Project description:We performed microarray analysis with two different chip platforms, Affymetrix and Agilent, on bone metastasis samples from breast cancer patients with only bone metastases and metastases in bone and visceral organs. We collected bone metastases biopsies from breast cancer patients with only bone metastases and metastases in bone and visceral organs. RNA was extracted from these samples and subjected to microarray analysis with the Agilent platform. Data were compared with a signsture obtained with the Affymetrix platform, to obtain a signature of differentially regulated genes between the two groups of patients This Series represents the Agilent data only. The Affymetrix data are provided in GEO Series GSE11078.
Project description:The molecular mechanisms underlying the development of bone metastases in breast cancer remain unclear. Disseminated tumour cells (DTCs) in the bone marrow of breast cancer patients are commonly identified, even in early stage disease, but their potential to initiate metastases is not known. The mechanism whereby DTCs become overt metastatic tumour cells (MTCs) is therefore, an area of considerable interest. This study explored the analysable yield of genetic material from human biopsy samples in order to describe differences in gene expression between DTCs and bone MTCs. Thirteen breast cancer patients with bone metastases underwent a CT-guided bone metastasis biopsy and a bone marrow biopsy. Tumour cells were enriched and gene expression profiling was conducted to identify differentially expressed genes. The analysable yield of sufficient RNA for microarray analysis was 60% from bone metastasis biopsies and 80% from bone marrow biopsies. A signature of 133 candidate genes differentially expressed between DTCs and MTCs was identified. Several genes relevant to breast cancer metastasis to bone (osteopontin, CTGF, parathyroid hormone receptor, EGFR) were significantly overexpressed in MTCs as compared to DTCs. Biopsies of bone metastases and bone marrow rarely yield enough tissue for robust molecular biology studies using clinical samples. The findings obtained however are interesting and seem to overlap with the bone metastasis gene expression signature described in murine xenograft models. Larger biopsy specimens or improved RNA extraction techniques may improve analysable yield and feasibility of these techniques. Gene expression profiling was utilized to compare DTCs obtained from bone marrow aspirates (A) to MTCs isolated from Computed Tomography (C) guided biopsies of bone metastases.
Project description:We performed microarray analysis with two different chip platforms, Affymetrix and Agilent, on bone metastasis samples from breast cancer patients with only bone metastases and metastases in bone and visceral organs.
Project description:The molecular mechanisms underlying the development of bone metastases in breast cancer remain unclear. Disseminated tumour cells (DTCs) in the bone marrow of breast cancer patients are commonly identified, even in early stage disease, but their potential to initiate metastases is not known. The mechanism whereby DTCs become overt metastatic tumour cells (MTCs) is therefore, an area of considerable interest. This study explored the analysable yield of genetic material from human biopsy samples in order to describe differences in gene expression between DTCs and bone MTCs. Thirteen breast cancer patients with bone metastases underwent a CT-guided bone metastasis biopsy and a bone marrow biopsy. Tumour cells were enriched and gene expression profiling was conducted to identify differentially expressed genes. The analysable yield of sufficient RNA for microarray analysis was 60% from bone metastasis biopsies and 80% from bone marrow biopsies. A signature of 133 candidate genes differentially expressed between DTCs and MTCs was identified. Several genes relevant to breast cancer metastasis to bone (osteopontin, CTGF, parathyroid hormone receptor, EGFR) were significantly overexpressed in MTCs as compared to DTCs. Biopsies of bone metastases and bone marrow rarely yield enough tissue for robust molecular biology studies using clinical samples. The findings obtained however are interesting and seem to overlap with the bone metastasis gene expression signature described in murine xenograft models. Larger biopsy specimens or improved RNA extraction techniques may improve analysable yield and feasibility of these techniques.
Project description:Targeted sequencing analyses was made on samples of PDX engrafted with breast cancer bone metastases, 2 PDX acquired resistance to palbociclib.
Project description:A significant proportion of patients with oestrogen receptor (ER) positive breast cancers (BC) develop resistance to endocrine treatments (ET) and relapse with metastatic disease. Bone is the most common metastatic site in ER+ patients, however bone metastases are technically challenging to biopsy and analyse. Difficulties concern both tumour tissue acquisition and techniques for analysis and RNA extractions. Patient-derived xenografts (PDX) of BC bone metastases have not been reported yet. For the first time we established PDX models from bone metastatic biopsies of patients progressing on ET and treated by vertebroplasty. PDX models were analysed at transcriptomic level and compared to patient’s early primary tumours to identify new therapeutic targets associated with endocrine resistance in the metastatic setting. Identification of activated signalling pathways in bone metastasis by comparative transcriptomic analyses of the bone metastasis derived PDX compared to the patients' primary breast tumor.
Project description:A significant proportion of patients with oestrogen receptor (ER) positive breast cancers (BC) develop resistance to endocrine treatments (ET) and relapse with metastatic disease. Bone is the most common metastatic site in ER+ patients, however bone metastases are technically challenging to biopsy and analyse. Difficulties concern both tumour tissue acquisition and techniques for analysis and RNA extractions. Patient-derived xenografts (PDX) of BC bone metastases have not been reported yet. For the first time we established PDX models from bone metastatic biopsies of patients progressing on ET and treated by vertebroplasty. PDX models were analysed at genomic level to identify new therapeutic targets associated with endocrine resistance in the metastatic setting. Identification of chromosomic alterations in bone metastasis derived PDX.
Project description:Bone is the primary site of breast cancer metastasis and complications associated with bone metastases can lead to a significantly decreased quality of life in these patients. Thus, it is essential to gain a better understanding of the molecular mechanisms that underlie the emergence and growth of breast cancer skeletal metastases. Methods: To search for novel molecular mediators that influence breast cancer bone metastasis, we generated gene expression profiles from laser capture micro-dissected trephine biopsies of both breast cancer bone metastases and primary breast tumors that metastasized to bone. Bioinformatics analysis identified genes that are differentially expressed in breast cancer bone metastases compared to primary mammary tumors. Results: ABCC5, an ATP-dependent transporter, was found to be overexpressed in breast cancer osseous metastases relative to primary mammary tumors. In addition, ABCC5 was significantly up-regulated in human and mouse breast cancer cell lines with high bone-metastatic potential. Stable knockdown of ABCC5 significant reduced bone metastatic burden and osteolytic bone destruction in mice. The decrease in osteolysis was further associated with diminished osteoclast numbers. Conclusions: Our data, for the first time, suggests that ABCC5 functions as a mediator of breast cancer skeletal metastasis. ABCC5 expression in breast cancer cells is important for the efficient bone resorption mediated by osteoclasts. Hence, ABCC5 may be a potential therapeutic target for breast cancer bone metastasis. primary breast tumors vs. bone trephine biopsies
Project description:Metastatic progression remains the major cause of death in human breast cancer. Cancer cells with cancer stem cell (CSC) properties drive initiation and growth of metastases at distant sites. We have previously established the breast cancer patient-derived tumor xenograft (PDX) mouse model in which CSC marker CD44+ cancer cells formed spontaneous microscopic metastases in the liver. In this PDX mouse, the expression levels of S100A10 and its family proteins were much higher in the CD44+ cancer cells metastasized to the liver than those at the primary site.