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Integration of molecular profiling and chemical imaging to elucidate fibroblast-microenvironment impact on cancer cell phenotype and endocrine resistance in breast cancer.

Holton SE, Bergamaschi A, Katzenellenbogen BS, Bhargava R - PLoS ONE (2014)

Bottom Line: Here, we applied a label-free chemical imaging modality, Fourier transform infrared (FT-IR) spectroscopic imaging, to identify cells that had transitioned to hormone-independent growth.Both the molecular and chemical profiles identified here were translated from cell culture to patient samples: a secreted protein signature was used to stratify patient populations based on gene expression and FT-IR was used to characterize breast tumor patient biopsies.Our findings underscore the role of mammary fibroblasts in promoting aggressiveness and endocrine therapy resistance in ER-positive breast cancers and highlight the utility of FT-IR for the further characterization of breast cancer samples.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.

ABSTRACT
The tumor microenvironment is known to play a key role in altering the properties and behavior of nearby cancer cells. Its influence on resistance to endocrine therapy and cancer relapse, however, is poorly understood. Here we investigate the interaction of mammary fibroblasts and estrogen receptor-positive breast cancer cells in three-dimensional culture models in order to characterize gene expression, cellular changes, and the secreted protein factors involved in the cellular cross-talk. We show that fibroblasts, which are the predominant cell type found in the stroma adjacent to the cancer cells in a tumor, induce an epithelial-to-mesenchymal transition in the cancer cells, leading to hormone-independent growth, a more invasive phenotype, and resistance to endocrine therapy. Here, we applied a label-free chemical imaging modality, Fourier transform infrared (FT-IR) spectroscopic imaging, to identify cells that had transitioned to hormone-independent growth. Both the molecular and chemical profiles identified here were translated from cell culture to patient samples: a secreted protein signature was used to stratify patient populations based on gene expression and FT-IR was used to characterize breast tumor patient biopsies. Our findings underscore the role of mammary fibroblasts in promoting aggressiveness and endocrine therapy resistance in ER-positive breast cancers and highlight the utility of FT-IR for the further characterization of breast cancer samples.

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Co-culture with human mammary fibroblasts down-regulates ERα and fosters hormone-independent growth of breast cancer cells.(A) Fibroblasts down-regulate ERα mRNA levels at 3 and 6 days and this effect increases with longer co-culture time. (B) HMF reduce the response of MCF-7 cells to estradiol, as measured by PR, and HMF increases basal Ki67 mRNA at 3 and 6 days and eliminates further increase by E2. (C) Co-culture with HMF increases the basal proliferation rate of MCF-7, and decreases the fold change of E2 stimulation of proliferation monitored at 3 days. (D) MCF-7M proliferation fails to respond to increasing concentrations of E2 (left panel) and MCF-7M growth is not inhibited by treatment with tamoxifen (right). Response in MCF-7 cells alone is shown for comparison.
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pone-0096878-g003: Co-culture with human mammary fibroblasts down-regulates ERα and fosters hormone-independent growth of breast cancer cells.(A) Fibroblasts down-regulate ERα mRNA levels at 3 and 6 days and this effect increases with longer co-culture time. (B) HMF reduce the response of MCF-7 cells to estradiol, as measured by PR, and HMF increases basal Ki67 mRNA at 3 and 6 days and eliminates further increase by E2. (C) Co-culture with HMF increases the basal proliferation rate of MCF-7, and decreases the fold change of E2 stimulation of proliferation monitored at 3 days. (D) MCF-7M proliferation fails to respond to increasing concentrations of E2 (left panel) and MCF-7M growth is not inhibited by treatment with tamoxifen (right). Response in MCF-7 cells alone is shown for comparison.

Mentions: We next examined whether co-culture with fibroblasts might alter response of ER+ cancer cells to hormones. As a prelude to using our models for this effort, the response of MCF-7 to estrogen was confirmed to be similar in monolayer and in 3D culture (Figure S3 in File S1). Interestingly, after co-culture, a sustained reduction in the mRNA level of ERα in MCF-7S was observed (Fig. 3A). Though reduced, the remaining ERα in MCF-7S cells was functional, as shown by induction of the estradiol (E2)-responsive genes progesterone receptor (PR) and Ki67 mRNA after treatment (Fig. 3B). The basal levels of Ki67 mRNA and cell proliferation were increased in the co-cultures, and after 6 days, the response to E2 was greatly diminished, indicating that MCF-7S/MCF-7M proliferation became increasingly hormone-independent (Fig. 3B and 3C). Accompanying this hormone-independent growth, the antiestrogen tamoxifen (Tam) was no longer effective in inhibiting the growth of MCF-7M (Fig. 3D).


Integration of molecular profiling and chemical imaging to elucidate fibroblast-microenvironment impact on cancer cell phenotype and endocrine resistance in breast cancer.

Holton SE, Bergamaschi A, Katzenellenbogen BS, Bhargava R - PLoS ONE (2014)

Co-culture with human mammary fibroblasts down-regulates ERα and fosters hormone-independent growth of breast cancer cells.(A) Fibroblasts down-regulate ERα mRNA levels at 3 and 6 days and this effect increases with longer co-culture time. (B) HMF reduce the response of MCF-7 cells to estradiol, as measured by PR, and HMF increases basal Ki67 mRNA at 3 and 6 days and eliminates further increase by E2. (C) Co-culture with HMF increases the basal proliferation rate of MCF-7, and decreases the fold change of E2 stimulation of proliferation monitored at 3 days. (D) MCF-7M proliferation fails to respond to increasing concentrations of E2 (left panel) and MCF-7M growth is not inhibited by treatment with tamoxifen (right). Response in MCF-7 cells alone is shown for comparison.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4016150&req=5

pone-0096878-g003: Co-culture with human mammary fibroblasts down-regulates ERα and fosters hormone-independent growth of breast cancer cells.(A) Fibroblasts down-regulate ERα mRNA levels at 3 and 6 days and this effect increases with longer co-culture time. (B) HMF reduce the response of MCF-7 cells to estradiol, as measured by PR, and HMF increases basal Ki67 mRNA at 3 and 6 days and eliminates further increase by E2. (C) Co-culture with HMF increases the basal proliferation rate of MCF-7, and decreases the fold change of E2 stimulation of proliferation monitored at 3 days. (D) MCF-7M proliferation fails to respond to increasing concentrations of E2 (left panel) and MCF-7M growth is not inhibited by treatment with tamoxifen (right). Response in MCF-7 cells alone is shown for comparison.
Mentions: We next examined whether co-culture with fibroblasts might alter response of ER+ cancer cells to hormones. As a prelude to using our models for this effort, the response of MCF-7 to estrogen was confirmed to be similar in monolayer and in 3D culture (Figure S3 in File S1). Interestingly, after co-culture, a sustained reduction in the mRNA level of ERα in MCF-7S was observed (Fig. 3A). Though reduced, the remaining ERα in MCF-7S cells was functional, as shown by induction of the estradiol (E2)-responsive genes progesterone receptor (PR) and Ki67 mRNA after treatment (Fig. 3B). The basal levels of Ki67 mRNA and cell proliferation were increased in the co-cultures, and after 6 days, the response to E2 was greatly diminished, indicating that MCF-7S/MCF-7M proliferation became increasingly hormone-independent (Fig. 3B and 3C). Accompanying this hormone-independent growth, the antiestrogen tamoxifen (Tam) was no longer effective in inhibiting the growth of MCF-7M (Fig. 3D).

Bottom Line: Here, we applied a label-free chemical imaging modality, Fourier transform infrared (FT-IR) spectroscopic imaging, to identify cells that had transitioned to hormone-independent growth.Both the molecular and chemical profiles identified here were translated from cell culture to patient samples: a secreted protein signature was used to stratify patient populations based on gene expression and FT-IR was used to characterize breast tumor patient biopsies.Our findings underscore the role of mammary fibroblasts in promoting aggressiveness and endocrine therapy resistance in ER-positive breast cancers and highlight the utility of FT-IR for the further characterization of breast cancer samples.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.

ABSTRACT
The tumor microenvironment is known to play a key role in altering the properties and behavior of nearby cancer cells. Its influence on resistance to endocrine therapy and cancer relapse, however, is poorly understood. Here we investigate the interaction of mammary fibroblasts and estrogen receptor-positive breast cancer cells in three-dimensional culture models in order to characterize gene expression, cellular changes, and the secreted protein factors involved in the cellular cross-talk. We show that fibroblasts, which are the predominant cell type found in the stroma adjacent to the cancer cells in a tumor, induce an epithelial-to-mesenchymal transition in the cancer cells, leading to hormone-independent growth, a more invasive phenotype, and resistance to endocrine therapy. Here, we applied a label-free chemical imaging modality, Fourier transform infrared (FT-IR) spectroscopic imaging, to identify cells that had transitioned to hormone-independent growth. Both the molecular and chemical profiles identified here were translated from cell culture to patient samples: a secreted protein signature was used to stratify patient populations based on gene expression and FT-IR was used to characterize breast tumor patient biopsies. Our findings underscore the role of mammary fibroblasts in promoting aggressiveness and endocrine therapy resistance in ER-positive breast cancers and highlight the utility of FT-IR for the further characterization of breast cancer samples.

Show MeSH
Related in: MedlinePlus