The more researchers learn about various cancers, the complexity of the human disease is becoming more obvious. For researchers to model this complexity ongoing studies involving patient derived xenograft (PDX) murine models continuously show significant advantages when compared to the conventional cell-line-derived xenograft (CDX) mice.

According to Inoue, et al in a paper recently published in peer-reviewed journal, Nature Review Urology, “Appropriate preclinical models that recapitulate the characteristics of malignancies are urgently required to efficiently develop new drugs and evaluate the biology of urological cancers.”  And although PDX models certainly have some noteworthy shortcomings – including higher costs, increased time required for tumor establishment, lack of (human or rodent) immune system and a reduced take rate of tumors –  researchers agree that their advantages have significant potential to revolutionize our understanding of cancer and the treatment of this malady.

The advantages associated with PDX mouse models that scientists are most excited about include:

• • Simple subcutaneous engrafting technique
  • Improved predictability of treatment outcomes and prognosis
  • Potential applications in personalized precision medical treatments
  • Allows for direct engraftment of human tumor cells
  • Ease of access to the subcutaneous tumor for biopsy
  • Preserved tumor heterogeneity and lineage hierarchy
  • No genetic manipulation or complicated breeding process is required
  • Allows for effective chronological tumor size monitoring

Hera BioLabs has created the SRG rat for PDX studies of human cancers which provide increased research benefits in additional to those described in the mouse. The larger size of the rat allows for larger tumor growth and more frequent or serial blood/tissue sampling. Our SCID rat strains have shown a higher tumor take rate and better growth kinetics compared to mouse for several traditionally difficult tumor models. In combination with humanization of the immune system, if PDX models are used in immunocompetent hosts (SCID rodents engrafted with a human immune system),  researchers will be better able to understand the immune response against a targeted tumor when studying immunotherapy treatment techniques in a preclinical setting.