matrigel in absence and presence of increasing concentrations of recombinant gal-7. (B) RT-PCR and zymography showing expression of MMP-9 by A2780 cells with or without 5 μM recombinant gal-7. (C) Effect of GM6001 on gal-7-induced Matrigel invasion of A2780 cells. (D) Migration of OVCAR-3 cells through Matrigel following suppression of gal-7. (E) Western blot analysis showing specific gal-7 suppression by the siRNA. (F) Effect of gal-7 suppression on MMP-9 mRNA expression and (G) in vitro cell motility. Velocity, accumulated distance, Euclidean distance and directionality were measured on individual OVCAR-3 cells (n = 60) tracked by live cell imaging using a scratch wound healing test. Images were captured every 10 min for 2 h. Error bars represent SEM. (H) Intracellular distribution of gal-7 inside OVCAR-3 cells. Gal-7 (green) and F-actin (red) were detected by immunofluorescence and visualized by confocal imagery. Nuclei were stained with DAPI (blue). Bar represents 10 μm. Results are representative of three independent experiments. Error bars represent SD except for (G) which are SEM.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Figure 4: Gal-7 increases the invasive behavior of ovarian cancer cells(A) Migration of A2780 cells through Matrigel in absence and presence of increasing concentrations of recombinant gal-7. (B) RT-PCR and zymography showing expression of MMP-9 by A2780 cells with or without 5 μM recombinant gal-7. (C) Effect of GM6001 on gal-7-induced Matrigel invasion of A2780 cells. (D) Migration of OVCAR-3 cells through Matrigel following suppression of gal-7. (E) Western blot analysis showing specific gal-7 suppression by the siRNA. (F) Effect of gal-7 suppression on MMP-9 mRNA expression and (G) in vitro cell motility. Velocity, accumulated distance, Euclidean distance and directionality were measured on individual OVCAR-3 cells (n = 60) tracked by live cell imaging using a scratch wound healing test. Images were captured every 10 min for 2 h. Error bars represent SEM. (H) Intracellular distribution of gal-7 inside OVCAR-3 cells. Gal-7 (green) and F-actin (red) were detected by immunofluorescence and visualized by confocal imagery. Nuclei were stained with DAPI (blue). Bar represents 10 μm. Results are representative of three independent experiments. Error bars represent SD except for (G) which are SEM.
Mentions: Release of galectins in the tumor microenvironment has been shown to play a central role in cancer progression, most notably by increasing the invasive properties of cancer cells through lectin-dependent interactions (As Reviewed in [14]). To test whether this was the case for gal-7 in ovarian cancer cells, A2780 cells were treated with increasing concentrations of recombinant human gal-7 and tested for their invasive properties using a standard Matrigel invasion assay. We found that addition of gal-7 to A2780 cells induced a dose-dependent and significant increase in their invasive behavior (P<0.001) (Fig. 4A). Interestingly, this increase correlated with higher expression of MMP-9 (Fig. 4B). The use of GM6001, a broad range MMP inhibitor, significantly reduced the invasive behavior that was observed after treatment with recombinant gal-7 (P<0.005) (Fig. 4C). Inhibition of endogenous gal-7 expression by siRNA also induced a significant reduction in their invasive properties (P<0.001) (Fig. 4D-E). However, suppression of gal-7 did not correlate with reduced levels of MMP-9 (Fig. 4F), suggesting that gal-7 may also function independently of MMPs, or that other MMPs are involved.

Bottom Line: Gal-7 expression correlated with a significant difference in the overall survival of patients with ovarian serous cystadenocarcinoma.Furthermore, using human EOC cell lines, we found that gal-7 expression was induced by mutant p53.Recombinant human gal-7 kills Jurkat T cells and human peripheral T cells, suggesting that gal-7 also has immunosuppressive properties.

View Article: PubMed Central - PubMed

Affiliation: INRS-Institut Armand-Frappier, Laval, Québec, Canada.

ABSTRACT
There is a critical need to develop effective new strategies for diagnosis and treatment of ovarian cancer. In the present work, we investigated the expression of galectin-7 (gal-7) in epithelial ovarian cancer (EOC) cells and studied its functional relevance. Immunohistochemical analysis of gal-7 expression in tissue microarrays showed that while gal-7 was not detected in normal ovarian tissues, positive cytoplasmic staining of gal-7 was detected in epithelial cells in all EOC histological subtypes but was more frequent in high grade tumors and metastatic samples. Gal-7 expression correlated with a significant difference in the overall survival of patients with ovarian serous cystadenocarcinoma. Furthermore, using human EOC cell lines, we found that gal-7 expression was induced by mutant p53. Mechanistically, Matrigel invasion assays and live cell imaging showed that gal-7 increased the invasive behavior of ovarian cancer cells by inducing MMP-9 and increasing cell motility. EOC cells can also secrete gal-7. Recombinant human gal-7 kills Jurkat T cells and human peripheral T cells, suggesting that gal-7 also has immunosuppressive properties. Taken together, our study validates the clinical significance of gal-7 overexpression in ovarian cancer and provides a rationale for targeting gal-7 to improve the outcome of patients with this disease.

Show MeSH
Related in: MedlinePlus