Stromal cell derived factor-1: its influence on invasiveness and migration of breast cancer cells in vitro, and its association with prognosis and survival in human breast cancer.
BACKGROUND
Stromal cell-derived factor (SDF)-1 (CXC chemokine ligand-12) is a member of the CXC subfamily of chemokines, which, through its cognate receptor (CXC chemokine receptor [CXCR]4), plays an important role in chemotaxis of cancer cells and in tumour metastasis. We conducted the present study to evaluate the effect of SDF-1 on the invasiveness and migration of breast cancer cells, and we analyzed the expression of SDF-1 and its relation to clinicopathological features and clinical outcomes in human breast cancer.


METHODS
Expression of SDF-1 mRNA in breast cancer, endothelial (HECV) and fibroblast (MRC5) cell lines and in human breast tissues were studied using RT-PCR. MDA-MB-231 cells were transfected with a SDF-1 expression vector, and their invasiveness and migration was tested in vitro. In addition, the expression of SDF-1 was investigated using immunohistochemistry and quantitative RT-PCR in samples of normal human mammary tissue (n = 32) and mammary tumour (n = 120).


RESULTS
SDF-1 expression was identified in MRC5, MDA-MB-435s and MDA-MB-436 cell lines, but CXCR4 expression was detected in all cell lines and breast tissues. An autocrine loop was created following transfection of MDA-MB-231 (which was CXCR4 positive and SDF-1 negative) with a mammalian expression cassette encoding SDF-1 (MDA-MB-231SDF1+/+) or with control plasmid pcDNA4/GFP (MDA-MB-231+/-). MDA-MB-231SDF1+/+ cells exhibited significantly greater invasion and migration potential (in transfected cells versus in wild type and empty MDA-MB-231+/-; P < 0.01). In mammary tissues SDF-1 staining was primarily seen in stromal cells and weakly in mammary epithelial cells. Significantly higher levels of SDF-1 were seen in node-positive than in node-negative tumours (P = 0.05), in tumours that metastasized (P = 0.05), and tumours from patients who died (P = 0.03) than in tumours from patients who were disease free. It was most notable that levels of SDF-1 correlated significantly with overall survival (P = 0.001) and incidence-free survival (P = 0.035).


CONCLUSIONS
SDF-1 can increase the invasiveness and migration of breast cancer cells. Its levels correlated with node involvement and long-term survival in patients with breast cancer. SDF-1 may therefore have potential value in assessing clinical outcomes of patients with breast cancer.
Kang
Hua
H
Wales College of Medicine, Cardiff University, Cardiff, UK.
Watkins
Gareth
G
Parr
Christian
C
Douglas-Jones
Anthony
A
Mansel
Robert E
RE
Jiang
Wen G
WG
D001940:Breast / Q000166:cytology; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D002465:Cell Movement; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D005260:Female; D005347:Fibroblasts; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D009361:Neoplasm Invasiveness / Q000503:physiopathology*; D011379:Prognosis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D019743:Chemokines, CXC