Dataset Information

The bromodomain protein TRIM28 controls the balance between growth and invasiveness in melanoma

ABSTRACT: Melanoma tumors are highly metastatic partly due to the ability of melanoma cells to transition between invasive and proliferative states, however, the mechanisms underlying this plasticity are still not fully understood. To identify new epigenetic regulators of melanoma plasticity, we combined data mining, tumor models, proximity proteomics, and CUT&RUN-sequencing. We focused on the druggable family of bromodomain epigenetic readers, and identified TRIM28 as a new regulator of melanoma plasticity. We found that TRIM28 promotes the expression of pro-invasive genes, and that TRIM28 controls the balance between invasiveness and growth of melanoma cells. We demonstrate that TRIM28 acts via the transcription factor JUNB, that directly regulates the expression of pro-invasive and pro-growth genes. Mechanistically, TRIM28 controls the expression of JUNB by negatively regulating its transcriptional elongation by RNA polymerase II. In conclusion, our results demonstrate that a TRIM28-JUNB axis controls the balance between invasiveness and growth in melanoma tumors and suggests that the bromodomain protein TRIM28 could be targeted to reduce tumor spread.

ORGANISM(S): Homo sapiens

PROVIDER: GSE210579 | GEO | 2022/08/08

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Dissection of melanoma heterogeneity through gene expression profiling has led to the identification of two major phenotypes, conventionally defined as “MITF high / proliferative” and “AXL high / invasive”. Tumors or single melanoma cells characterized by a predominant AXL-related gene program show enhanced expression of sets of genes involved in motility, invasion and regulation of epithelial-mesenchymal transition (EMT), while these genes are downregulated in tumors or cells with a predominant MITF-related gene program. The activation of the AXLhi/MITFlo invasive gene program in melanoma is characterized by aberrant expression of transcription factors (TFs) involved in the embryonic EMT process. Additional master genes involved in promoting melanoma growth and invasive state have been identified within the family of epigenetic regulators. Two of these genes, RNF2 and EZH2, components of the polycomb repressive complexes 1 and 2, act by epigenetically silencing tumor suppressors that in turn regulate the invasive and EMT-like phenotype of melanoma cells. Additional master genes involved in promoting melanoma growth and invasive state have been identified within the family of epigenetic regulators. Two of these genes, RNF2 and EZH2, components of the polycomb repressive complexes 1 and 2, act by epigenetically silencing tumor suppressors that in turn regulate the invasive and EMT-like phenotype of melanoma cells. Here we provide evidence for a new actionable pathway that controls melanoma EMT-like/invasive phenotype. We show that in MITFlo melanomas, the TF NFATc2 controls the EMT-like transcriptional program, the invasive ability of neoplastic cells, as well as in-vitro and in-vivo growth, through a pathway that functionally links c-myc to FOXM1 and EZH2. Targeting of NFATc2, FOXM1 or EZH2 inhibited melanoma migratory and invasive activity. Moreover, pharmacological co-targeting of NFATc2 and EZH2 promoted apoptosis of BRAF-mutant melanomas with intrinsic resistance to BRAF inhibition.

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.

Dataset Information

The bromodomain protein TRIM28 controls the balance between growth and invasiveness in melanoma

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets