184AA3: a xenograft model of ER+ breast adenocarcinoma

Abstract

Purpose Despite the prevalence and significant morbidity resulting from estrogen receptor positive (ER+) breast adenocarcinomas, there are only a few models of this cancer subtype available for drug development, and arguably none for studying etiology. Those models that do exist have questionable clinical relevance. Methods Given our goal of developing luminal models, we focused on six cell lines derived by minimal mutagenesis from normal human breast cells, and asked if any could generate clinically relevant xenografts, which we then extensively characterized. Results Xenografts of one cell line, 184AA3, consistently formed ER+ adenocarcinomas that had a high proliferative rate and other features consistent with “luminal B” intrinsic subtype. Squamous and spindle cell/mesenchymal differentiation was absent, in stark contrast to other cell lines that we examined or others have reported. We explored intratumoral heterogeneity produced by 184AA3 by immunophenotyping xenograft tumors and cultured cells, and characterized marker expression by immunofluorescence and flow cytometry. A CD44High subpopulation was discovered, yet their tumor forming ability was far less than CD44Low cells. Single cell cloning revealed the phenotypic plasticity of 184AA3, consistent with the intratumoral heterogeneity observed in xenografts. Characterization of ER expression in cultures revealed ER protein and signaling is intact, yet when estrogen was depleted in culture, and in vivo, it did not impact cell or tumor growth, analogous to therapeutically resistant ER+ cancers. Conclusions This model is appropriate for studies of the etiology of ovarian hormone independent adenocarcinomas, for identification of therapeutic targets, predictive testing and drug development.

Microenvironment-Induced Non-sporadic Expression of the AXL and cKIT Receptors Are Related to Epithelial Plasticity and Drug Resistance

“…The tumorigenic cell line 184AA3 emerged from 184Aa following insertional mutagenesis that inactivated p53 function (Stampfer et al, 2003 ). It exhibits increased genomic instability and forms clinically relevant ER+ luminal adenocarcinomas in the mouse xenograft model (Stampfer et al, 2003 ; Hines et al, 2016 ). To evaluate how the HMEC progression series responds to normal-like and stroma-like microenvironments, we cultured single cell suspensions in laminin-rich ECM [lrECM (matrigel)] and COL1 3D gels, respectively.…”

Protein biomarkers for subtyping breast cancer and implications for future research

“…Shinoda et al have shown prognostic significance of ER, HER2 and caveolin-1 IHC in canine mammary gland tumors, which mirrors prognostic data for humans [208]. An example of improved animal modelling is the currently available xenograft model of ER+ breast adenocarcinoma that maintains an intact microenvironment [209]. This model recapitulates breast architecture which is critical for decoding spatial and temporal tumor-stromal interactions.…”

Fibronectin rescues estrogen receptor α from lysosomal degradation in breast cancer cells

“…We used two well-known cellular models of ERα-positive human breast adenocarcinoma: MCF7 and T47D. These cell lines have been widely used and validated for the study of ERα activity because primary culture of normal or tumor human breast tissues leads to the loss of ERα expression (Graham et al, 2009; Hines et al, 2016). We demonstrate that FN prolongs ERα half-life and strengthens its transcriptional activity.…”