**Part 2**

**Breast Cancer and Microenvironment** 

126 Breast Cancer – Focusing Tumor Microenvironment, Stem Cells and Metastasis

[67] Marise R., Voss H.V., Groep P.V., Bart J., Wall E.V., Diest P.J. Expression of the stem cell marker ALDH1 in BRCA1 related breast cancer. Cellular Oncology 2011;34:3-10 [68] Chaje`s V., Joulin V., Clavel-Chapelon F. The fatty acid desaturation index of blood

factor of breast cancer risk. Current Opinion in Lipidology 2011; 22(1):6-10

lipids, as a biomarker of hepatic stearoyl-CoA desaturase expression, is a predictive

**7** 

*1CBRL,* 

*1,2México 3,4USA* 

**Novel Insights Into the Role of Inflammation** 

*2Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad* 

*3Life Science & Astrobiology Division, NASA Ames Research Center, Moffett Field, CA,* 

In the past decades the major focus of cancer research has been the transformed tumor cells itself, while the role of cellular microenvironment in tumorigenesis has not been widely explored. Several studies have demonstrated the ability of stroma to regulate the growth and differentiation state of breast cancer cells, and the invasive behaviour, and polarity of normal mammary epithelial and breast carcinomas are influenced by tumor microenvironment, immune and stromal cells (Bissell, et al., 2002, Radisky & Radisky, 2007, Tlsty, 2001, Tlsty & Hein, 2001). In addition, genetic abnormalities, such as loss of heterozygosity, occur not only in cancer cells, but in stromal cells as well (Kurose, et al.,

It is believed that a better understanding of the tumor microenvironment could help render more accurate diagnostics or assist in predicting tumor aggressiveness (i.e., bad prognosis)

By the end of the nineteenth century, the English surgeon S. Paget suggested the idea that, in order for breast cancer to develop, a specific "seeding" process must occur and, for this primary onset to metastasize to a specific distant organ, particular stromal features would be required postulating his "seed and soil" hypothesis (Paget, 1889). His work greatly contributed to somewhat earlier observations by T. Langhans who first used the word stroma to describe the connective tissue, vessels and other components between tumors (Langhans, 1879) and to the theory postulated by R. Virchow suggesting a possible origin of cancer at sites of chronic inflammation (Balkwill& Mantovani, 2001). A century later, researchers such as B. Mintz and K. Illmensee in general, as well as M. Bisell, in breast cancer in particular, pointed to the tumor milieu as an essential component of neoplasias, not only for cancer evolution but also for cancer instigation (Mintz & Illmensee, 1975; Lochter & Bissell, 1995). Together these and additional findings had painted a broad picture of the complexity of tumor microenvironment, where diverse stromal cells interact with

**1. Introduction** 

2002, Kurose, et al., 2001, Moinfar, et al., 2000).

thus facilitating the design of personalized treatments.

**in Promoting Breast Cancer Development** 

*4Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, PA,* 

J. Valdivia-Silva3,, J. Franco-Barraza4, E. Cukierman4 and E.A. García-Zepeda1,2

*Nacional Autónoma de México,* 
