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Expression and functions of galectin-7 in human and murine melanomas.

Biron-Pain K, Grosset AA, Poirier F, Gaboury L, St-Pierre Y - PLoS ONE (2013)

Bottom Line: Using the experimental melanoma B16F1 cell line, we found that melanoma cells can express galectin-7 at the primary tumor site and in lung metastasis.Overexpression of galectin-7, however, was insufficient to modulate the growth of tumors induced by the subcutaneous injection of B16F1 cells.It also failed to modulate the dissemination of B16F1 cells to the lung.

View Article: PubMed Central - PubMed

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

ABSTRACT
The identification of galectin-7 as a p53-induced gene and its ability to induce apoptosis in many cell types support the hypothesis that galectin-7 has strong antitumor activity. This has been well documented in colon cancer. However, in some cases, such as breast cancer and lymphoma, its high expression level correlates with aggressive subtypes of cancer, suggesting that galectin-7 may have a dual role in cancer progression. In fact, in breast cancer, overexpression of galectin-7 alone is sufficient to promote metastasis to the bone and lung. In the present work, we investigated the expression and function of galectin-7 in melanoma. An analysis of datasets obtained from whole-genome profiling of human melanoma tissues revealed that galectin-7 mRNA was detected in more than 90% of biopsies of patients with nevi while its expression was more rarely found in biopsies collected from patients with malignant melanoma. This frequency, however, was likely due to the presence of normal epidermis tissues in biopsies, as shown our studies at the protein level by immunohistochemical analysis. Using the experimental melanoma B16F1 cell line, we found that melanoma cells can express galectin-7 at the primary tumor site and in lung metastasis. Moreover, we found that overexpression of galectin-7 increased the resistance of melanoma cells to apoptosis while inducing de novo egr-1 expression. Overexpression of galectin-7, however, was insufficient to modulate the growth of tumors induced by the subcutaneous injection of B16F1 cells. It also failed to modulate the dissemination of B16F1 cells to the lung.

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Effect of quercetin on B16F1 cells overexpressing galectin-7 on apoptosis and EGR-1 expression.B16F1 cells overexpressing galectin-7 (+) or controls (–) were treated with various doses of quercetin. A) Apoptotic sensitivity was analyzed by western blotting for cleaved PARP-1 detection. B) RT-PCR analysis of galectin-7 and EGR-1 mRNA expression. C) Western blot analysis for EGR-1 detection, 293 cells transfected with EGF were used as a positive control. Actin was used as a loading and specificity control. D) Dual luciferase assay of B16F1 transfectant cells overexpressing galectin-7 (□) or controls (▪) co-transfected with luciferase reporter plasmids with an EGR-1 promoter and pRLSV40-Renilla vector as a transfection control and treated with various doses of quercetin for 24 h. A mixture of three clones of B16F1-G7 was used (G7 #5, 10 and 14) for all of these experiments.
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pone-0063307-g005: Effect of quercetin on B16F1 cells overexpressing galectin-7 on apoptosis and EGR-1 expression.B16F1 cells overexpressing galectin-7 (+) or controls (–) were treated with various doses of quercetin. A) Apoptotic sensitivity was analyzed by western blotting for cleaved PARP-1 detection. B) RT-PCR analysis of galectin-7 and EGR-1 mRNA expression. C) Western blot analysis for EGR-1 detection, 293 cells transfected with EGF were used as a positive control. Actin was used as a loading and specificity control. D) Dual luciferase assay of B16F1 transfectant cells overexpressing galectin-7 (□) or controls (▪) co-transfected with luciferase reporter plasmids with an EGR-1 promoter and pRLSV40-Renilla vector as a transfection control and treated with various doses of quercetin for 24 h. A mixture of three clones of B16F1-G7 was used (G7 #5, 10 and 14) for all of these experiments.

Mentions: The expression of galectin-7 in B16 cells significantly reduced their cellular motility (Fig. 4). While galectin-7 did not affect the in vitro proliferation rate of the cells, it did inhibit their sensitivity to apoptosis induced by quercetin in a dose-dependent manner (Fig. 5and Figure S3). This effect of galectin-7 on quercetin-induced apoptosis was concomitant with its ability to upregulate both the mRNA and protein levels of EGR-1, consistent with previous results obtained in human colon carcinoma cell line [32]. EGR-1 is a master regulator that plays an important role in a variety of cellular processes in cancer cells [33]. The ability of galectin-7 to increase EGR-1 at the transcriptional level in B16F1 cells was confirmed using a reporter vector encoding the egr-1 promoter (Fig. 5d).


Expression and functions of galectin-7 in human and murine melanomas.

Biron-Pain K, Grosset AA, Poirier F, Gaboury L, St-Pierre Y - PLoS ONE (2013)

Effect of quercetin on B16F1 cells overexpressing galectin-7 on apoptosis and EGR-1 expression.B16F1 cells overexpressing galectin-7 (+) or controls (–) were treated with various doses of quercetin. A) Apoptotic sensitivity was analyzed by western blotting for cleaved PARP-1 detection. B) RT-PCR analysis of galectin-7 and EGR-1 mRNA expression. C) Western blot analysis for EGR-1 detection, 293 cells transfected with EGF were used as a positive control. Actin was used as a loading and specificity control. D) Dual luciferase assay of B16F1 transfectant cells overexpressing galectin-7 (□) or controls (▪) co-transfected with luciferase reporter plasmids with an EGR-1 promoter and pRLSV40-Renilla vector as a transfection control and treated with various doses of quercetin for 24 h. A mixture of three clones of B16F1-G7 was used (G7 #5, 10 and 14) for all of these experiments.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3643947&req=5

pone-0063307-g005: Effect of quercetin on B16F1 cells overexpressing galectin-7 on apoptosis and EGR-1 expression.B16F1 cells overexpressing galectin-7 (+) or controls (–) were treated with various doses of quercetin. A) Apoptotic sensitivity was analyzed by western blotting for cleaved PARP-1 detection. B) RT-PCR analysis of galectin-7 and EGR-1 mRNA expression. C) Western blot analysis for EGR-1 detection, 293 cells transfected with EGF were used as a positive control. Actin was used as a loading and specificity control. D) Dual luciferase assay of B16F1 transfectant cells overexpressing galectin-7 (□) or controls (▪) co-transfected with luciferase reporter plasmids with an EGR-1 promoter and pRLSV40-Renilla vector as a transfection control and treated with various doses of quercetin for 24 h. A mixture of three clones of B16F1-G7 was used (G7 #5, 10 and 14) for all of these experiments.
Mentions: The expression of galectin-7 in B16 cells significantly reduced their cellular motility (Fig. 4). While galectin-7 did not affect the in vitro proliferation rate of the cells, it did inhibit their sensitivity to apoptosis induced by quercetin in a dose-dependent manner (Fig. 5and Figure S3). This effect of galectin-7 on quercetin-induced apoptosis was concomitant with its ability to upregulate both the mRNA and protein levels of EGR-1, consistent with previous results obtained in human colon carcinoma cell line [32]. EGR-1 is a master regulator that plays an important role in a variety of cellular processes in cancer cells [33]. The ability of galectin-7 to increase EGR-1 at the transcriptional level in B16F1 cells was confirmed using a reporter vector encoding the egr-1 promoter (Fig. 5d).

Bottom Line: Using the experimental melanoma B16F1 cell line, we found that melanoma cells can express galectin-7 at the primary tumor site and in lung metastasis.Overexpression of galectin-7, however, was insufficient to modulate the growth of tumors induced by the subcutaneous injection of B16F1 cells.It also failed to modulate the dissemination of B16F1 cells to the lung.

View Article: PubMed Central - PubMed

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

ABSTRACT
The identification of galectin-7 as a p53-induced gene and its ability to induce apoptosis in many cell types support the hypothesis that galectin-7 has strong antitumor activity. This has been well documented in colon cancer. However, in some cases, such as breast cancer and lymphoma, its high expression level correlates with aggressive subtypes of cancer, suggesting that galectin-7 may have a dual role in cancer progression. In fact, in breast cancer, overexpression of galectin-7 alone is sufficient to promote metastasis to the bone and lung. In the present work, we investigated the expression and function of galectin-7 in melanoma. An analysis of datasets obtained from whole-genome profiling of human melanoma tissues revealed that galectin-7 mRNA was detected in more than 90% of biopsies of patients with nevi while its expression was more rarely found in biopsies collected from patients with malignant melanoma. This frequency, however, was likely due to the presence of normal epidermis tissues in biopsies, as shown our studies at the protein level by immunohistochemical analysis. Using the experimental melanoma B16F1 cell line, we found that melanoma cells can express galectin-7 at the primary tumor site and in lung metastasis. Moreover, we found that overexpression of galectin-7 increased the resistance of melanoma cells to apoptosis while inducing de novo egr-1 expression. Overexpression of galectin-7, however, was insufficient to modulate the growth of tumors induced by the subcutaneous injection of B16F1 cells. It also failed to modulate the dissemination of B16F1 cells to the lung.

Show MeSH
Related in: MedlinePlus