Hormonally responsive breast cancer cells in a microfluidic co-culture model as a sensor of microenvironmental activity

Abstract

Breast cancer cell growth and therapeutic response are manipulated extrinsically by microenvironment signals. Despite recognition of the importance of the microenvironment in a variety of tumor processes, predictive measures that incorporate the activity of the surrounding cellular environment are lacking. In contrast, tumor cell biomarkers are well established in the clinic. Expression of Estrogen Receptor-alpha (ERα) is the primary defining feature of hormonally responsive tumors and is the molecular target of therapy in the most commonly diagnosed molecular subtype of breast cancer. While a number of soluble factors have been implicated in ERα activation, the complexity of signaling between the cellular microenvironment and the cancer cell implies multivariate control. The cumulative impact of the microenvironment signaling, which we define as microenvironmental activity, is more difficult to predict based on the sum of its parts. Here we tested the impact of an array of microenvironments on ERα signaling utilizing a microfluidic co-culture model. Quantitative immunofluorescence was employed to assess changes in ERα protein levels, combined with gene expression and phosphorylation status, as measures of activation. Analysis of microenvironment-induced growth under the same conditions revealed a previously undescribed correlation between growth and ERα protein down-regulation. These data suggest an expanded utility for the tumor biomarker ERα, in which the combination of dynamic regulation of ERα protein and growth in a breast cancer biosensor cell become a read-out of the microenvironmental activity.

Transitions from mono- to co- to tri-culture uniquely affect gene expression in breast cancer, stromal, and immune compartments

“…For example, different cell isolation processes have been shown to cause variable changes in gene expression profiles (Beliakova-Bethell et al 2014). Compartmentalized microscale systems have been used to maintain separate populations that interact through paracrine signals (Berry et al 2014; Domenech et al 2012; Domenech et al 2009; Torisawa et al 2010; Young et al 2012; Lang et al 2013). Diffusion ports between compartments allow soluble signals to spread by diffusion while maintaining separation of the individual cell populations.…”

“…Diffusion ports between compartments allow soluble signals to spread by diffusion while maintaining separation of the individual cell populations. In addition, the scale prevents flow between compartments and maintains media content separation long enough for one cell population to be seeded or lysed without disturbing the other population(s) (Berry et al 2014; Lang et al 2013; Domenech et al 2009). Unique to this device is that it allows for cell type configurations with increasing heterotypic complexity, such that we could compare mono-, co-, and tri-culture gene associated regulation patterns in all three individual cell types.…”

Progress towards understanding heterotypic interactions in multi-culture models of breast cancer

“…For example, we describe in this section simple compartmentalized, complex compartmentalized, self-organized direct, and direct with imposed structure methods. The most straightforward microscale models use laminar flow to pattern cell types in compartmentalized culture, with compartments often connected by diffusion ports 75,76 . These features maintain separated populations but allow for paracrine signaling.…”

Advances in the Treatment of Breast Cancer-Emphasis on fertility preservation-A Case Report

“…With the recent advances in breast cancer treatment the 5 year survival rate has increased to 89.7% in the United States [2]. With further improvements in the treatment of breast cancer and more sophisticated models one expects there to be an increased number of young women who may require fertility treatments [3][4][5][6]. "With newer methods regarding breast cancer treatment, five year survival rates are anticipated to improve as well as 20 year survival rates.…”