1. Organoids represent a more accurate cancer model for studying the breast tissue microenvironment
Organoids are tissue-derived adult stem cells that can be grow into self-organizing organotypic structures. Due to their derivation from human tissue, organoids can more accurately model the interactions between healthy human tissue and cancer, enabling patient-specific drug testing and development of tailored therapeutic regimens.
The CODEX® platform can image organoids utilizing a straightforward sample preparation and the standardized CODEX experimental protocol, generating not only beautiful data but cell-cell multi-marker spatial analysis to accurately investigate the interactions that affect biological outcomes and to understand the biological mechanism at work all at single-cell resolution.
2. Culturing organoids can be straightforward
Akoya’s applications team joined forces with Dr. Xiaojiang Cui out of Cedars-Sinai Medical Center, Los Angeles, CA to generate human breast tissue mimetic organoid models. They began by using fresh human breast tissue specimens harvested during mammaplasty reduction and prophylactic surgeries. These tissues were then cut and digested overnight and the breast microtissue containing stroma components were collected via centrifugation. They were then cultured in 3D using a matrix mixture containing Matrigel, collagen I, and specially formulated organoid medium.
Using culture inserts, a “sandwich” method was utilized, in which 1 layer of matrix mixture was added, followed by 2 layers of organoids and matrix mixture, and a final layer of matrix mixture. Imaging analyses, including immunohistochemistry, immunofluorescence, and highly multiplexed CODEX imaging, were used to study cellular marker expression in the organoids.
Fresh tissue derived breast organoids are cultured and grown. Organoids are preserved using standard FFPE tissue preservation techniques and sectioned onto a CODEX coverslip. Once tissue sections are selected, they proceed through CODEX FFPE sample preparation protocol. Sections are then imaged on the CODEX platform
3. Organoids are paving the way for novel diagnostic screenings
The team’s 3D culture system is distinct in that it is capable of growing patient-derived breast organoids for over 3 weeks.
Once the organoid models are made, imaging can be done to assess whether the cultured organoids are an accurate representation of the cancer in question as well as therapeutic efficacy. The CODEX platform can image organoids utilizing a straightforward sample preparation and the standardized CODEX experimental protocol, generating not only beautiful data but cell-cell multi-marker spatial analysis to accurately the breast tissue microenvironment at single-cell resolution. The team’s CODEX imaging consisted of a 25-plex panel allowing for the investigation of 25 antigens for different cell types, facilitating detailed characterizations of the organoid microarchitecture.
Within the organoids themselves we can see breast tissue microstructures with ducts and lobules along with stromal cell types normally found in human breast. For the first time, different stromal cell types were grown alongside the mammary epithelium in the organoid system. The cultured breast organoids are hormone responsive and can be subcultured. The team also found that BRCA1 mutant organoids are more sensitive to estrogen and progesterone treatment compared with BRCA1 wildtype, as indicated by organoid size changes.
The BRCA1 mutant organoids displayed unique gene expression profiles related to oxidative stress and DNA damage response. These types of models will serve as the foundation for refining a breast organoid system that can faithfully recapitulate the physiology of human breast tissue. It will pave the way for a novel screening system that will test the pathogenesis of breast cancer and associated risk factors.
A pre-existing 25-plex CODEX antibody panel developed for studying breast cancer tissues which successfully imaged the fresh tissue derived breast organoid.
To learn more about why breast organoid models are useful tools for studying both normal and diseased human mammary gland development and cell processes, watch Dr. Xiaojiang Cui’s webinar (live on December 8th).
