Project description:Several single-cell studies have reported transcriptomic, genomic and epigenomic dysregulation in breast cancer tissue. However, the peripheral immune landscape of breast cancer patients remains poorly understood. We report the analysis of the single-cell transcriptomes of more than 110,000 peripheral blood mononuclear cells (PBMCs) of healthy and metastatic breast cancer patients. Integrated analysis revealed depleted memory B cells (BMEM) and T cell subpopulations, including transitional CD8 T, CD4 naïve, CD4 ribosome and MAIT cells in the circulating immune landscape of metastatic breast cancer patients. Nevertheless, metastatic breast cancer patients showed marked enrichment of pro-inflammatory NKG7 high monocytes, M1 macrophages, migratory myeloid, T memory stem cells (TSCM), CD4 T effector memory (TEM) and CD4 T central memory (TCM) cells. Further, interrogation of single-cell transcriptomes based on metastatic disease state, i.e. stable vs progressive, revealed distinct compositional and transcriptional changes in PBMCs correlated with the metastatic burden. The antigen inexperienced CD4 naïve T cells and cytotoxic MAIT cells are further depleted in the progressive metastatic stage. Surprisingly, the pro-inflammatory classical monocytes and CD4 T effector memory (TEM) cells are also depleted in the progressive metastatic state, indicating their potential role in stable metastatic disease. Lastly, the receptor-ligand relationships, such as cell-cell contact, ECM-receptor interactions, and cytokine transcription profiles, were tightly associated with metastatic burden. Collectively, our study provides unique molecular insight into the peripheral immune system operating in metastatic breast cancers and identified novel surrogate biomarkers of metastatic disease.
Project description:Metastatic cancer cells, originating from cancer stem cells with metastatic capacity, utilize nutrient flexibility to overcome the hurdles of metastatic cascade. However, the nutrient supply for maintaining the stemness potentials of metastatic cancer cells remains unknown. Here, we revealed that metastatic breast cancer cells maintain stemness and initiate metastasis upon detachment via uptaking and oxidating lactate. In detached metastasizing breast cancer cells, lactate was incorporated into tricarboxylic acid cycle and boosted oxidative phosphorylation, and then promoted the stemness potentials via α-KG-DNMT3B-mediated SOX2 hypomethylation. Moreover, lactate was uptake and oxidated in mitochondria by CD147/MCT1/LDHB complex, whose existence correlates to the stemness potentials and tumor metastasis in breast cancer patients. An intracellularly expressed single chain variable fragment targeting mitochondrial CD147 (mito-CD147 scFv) effectively disrupted mitochondrial CD147/MCT1/LDHB complex, inhibited lactate-induced stemness potentials, depleted circulating breast cancer cells and reduced metastatic burden, suggesting a promising clinical application in reducing lactate-fueled metastasis.
Project description:Estrogen receptor (ER)-positive luminal breast cancer is a subtype with generally lower risk of metastasis to most distant organs. However, bone recurrence occurs preferentially in luminal cancer. The mechanisms of the subtype-specific organotropism remain elusive. Here we show that an ER-regulated secretory protein SCUBE2 contributes to bone tropism of luminal breast cancer. Single-cell RNA sequencing analysis reveals osteoblastic enrichment by SCUBE2 in early bone-metastatic niches. SCUBE2 facilitates release of tumor membrane-anchored SHH to activate Hedgehog signaling in mesenchymal stem cells, thus promoting osteoblast differentiation. Osteoblasts deposit collagens to suppress NK cells via the inhibitory LAIR1 signaling and promote tumor colonization. SCUBE2 expression and secretion are associated with osteoblast differentiation and bone metastasis in human tumors. Targeting Hedgehog by Sonidegib and targeting SCUBE2 with a neutralizing antibody both effectively suppress bone metastasis in multiple metastasis models. Overall, our findings provides an explanation for bone preference in luminal breast cancer and new approaches for metastasis treatment.
Project description:Breast cancer is a curable disease if it is diagnosed at an early stage. However, only little options are left once the tumor is metastasized to distant organs, and more than 90% of breast cancer death is attributed to metastatic disease. The process of metastasis is highly complex and involves many steps for successful colonization of tumor cells at a target organ. According to the cancer stem cell (CSC) theory, which still remains a hypothesis, these metastatic cells must have stem cell-like capability for their self-renewal in addition to their invasive ability. Therefore, it has been predicted that a “metastatic stem cell”, which is distinct from a cancer stem cell, must exist in the primary tumor mass. To identify genes that are involved in metastasis of CSCs, we isolated CSC populations from a well-established model cell line of breast cancer, MDA-MB231, and that of highly metastatic variants, 231BoM-1833 and 231BrM-2a, using CD24, CD44 and EpCAM (ESA), which have been identified as surface markers for CSCs in breast cancers. Overall yield of CSCs from these cells ranged from 2% to 4%. We then performed global expression profile analysis for these CSCs using the Affymetrix Human Gene 1.0ST array. CSC populations (CD24-/CD44+/ESA+) from MDA-MB231, 231BoM-1833 and 231BrM-2a were isolated by magnetic-activated cell sorting (MACS) using specific antibodies to these surface markers. The total RNA was isolated from the CSC populations using the RNeasy RNA isolation kit (Qiagen). The RNA was then converted to cDNA and they were hybridized to the Human Gene 1.0ST chip (Affymetrix). The data was normalized using the RMA algorithm of the Expression Console software (Affymetrix). A comparison of transcriptional profiles was then performed in CSCs of highly metastatic cell lines (231BoM-1833 and 231BrM-2a) compared to the CSCs of MDA-MB-231.
Project description:Analysis of MDA-MB-231 breast cancer cells depleted for High Mobility Group A1 (HMGA1) using siRNA. HMGA1 is involved in invasion and metastasis in breast cancer cells. Results identify the specific transcriptional program induced by HMGA1 in highly metastatic breast cancer cells.
Project description:Aggressive cancers and normal stem cells often share similar molecular and functional traits. It is unclear if aggressive phenotypes of prostate cancer molecularly resemble normal stem cells residing within the human prostate. We performed high-throughput RNA sequencing on uncultured, highly purified epithelial populations from human prostates obtained after radical prostatectomy. We found the basal population to be defined by genes associated with developmental programs, epigenetic remodeling, and invasiveness. We further generated a 91-gene basal signature and applied it to gene expression datasets from patients with organ-confined or castration-resistant, metastatic prostate cancer. Metastatic prostate cancer was more enriched for the basal stem cell signature than organ-confined prostate cancer. Moreover, histological subtypes within prostate cancer metastases varied in their enrichment of the stem cell signature with small cell neuroendocrine carcinoma being the most stem cell-like. Bioinformatic analysis of the basal cell and two human small cell gene signatures identified a set of E2F target genes common to all three signatures. These results suggest that the most aggressive variants of prostate cancer share a core transcriptional program with normal prostate basal stem cells. Transcriptional analysis of 10 uncultured prostatic basal and luminal populations from either the benign or malignant prostate tissue of 8 human prostate cancer patients by high-throughput RNA-seq