Earlier research primarily attributed the effects of mesenchymal stem cell (MSC) therapies to their capacity for local engrafting and differentiating into multiple tissue types. However, recent studies have revealed that implanted cells do not survive for long, and that the benefits of MSC therapy could be due to the vast array of bioactive factors they produce, which play an important role in the regulation of key biologic processes. Secretome derivatives, such as conditioned media or exosomes, may present considerable advantages over cells for manufacturing, storage, handling, product shelf life and their potential as a ready-to-go biologic product. Nevertheless, regulatory requirements for manufacturing and quality control will be necessary to establish the safety and efficacy profile of these products. Among MSCs, human uterine cervical stem cells (hUCESCs) may be a good candidate for obtaining secretome-derived products. hUCESCs are obtained by Pap cervical smear, which is a less invasive and painful method than those used for obtaining other MSCs (for example, from bone marrow or adipose tissue). Moreover, due to easy isolation and a high proliferative rate, it is possible to obtain large amounts of hUCESCs or secretome-derived products for research and clinical use.

Our data indicate that tumor-derived CAFs can induce up-regulation of genes involved in breast cancer progression. Our data additionally indicate that CAFs, especially those derived from MMP11+ MIC tumors, can promote breast cancer cell invasion and angiogenesis.

Although the mechanisms underlying the genesis and progression of breast cancer are better understood than ever, it is still the most frequent malignant tumor in women and one of the leading causes of cancer death. Therefore, we need to establish new approaches that lead us to better understand the prognosis of this heterogeneous systemic disease and to propose new therapeutic strategies. Cancer is not only a malignant transformation of the epithelial cells merely based on their autonomous or acquired proliferative capacity. Today, data support the concept of cancer as an ecosystem based on a cellular sociology, with diverse components and complex interactions between them. Among the different cell types that make up the stroma, which have a relevant role in the dynamics of tumor/stromal cell interactions, the main ones are cancer associated fibroblasts, endothelial cells, immune cells and mesenchymal stromal cells. Several factors expressed by the stroma of breast carcinomas are associated with the development of metastasis, such as matrix metalloproteases, their tissular inhibitors or some of their regulators like integrins, cytokines or toll-like receptors. Based on the expression of these factors, two types of breast cancer stroma can be proposed with significantly different influence on the prognosis of patients. In addition, there is evidence about the existence of bi-directional signals between cancer cells and tumor stroma cells with prognostic implications, suggesting new therapeutic strategies in breast cancer.

The aim of this work was to evaluate the expression and clinical relevance of some cytokines in breast carcinomas. An immunohistochemical study using tissue arrays and specific antibodies against interleukin 1β (IL-1β), IL-6, IL-10, IL-17, interferon β (IFNβ) and nuclear factor kappa B (NFκB) was performed in 108 breast carcinomas. Most studied cytokines were mainly expressed by cancer cells but also by stromal cells as cancer-associated fibroblasts (CAFs) or mononuclear inflammatory cells (MICs). Global expression (score) of IL-1β and IL-17 was positively associated with histological grade; human epidermal growth factor receptor 2-positive tumors showed a higher global expression of IFNβ but a lower global expression of NFκB; and node-negative tumors showed a higher global expression of IL-6. High score of IL-6 was significantly associated with both longer relapse free-survival (RFS) and overall survival (OS). Moreover, the expression of IL-1β by each stromal cells (CAFs and MICs) was significantly associated with both longer RFS and OS, whereas the expression of IL-10 by these cells was significantly associated with both shorter RFS and OS. However, the combination of IL-1β, IL-6 and IL-10 expression by MICs reached an important association with prognosis and improved our previously reported prognostic signification based on the matrix metalloprotease 11 status by MICs. The combination of IL-1β, IL-6 and IL-10 expression by MICs was significant and independently associated with distant RFS in a multivariate analysis. Therefore, the combination of the expression of IL-1β, IL-6 and IL-10 may serve as promising biomarkers of MICs with prognostic significance, contributing to a better characterization of breast carcinomas microenvironment.

No abstract