Project description:Dissemination of cancer stem cells (CSCs) serves as the basis of metastasis. Recently, we demonstrated that circulating prostate cancer (PCa) targets the hematopoietic stem cell (HSCs) ‘niche’ in marrow during dissemination. Once in the niche, disseminated tumor cells (DTCs) may remain dormant for extended periods. As the major function of the HSC niche is to maintain stem cell functions, we hypothesized that the niche regulates CSC activities of DTCs. We show that DTCs recovered from marrow were significantly enriched for a CSC phenotype. Critically, the conversion of DTCs to CSCs is regulated by niche. The data demonstrate that the niche plays a significant role in maintaining tumor-initiating PCa in marrow and suggests a functional relationship between CSCs and dormancy. Understanding how the marrow niche regulates the conversion of DTCs to CSCs is critical for the development of therapeutics specifically targeting skeletal bone metastasis and dormancy. We used microarrays to determine the global changes in gene expression underlying the significant roles of the marrow niche in activating cancer stem-like cell programs of prostate caner.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Bone is the most frequent site of metastasis in prostate cancer (PCa) and patients with bone metastases are deemed incurable. Targeting prostate cancer cells that disseminated to the bone marrow (BM) prior to surgery and before metastatic outgrowth may therefore prevent lethal metastasis. This prompted us to directly analyse the transcriptome of disseminated cancer cells (DCC) isolated from non-metastatic (UICC stage M0) prostate cancer patients. We screened 105 BM samples of M0-stage prostate cancer patients and 18 BM samples of patients without malignancy for the presence of EpCAM+ single cells. In total we isolated 270 cells from both groups by micromanipulation and globally amplified their mRNA. We used targeted transcriptional profiling to unambiguously identify DCCs for subsequent in-depth analysis. Transcriptomes of all cells were examined for the expression of EPCAM, KRT8, KRT18, KRT19, KRT14, KRT6a, KRT5, KLK3 (PSA), MAGEA2, MAGEA4, PTPRC (CD45), CD33, CD34, CD19, GYPC, SCL4A1 (band 3), and HBA2. Using these transcripts we found it impossible to reliably identify true DCCs. We then applied combined genome and transcriptome analysis of single cells and found that EpCAM+ cells from controls expressed transcripts thought to be epithelial-specific, while true DCCs may express haematopoietic transcripts. These results point to an unexpected plasticity of epithelial cancer cells in bone marrow and question common transcriptional criteria to identify DCCs. Array-CGH was used to analyze EpCAM-positive single cells isolated from bone marrow of M0-stage prostate cancer patients, and individuals without cancer. The purpose was to demonstrate that cells with genomic aberrations are true tumour cells.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:Prostate cancer (PCa) disseminated tumor cells (DTC) in the bone marrow (BM) can remain dormant for prolonged periods before recurrence. Our aim was to characterize individual prostate DTC, analyze tumor cell heterogeneity, and identify markers of tumor dormancy.
Project description:Disseminated epithelial cells can be isolated from the bone marrow of a far greater frac-tion of prostate-cancer patients than the fraction of patients who progress to metastatic disease. To provide a better understanding of these cells, we have characterized their genomic altera-tions. We first present an array comparative genomic hybridization method capable of detecting genomic changes in the small number of disseminated cells (10-20) that can typically be ob-tained from bone-marrow aspirates of prostate-cancer patients. We show multiple regions of copy-number change, including alterations common in prostate cancer, such as 8p loss, 8q gain, and gain encompassing the androgen-receptor gene on Xq, in the disseminated cell pools from 11 metastatic patients. We found fewer and less striking genomic alterations in the 48 pools of disseminated cells from patients with organ-confined disease. However, we identify changes shared by these samples with their corresponding primary tumors and prostate-cancer altera-tions reported in the literature, evidence that these cells, like those in advanced disease, are disseminated tumor cells (DTCs). We also demonstrate that DTCs from patients with advanced and localized disease share several abnormalities, including losses containing cell-adhesion genes and alterations reported to associate with progressive disease. These shared alterations might confer the capability to disseminate or establish secondary disease. Overall, the spectrum of genomic deviations is evidence for metastatic capacity in advanced-disease DTCs and varia-tion in that capacity in DTCs from localized disease. Our analysis lays the foundation for eluci-dation of the relationship between DTC genomic alterations and progressive prostate cancer. Keywords: array comparative genomic hybridization, prostate cancer, disseminated cells
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs. One-condition experment, gene expression of 3A6
Project description:Prostate cancer (PCa) disseminated tumor cells (DTC) in the bone marrow (BM) can remain dormant for prolonged periods before recurrence. Our aim was to characterize individual prostate DTC, analyze tumor cell heterogeneity, and identify markers of tumor dormancy. Custom Agilent 44K whole human genome expression oligonucleotide microarrays were used to profile single disseminated tumor cells isolated from bone marrow (BM) samples of four patients with no evidence of disease (NED) upon follow-up and six advanced disease (ADV) prostate cancer patients. Essentially, a two-step selection process was employed, in which anti-CD45 and anti-CD61 conjugated to immunomagnetic beads were used for negative selection, and anti-HEA was used for positive selection. Cells were then fluorescently stained for BerEP4, counter stained with RPE anti-CD45, and individually selected (10 single cells each per patient) under fluorescent light using a micropipette system for further analysis. RNA was amplified using the WT-Oviation one-direct system and hybridized against a common reference pool of prostate tumor cell lines.