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C/EBPβ expression is an independent predictor of overall survival in breast cancer patients by MHCII/CD4-dependent mechanism of metastasis formation.

Kurzejamska E, Johansson J, Jirström K, Prakash V, Ananthaseshan S, Boon L, Fuxe J, Religa P - Oncogenesis (2014)

Bottom Line: Immunohistochemical analyses showed that C/EBPβ inhibition leads to increased major histocompatibility complex II (MHCII) expression, followed by the accumulation of CD45-, CD3- and CD4-positive (CD4+) lymphocytes in the tumors.Additionally, anti-CD3 and anti-CD4 treatments of C/EBPβ-silenced tumor-bearing mice resulted in reverting the C/EBPβ effect on tumor growth and metastasis.The mechanism of metastasis formation involves immunologic response depending on C/EBPβ-mediated activation of MHCII and accumulation of CD4+ lymphocytes in the tumor.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Medicine, Centre for Molecular Medicine, Karolinska Institute, Stockholm, Sweden [2] Postgraduate School of Molecular Medicine, Department of Internal Medicine and Hypertension, Medical University of Warsaw, Warsaw, Poland.

ABSTRACT
CCAAT-enhancer binding protein β (C/EBPβ) is a transcription factor that has a critical role in mammary gland development and breast cancer progression. Loss of C/EBPβ increases metastatic dissemination of mouse mammary tumor cells. However, the mechanism by which C/EBPβ expression affects metastasis formation remains unknown. This study aims at determining the relationship between C/EBPβ and survival of breast cancer patients, and elucidating C/EBPβ's link with metastasis formation. C/EBPβ expression was evaluated in 137 cases of human breast cancer, and the correlation with overall survival was estimated by Kaplan-Meier analysis. Additionally, the mouse 4T1 tumor model was used for in vivo studies. Decreased C/EBPβ expression was found to be associated with shorter overall survival of breast cancer patients. In the murine 4T1 model, loss of C/EBPβ affects tumor growth, morphology and promotes metastatic spread to the lungs. Immunohistochemical analyses showed that C/EBPβ inhibition leads to increased major histocompatibility complex II (MHCII) expression, followed by the accumulation of CD45-, CD3- and CD4-positive (CD4+) lymphocytes in the tumors. Inflammation involvement in C/EBPβ-mediated metastasis formation was confirmed by DNA microarray and by experiments on CD4+ cell-deprived nude mice. Additionally, anti-CD3 and anti-CD4 treatments of C/EBPβ-silenced tumor-bearing mice resulted in reverting the C/EBPβ effect on tumor growth and metastasis. Altogether, C/EBPβ is a predictor of overall survival in breast cancer patients, and affects tumor growth, morphology and lung metastasis formation in murine 4T1 model. The mechanism of metastasis formation involves immunologic response depending on C/EBPβ-mediated activation of MHCII and accumulation of CD4+ lymphocytes in the tumor.

No MeSH data available.


Related in: MedlinePlus

Effect of loss of C/EBPβ expression on tumor growth and morphology. (a) Left panel—light microscopy pictures and immunofluorescence staining of 4T1 cells; right panel—western blot showing small interfering RNA (siRNA) knockdown of C/EBPβ. (b) Left panel—4T1 tumor growth (sh control vs sh C/EBPβ) in BALB/c mice (n=8 mice per group); right panel—4T1 tumor cell proliferation (MTT assay). (c) Tumor morphology (sh control on left and sh C/EBPβ on right panel). (d) Tumor vessels stained by endothelial marker CD31 (sh control on upper left and sh C/EBPβ on upper right panel) and average tumor vessel count per field (n), whole-mount immunohistochemistry of tumor vasculature analyzed by Visiopharm software (middle panels), graphs of average tumor vessel area per field, average vessel length per field (in pixels), average number of branch points in tumor vessels per field (n) and average pericyte coverage of tumor vessels per field (in percentage).
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fig2: Effect of loss of C/EBPβ expression on tumor growth and morphology. (a) Left panel—light microscopy pictures and immunofluorescence staining of 4T1 cells; right panel—western blot showing small interfering RNA (siRNA) knockdown of C/EBPβ. (b) Left panel—4T1 tumor growth (sh control vs sh C/EBPβ) in BALB/c mice (n=8 mice per group); right panel—4T1 tumor cell proliferation (MTT assay). (c) Tumor morphology (sh control on left and sh C/EBPβ on right panel). (d) Tumor vessels stained by endothelial marker CD31 (sh control on upper left and sh C/EBPβ on upper right panel) and average tumor vessel count per field (n), whole-mount immunohistochemistry of tumor vasculature analyzed by Visiopharm software (middle panels), graphs of average tumor vessel area per field, average vessel length per field (in pixels), average number of branch points in tumor vessels per field (n) and average pericyte coverage of tumor vessels per field (in percentage).

Mentions: C/EBPβ knockdown was confirmed by immunofluorescence staining of the cells and western blot (Figure 2a). Mouse experiments using those cells showed that loss of C/EBPβ expression affects tumor growth and morphology. C/EBPβ-silenced tumors grew smaller compared with non-silenced tumors (133±16 vs 342±150 mm3; P=0.04), although there was no difference in proliferation rate assessed by in vitro assay (Figure 2b).


C/EBPβ expression is an independent predictor of overall survival in breast cancer patients by MHCII/CD4-dependent mechanism of metastasis formation.

Kurzejamska E, Johansson J, Jirström K, Prakash V, Ananthaseshan S, Boon L, Fuxe J, Religa P - Oncogenesis (2014)

Effect of loss of C/EBPβ expression on tumor growth and morphology. (a) Left panel—light microscopy pictures and immunofluorescence staining of 4T1 cells; right panel—western blot showing small interfering RNA (siRNA) knockdown of C/EBPβ. (b) Left panel—4T1 tumor growth (sh control vs sh C/EBPβ) in BALB/c mice (n=8 mice per group); right panel—4T1 tumor cell proliferation (MTT assay). (c) Tumor morphology (sh control on left and sh C/EBPβ on right panel). (d) Tumor vessels stained by endothelial marker CD31 (sh control on upper left and sh C/EBPβ on upper right panel) and average tumor vessel count per field (n), whole-mount immunohistochemistry of tumor vasculature analyzed by Visiopharm software (middle panels), graphs of average tumor vessel area per field, average vessel length per field (in pixels), average number of branch points in tumor vessels per field (n) and average pericyte coverage of tumor vessels per field (in percentage).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4259962&req=5

fig2: Effect of loss of C/EBPβ expression on tumor growth and morphology. (a) Left panel—light microscopy pictures and immunofluorescence staining of 4T1 cells; right panel—western blot showing small interfering RNA (siRNA) knockdown of C/EBPβ. (b) Left panel—4T1 tumor growth (sh control vs sh C/EBPβ) in BALB/c mice (n=8 mice per group); right panel—4T1 tumor cell proliferation (MTT assay). (c) Tumor morphology (sh control on left and sh C/EBPβ on right panel). (d) Tumor vessels stained by endothelial marker CD31 (sh control on upper left and sh C/EBPβ on upper right panel) and average tumor vessel count per field (n), whole-mount immunohistochemistry of tumor vasculature analyzed by Visiopharm software (middle panels), graphs of average tumor vessel area per field, average vessel length per field (in pixels), average number of branch points in tumor vessels per field (n) and average pericyte coverage of tumor vessels per field (in percentage).
Mentions: C/EBPβ knockdown was confirmed by immunofluorescence staining of the cells and western blot (Figure 2a). Mouse experiments using those cells showed that loss of C/EBPβ expression affects tumor growth and morphology. C/EBPβ-silenced tumors grew smaller compared with non-silenced tumors (133±16 vs 342±150 mm3; P=0.04), although there was no difference in proliferation rate assessed by in vitro assay (Figure 2b).

Bottom Line: Immunohistochemical analyses showed that C/EBPβ inhibition leads to increased major histocompatibility complex II (MHCII) expression, followed by the accumulation of CD45-, CD3- and CD4-positive (CD4+) lymphocytes in the tumors.Additionally, anti-CD3 and anti-CD4 treatments of C/EBPβ-silenced tumor-bearing mice resulted in reverting the C/EBPβ effect on tumor growth and metastasis.The mechanism of metastasis formation involves immunologic response depending on C/EBPβ-mediated activation of MHCII and accumulation of CD4+ lymphocytes in the tumor.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Medicine, Centre for Molecular Medicine, Karolinska Institute, Stockholm, Sweden [2] Postgraduate School of Molecular Medicine, Department of Internal Medicine and Hypertension, Medical University of Warsaw, Warsaw, Poland.

ABSTRACT
CCAAT-enhancer binding protein β (C/EBPβ) is a transcription factor that has a critical role in mammary gland development and breast cancer progression. Loss of C/EBPβ increases metastatic dissemination of mouse mammary tumor cells. However, the mechanism by which C/EBPβ expression affects metastasis formation remains unknown. This study aims at determining the relationship between C/EBPβ and survival of breast cancer patients, and elucidating C/EBPβ's link with metastasis formation. C/EBPβ expression was evaluated in 137 cases of human breast cancer, and the correlation with overall survival was estimated by Kaplan-Meier analysis. Additionally, the mouse 4T1 tumor model was used for in vivo studies. Decreased C/EBPβ expression was found to be associated with shorter overall survival of breast cancer patients. In the murine 4T1 model, loss of C/EBPβ affects tumor growth, morphology and promotes metastatic spread to the lungs. Immunohistochemical analyses showed that C/EBPβ inhibition leads to increased major histocompatibility complex II (MHCII) expression, followed by the accumulation of CD45-, CD3- and CD4-positive (CD4+) lymphocytes in the tumors. Inflammation involvement in C/EBPβ-mediated metastasis formation was confirmed by DNA microarray and by experiments on CD4+ cell-deprived nude mice. Additionally, anti-CD3 and anti-CD4 treatments of C/EBPβ-silenced tumor-bearing mice resulted in reverting the C/EBPβ effect on tumor growth and metastasis. Altogether, C/EBPβ is a predictor of overall survival in breast cancer patients, and affects tumor growth, morphology and lung metastasis formation in murine 4T1 model. The mechanism of metastasis formation involves immunologic response depending on C/EBPβ-mediated activation of MHCII and accumulation of CD4+ lymphocytes in the tumor.

No MeSH data available.


Related in: MedlinePlus