Project description:Disseminated tumor cells (DTCs) in the bone marrow can be detected in patients with solid tumors early on in disease progression. Via interaction with mesenchymal stromal cells (MSCs) these tumor cells may interfere with hematopoiesis. Using appropriate co-culture models, we investigated whether DTCs can change the bone marrow microenvironment by modulating MSC function with a special emphasis on their chemoattractive activity towards hematopoietic stem and progenitor cells (HSPCs). Human bone marrow derived MSCs as well as an immortalised MSC line (SCP-1) were co-cultured with MCF-7, MDA-MB231 breast carcinoma or MCF-10A non-malignant breast epithelial cells or their conditioned medium. Gene expression analysis of SCP-1 cells cultured with MCF-7 conditioned medium revealed SDF-1/CXCL12 as one of the significantly downregulated genes. Both tumor cell lines caused an inhibited SDF-1 promoter activity in SCP-1 cells, whereby MCF-7 medium decreased it to 77% and MDA-MB231 to 47%. Moreover, the SDF-1 mRNA and protein levels were significantly reduced. As a functional consequence of lower SDF-1 levels, we detected a decreased trans-well migration potential of CD34+ HSPC to MSC/tumor cell co-cultures or conditioned medium. The specificity of this chemokine mediated effect was confirmed by blocking studies with the CXCR4 antagonist AMD3100. Downregulation of SP1 transcription factor and increased miR23a levels in MSCs after contact with tumor cell medium as well as an enhanced TGFb1 expression were identified as potential molecular regulators of SDF-1 activity in MSCs. We propose an additional mechanism by which tumor cells affect the niche environment of HSPCs and therefore negatively impact hematopoiesis. Gene expression of human immortalized mesenchymal stromal cells (SCP-1) was investigated after incubation with conditioned medium of the breast carcinoma cell line MCF-7 for 24, 48, and 72 hours. Three independent experiments were performed at each time.
Project description:Human mesenchymal stem cell (MSC)-conditioned medium (CM) was previously reported to affect the biology of tumor cells; however, the precise mechanisms remain unclear. Here, we show that MSCs secreted 40- to 100-nm particles, which have the typical characteristics of exosomes, and these MSC-derived exosomes promoted migration of the breast cancer cell line MCF7. To further investigate the effect of MSC-exosomes on MCF7, we analyzed the gene expression profiles of MCF7 treated with or without MSC-exosomes for 24 h.
Project description:Human mesenchymal stem cell (MSC)-conditioned medium (CM) was previously reported to affect the biology of tumor cells; however, the precise mechanisms remain unclear. Here, we show that MSCs secreted 40- to 100-nm particles, which have the typical characteristics of exosomes, and these MSC-derived exosomes promoted migration of the breast cancer cell line MCF7. To further investigate the effect of MSC-exosomes on MCF7, we analyzed the gene expression profiles of MCF7 treated with or without MSC-exosomes for 24 h. Investigation of whole genome gene expression level changes in breast cancer cell line MCF7 which were treated with or without mesenchymal stem cell-derived exosomes. This study uses total RNA recovered from two samples. One sample is MCF7 treated with PBS for 24 hours and another one is MCF7 treated with mesenchymal stem cell-derived exosomes for 24hours. The ultimate concentration of mesenchymal stem cell-derived exosomes used in this experiment was 400ng/ul.
Project description:4T1 mammary cancer cells exihibit higher proliferation and metastatic ability when cultured in conditioned medium from mesenchymal stem cells . Also, co-implantation with MSCs, 4T1 tumors show higher tumor growth and metastasis. We used microarrays to detail the global programme of gene expression underlying the alteration of cell behaviour
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:Disseminated tumor cells (DTCs) in the bone marrow can be detected in patients with solid tumors early on in disease progression. Via interaction with mesenchymal stromal cells (MSCs) these tumor cells may interfere with hematopoiesis. Using appropriate co-culture models, we investigated whether DTCs can change the bone marrow microenvironment by modulating MSC function with a special emphasis on their chemoattractive activity towards hematopoietic stem and progenitor cells (HSPCs). Human bone marrow derived MSCs as well as an immortalised MSC line (SCP-1) were co-cultured with MCF-7, MDA-MB231 breast carcinoma or MCF-10A non-malignant breast epithelial cells or their conditioned medium. Gene expression analysis of SCP-1 cells cultured with MCF-7 conditioned medium revealed SDF-1/CXCL12 as one of the significantly downregulated genes. Both tumor cell lines caused an inhibited SDF-1 promoter activity in SCP-1 cells, whereby MCF-7 medium decreased it to 77% and MDA-MB231 to 47%. Moreover, the SDF-1 mRNA and protein levels were significantly reduced. As a functional consequence of lower SDF-1 levels, we detected a decreased trans-well migration potential of CD34+ HSPC to MSC/tumor cell co-cultures or conditioned medium. The specificity of this chemokine mediated effect was confirmed by blocking studies with the CXCR4 antagonist AMD3100. Downregulation of SP1 transcription factor and increased miR23a levels in MSCs after contact with tumor cell medium as well as an enhanced TGFb1 expression were identified as potential molecular regulators of SDF-1 activity in MSCs. We propose an additional mechanism by which tumor cells affect the niche environment of HSPCs and therefore negatively impact hematopoiesis.
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: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. Two-condition experiment, Normoxic MSCs vs. Hypoxic MSCs.
Project description:4T1 mammary cancer cells exihibit higher proliferation and metastatic ability when cultured in conditioned medium from mesenchymal stem cells . Also, co-implantation with MSCs, 4T1 tumors show higher tumor growth and metastasis. We used microarrays to detail the global programme of gene expression underlying the alteration of cell behaviour RNA was extrated from 4T1 cells cultured in MSC-CM or regular medium as well as 4T1 cells isolated from co-cultured with MSCs. Gene expression of these cell groups was acquired from Affymetrix microarray analysis using mouse 430 2.0 array chip.
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