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Updated: Jun 15, 2026
09:44
In Vitro Evaluation of Oncogenic Transformation in Human Mammary Epithelial Cells
Published on: September 24, 2020
Species- and cell type-specific requirements for cellular transformation.
Annapoorni Rangarajan1, Sue J Hong, Annie Gifford
1Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.
Cancer Cell
|August 25, 2004
Summary
Human cells need more genetic alterations for cancer development than mouse cells. Transforming human cells requires six pathway changes, compared to two for mouse cells, highlighting significant species-specific differences in neoplastic transformation.
Area of Science:
- Cell biology
- Cancer research
- Genetics
Background:
- Neoplastic transformation, the process by which normal cells become cancerous, is a complex multistep process.
- Existing evidence suggests species-specific differences in the genetic alterations required for this transformation, with human cells potentially requiring more changes than murine cells.
- A precise enumeration of these differences has been lacking.
Purpose of the Study:
- To precisely enumerate the genetic changes required for neoplastic transformation in human versus murine cells.
- To identify the specific signaling pathways involved in tumorigenic conversion across different cell types.
- To compare the minimum genetic alterations necessary for cancer development in distinct species and cell lineages.
Main Methods:
- Comparative analysis of genetic alterations in murine and human fibroblasts.
- Perturbation of key signaling pathways including p53, Raf, pRb, PP2A, telomerase, Ral-GEFs, and PI3K.
- Assessment of tumorigenic conversion in different human cell types (fibroblasts, embryonic kidney cells, mammary epithelial cells).
Main Results:
- Two signaling pathway perturbations (p53 and Raf) were sufficient for tumorigenic conversion of murine fibroblasts.
- Six signaling pathway perturbations (p53, pRb, PP2A, telomerase, Raf, and Ral-GEFs) were required for human fibroblasts.
- Cell type-specific requirements were observed in human cells: immortalized fibroblasts (Raf, Ral-GEFs), embryonic kidney cells (PI3K, Ral-GEFs), and mammary epithelial cells (Raf, PI3K, Ral-GEFs).
Conclusions:
- Human cells require significantly more genetic alterations for neoplastic transformation than murine cells.
- The specific signaling pathways involved in tumorigenesis differ between species and are cell type-dependent.
- Understanding these differences is crucial for developing targeted cancer therapies and elucidating the fundamental mechanisms of carcinogenesis.
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