Kandalaft, L. | bioRxiv Science

bioRxiv2024

Myeloid cell networks determine reinstatement of original immune environments in recurrent ovarian cancer

Immunotherapy has produced disappointing results in recurrent ovarian cancer (OC). However, the prognostic value of tumour-infiltrating lymphocytes (TILs) is largely based on the analysis of treatment-naive tumours. To understand the immunobiology of recurrent cancers, and their evolution, we profiled 170 patient-matched primary-recurrent OC samples from 69 patients of two independent cohorts. By capturing heterogeneous TIL distributions, we identified four immune phenotypes associated with differential prognosis, TILs states and TILs:myeloid networks, which dictate malignant evolution after chemotherapy and recurrence. Notably, recurrent tumours recapitulate the immunogenic patterns of original cancers. Mirroring inflamed human OC, preclinical recurrent Brca1mut tumours maintained activated TILs:dendritic cells (DCs) niches and immunostimulatory tumour-associated macrophages (TAMs). Conversely, recurrent Brca1wt tumours displayed loss of TILs:DCs niches and accumulated immunosuppressive myeloid networks featuring Trem2/ApoEhigh TAMs and Nduf4l2high/Galectin3high malignant states. Our study highlights that persistent immunogenicity in recurrent OC is governed by the crosstalk between dissimilar myeloid cells and TILs, which is BRCA-dependent.

immunology↗

bioRxiv2023

Dissection and reconstruction of the colorectal cancer tumor microenvironment

Patient-derived organoids (PDOs) are the reference in vitro human disease models. However, the utility of colorectal cancer (CRC) PDOs is hindered by the lack of a tumor microenvironment (TME). To address this limitation, we built a living biobank of CRC PDOs with autologous stromal and immune TME. We characterized the original tumors and traditional monocultures using single-cell RNA-seq (scRNA-seq) and whole exome sequencing (WES) to obtain insights into cell type selection and phenotypic drift in culture. Subsequently, we developed culture conditions supporting all cell types to recapitulate the CRC-TME around PDOs. From the transcriptomes of >180k cells obtained from 260 such co-cultures, we illuminated the mutual influence of cells within CRC tumors. Based on original tumor data, atlases of predicted interactions and transcriptional networks elucidated why monocultures were altered and suggested that TME reconstruction more accurately reflected original tumor behavior. We found that inflammatory signals were absent in vitro and recovered upon co-culture with tumor-infiltrating lymphocytes (TILs). We also functionally confirmed that stromal, not cancer cells, mediated immune evasion. Additionally, stroma induced an invasive phenotype in cancer cells. From this deep dive into CRC-TME interactions, we built the human CRC-TME atlas (https://crc-tme.com/), an online portal for interactive exploration of gene expression data, prediction of cell-cell interactions at the pathway and receptor/ligand levels, transcriptional networks, and more. We anticipate PDO cultures with reconstructed TMEs will be valuable for discovery efforts, preclinical studies, and personalized medicine, with the atlas as a framework and inspiration for future CRC-TME studies.

cancer biology↗