A single-cell landscape of high-grade serous ovarian cancer
Nature Medicine. 2020;26(8):1271-1279. DOI 10.1038/s41591-020-0926-0. PMID 32572264. PMCID PMC7723336.
How to cite
AMA
Izar B, Tirosh I, Stover EH, Wakiro I, Cuoco MS, Alter I, et al. A single-cell landscape of high-grade serous ovarian cancer. Nat Med. 2020;26(8):1271-1279. doi:10.1038/s41591-020-0926-0APA
Izar, B., Tirosh, I., Stover, E. H., Wakiro, I., Cuoco, M. S., Alter, I., et al. (2020). A single-cell landscape of high-grade serous ovarian cancer. Nature Medicine, 26(8), 1271-1279. https://doi.org/10.1038/s41591-020-0926-0BibTeX
@article{izar2020singlecell,
title = {A single-cell landscape of high-grade serous ovarian cancer},
author = {Izar, B. and Tirosh, I. and Stover, E. H. and Wakiro, I. and Cuoco, M. S. and Alter, I. and others},
journal = {Nature Medicine},
volume = {26},
number = {8},
pages = {1271-1279},
year = {2020},
doi = {10.1038/s41591-020-0926-0},
pmid = {32572264}
}High-grade serous ovarian cancer is often read through bulk molecular subtypes, but those averages hide which cells are actually present in a tumor and how the mix shifts from one patient to the next.
The authors used single-cell RNA sequencing to profile 35,957 cells across three cohorts of ascites and primary tumors, including about 11,000 from the ascites of 11 patients, together with 795 cells from patient-derived xenograft models. They found that the immunoreactive and mesenchymal subtypes track the abundance of immune cells and fibroblasts rather than distinct cancer-cell populations, and that malignant cells share inflammatory programs with a targetable JAK/STAT vulnerability. To confirm one of those programs in intact tissue, they imaged MHC Class II and pan-cytokeratin on a RareCyte CyteFinder scanner, showing MHC Class II-expressing cancer cells in independent primary tumors.
Key findings
- Single-cell RNA-seq reframed the molecular subtypes of high-grade serous ovarian cancer. Profiling about 11,000 cells from 22 ascites specimens across 11 patients showed the immunoreactive and mesenchymal subtypes reflect the abundance of immune infiltrates and fibroblasts, not distinct subsets of malignant cells.
- A shared inflammatory program pointed to a targetable JAK/STAT vulnerability. The program recurred across a separate validation set of roughly 25,000 cells from additional ascites samples and primary tumors, and JAK/STAT inhibition had potent anti-tumor activity in short-term cultures and PDX models.
- Immunofluorescence on a RareCyte CyteFinder scanner confirmed the finding in tissue. Two-color staining for MHC Class II and pan-cytokeratin, imaged at 10X, showed MHC Class II-expressing cancer cells in independent primary HGSOC tumors.
CyteFinder in the methods
“Formalin-fixed, paraffin-embedded (FFPE) tissues were cut at a thickness of 5 μm and mounted on glass slides. Direct immunofluorescence was performed as previously described 47 using the following antibodies (manufacturer, clone, dilution): anti-HLA-DPB1-Alexa 647 (Abcam, Clone EPR11226 , 1:50) and anti-Pan-Cytokeratin-eFluor 570 (ThermoFisher Science, AE1/AE3, 1:100). Images were acquired on CyteFinder slide scanning fluorescence microscope (RareCyte Inc. Seattle WA) using a 10X objective.”
— Izar et al., Nature Medicine (2020), Methods, “Immunofluorescence”
Disclosure: RareCyte is named in the competing-interests statement of the publication cited above.
Why it matters for CyteFinder users
If a single-cell or genomic result needs confirming in intact tissue, this study shows the part a RareCyte CyteFinder scanner can play. The discovery here came from single-cell RNA sequencing, which flagged a subpopulation of ovarian cancer cells expressing MHC Class II. A sequencing readout alone cannot show that those cells sit in real tissue, so the authors turned to direct immunofluorescence: they stained independent primary tumors for MHC Class II and pan-cytokeratin and acquired the images on a CyteFinder slide-scanning fluorescence microscope at 10X. That image is what let them state, at the protein and spatial level, that MHC Class II-expressing cancer cells are present in patient tumors and not only in dissociated single-cell data. For your own work the pattern is the point: the CyteFinder is a whole-slide fluorescence scanner you can use to take a specific, antibody-defined question back into tissue and see where the signal actually is. When a marker matters, that tissue-level confirmation is often what turns a single-cell observation into evidence.
