zAvatars for anti-cancer therapy screening in digestive cancers

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zAvatars for anti-cancer therapy screening in digestive cancers

Friday, 16.09.2022

The capacity to distinguish tumors that will benefit from anti-cancer treatments from those that will not remains a challenge. Patient-derived xenografts (PDXs), also called “avatars,” are generated by the implantation of human primary tumor cells or tissues into a host animal.

Many PDX models have been developed to be used as a platform for drug screening in cancer research and precision medicine, mainly using mouse models. However, mouse models require a long time for tumor growth, which is not compatible with first clinical decisions.

In this context, the zebrafish PDX model (zPDX or zAvatar) has been recognized as a promising in vivo model to directly challenge patient cells with anti-cancer therapies. zAvatars, have become a very attractive and advantageous model given the numerous characteristics, namely the requirement of only a small number of transplanted cells, with no need for previous in vitro expansion; and, importantly, lower time requirements, as the assay takes only ∼2 weeks. Also, it allows the evaluation of crucial cancer hallmarks, such as cell proliferation and metastatic and angiogenic potentials.

In summary, zAvatars are emerging a fast in vivo assay with unprecedented cellular resolution that can be used to personalize cancer treatment, which might represent a novel complementary approach in the therapeutic decision making process.

The present article describes how to generate zAvatars from resected digestive cancers from surgeries, and how to then use them for anti-cancer therapy screening. We describe the steps for tumor sample collection and cryopreservation, sample preparation and fluorescent labeling for microinjection into zebrafish embryos, drug administration, and analysis of tumor behavior by single-cell confocal imaging. Our goal with this work is to help the community to use the model in the most correct and reproducible way.

 

Authors and Affiliations:

Bruna Costa; Marta Estrada, Mariana Barroso e Rita Fior.

Champalimaud Research, Champalimaud Foundation, Lisbon, Portugal.

 

Abstract:

Patient-derived xenografts (PDXs), also called “avatars,” are generated by the implantation of human primary tumor cells or tissues into a host animal. Given the complexity and unique characteristics of each tumor, PDXs are models of choice in cancer research and precision medicine. In this context, the zebrafish PDX model (zPDX or zAvatar) has been recognized as a promising in vivo model to directly challenge patient cells with anti-cancer therapies in a personalized manner. The assay relies on the injection of tumor cells from patients into zebrafish embryos to then test and identify the best available drug combination for a particular patient. Compared to mouse PDXs, zAvatar assays take less time and do not require in vitro or in vivo cell expansion. The present article describes how to generate zAvatars from resected digestive cancer from surgeries and how to then use them for anti-cancer therapy screening. We describe the steps for tumor sample collection and cryopreservation, sample preparation and fluorescent labeling for microinjection into zebrafish embryos, drug administration, and analysis of tumor behavior by single-cell confocal imaging. We provide detailed protocols and helpful tips for performing this assay, and we address the technical challenges associated with the workflow.

 

Journal: Current Protocols

 

Linkhttps://currentprotocols.onlinelibrary.wiley.com/doi/abs/10.1002/cpz1.415