Project description:Hematopoietic stem/progenitor cells (HS/PCs) were transduced with lentiviral vectors overexpressing OFP and either miR-511-3p or a control, mutated miRNA sequence (miR-511-3p-mut). The transduced HS/PCs were then transplanted in recipient C57BL/6 mice. Tumors (Lewis lung carcinomas, LLC) were injected s.c. 4 weeks after HS/PC transplant. Lentiviral vector-transduced (OFP+), tumor-associated macrophages (TAMs) were isolated 4 weeks after LLC injection by fluorescence-activated cell sorting. Gene expression profiles of TAMs overexpressing either miR-511-3p or miR-511-3p-mut were obtained from 3 independent biological samples/each. Gene expression profiles of miRNA-overexpressing TAMs were then compared with the gene expression profiles of wild-type TAMs isolated from LLCs grown in nontransplanted C57BL/6 mice; the latter TAMs were subfractioned into MRC1+CD11c(low) or CD11c+MRC1(low) subsets before RNA isolation and analysis. Comparison of gene expression profiles of TAMs revealed that miR-511-3p overexpression tunes down the expression of multiple genes that are classically upregulated in protumoral MRC1+CD11c(low) TAMs. TAMs were isolated from Lewis lung carcinomas grown s.c. in C57BL/6 mice.
Project description:Hematopoietic stem/progenitor cells (HS/PCs) were transduced with lentiviral vectors overexpressing OFP and either miR-511-3p or a control, mutated miRNA sequence (miR-511-3p-mut). The transduced HS/PCs were then transplanted in recipient C57BL/6 mice. Tumors (Lewis lung carcinomas, LLC) were injected s.c. 4 weeks after HS/PC transplant. Lentiviral vector-transduced (OFP+), tumor-associated macrophages (TAMs) were isolated 4 weeks after LLC injection by fluorescence-activated cell sorting. Gene expression profiles of TAMs overexpressing either miR-511-3p or miR-511-3p-mut were obtained from 3 independent biological samples/each. Gene expression profiles of miRNA-overexpressing TAMs were then compared with the gene expression profiles of wild-type TAMs isolated from LLCs grown in nontransplanted C57BL/6 mice; the latter TAMs were subfractioned into MRC1+CD11c(low) or CD11c+MRC1(low) subsets before RNA isolation and analysis. Comparison of gene expression profiles of TAMs revealed that miR-511-3p overexpression tunes down the expression of multiple genes that are classically upregulated in protumoral MRC1+CD11c(low) TAMs.
Project description:Oxaliplatin (oxPt) resistance in colorectal cancers (CRC) is a major unsolved problem. Consequently, predictive markers and a better understanding of resistance mechanisms are urgently needed. To investigate if the recently identified predictive miR-625-3p is functionally involved in oxPt resistance, stable and inducible models of miR-625-3p dysregulation were analyzed. Ectopic expression of miR-625-3p in CRC cells led to increased resistance towards oxPt. The mitogen-activated protein kinase (MAPK) kinase 6 (MAP2K6/MKK6) – an activator of p38 MAPK - was identified as a functional target of miR-625-3p, and, in agreement, was down-regulated in patients not responding to oxPt therapy. The miR-625-3p resistance phenotype could be reversed by anti-miR-625-3p treatment and by ectopic expression of a miR-625-3p insensitive MAP2K6 variant. Transcriptome, proteome and phosphoproteome profiles revealed inactivation of MAP2K6-p38 signaling as a possible driving force behind oxPt resistance. We conclude that miR-625-3p induces oxPt resistance by abrogating MAP2K6-p38 regulated apoptosis and cell cycle control networks.
Project description:Chemotherapies have been shown to enhance anti-tumor immunity, but whether chemotherapies affect tumor-associated macrophages (TAMs) is still unclear. We found TAMs is different before and after chemotherapy by comparing proteomic profiles of TAMs before and after chemotherapy.
Project description:Chemotherapies have been shown to enhance anti-tumor immunity, but whether chemotherapies affect tumor-associated macrophages (TAMs) is still unclear. We found TAMs is different before and after chemotherapy by comparing proteomic profiles of TAMs before and after chemotherapy.
Project description:Oxaliplatin (oxPt) resistance in colorectal cancers (CRC) is a major unsolved problem. Consequently, predictive markers and a better understanding of resistance mechanisms are urgently needed. To investigate if the recently identified predictive miR-625-3p is functionally involved in oxPt resistance, stable and inducible models of miR-625-3p dysregulation were analyzed. Ectopic expression of miR-625-3p in CRC cells led to increased resistance towards oxPt. The mitogen-activated protein kinase (MAPK) kinase 6 (MAP2K6/MKK6) – an activator of p38 MAPK - was identified as a functional target of miR-625-3p, and, in agreement, was down-regulated in patients not responding to oxPt therapy. The miR-625-3p resistance phenotype could be reversed by anti-miR-625-3p treatment and by ectopic expression of a miR-625-3p insensitive MAP2K6 variant. Transcriptome, proteome and phosphoproteome profiles revealed inactivation of MAP2K6-p38 signaling as a possible driving force behind oxPt resistance. We conclude that miR-625-3p induces oxPt resistance by abrogating MAP2K6-p38 regulated apoptosis and cell cycle control networks. Experimental design for mass spectrometry SILAC experiments can be found at https://figshare.com/s/8e79f008e0e58ec6efc2 or https://doi.org/10.6084/m9.figshare.4888139
Project description:Tumor-associated macrophages (TAMs),the main part of immune cells in tumor microenvironment (TME),play a potent role in promoting tumorigenesis through mechanisms such as stimulating angiogenesis, enhancing tumor migration and suppressing antitumor immunity. MicroRNAs (miRNAs) are considered as crucial regulators in multiple biological processes. The relationship between miRNAs and macrophages function has been extensively reported, but the roles that miRNAs play in regulating TAMs phenotype remains unclear. In this study, we screened highly-expressed microRNAs in TAMs, and first identified that miR-100 represented a TAMs-high expression pattern and maintained TAMs phenotype by targeting mTOR signaling pathway. Moreover, miR-100 expression level in TAMs was positively related to IL-1ra secretion, a traditional immune-suppressive cytokine, which was determined to promote tumor cells stemness via stimulating Hedgehog pathway. Mechanism study suggested that mTOR/Stat5a pathway was involved in IL-1ra transcriptional regulation process mediated by miR-100. More importantly, tumor metastasis and invasion capacity were significantly decreased in a 4T1 mouse breast cancer model injected intratumorally with miR-100 antagomir, and combination therapy with cisplatin showed much better benefit. In this study, we confirmed that highly expressed miR-100 maintains the phenotype of TAMs and promotes tumor metastasis via enhancing IL-1ra secretion. Interfering miR-100 expression of TAMs in mouse breast cancer model could inhibit TAMs pro-tumor function and reduce tumor metastasis, which suggested that miR-100 could serve as a potential therapy target to remodel tumor microenvironment in breast cancer.
Project description:Active immunotherapy is a promising strategy for anti-angiogenic cancer therapy. Recently, we have reported that a vaccine using human umbilical vein endothelial cells (HUVECs) induced specific anti-endothelial immune responses in the most of immunized patients, and resulted in tumor regression in some patients with recurrent malignant brain tumors, whereas not in colorectal cancer patients. In this study, we hypothesized that non-hypoxic perivascular tumor associated macrophages (TAMs) in colorectal cancer, but not in glioblastoma, might negatively alter the therapeutic efficacy of anti-angiogenic active immunotherapy. To test this hypothesis, we examined global gene expression profiles of non-hypoxic macrophages stimulated in vitro by soluble factors released from tumor cells of human glioblastoma U-87MG (‘brain TAMs’) or colorectal adenocarcinoma HT-29 (‘colon TAMs’). Murine non-hypoxic TAMs were induced in vitro by incubation with soluble factors released from human cancer cell lines U-87MG ('brain TAMs') or HT-29 ('colon TAMs'), for RNA extraction and subsequent hybridization on Affymetrix microarrays. To evaluate homogeneous macrophage populations at different tumour developmental stages, RNA aliquots of control macrophages and TAMs obtained at five different time-points, i.e. 8h, 16h, 24h, 32h and 40h, were pooled and used for screening of differentially expressed genes. The experiments for TAMs as well as for control unstimulated macrophages were performed in triplicates.
Project description:Macrophages have been implicated in breast cancer progression and metastasis, but relatively little is known about the genes and pathways that are involved. Using a conditional allele of Ets2 in the mouse, we have identified Ets2 as a critical gene in tumor associated macrophages (TAMs) that specifically promotes mammary tumor metastasis. Loss of Ets2 in TAMs decreased the frequency and size of lung metastases without impacting primary tumor burden. Expression profiling of isolated tumor macrophages established that Ets2 deficiency resulted in the de-repression of a defined set of anti-angiogenic genes. Activation of this transcriptional program correlated with decreased angiogenesis in metastatic tumors and decreased metastatic growth. Comparison of this Ets2-specific TAM expression profile with human breast cancer profiles revealed a macrophage gene expression signature that could predict overall survival of estrogen receptor negative patients. In summary, we have identified a critical factor, Ets2, in TAMs that represses a transcriptional program to promote the growth of mammary tumor metastases in the lung. Breast TAMs were isolated from early-stage PyMT-induced mammary tumors expressing Ets2 and also from the tumors with Ets2-deficient TAMs. Since macrophages have also been implicated in normal mammary gland remodeling, normal remeodeling macrophages were also purified from females expressing Ets2 and the ones where Ets2 is deleted in the macrophages. One RNA sample was extracted from each genetic group for gene-expression profiling.