MMP1 and MMP11 Expression in Peripheral Blood Mononuclear Cells upon Their Interaction with Breast Cancer Cells and Fibroblasts.

Noemi Eiro,Francisco J. Vizoso,María Fraile,Francisco Domínguez,Berta Fernández,Nagore de Pablo,Luis O. González,Sandra Cid,Nuria Aguado

doi:10.3390/ijms22010371

Abstract

Tumor-infiltrating immune cells phenotype is associated with tumor progression. However, little is known about the phenotype of the peripheral blood mononuclear cells (PBMC) from breast cancer patients. We investigated MMP1 and MMP11 expression in PBMC from breast cancer patients and we analyzed gene expression changes upon their interaction with cancer cells and cancer-associated fibroblasts (CAF). We measured the impact of PBMC on proinflammatory gene expression in breast cancer cells, normal fibroblast (NF), and CAF and the impact on proliferation and invasiveness capacity of breast cancer cells. Gene expression of MMP1 and MMP11 in PBMC from breast cancer patients (n = 54) and control (n = 28); expression of IL1A, IL6, IL17, IFNβ, and NFĸB in breast cancer cell lines (MCF-7 and MDA-MB-231); and, additionally, IL10 and MMP11 in CAF and NF were analyzed by qRT-PCR before and after co-culture. Our results show the existence of a subpopulation of breast cancer patients (25.9%) with very high levels of MMP11 gene expression in PBMC. Also, gene expression of MMP1 and MMP11 increases in PBMC after co-culture with breast cancer cell lines, NF or CAF. PBMC from healthy or breast cancer patients induce an increased proliferation rate on MCF-7 and an increased invasiveness capacity of MDA-MB-231. Finally, we show a differential expression profile of inflammatory genes in NF and CAF when co-cultured with control or breast cancer PBMC. We have observed that MMPs’ expression in PBMC is regulated by the microenvironment, while the expression of inflammatory genes in NF or CAF is differentially regulated by PBMC. These findings confirm the importance of the crosstalk between stromal cells and suggest that PBMC would play a role in promoting aggressive tumor behavior.

Highlights

Breast cancer is a complex and heterogeneous disease
Basal gene expression of MMP1 and MMP11 was studied in peripheral blood mononuclear cells (PBMC) from breast cancer patients (BC-PBMC) and healthy women
We decided to establish an arbitrary threshold considering the highest MMP11 gene expression in compared to PBMC from healthy women (C-PBMC) as a cut-off point. This threshold allowed the identification of a subgroup of breast cancer patients (n = 14, 25.9% of total BC-patients) with significantly higher MMP11 gene expression (Figure 1B). This finding suggested that MMP11 gene expression in PBMC might contribute to identifying a subset of patients with breast cancer

Summary

Introduction

Neoformed tumor mass is constituted by cancer cells and by an important stromal component. Cancer-associated fibroblasts (CAF) and tumor-infiltrating immune cells are key cellular components of the tumor stroma. The latter derive from peripheral blood mononuclear cells (PBMC). The immune system plays paradoxical roles in tumorigenesis [1]. Matrix metalloproteases (MMPs) are zinc-dependent endopeptidases playing an important role in the degradation of the stromal connective tissue and basement membrane components, which are key elements during tumor invasion and metastasis. MMPs can participate in metastasis by remodeling the extracellular matrix, and through their ability to cleave and activate growth factors, cell adhesion molecules, and cell surface receptor, resulting in an anti-apoptotic and/or pro-angiogenic effects [5]

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