Accelerated preclinical testing using transplanted tumors from genetically engineered mouse breast cancer models

Lyuba Varticovski1, Melinda G Hollingshead, Ana I Robles

  • 1Center for Cancer Research, National Cancer Institute, Frederick, Maryland. varticol@mail.nih.gov

Abstract

Insights

Transplanting tumors from genetically engineered mouse models (GEMs) offers a reproducible method for preclinical cancer therapy testing. This approach overcomes challenges like variable tumor growth and allows for consistent metastasis studies.

Area of Science:

  • Oncology
  • Genetics
  • Preclinical Research

Background:

  • Genetically engineered mouse (GEM) models are crucial for preclinical cancer therapy testing.
  • However, challenges such as variable tumor latency, incomplete penetrance, and complex breeding hinder their utility.
  • A novel transplantation strategy is needed to improve the reliability of these models.

Purpose of the Study:

  • To describe and validate a tumor transplantation strategy for genetically engineered mouse models.
  • To overcome limitations of traditional GEM models in preclinical cancer therapy research.
  • To establish a reproducible method for generating mammary tumors in mice for drug testing.

Main Methods:

  • Tumor fragments or cell suspensions from various GEMs (e.g., MMTV-PyMT, Her2/neu, wnt1) were transplanted into syngeneic or immunosuppressed mice.
  • Tumor development, histopathology, gene expression, and metastasis were monitored.
  • Serial passages and drug sensitivity assays were performed.

Main Results:

  • Transplanted anterior tumors grew faster than posterior tumors, with growth rate correlating to cell number.
  • The transplantation method was reproducible across multiple GEMs.
  • High metastasis rates were observed in PyMT, BRCA1/p53(+/-), and wnt1/p53(+/-) models (>90%, 40%, 40% respectively).
  • Transplanted PyMT tumors showed similar gene expression and drug sensitivity to original tumors.

Conclusions:

  • Tumor transplantation in GEMs provides a consistent cohort of mice with synchronized tumor development.
  • This method facilitates well-defined metastasis studies within a characterized genetic background.
  • The strategy enhances the reliability of preclinical anticancer therapy testing using GEM models.