Project description:Among hallmarks of cancer is impaired proteostasis, that is characterized by increased oncoprotein stability. Here we demonstrate that RNF4, a ubiquitin ligase implicated in the stabilization of short-lived oncoproteins, is important for melanoma tumorigenesis. High levels of RNF4 in melanoma patient-derived specimens coincide with poor prognosis. Accordingly, RNF4, is essential for the growth and migration and survival of melanoma cells, both in culture and in xenograft models. RNA-seq analyses of RNF4-expressing tumors identified a gene signature related to melanoma growth and migration. Among the upstream regulators of RNF4-dependent gene signature are c-Myc and HIF1a which exhibit elevated protein levels that also coincided with stabilization of the translation initiation regulator p-eIF2a. Correspondingly, the effects of RNF4 on melanomagenesis are p-eIF2a-dependent, thus highlighting an unexpected regulatory axis in melanoma via RNF4-and ubiquitin-dependent protein stabilization
Project description:Metastasis is the deadliest phase of cancer progression. Experimental models using immunodeficient mice have been used to gain insights into the mechanisms of metastasis. We report here the identification of a “metastasis aggressiveness gene expression signature” derived using human melanoma cells selected based on their metastatic potentials in a xenotransplant metastasis model. Comparison with expression data from human melanoma patients shows that this metastasis gene signature correlates with the aggressiveness of melanoma metastases in human patients. Many genes encoding secreted and membrane proteins are included in the signature, suggesting the importance of tumor-microenvironment interactions during metastasis. Keywords: disease state
Project description:Metastasis is the deadliest phase of cancer progression. Experimental models using immunodeficient mice have been used to gain insights into the mechanisms of metastasis. We report here the identification of a “metastasis aggressiveness gene expression signature” derived using human melanoma cells selected based on their metastatic potentials in a xenotransplant metastasis model. Comparison with expression data from human melanoma patients shows that this metastasis gene signature correlates with the aggressiveness of melanoma metastases in human patients. Many genes encoding secreted and membrane proteins are included in the signature, suggesting the importance of tumor-microenvironment interactions during metastasis. Keywords: disease state analysis
Project description:Metastasis is the deadliest phase of cancer progression. Experimental models using immunodeficient mice have been used to gain insights into the mechanisms of metastasis. We report here the identification of a “metastasis aggressiveness gene expression signature” derived using human melanoma cells selected based on their metastatic potentials in a xenotransplant metastasis model. Comparison with expression data from human melanoma patients shows that this metastasis gene signature correlates with the aggressiveness of melanoma metastases in human patients. Many genes encoding secreted and membrane proteins are included in the signature, suggesting the importance of tumor-microenvironment interactions during metastasis. Keywords: disease state
Project description:Metastasis is the deadliest phase of cancer progression. Experimental models using immunodeficient mice have been used to gain insights into the mechanisms of metastasis. We report here the identification of a âmetastasis aggressiveness gene expression signatureâ derived using human melanoma cells selected based on their metastatic potentials in a xenotransplant metastasis model. Comparison with expression data from human melanoma patients shows that this metastasis gene signature correlates with the aggressiveness of melanoma metastases in human patients. Many genes encoding secreted and membrane proteins are included in the signature, suggesting the importance of tumor-microenvironment interactions during metastasis. Experiment Overall Design: test signature genereated from experiments of parental cell line vs xenograft model
Project description:Metastasis is the deadliest phase of cancer progression. Experimental models using immunodeficient mice have been used to gain insights into the mechanisms of metastasis. We report here the identification of a âmetastasis aggressiveness gene expression signatureâ derived using human melanoma cells selected based on their metastatic potentials in a xenotransplant metastasis model. Comparison with expression data from human melanoma patients shows that this metastasis gene signature correlates with the aggressiveness of melanoma metastases in human patients. Many genes encoding secreted and membrane proteins are included in the signature, suggesting the importance of tumor-microenvironment interactions during metastasis. Experiment Overall Design: parental cell line vs xenograft model
Project description:Melanoma is the most aggressive form of skin cancer with estimated 48,000 deaths worldwide. The polyphenol curcumin derived from the plant Curcuma longa is well known for its anti-inflammatory and anti-cancerogenic properties. Accordingly, dietary intake of this compound may be suitable for melanoma prevention. However, how this compound affects basic cellular mechanisms in developing melanoma still remains elusive. Therefore, the aim of this study was to investigate for the first time the impact of oral curcumin administration on the miRNA signature of engrafting melanoma. For this purpose, the effects of a 4% curcumin diet on murine B78H1 melanoma were tested in a flank model. Curcumin diet or standard chow (control) was administered two weeks prior to tumor initiation until termination of the experiment. Highly significant chip-based miRNA array analysis was deployed to detect alterations in the miRNA signature of the tumors. Curcumin treatment significantly reduced the growth of the flank tumors. Furthermore the miRNA expression signature in tumors was substantially altered by curcumin intake with mmu-miR-205-5p over 100 times higher expressed when compared to controls. Putative targets of curcumin-induced up-regulated miRNAs were enriched in o-glycan biosynthesis, endoplasmatic reticulum protein processing and different cancer-related pathways. These findings demonstrate a profound alteration of the miRNA expression signature in engrafting curcumin-treated melanoma with mmu-miR-205-5p being up-regulated most significantly. Treatment of male C57BL/6 mice with induced flank tumors (injection of B78H1 cells) either with standard mouse chow (control n=6) or chow enriched with 4% of curcumin (treatment group n=7 )
Project description:Metastasis is the deadliest phase of cancer progression. Experimental models using immunodeficient mice have been used to gain insights into the mechanisms of metastasis. We report here the identification of a âmetastasis aggressiveness gene expression signatureâ derived using human melanoma cells selected based on their metastatic potentials in a xenotransplant metastasis model. Comparison with expression data from human melanoma patients shows that this metastasis gene signature correlates with the aggressiveness of melanoma metastases in human patients. Many genes encoding secreted and membrane proteins are included in the signature, suggesting the importance of tumor-microenvironment interactions during metastasis. Experiment Overall Design: parental cell line vs xenograft model
Project description:Summary: Melanoma spheroids grown under neural crest cell conditions are highly plastic migratory/invasive tumor cells endowed with immunomodulator function Background: The aggressiveness of melanoma tumors is likely to rely on their well-recognized heterogeneity and plasticity. Melanoma comprises multi subpopulations of cancer cells some of which may possess stem cell-like properties supporting the notion of plasticity. Although useful for certain tumors, the use of the sphere-formation assay to identify stem cell-like or tumor initiating cells subpopulations in human melanoma has been recently challenged. Our study reveals that this assay predicts a functional phenotype associated with aggressive behavior of tumor cells. Methodology/Principal Findings: We analyzed the molecular and functional phenotypes of melanoma spheroids formed in neural crest cell medium. Whether from metastatic (SLM8) or advanced primary (Mela1) tumors, spheroid cells expressed melanoma-associated markers. They displayed higher capacity to differentiate along mesenchymal lineages, and showed enhanced expression of SOX2, NANOG, KLF4, and/or OCT4 transcription factors, but not extensive self-renewal or enhanced tumorigenicity when compared to their adherent counterparts. To determine whether melanoma spheroids in our model could predict a molecular or functional phenotype, we performed gene expression profiling experiments using Affymetrix microarrays. Gene expression profiling attributed a neural crest cell signature to these spheroids and indicated that a migratory/invasive and immune-function modulating program could be associated with these cells. In vitro assays confirmed that these spheroids are endowed with enhanced migratory/invasive capacities. In immune activation assays, spheroid cells elicited a poorer allogenic response from immune cells and inhibited mitogen-dependent T cells activation and proliferation more efficiently than their adherent counterparts. Thus, our findings reveal novel immune-modulator function of melanoma spheroid cells and suggest specific roles for these spheroids in invasion and in evasion of antitumor immunity. Conclusion/Significance: The association of a more plastic, invasive and evasive, thus a more aggressive tumor phenotype with melanoma spheroid cells reveals a previously unrecognized aspect of tumor cells expanded as spheroid cultures. While of limited efficiency for melanoma initiating cell identification, our melanoma spheroid model predicted aggressive phenotype and could therefore, be constructive to investigate melanoma aggressiveness, relevant to patients and clinical transferability. 12 Total samples were analyzed: SLM8 adherent (SLMA) and spheroids (SLMS) cells, and Mela1 adherent (MelaA) and spheroid (MelaS) cells, all performed in triplicates. Paired statistical analyses were performed using Student's paired t-test on the gene signal intensities (gene level) and results were considered statistically significant at p-values <=0.05 and fold-change >=1.5.