Single-cell analysis reveals immune modulation and metabolic switch in tumor-draining lymph nodes

Abstract

Lymph-node metastasis is a prognosis factor for poor clinical outcome of breast cancer patients. Currently, how breast cancer cells establish pre-metastatic niche in the tumor-draining lymph nodes (TDLNs) is still unclear. To address this question, we isolated heterogeneous cells including immune and stromal cells from naive lymph nodes (LNs) of the FVB/NJ mice and TDLNs of the MMTV-PyMT mice. Single-cell RNA sequencing was performed to investigate the transcriptome of the cells and various bioinformatics analyses were used to identify the altered pathways. Our results revealed several significant changes between naïve LNs and TDLNs. First, according to immunologic signature and pathway analysis, CD4+ and CD8 + T cells showed upregulated angiogenesis pathway genes and higher regulatory T (Treg)-associated genes while they demonstrated downregulation of interferon response and inflammatory response gene signatures, concurrently suggesting an immunosuppressive microenvironment in the TDLNs. Second, profiling of B cells showed down-regulation of marginal zone B lymphocytes in the TDLNs, which was validated by flow cytometric analysis. Third, we found the enhancement of oxidative phosphorylation pathway in the fibroblastic reticular cells (FRCs) of the MMTV-PyMT mice and the elevation of related genes including Prdx3, Ndufa4 and Uqcrb, suggesting massive ATP consumption and TCA cycle metabolism in the FRCs. Collectively, our results reveal the reprogramming of TDLNs during breast cancer progression at single-cell level in a spontaneous breast cancer model and suggest the changes in immune modulation and metabolic switch are key alterations in the preparation of pre-metastatic niche by breast cancer cells.

Integrated single-cell transcriptome analysis of the tumor ecosystems underlying cervical cancer metastasis

“…Lee et al reported that LN metastasis requires tumor cells to undergo a metabolic shift to fatty acid oxidation (FAO), mediated by a selectively activated transcriptional co-activator Yes-associated protein (YAP) (33). The conclusion was also confirmed by Li et al, who reported immune regulation and metabolic switch in tumor-draining lymph nodes (34). Another key finding was the recognition of EMT programs in metastatic tumor cells.…”

Reprogramming of sentinel lymph node microenvironment during tumor metastasis

“…Recently, we performed single-cell RNA sequencing to explore alterations in gene expressions in different cell populations in the SLN and identified the molecular pathways altered in T cells in the SLN [ 66 ]. Our results showed that angiogenesis-related gene sets were significantly upregulated in Cd4 + , and Cd8 + T-cells and Tregs.…”

The Multifaceted Effects of Breast Cancer on Tumor-Draining Lymph Nodes

“…FRCs were significantly expanded in 4T1 murine BC TDLNs. 52 Through single-cell RNA sequencing, Li et al 53 revealed that the FRCs in mouse mammary tumor viruspolyoma middle tumor-antigen murine BC TDLNs were more metabolically active relative to normal LNs. This metabolic activity may contribute to the development of the premetastatic niche in TDLNs through lymph node remodeling caused by increased lymph flow.…”