Potential Role of Monocyte Potential Role of Monocyte Chemotactic Protein 1 (MCP-1) Chemotactic Protein 1 (MCP-1)

in the Breast Cancer in the Breast Cancer MicroenvironmentMicroenvironment

MC Hartmann, RM Dwyer, MP Boyle, SM Potter and MJ Kerin

Department of Surgery, National University of Ireland, Galway

Introduction

Breast cancer is the leading type of female cancer in women in Ireland

Despite advances in diagnosis and therapy, there are few options available for treatment of advanced disease

Further understanding of the mechanisms involved in cancer spread from the primary tumour site is important to develop novel therapies

The primary tumour microenvironment plays an important part in tumour progression

Breast tumour microenvironment

Neoplastic epithelial cells co-exist in carcinomas with a biologically complex stroma, composed of various types of stromal cells and extracellular matrix

Cross talk between epithelial and stromal cells is mediated by chemokine signalling

Monocyte Chemotactic Protein 1 (MCP-1)

Tumour stromal cells

Tumour epithelial cells

MCP-1/ CCL2

Tumour stromal cells

Tumour epithelial cells

MCP-1/ CCL2

MCP-1 In Breast Cancer:MCP-1 In Breast Cancer: MCP-1 is a chemotactic cytokine, primary role in MCP-1 is a chemotactic cytokine, primary role in

inflammation. inflammation.

Whole tumour explants secrete high levels of MCP-1.Whole tumour explants secrete high levels of MCP-1.

Tumour stromal cells secrete significantly higher levels than Tumour stromal cells secrete significantly higher levels than normal stromal cells. normal stromal cells. Epithelial cells express its receptor, Epithelial cells express its receptor, CCR2CCR2

Effect of MCP-1 on epithelial cell gene expression is unknownEffect of MCP-1 on epithelial cell gene expression is unknown

Aim

Investigate the effect of Monocyte Investigate the effect of Monocyte Chemotactic Protein-1 on breast cancer Chemotactic Protein-1 on breast cancer cell cell proliferationproliferation and gene expression and gene expression

Methods

Breast cancer cell lines SK-BR-3

PR-, ER-, HER2/neu ++ T47 D

ER+, PR+, HER2/neu low MDA-MB 231

ER-, PR-, HER2/neu – Breast cancer cell lines incubated

with recombinant human MCP-1 for 72hrs Cells harvested and RNA extracted Changes in proliferation analysed

T47D

Cells incubated with MCP-1

Real Time Quantitative

PCR

ELK-1, VIL-2 MKi67, BAG-1, Bcl-2

PPIA, MRPL19

RNA Extraction

Methods

cDNA synthesis

Oxyluciferin+AMP + PPi + CO2

ATP+Luciferin+O2

Luciferase

Mg++ LIGHT

Cell Proliferation

Gene expression

MCP-1 mediated changes in gene expression in T47D

cells

0

1

2

3

4

5

6

BC L2 BAG1 VIL -2 E LK -1

Fol

d Cha

nge

in G

ene

Exp

ress

ion

* p<0.05

*

*

MCP-1 mediated changes in gene expression in SK-BR-3

cells

0

1

2

3

4

BCL2 BAG1 VIL-2 ELK-1

Fold

Cha

nge

in G

ene E

xpre

ssio

n

* p<0.05

**

MCP-1 mediated change in gene expression of MDA-

MB-231 cells

0

1

2

3

4

BCL2 BAG1 VIL-2 ELK-1

Fol

d Cha

nge

in G

ene

Exp

ress

ion

* p<0.05

*

Effect of MCP-1 on Cell Proliferation

Rela

tive

Pro

life

rati

on

(%

)

0

10

20

30

40

50

60

70

80

90

100

T47D T47D MDA-MB-231MDA-MB-231

+ MCP-1

Well Content

+ MCP-1

SK-BR-3 SK-BR-3

+ MCP-1

Summary

Up regulation of BAG-1 and Bcl-2 in Up regulation of BAG-1 and Bcl-2 in T47D and SK-BR-3 cellsT47D and SK-BR-3 cells

Up regulation of VIL 2 in MDA-MB-231Up regulation of VIL 2 in MDA-MB-231

No significant change in breast cancer No significant change in breast cancer cell proliferation in response to MCP-1cell proliferation in response to MCP-1

Conclusion

MCP-1 has a potentially important role MCP-1 has a potentially important role in the breast tumour microenvironment. in the breast tumour microenvironment.

The results presented suggest it may The results presented suggest it may exert its effect by promotion of tumour exert its effect by promotion of tumour cell survival through upregulation of cell survival through upregulation of anti-apoptotic factors and pro-anti-apoptotic factors and pro-migratory factors and thus may be a migratory factors and thus may be a target for therapeutic interventiontarget for therapeutic intervention..