Unbiased genomic analysis of multiple stages of lung cancer development
ABSTRACT: To uncover the gene expression alterations that occur during lung cancer progression, we interrogated the gene expression state of neoplastic cells at different stages of malignant progression. We initiated tumors in KrasLSL-G12D/+;p53flox/flox;R26LSL-tdTomato (KPT) mice with a pool of barcoded lentiviral-Cre vectors and purified Tomatopositive cancer cells away from the diverse and variable stromal cell populations. Five to nine months after tumor initiation, cancer cells were isolated from individual primary tumors and metastases using fluorescence-activated cell sorting. Sequencing of the barcode region of the integrated lentiviral vectors established primary tumor-metastasis and metastasis-metastasis relationships. Tumor barcoding allowed us to unequivocally distinguish non-metastatic primary tumors (TnonMet) from those primary tumors that had seeded metastases (TMet). We profiled 10 TnonMet samples as well as TMet and metastasis (Met) samples representing 12 metastatic events. To examine additional earlier stages of lung cancer development, we also analyzed premalignant cells from hyperplasias that develop in KPT mice shortly after tumor initiation (KPT-Early; KPT-E), as well as tumors from KrasG12D;R26LSL-tdTomato (KT) mice which rarely gain metastatic ability Overall design: This study includes 52 samples: 3 KP late samples, 3KPT early samples,10 non-metastatic primary tumors, 9 metastatic primary tumors, and 27 metastasis in different organs. total RNA was isolated and prepared for sequencing using the Ovation® RNA-Seq system and Illumina TruSeq DNA kit (v2) to generate 100bp paired end reads. Reads were aligned to mm10.
Project description:Metastasis formation is the major cause for cancer-related deaths and the underlying mechanisms remain poorly understood. In this study we describe spontaneous metastasis xenograft mouse models of human neuroblastoma used for unbiased identification of metastasis-related proteins by applying an infrared laser (IR) for sampling primary tumor and metastatic tissues, followed by mass spectrometric proteome analysis. IR aerosol samples were obtained from ovarian and liver metastases, which were indicated by bioluminescence imaging (BLI), and matched subcutaneous primary tumors. Corresponding histology proved the human origin of metastatic lesions. Ovarian metastases were commonly larger than liver metastases indicating differential outgrowth capacities. Among ~1,700 proteins identified at each of the three sites, 89 proteins were differentially regulated in ovarian metastases while 290 proteins were regulated in liver metastases. There was an overlap of 26 and 10 proteins up- and down-regulated at both metastatic sites, respectively, most of which were so far not related to metastasis such as LYPLA2, ACTL8, EIF4B, LGALS7, GFAP, and ELAVL4. Moreover, we established in vitro sublines from primary tumor and metastases and demonstrate differences in cellular protrusions, migratory/invasive potential and glycosylation. Summarized, this work identified several novel putative drivers of metastasis formation that are tempting candidates for future functional studies.
Project description:How organ-specific metastatic traits accumulate in primary tumors remains unknown. We identified a role of the primary tumor stroma in selecting breast cancer cells that are primed for metastasis in the bone. A fibroblast-rich stroma in breast tumors creates a microenvironment that is similar to that of bone metastases in its abundance of the cytokines CXCL12 and IGF1. Heterogeneous breast cancer cell populations growing in such mesenchymal environment evolve towards a preponderance of clones that thrive on CXCL12 and IGF1. Fibroblast-driven selection of bone metastatic clones in mammary tumors is suppressed by CXCL12 and IGF1 receptor inhibition. Thus, a fibroblast-rich stroma in breast tumors can pre-select bone metastatic seeds, promoting the evolution of metastatic traits and the interplay between a primary tumor and its distant metastases. Affymetrix U133 Plus2 arrays were hybridized according to the manufacturer's procedure using RNA extracted from 47 primary breast tumors. Specific gene sets were evaluated in this cohort.
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:We established an in vivo model of organ-specific colorectal cancer metastasis and demonstrated that the CD110+ tumor initiating cells contribute for colorectal liver metastasis. To gain a deeper understanding of its metastatic capacity, we performed a genome-wide transcriptome analysis on the CD110+ tumor cells derived from primary colon xenografts and their matched liver metastases. Results provide important information of the responses of the CD110+ cells during the process of liver colonization. Total RNA obtained from the CD110+ cells sorted from primary colorectal tumors (CRC102-PT and CRC108-PT) compared to those from the corresponding liver metastases (CRC102-LM and CRC108-LM).
Project description:HGSOC, the most aggressive form of OC, is characterized by insidious onset, rapid intraperitoneal spread and development of massive ascites. Peritoneal adhesion was considered as the first step of abdominal metastasis, underscoring that only tumor cells gain access to peritoneal adherence contribute to metastasis. Studies on ovarian cancer progression were mainly focused on the primary and metastatic tumor cells, while understanding of the ascitic tumor cells is limited. We hypothesized that uncovering the gene expression profiles of ascitic tumor cells from high grade serous ovarian cancer patients will allow us to understand more specifically their unique phenotype which mediates the peritoneal adhesion. In this study, gene expression profiling was completed for 15 magnetic sorted tumor cells samples from matched primary tumors, ascites and metastases of 5 high grade serous ovarian cancer patients. By comparing the expression data from ascitic tumor cells with primary and metastasis tumor cells, we identified a set of differential expressed genes in ovarian ascitic tumor cells advantageous for peritoneal adhesion and metastasis. Further study revealed that ascites microenvironment modulated the ascitic tumor cells phenotype and contributed to ovarian cancer dissemination through facilitating CAFs in formation of compact spheroids with ascitic tumor cells. We used microarrays to profile the expression of 15 matched tumor cells samples in order to identify molecular alteration between primary tumor cells, ascitic tumor cells and metastatic tumor cells in high grade serous ovarian cancer. Overall design: Transcriptome profiling analyses were performed on 15 magnetical sorted epithelial tumor samples from matched primary tumors, ascites and metastases in high grade serous ovarian cancer patients, using the Affymetrix human genome U133 Plus 2.0 microarray.
Project description:Background & Aims: The metastatic process is complex and remains a major obstacle in the management of colorectal cancer (CRC). To gain a better insight into the biologic events driving the metastatic process we investigated genomic aberrations in a large cohort of matched CRC primaries and distant metastases from various sites. Methods: In total, 62 primary colorectal cancers, 62 matched normal specimens, and 68 matched metastases (from liver, lung, ovary, omentum, and distant lymph nodes) were analyzed by high resolution array comparative genomic hybridization (array CGH) for DNA copy number changes. Findings were validated using a publicly available dataset consisting of 21 primary tumors and matched liver metastases. Fluorescence in situ hybridization (FISH) was used to confirm some of the DNA copy number changes observed. Results: Overall patterns of DNA copy number aberrations were highly similar between primary tumors and their metastases, confirming clonality. Additional copy number aberrations in metastasis are rare and rather than recurrent they were sporadic for individual patients. The only recurrent differences between primary tumors and their metastases were two chromosomal regions, 6q21 and 8q24.21 encompassing the MYC oncogene, that coamplified in three metastases of two patients (3.2%). FISH analysis confirmed the high level co-amplification in the metastasis, which were not detected in their primary tumors. Conclusions: Primary CRC and their metastases show highly similar patterns of DNA copy number changes, additional copy number aberrations in metastasis are rare and recurrences exceptional. These observations are consistent with the hypothesis that the metastatic potential is predestined early in the development of the primary tumor. In total, 62 primary colorectal cancers, 62 matched normal specimens, and 68 matched metastases (liver, lung, ovarian, omentum and distant lymph nodes) were analyzed by high resolution array comparative genomic hybridization (array CGH).
Project description:Background: Metastases result in 90% of all cancer deaths. Prostate cancer primary tumors evolve to become metastatic through selective alterations, such as amplification and deletion of genomic DNA. Methods: Genomic DNA copy number alterations were used to develop a gene signature that measured the metastatic potential of a prostate cancer primary tumor. We studied the genomic landscape of these alterations in 294 primary tumors and 49 metastases from 5 independent cohorts. Receiver-operating characteristic cross-validation and Kaplan-Meier survival analysis were performed to assess the accuracy of our predictive model. The signature was measured in a panel of 337 cancer cell lines from 29 different tissue origins. Results: We identified 399 copy number alterations around genes that were over-represented in metastases and predictive of whether a primary tumor will metastasize. Cross-validation analysis resulted in a predictive accuracy of 80.5% and log rank analysis of the metastatic potential score was significantly related to the endpoint of metastasis-free survival (p=0.014). The metastatic signature was observed in cell lines originating from lung, breast, colon, thyroid, rectum, pancreas and melanoma. The signature was comprised in part of genes of known or putative metastatic role — 8 solute carrier genes, 6 Cadherin family genes and 5 potassium channel genes — that function in metabolism, cell-to-cell adhesion and escape from anoikis/apoptosis. Conclusions: Somatic Copy number alterations are an independent predictor of metastatic potential. The data indicate a prognostic utility for using primary tumor genomics to assist in clinical decision making and developing therapeutics for prostate and likely other cancers. Overall design: genomic DNA from 29 prostate cancer tumors with matched normals run on Affymetrix 6.0 SNP arrays.
Project description:Variable tumor cellularity can limit sensitivity and precision in comparative genomics, because differences in tumor content can result in misclassifying truncal mutations as region-specific private mutations in stroma-rich regions, especially when studying tissue specimens of mediocre tumor cellularity such as LUADs. To address this issue, we refined a nuclei flow-sorting approach by sorting nuclei based on ploidy and the LUAD lineage marker thyroid transcription factor 1 (TTF-1) and applied this method to investigate genome-wide somatic copy number aberrations (SCNA) and mutations of 409 cancer genes in 39 tumor populations obtained from 16 primary tumors and 21 matched metastases. This approach increased the mean tumor purity from 54% (range: 7-89%) of unsorted material to 92% (range: 79-99%) after sorting. Despite this rise in tumor purity, we detected limited genetic heterogeneity between primary tumors and their metastases. In fact, 88% of SCNAs and 80% of mutations were propagated from primary tumors to metastases and low allele frequency mutations accounted for much of the mutational heterogeneity. Even though the presence of SCNAs indicated a history of chromosomal instability (CIN) in all tumors, metastases did not have more SCNAs than primary tumors. Moreover, tumors with biallelic TP53 or ATM mutations had high numbers of SCNAs, yet they were associated with a low interlesional genetic heterogeneity. The results of our study thus provide evidence that most macroevolutionary events occur in primary tumors before metastatic dissemination and advocate for a limited degree of CIN over time and space in this cohort of LUADs. Sampling of primary tumors thus may suffice to detect most mutations and SCNAs. In addition, metastases but not primary tumors had seeded additional metastases in three of four patients; this provides a genomic rational for surgical treatment of such oligometastatic LUADs. Overall design: In total, there are 39 copy number Agilent 180k SurePrint arrays, representing 16 patients with 37 LUAD tumor samples, including 35 fresh frozen tissues and 2 FFPE tissues. There are 11 patients with primary tumor and one matched metastasis (22 arrays, one for each sample), 3 patients with primary tumor and two matched metastasis (9 arrays, one for each sample), one patient with primary tumor and three matched metastasis (4 arrays, one for each sample) and one patient with multiple populations in the primary tumor and one metastasis (4 arrays, 3 for each population in the primary tumor and 1 for the metastasis).
Project description:Background: Metastases result in 90% of all cancer deaths. Prostate cancer primary tumors evolve to become metastatic through selective alterations, such as amplification and deletion of genomic DNA. Methods: Genomic DNA copy number alterations were used to develop a gene signature that measured the metastatic potential of a prostate cancer primary tumor. We studied the genomic landscape of these alterations in 294 primary tumors and 49 metastases from 5 independent cohorts. Receiver-operating characteristic cross-validation and Kaplan-Meier survival analysis were performed to assess the accuracy of our predictive model. The signature was measured in a panel of 337 cancer cell lines from 29 different tissue origins. Results: We identified 399 copy number alterations around genes that were over-represented in metastases and predictive of whether a primary tumor will metastasize. Cross-validation analysis resulted in a predictive accuracy of 80.5% and log rank analysis of the metastatic potential score was significantly related to the endpoint of metastasis-free survival (p=0.014). The metastatic signature was observed in cell lines originating from lung, breast, colon, thyroid, rectum, pancreas and melanoma. The signature was comprised in part of genes of known or putative metastatic role — 8 solute carrier genes, 6 Cadherin family genes and 5 potassium channel genes — that function in metabolism, cell-to-cell adhesion and escape from anoikis/apoptosis. Conclusions: Somatic Copy number alterations are an independent predictor of metastatic potential. The data indicate a prognostic utility for using primary tumor genomics to assist in clinical decision making and developing therapeutics for prostate and likely other cancers. genomic DNA from 29 prostate cancer tumors with matched normals run on Affymetrix 6.0 SNP arrays.
Project description:Despite major advances in understanding the molecular and genetic basis of cancer, metastasis remains the cause of >90% of cancer-related mortality1. Understanding metastasis initiation and progression is critical to develop new therapeutic strategies to treat and prevent metastatic disease. Prevailing theories hypothesize that metastases are seeded by rare tumor cells with unique properties, which may function like stem cells in their ability to initiate and propagate metastatic tumors.2 3-5 However, the identity of metastasis-initiating cells in human breast cancer remains elusive, and whether metastases are hierarchically organized is unknown.2 Here we show at the single-cell level that early stage metastatic cells possess a distinct stem-like gene expression signature. To identify and isolate metastatic cells from patient-derived xenograft (PDX) models of human breast cancer, we developed a highly sensitive FACS-based assay, which allowed us to enumerate metastatic cells in mouse peripheral tissues. We compared gene signatures in metastatic cells from tissues with low vs. high metastatic burden. Metastatic cells from low-burden tissues were distinct due to their increased expression of stem cell, EMT, pro-survival, and dormancy-associated genes. In contrast, metastatic cells from high-burden tissues were similar to primary tumor cells, which were more heterogeneous and expressed higher levels of luminal differentiation genes. Transplantation of stem-like metastatic cells from low-burden tissues showed that they have significant tumor-initiating capacity, and differentiate to produce luminal-like cancer cells. Progression to high metastatic burden was associated with increased proliferation and cMYC expression, which could be attenuated by treatment with cyclin dependent kinase (CDK) inhibitors. These findings support a hierarchical model for metastasis, where metastases are initiated by stem-like cells that proliferate and differentiate to produce advanced metastatic disease. Overall design: 1022 sampels