Project description:The lungs are a frequent target of metastatic breast cancer cells, but the underlying molecular mechanisms are unclear. All existing data were obtained either using statistical association between gene expression measurements found in primary tumors and clinical outcome, or using experimentally derived signatures from mouse tumor models. Here, we describe a distinct approach that consists to utilize tissue surgically resected from lung metastatic lesions and compare their gene expression profiles with those from non-pulmonary sites, all coming from breast cancer patients. We demonstrate that the gene expression profiles of organ-specific metastatic lesions can be used to predict lung metastasis in breast cancer. We identified a set of 21 lung metastasis-associated genes. Using a cohort of 72 lymph node-negative breast cancer patients, we developed a six-gene prognostic classifier that discriminated breast primary cancers with a significantly higher risk of lung metastasis. We then validated the predictive ability of the six-gene signature in 3 independent cohorts of breast cancers consisting of a total of 721 patients. Finally, we demonstrated that the signature improves risk stratification independently of known standard clinical parameters and a previously established lung metastasis signature based on an experimental breast cancer metastasis model. Keywords: Disease state analysis
Project description:The lungs are a frequent target of metastatic breast cancer cells, but the underlying molecular mechanisms are unclear. All existing data were obtained either using statistical association between gene expression measurements found in primary tumors and clinical outcome, or using experimentally derived signatures from mouse tumor models. Here, we describe a distinct approach that consists to utilize tissue surgically resected from lung metastatic lesions and compare their gene expression profiles with those from non-pulmonary sites, all coming from breast cancer patients. We demonstrate that the gene expression profiles of organ-specific metastatic lesions can be used to predict lung metastasis in breast cancer. We identified a set of 21 lung metastasis-associated genes. Using a cohort of 72 lymph node-negative breast cancer patients, we developed a six-gene prognostic classifier that discriminated breast primary cancers with a significantly higher risk of lung metastasis. We then validated the predictive ability of the six-gene signature in 3 independent cohorts of breast cancers consisting of a total of 721 patients. Finally, we demonstrated that the signature improves risk stratification independently of known standard clinical parameters and a previously established lung metastasis signature based on an experimental breast cancer metastasis model. Experiment Overall Design: We used microarrays to identify lung metastasis-related genes in a series of 23 patients with breast cancer metastases. No replicate, no reference sample.
Project description:Mental stress is widely recognized as a significant risk factor for breast cancer, exerting detrimental effects on both progression and prognosis. Its specific role in regulating breast cancer metastasis remains explorable. Herein, we prepared chronic stress models with MMTV-PyMT-derived spontaneous mammary tumor mice and GFP-4T1-transplanted metastatic breast cancer mice, followed by examinations of lung metastasis and single-cell sequencing analysis of the pre-metastatic lung microenvironment. Upon chronic stress stimulation, we observed a notable increase in tumor growth and lung metastasis, which was accompanied by the induction of a novel subtype of neutrophils, designated as cancer-stress primed neutrophils (Neu_CSP), characterized by the overexpression of Ccl3, Ccl4, Cxcl2, Il1r2, and C/ebpβ. Pseudotime trajectory analysis demonstrated that chronic stress caused a shift of neutrophils from the cancer primed neutrophils (Neu_CP) subtype to the Neu_CSP subtype in the lung. The glucocorticoid receptor NR3C1 mediated the stress hormone corticosterone (CORT)-induced expression of C/ebpβ in neutrophils, which thereafter promoted the expression of Ccl3 and Ccl4 at the transcriptional level. The differentiation of neutrophils into the Neu_CSP subtype promoted the lung metastasis of Ccr1+ breast cancer cells via chemotactic interactions between Ccl3/Ccl4 in neutrophils and Ccr1 in cancer cells. We used anti-Ly6G antibody to deplete neutrophils, or applied an optimized CRISPR/Cas9 approach for conditional knockout of Ccl3/Ccl4 in neutrophils, or used BX471 to inhibit CCR1 in breast cancer cells, all significantly reduced lung metastases in breast cancer both in vitro and in vivo. This study not only demonstrates a novel stress-neutrophil-cancer axis promoting lung metastasis in breast cancer, but also provides potential strategies for preventing or reducing lung metastasis by targeting the Neu_CSP subtype of neutrophils or CCR1(+) breast cancer cells.
Project description:IL13Rα2 overexpression promotes metastasis of basal-like breast cancers IL13Rα2 depletion in highly metastatic breast cancer cells suppresses lung metastases formation by upregulating TP63 and decreasing their migratory potential
Project description:The skeleton is the most common metastasis site of breast cancer cells and the molecular underpinning of this process is incompletely understood. The tumor suppressor gene deleted in liver cancer-1 (DLC1) encodes a multi-domain protein including a RhoGTPase activating protein (RhoGAP) domain and has been reported to suppress the lung colonization of breast cancer cells. However, the role of DLC1 in breast cancer bone metastasis and the importance of RhoGAP-dependent and -independent pathways in this process remain unclear. Here, we showed that DLC1 silencing is linked to enhanced bone-tropism of breast cancer cell lines and poor prognosis of clinical samples. In the study presented here, DLC1 was overexpressed in the SCP2 breast cancer cells, and the control SCP2 and overexpression cells were treated with TGFbeta. Microarray profiling of mRNA levels was performed in the control and overexpression cells with or without TGFbeta treatment.
Project description:Breast cancer metastases develop in the bone more frequently than any other site, and are a common cause of morbidity in the form of bone pain, pathological fractures, nerve compression, and life-threatening hypercalcemia. Despite ongoing research efforts, the molecular and cellular mechanisms that regulate breast cancer cell homing to and colonization of the bone as well as resultant pathological bone alteration remain poorly understood. To identify key mediators promoting breast cancer metastasis to bone, we utilized an immunocompetent, syngeneic murine model of breast cancer metastasis employing the mammary tumor cell line NT2.5. Following intracardiac injection of NT2.5 cells in neu-N mice, metastases developed in the bone, liver, and lung, closely mimicking the anatomical distribution of metastases in breast cancer patients. Using an in vivo selection process, we established NT2.5 sub-lines demonstrating an enhanced ability to colonize the bone and liver. Genome-wide cDNA microarray analysis comparing gene expression between parental NT2.5 cells and established sub-lines was performed. Individual samples of RNA from parental NT2.5 cells, early passage (BO3 and LI1) sub-lines, and final passage (BO6 and LI3) sub-lines were compared using GeneChip® Mouse Genome 430 2.0 Arrays