Project description:Molecular drivers underlying bone metastases in human cancer are not well understood, in part due to constraints in bone tissue sampling. Here, we undertook RNA sequencing of circulating tumor cells (CTCs) obtained from blood samples of women with metastatic estrogen receptor (ER)+ breast cancer, comparing cases with progression in bone versus visceral organs. Among the activated cellular pathways in CTCs from bone-predominant breast cancer is Androgen Receptor (AR) signaling. AR gene expression is evident, as is its constitutively active splicing variant AR-v7. AR expression within CTCs is correlated with the duration of treatment with aromatase inhibitors, suggesting that it may contribute to acquired resistance to anti-estrogen therapy. In an established breast cancer xenograft model, a bone-tropic derivative displays increased AR expression, whose genetic or pharmacologic suppression reduces metastases to bone but not to lungs. Together, these observations identify AR signaling in CTCs from women with bone-predominant ER+ breast cancer, and provide a rationale for testing androgen inhibitors in this subset of patients.
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: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: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: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.
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:For single cell RNA sequencing analysis, whole cell population isolated from two breast cancer bone metastases and associated organoid models were analyzed by 10X genomic single cell RNA platform. Raw BCL files from Novaseq6000 was converted to FASTQ files with cellranger (Version: 3.1.0) mkfastq function. Cellranger count function was then applied for read alignment, barcode and UMI counting using GRCh38 as reference. scCB2 and DoubletFinder were used to predict and remove empty droplets and doublets of single cell data. Cells with number of features less 300 and more than 9000 were further filtered out based on the distribution of number of features. For bulk RNA sequencing, RNA were extracted from FFPE preserved primary tumor and bone metastasis. Library was prepared with TruSeq Stranded mRNA for FFPE kit, and sequenced by NextSeq 500 with high output 150 cycle kit.