Humanized Mice May Revolutionize Cancer Drug Discovery

Curator: Stephen J. Williams, Ph.D.

Word Cloud by Zach Day

Decades ago cancer research and the process of oncology drug discovery was revolutionized by the development of mice deficient in their immune system, allowing for the successful implantation of human-derived tumors. The ability to implant human tumors without rejection allowed researchers to study how the kinetics of human tumor growth in its three-dimensional environment, evaluate potential human oncogenes and drivers of oncogenesis, and evaluate potential chemotherapeutic therapies. Indeed, the standard preclinical test for antitumor activity has involved the subcutaneous xenograft model in immunocompromised (SCID or nude athymic) mice. More detail is given in the follow posts in which I describe some early pioneers in this work as well as the development of large animal SCID models:

Heroes in Medical Research: Developing Models for Cancer Research

The SCID Pig: How Pigs are becoming a Great Alternate Model for Cancer Research

The SCID Pig II: Researchers Develop Another SCID Pig, And Another Great Model For Cancer Research

This strategy (putting human tumor cells into immunocompromised mice and testing therapeutic genes and /or compounds) has worked extremely well for most cytotoxic chemotherapeutics (those chemotherapeutic drugs with mechanisms of action related to cell kill, vital cell functions, and cell cycle). For example the NCI 60 panel of human tumor cell lines has proved predictive for the chemosensitivity of a wide range of compounds.

• The NCI-60 panel has been used by the Developmental Therapeutics Program (DTP) of the U.S. National Cancer Institute (NCI) to screen >100,000 chemically defined compounds plus a large number of natural product extracts for anticancer activity since 1990 [1-3]
• Expression (microarray data) with bioinformatic strategies can use efficacy in one cell type to predict efficacy in cell types not in the panel in A strategy for predicting the chemosensitivity of human cancers and its application to drug discovery however in Coombes, Wang and Baggerly in Genomic Signatures on the NCI60 cell lines DO NOT predict patient response to chemotherapy, and [5] where the authors could not reproduce the results in [4] and discussed in Putting Oncology Patients at Risk and a RETRACTED paper in [6] relying on miRNA signatures.

Even though the immunocompromised model has contributed greatly to the chemotherapeutic drug discovery process. using these models to develop the new line of immuno-oncology products has been met with challenges three which I highlight below with curated database of references and examples.

From a practical standpoint development of a mouse which can act as a recipient for human tumors yet have a humanized immune system allows for the preclinical evaluation of antitumoral effect of therapeutic antibodies without the need to use neutralizing antibodies to the comparable mouse epitope,   thereby reducing the complexity of the study and preventing complications related to pharmacokinetics.

Champions Oncology Files Patents for Use of PDX Platform in Immune-Oncology

Hackensack, NJ – August 17, 2015 – Champions Oncology, Inc. (OTC: CSBR), engaged in the development of advanced technology solutions and services to personalize the development and use of oncology drugs, today announced that it has filed two patent applications with the United States Patent and Trademark Office (USPTO) relating to the development and use of mice with humanized immune systems to test immune-oncology drugs and therapeutic cancer vaccines.

Dr. David Sidransky, the founder and Chairman of Champions Oncology commented, “Drug development ‎in the immune-oncology space is fundamentally changing our approach to cancer treatment. These patents represent potentially invaluable tools for developing and personalizing immune therapy based on cutting edge sequence analysis, bioinformatics and our unique in vivo models.”

Joel Ackerman, Chief Executive Officer of Champions Oncology stated, “Developing intellectual property related to our Champions TumorGraft® platform has been an important component of strategy. The filing of these patents is an important milestone in leveraging our research and development investment to expand our platform and create proprietary tools for use by our pharmaceutical partners. We continue to look for additional revenue streams to supplement our fee-for-service business and we believe these patents will help us capture more of the value we create for our customers in the future.”

The first patent filing covers the methodology used by the Company to create a mouse model, containing a humanized immune system and a human tumor xenograft, which is capable of testing the efficacy of immune-oncology agents, both as single agents and in combination with anti-neoplastic drugs. The second patent filing relates to the detection of neoantigens and their role in the development of anti-cancer vaccines.

Keren Pez, Chief Scientific Officer, explained, “In the last few years, there has been a significant increase in cancer research that focuses on exploring the power of the human immune system to attack tumors. However, it’s challenging to test immune-oncology agents in traditional animal models due to the major differences between human and murine immune systems. The Champions ImmunoGraft™ platform has the unique ability of mimicking a human adaptive immune response in the mice, which allows us to specifically evaluate a variety of cancer therapeutics that modulate human immunity.

“Therapeutic vaccines that trigger the immune system to mount a response against a growing tumor are another area of intense interest. The development of an effective vaccine remains challenging but has an outstanding curative potential. Tumors harbor mutations in DNA that result in the translation of aberrant proteins. While these proteins have the potential to provoke an immune response that destructs early-stage cancer development, often the immune response becomes insufficient. Vaccines can trigger it by proactively challenging the system with these specific mutated peptides. Nevertheless, developing anti-cancer vaccines that effectively inhibit tumor growth has been complicated, partially due to challenges in finding the critical mutations, among others difficulties. With the more recent advances in genome sequencing, it’s now possible to identify tumor-specific antigens, or neoantigens, that naturally develop as an individual’s tumor grows and mutates,” she continued.

Traumatic spinal cord injury in mice with human immune systems.

Carpenter RS, Kigerl KA, Marbourg JM, Gaudet AD, Huey D, Niewiesk S, Popovich PG.

Exp Neurol. 2015 Jul 17;271:432-444. doi: 10.1016/j.expneurol.2015.07.011. [Epub ahead of print]

Inflamm Bowel Dis. 2015 Jul;21(7):1652-73. doi: 10.1097/MIB.0000000000000446.

Use of Humanized Mice to Study the Pathogenesis of Autoimmune and Inflammatory Diseases.

Koboziev I¹, Jones-Hall Y, Valentine JF, Webb CR, Furr KL, Grisham MB.

Author information

Abstract

Animal models of disease have been used extensively by the research community for the past several decades to better understand the pathogenesis of different diseases and assess the efficacy and toxicity of different therapeutic agents. Retrospective analyses of numerous preclinical intervention studies using mouse models of acute and chronic inflammatory diseases reveal a generalized failure to translate promising interventions or therapeutics into clinically effective treatments in patients. Although several possible reasons have been suggested to account for this generalized failure to translate therapeutic efficacy from the laboratory bench to the patient’s bedside, it is becoming increasingly apparent that the mouse immune system is substantially different from the human. Indeed, it is well known that >80 major differences exist between mouse and human immunology; all of which contribute to significant differences in immune system development, activation, and responses to challenges in innate and adaptive immunity. This inconvenient reality has prompted investigators to attempt to humanize the mouse immune system to address important human-specific questions that are impossible to study in patients. The successful long-term engraftment of human hematolymphoid cells in mice would provide investigators with a relatively inexpensive small animal model to study clinically relevant mechanisms and facilitate the evaluation of human-specific therapies in vivo. The discovery that targeted mutation of the IL-2 receptor common gamma chain in lymphopenic mice allows for the long-term engraftment of functional human immune cells has advanced greatly our ability to humanize the mouse immune system. The objective of this review is to present a brief overview of the recent advances that have been made in the development and use of humanized mice with special emphasis on autoimmune and chronic inflammatory diseases. In addition, we discuss the use of these unique mouse models to define the human-specific immunopathological mechanisms responsible for the induction and perpetuation of chronic gut inflammation.

J Immunother Cancer. 2015 Apr 21;3:12. doi: 10.1186/s40425-015-0056-2. eCollection 2015.

Human tumor infiltrating lymphocytes cooperatively regulate prostate tumor growth in a humanized mouse model.

Roth MD¹, Harui A¹.

Author information

Abstract

BACKGROUND:

The complex interactions that occur between human tumors, tumor infiltrating lymphocytes (TIL) and the systemic immune system are likely to define critical factors in the host response to cancer. While conventional animal models have identified an array of potential anti-tumor therapies, mouse models often fail to translate into effective human treatments. Our goal is to establish a humanized tumor model as a more effective pre-clinical platform for understanding and manipulating TIL.

METHODS:

The immune system in NOD/SCID/IL-2Rγnull (NSG) mice was reconstituted by the co-administration of human peripheral blood lymphocytes (PBL) or subsets (CD4+ or CD8+) and autologous human dendritic cells (DC), and animals simultaneously challenged by implanting human prostate cancer cells (PC3 line). Tumor growth was evaluated over time and the phenotype of recovered splenocytes and TIL characterized by flow cytometry and immunohistochemistry (IHC). Serum levels of circulating cytokines and chemokines were also assessed.

RESULTS:

A tumor-bearing huPBL-NSG model was established in which human leukocytes reconstituted secondary lymphoid organs and promoted the accumulation of TIL. These TIL exhibited a unique phenotype when compared to splenocytes with a predominance of CD8+ T cells that exhibited increased expression of CD69, CD56, and an effector memory phenotype. TIL from huPBL-NSG animals closely matched the features of TIL recovered from primary human prostate cancers. Human cytokines were readily detectible in the serum and exhibited a different profile in animals implanted with PBL alone, tumor alone, and those reconstituted with both. Immune reconstitution slowed but could not eliminate tumor growth and this effect required the presence of CD4+ T cell help.

CONCLUSIONS:

Simultaneous implantation of human PBL, DC and tumor results in a huPBL-NSG model that recapitulates the development of human TIL and allows an assessment of tumor and immune system interaction that cannot be carried out in humans. Furthermore, the capacity to manipulate individual features and cell populations provides an opportunity for hypothesis testing and outcome monitoring in a humanized system that may be more relevant than conventional mouse models.

Methods Mol Biol. 2014;1213:379-88. doi: 10.1007/978-1-4939-1453-1_31.

A chimeric mouse model to study immunopathogenesis of HCV infection.

Bility MT¹, Curtis A, Su L.

Author information

Abstract

Several human hepatotropic pathogens including chronic hepatitis C virus (HCV) have narrow species restriction, thus hindering research and therapeutics development against these pathogens. Developing a rodent model that accurately recapitulates hepatotropic pathogens infection, human immune response, chronic hepatitis, and associated immunopathogenesis is essential for research and therapeutics development. Here, we describe the recently developed AFC8 humanized liver- and immune system-mouse model for studying chronic hepatitis C virus and associated human immune response, chronic hepatitis, and liver fibrosis.

PMID:

25173399

[PubMed – indexed for MEDLINE]

PMCID:

PMC4329723

Free PMC Article

• · Images from this publication.See all images (3)Free text

Immune humanization of immunodeficient mice using diagnostic bone marrow aspirates from carcinoma patients.

Werner-Klein M, Proske J, Werno C, Schneider K, Hofmann HS, Rack B, Buchholz S, Ganzer R, Blana A, Seelbach-Göbel B, Nitsche U, Männel DN, Klein CA.

PLoS One. 2014 May 15;9(5):e97860. doi: 10.1371/journal.pone.0097860. eCollection 2014.

From 2015 AACR National Meeting in Philadelphia

References

1. Paull KD, Shoemaker RH, Hodes L, Monks A, Scudiero DA, Rubinstein L, Plowman J, Boyd MR. J Natl Cancer Inst. 1989;81:1088–1092. [PubMed]
2. Shi LM, Fan Y, Lee JK, Waltham M, Andrews DT, Scherf U, Paull KD, Weinstein JN. J Chem Inf Comput Sci. 2000;40:367–379. [PubMed]
3. Monks A, Scudiero D, Skehan P, Shoemaker R, Paull K, Vistica D, Hose C, Langley J, Cronise P, Vaigro-Wolff A, et al. J Natl Cancer Inst. 1991;83:757–766. [PubMed]
4. Potti A, Dressman HK, Bild A, et al. Genomic signatures to guide the use of chemotherapeutics. Nat Med. 2006;12:1294–1300. [PubMed]
5. Baggerly KA, Coombes KR. Deriving chemosensitivity from cell lines: forensic bioinformatics and reproducible research in high-throughput biology. Ann Appl Stat. 2009;3:1309–1334.
6. Carlson, B. Putting Oncology Patients at Risk Biotechnol Healthc. 2012 Fall; 9(3): 17–21.
7. Salter KH, Acharya CR, Walters KS, et al. An Integrated Approach to the Prediction of Chemotherapeutic Response in Patients with Breast Cancer. Ouchi T, ed. PLoS ONE. 2008;3(4):e1908. NOTE RETRACTED PAPER

Other posts on this site on Animal Models, Disease and Cancer Include:

Heroes in Medical Research: Developing Models for Cancer Research

Guidelines for the welfare and use of animals in cancer research

Model mimicking clinical profile of patients with ovarian cancer @ Yale School of Medicine

Vaccines, Small Peptides, aptamers and Immunotherapy [9]

Immunotherapy in Cancer: A Series of Twelve Articles in the Frontier of Oncology by Larry H Bernstein, MD, FCAP

Mouse With ‘Humanized Version’ Of Human Language Gene Provides Clues To Language Development

The SCID Pig: How Pigs are becoming a Great Alternate Model for Cancer Research

The SCID Pig II: Researchers Develop Another SCID Pig, And Another Great Model For Cancer Research