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CD44 increases the efficiency of distant metastasis of breast cancer.

McFarlane S, Coulter JA, Tibbits P, O'Grady A, McFarlane C, Montgomery N, Hill A, McCarthy HO, Young LS, Kay EW, Isacke CM, Waugh DJ - Oncotarget (2015)

Bottom Line: Metastasis is the predominant cause of death from cancer yet we have few biomarkers to predict patients at increased risk of metastasis and are unable to effectively treat disseminated disease.Loss of CD44 attenuated tumor cell adhesion to endothelial cells and reduced cell invasion but did not affect proliferation in vitro.We conclude that elevated CD44 expression on tumour cells within the systemic circulation increases the efficiency of post-intravasation events and distant metastasis in vivo, consistent with its association with increased distant recurrence and reduced disease-free survival in patients.

View Article: PubMed Central - PubMed

Affiliation: Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland.

ABSTRACT
Metastasis is the predominant cause of death from cancer yet we have few biomarkers to predict patients at increased risk of metastasis and are unable to effectively treat disseminated disease. Analysis of 448 primary breast tumors determined that expression of the hylauronan receptor CD44 associated with high grade (p = 0.046), ER- (p = 0.001) and PR-negative tumors (p = 0.029), and correlated with increased distant recurrence and reduced disease-free survival in patients with lymph-node positive or large tumors. To determine its functional role in distant metastasis, CD44 was knocked-down in MDA-MB-231 cells using two independent shRNA sequences. Loss of CD44 attenuated tumor cell adhesion to endothelial cells and reduced cell invasion but did not affect proliferation in vitro. To verify the importance of CD44 to post-intravasation events, tumor formation was assessed by quantitative in vivo imaging and post-mortem tissue analysis following an intra-cardiac injection of transfected cells. CD44 knock-down increased survival and decreased overall tumor burden at multiple sites, including the skeleton in vivo. We conclude that elevated CD44 expression on tumour cells within the systemic circulation increases the efficiency of post-intravasation events and distant metastasis in vivo, consistent with its association with increased distant recurrence and reduced disease-free survival in patients.

No MeSH data available.


Related in: MedlinePlus

CD44 expression promotes bone metastasis(A) Normalised quantification of bioluminescent signals from mice hind limbs injected with indicated clones. Data represents the mean ± SEM (n = 6; *p < 0.05 by t-test). (B) Representative digital radiographs of hindlimbs from mice in each experimental group. White arrows indicate osteolytic bone lesions. (C) Representative demineralized bone sections from each experimental group. H&E-stained sections showing complete replacement of bone marrow by tumor in shNT-mice (left) compared with absence of tumor cells in mice injected with sh#1 and sh#2 clones (middle and left). All images are x50 magnification with scale bar equal to 100 μm. (D) Representative tumor-specific CD44 immunoreactivity (note strong membraneous staining) and corresponding H&E stain of demineralized bone sections from mice inoculated with MDA-MB-231 shNT cells. Magnification is x50 for H&E image (left) and left image of CD44 immunoreactivity and x200 for right image of CD44 staining; scale bar equal to 100 mm. T = tumor BM = bone marrow.
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Figure 4: CD44 expression promotes bone metastasis(A) Normalised quantification of bioluminescent signals from mice hind limbs injected with indicated clones. Data represents the mean ± SEM (n = 6; *p < 0.05 by t-test). (B) Representative digital radiographs of hindlimbs from mice in each experimental group. White arrows indicate osteolytic bone lesions. (C) Representative demineralized bone sections from each experimental group. H&E-stained sections showing complete replacement of bone marrow by tumor in shNT-mice (left) compared with absence of tumor cells in mice injected with sh#1 and sh#2 clones (middle and left). All images are x50 magnification with scale bar equal to 100 μm. (D) Representative tumor-specific CD44 immunoreactivity (note strong membraneous staining) and corresponding H&E stain of demineralized bone sections from mice inoculated with MDA-MB-231 shNT cells. Magnification is x50 for H&E image (left) and left image of CD44 immunoreactivity and x200 for right image of CD44 staining; scale bar equal to 100 mm. T = tumor BM = bone marrow.

Mentions: A high level of metastasis to the hind limbs was clearly evident. Subsequent analysis of hind limbs revealed a reduced tumor burden 4-weeks post-injection in CD44-depleted conditions, with a 1132-fold lower signal detected in the sh#1-transfected model (n = 6, p = 0.033) and 1137-fold decrease observed in the sh#2-transfected model (n = 6, p = 0.047) relative to the shNT control (Fig. 4A). X-ray analysis confirmed the presence of osteolytic lesions in the tibia of mice injected with the shNT-transfected MDA-MB-231 cells. In contrast, bone resorption was not apparent in the hind limbs of mice injected with either of the CD44-depleted MDA-MB-231 cells (Fig. 4B). The presence of bone metastasis was confirmed by histology. H&E stained de-mineralized bone sections revealed a decreased tumor burden in the bones of animals injected with sh#1- or sh#2-transfected MDA-MB-231 cells (Fig. 4C). Immunohistochemistry confirmed that bone metastases arising from injection of shNT-transfected MDA-MB-231 cells were strongly positive for CD44 (Fig. 4D).


CD44 increases the efficiency of distant metastasis of breast cancer.

McFarlane S, Coulter JA, Tibbits P, O'Grady A, McFarlane C, Montgomery N, Hill A, McCarthy HO, Young LS, Kay EW, Isacke CM, Waugh DJ - Oncotarget (2015)

CD44 expression promotes bone metastasis(A) Normalised quantification of bioluminescent signals from mice hind limbs injected with indicated clones. Data represents the mean ± SEM (n = 6; *p < 0.05 by t-test). (B) Representative digital radiographs of hindlimbs from mice in each experimental group. White arrows indicate osteolytic bone lesions. (C) Representative demineralized bone sections from each experimental group. H&E-stained sections showing complete replacement of bone marrow by tumor in shNT-mice (left) compared with absence of tumor cells in mice injected with sh#1 and sh#2 clones (middle and left). All images are x50 magnification with scale bar equal to 100 μm. (D) Representative tumor-specific CD44 immunoreactivity (note strong membraneous staining) and corresponding H&E stain of demineralized bone sections from mice inoculated with MDA-MB-231 shNT cells. Magnification is x50 for H&E image (left) and left image of CD44 immunoreactivity and x200 for right image of CD44 staining; scale bar equal to 100 mm. T = tumor BM = bone marrow.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4484469&req=5

Figure 4: CD44 expression promotes bone metastasis(A) Normalised quantification of bioluminescent signals from mice hind limbs injected with indicated clones. Data represents the mean ± SEM (n = 6; *p < 0.05 by t-test). (B) Representative digital radiographs of hindlimbs from mice in each experimental group. White arrows indicate osteolytic bone lesions. (C) Representative demineralized bone sections from each experimental group. H&E-stained sections showing complete replacement of bone marrow by tumor in shNT-mice (left) compared with absence of tumor cells in mice injected with sh#1 and sh#2 clones (middle and left). All images are x50 magnification with scale bar equal to 100 μm. (D) Representative tumor-specific CD44 immunoreactivity (note strong membraneous staining) and corresponding H&E stain of demineralized bone sections from mice inoculated with MDA-MB-231 shNT cells. Magnification is x50 for H&E image (left) and left image of CD44 immunoreactivity and x200 for right image of CD44 staining; scale bar equal to 100 mm. T = tumor BM = bone marrow.
Mentions: A high level of metastasis to the hind limbs was clearly evident. Subsequent analysis of hind limbs revealed a reduced tumor burden 4-weeks post-injection in CD44-depleted conditions, with a 1132-fold lower signal detected in the sh#1-transfected model (n = 6, p = 0.033) and 1137-fold decrease observed in the sh#2-transfected model (n = 6, p = 0.047) relative to the shNT control (Fig. 4A). X-ray analysis confirmed the presence of osteolytic lesions in the tibia of mice injected with the shNT-transfected MDA-MB-231 cells. In contrast, bone resorption was not apparent in the hind limbs of mice injected with either of the CD44-depleted MDA-MB-231 cells (Fig. 4B). The presence of bone metastasis was confirmed by histology. H&E stained de-mineralized bone sections revealed a decreased tumor burden in the bones of animals injected with sh#1- or sh#2-transfected MDA-MB-231 cells (Fig. 4C). Immunohistochemistry confirmed that bone metastases arising from injection of shNT-transfected MDA-MB-231 cells were strongly positive for CD44 (Fig. 4D).

Bottom Line: Metastasis is the predominant cause of death from cancer yet we have few biomarkers to predict patients at increased risk of metastasis and are unable to effectively treat disseminated disease.Loss of CD44 attenuated tumor cell adhesion to endothelial cells and reduced cell invasion but did not affect proliferation in vitro.We conclude that elevated CD44 expression on tumour cells within the systemic circulation increases the efficiency of post-intravasation events and distant metastasis in vivo, consistent with its association with increased distant recurrence and reduced disease-free survival in patients.

View Article: PubMed Central - PubMed

Affiliation: Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland.

ABSTRACT
Metastasis is the predominant cause of death from cancer yet we have few biomarkers to predict patients at increased risk of metastasis and are unable to effectively treat disseminated disease. Analysis of 448 primary breast tumors determined that expression of the hylauronan receptor CD44 associated with high grade (p = 0.046), ER- (p = 0.001) and PR-negative tumors (p = 0.029), and correlated with increased distant recurrence and reduced disease-free survival in patients with lymph-node positive or large tumors. To determine its functional role in distant metastasis, CD44 was knocked-down in MDA-MB-231 cells using two independent shRNA sequences. Loss of CD44 attenuated tumor cell adhesion to endothelial cells and reduced cell invasion but did not affect proliferation in vitro. To verify the importance of CD44 to post-intravasation events, tumor formation was assessed by quantitative in vivo imaging and post-mortem tissue analysis following an intra-cardiac injection of transfected cells. CD44 knock-down increased survival and decreased overall tumor burden at multiple sites, including the skeleton in vivo. We conclude that elevated CD44 expression on tumour cells within the systemic circulation increases the efficiency of post-intravasation events and distant metastasis in vivo, consistent with its association with increased distant recurrence and reduced disease-free survival in patients.

No MeSH data available.


Related in: MedlinePlus