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Updated: May 15, 2026
Mammosphere Formation Assay from Human Breast Cancer Tissues and Cell Lines
Published on: March 22, 2015
Proteomic comparison of mcf-7 tumoursphere and monolayer cultures
Brian J Morrison1, Marcus L Hastie, Yadveer S Grewal
1School of Biomolecular and Physical Sciences, Griffith University, Brisbane, Queensland, Australia.
Abstract:
Breast cancer is a heterogeneous disease, composed of tumour cells with differing gene expressions and phenotypes. Very few antigens have been identified and a better understanding of tumour initiating-cells as targets for therapy is critically needed. Recently, a rare subpopulation of cells within tumours has been described with the ability to: (i) initiate and sustain tumour growth; (ii) resist traditional therapies and allow for secondary tumour dissemination; and (iii) display some of the characteristics of stem cells such as self-renewal. These cells are termed tumour-initiating cells or cancer stem cells, or alternatively, in the case of breast cancer, breast cancer stem cells. Previous studies have demonstrated that breast cancer stem cells can be enriched for in "tumoursphere" culture. Proteomics represents a novel way to investigate protein expression between cells. We hypothesise that characterisation of the proteome of the breast cancer line MCF-7 tumourspheres compared to adherent/differentiated cells identifies proteins of novel interest for further isolating or targeting breast cancer stem cells. We present evidence that: (i) the proteome of adherent cells is different to the proteome of cells grown in sphere medium from either early passage (passage 2) or late passage (passage 5) spheres; (ii) that spheres are enriched in expression of a variety of tumour-relevant proteins (including MUC1 and Galectin-3); and (iii) that targeting of one of these identified proteins (galectin-3) using an inhibitor (N-acetyllactosamine) decreases sphere formation/self-renewal of MCF-7 cancer stem cells in vitro and tumourigenicity in vivo. Hence, proteomic analysis of tumourspheres may find use in identifying novel targets for future therapy. The therapeutic targeting of breast cancer stem cells, a highly clinically relevant sub-population of tumour cells, has the potential to eliminate residual disease and may become an important component of a multi-modality treatment of cancer.
Insights
Proteomic analysis of breast cancer stem cells in tumorspheres identified Galectin-3 as a therapeutic target. Inhibiting Galectin-3 reduced cancer stem cell self-renewal and tumor growth, offering new treatment strategies.
Area of Science:
- Oncology
- Proteomics
- Cancer Stem Cell Biology
Background:
- Breast cancer is heterogeneous, necessitating novel therapeutic targets.
- Cancer stem cells (CSCs) drive tumor growth, resistance, and metastasis.
- Identifying CSC-specific targets is crucial for effective breast cancer treatment.
Purpose of the Study:
- To characterize the proteome of breast cancer stem cells enriched in tumorspheres.
- To identify novel protein targets for isolating or targeting breast cancer stem cells.
- To evaluate the therapeutic potential of targeting identified proteins.
Main Methods:
- Enrichment of breast cancer stem cells using tumorsphere culture.
- Proteomic analysis comparing tumorsphere and adherent MCF-7 cells.
- In vitro and in vivo evaluation of Galectin-3 inhibition.
Main Results:
- Proteomic profiles of tumorsphere and adherent cells significantly differed.
- Tumorspheres showed enriched expression of tumor-relevant proteins, including MUC1 and Galectin-3.
- Galectin-3 inhibition reduced CSC self-renewal in vitro and tumorogenicity in vivo.
Conclusions:
- Proteomic analysis of tumorspheres is a viable method for identifying novel CSC targets.
- Galectin-3 represents a promising therapeutic target for breast cancer stem cells.
- Targeting breast cancer stem cells holds potential for eliminating residual disease and improving treatment outcomes.
