Malignant melanoma is a common and frequently lethal disease. Current therapeutic interventions have little effect on survival, emphasizing the need for a better understanding of the genetic, epigenetic, and phenotypic changes in melanoma formation and progression. We identified genes that were not previously known to be silenced by methylation in melanoma using a microarray-based screen following treatment of melanoma cell lines with the DNA methylation inhibitor 5-Aza-2'-deoxycytidine.
Epigenetic silencing of novel tumor suppressors in malignant melanoma.
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View SamplesThe effects of constitutively active Hypoxia Inducible Factor (HIF) and inactivated von Hippel-Lindau tumor suppressor gene product (pVHL) were examined in a mouse model. Conditionally expressed, constitutively active HIF-1a and HIF-2a were compared with inactivated pVHL.
Failure to prolyl hydroxylate hypoxia-inducible factor alpha phenocopies VHL inactivation in vivo.
Specimen part
View SamplesDrug resistance invariably limits the clinical efficacy of targeted therapy with kinase inhibitors against cancer. We found that targeted therapy with BRAF, ALK, or EGFR inhibitors induces a complex network of secreted signals in drug-stressed melanoma and lung adenocarcinoma cells. This therapy-induced secretome (TIS) stimulates the outgrowth, infiltration and metastasis of drug-resistant cancer clones in the tumour. Additionally, the TIS supports the survival of drug-sensitive cells, contributing to incomplete tumour regression. We used transcriptomic analysis of sensitive tumour cells and xenograft tumours treated with vehicle, vemurafenib, or crizotinib to identify the transcriptional drivers and to dissect the TIS in melanoma (A375, Colo800, UACC62) and lung adenocarcinoma (H3122). In addition, we utilize cell type–specific mRNA purification by translating ribosome affinity purification (TRAP) to identify pathways that are up-regulated in resistant cells (A375R) in response to the regressing tumour microenvironment. Overall design: Analysis of the response of drug sensitive melanoma and lung adenocarcinoma cells to pharmacological inhibition of their driver oncogene and gene expression analysis of drug resistant cancer cells responding to different tumor microenvironments.
Therapy-induced tumour secretomes promote resistance and tumour progression.
No sample metadata fields
View SamplesPurpose: Eliciting effective anti-tumor immune responses in patients who fail checkpoint inhibitor therapy is a critical challenge in cancer immunotherapy, and in such patients, tumor-associated myeloid cells and macrophages (TAMs) are promising therapeutic targets. We demonstrate in an autochthonous, poorly immunogenic mouse model of melanoma that combination therapy with an agonistic anti-CD40 mAb and CSF1R inhibitor potently suppressed tumor growth. Microwell assays to measure multiplex protein secretion by single cells identified that untreated tumors have distinct TAM subpopulations secreting MMP9 or co-secreting CCL17/22, characteristic of an M2-like state. Combination therapy reduced the frequency of these subsets, while simultaneously inducing a separate polyfunctional inflammatory TAM subset co-secreting TNF?, IL-6, and IL-12. Tumor suppression by this combined therapy was partially dependent on T cells, TNF? and IFN?. Together, this study demonstrates the potential for targeting TAMs to convert a “cold” into an “inflamed” tumor microenvironment capable of eliciting protective T cell responses. Methods: Total RNA was purified with the use of QIAzol and RNeasy Mini kit (QIAGEN), in which an on-column DNase treatment was included. Purified RNA was submitted to the Yale Center for Genomic Analysis where it was subjected to mRNA isolation and library preparation. Non-strand specific libraries were generated from 50ng total RNA using the SMARTer Ultra Low Input RNA for Illumina Sequencing kit. Libraries were pooled, six samples per lane, and sequenced on an Illumina HiSeq 2500 (75-bp paired end reads), and aligned using STAR to the GRCm38 (mm10) reference genome. A count-based differential expression protocol was adapted for this analysis(Anders et al., 2013); mappable data were counted using HTSeq, and imported into R for differential expression analysis using the DESeq2.To find differentially regulated sets of genes for signature generation, a 1.5-Log2 fold-change difference between samples and p-adjusted (Holm-Sidak) = 0.01 was used. Results: To begin to understand how these treatments modulated T cells to control tumor growth, and to possibly illuminate additional biomarkers of response, we examined the transcriptomes of CD11b+ Ly6G- cells treated with CD40 or CSF1Ri, alone or in combination, relative to control, using high throughput RNA-sequencing. Principal components analysis (PCA) on the genome-wide dataset demonstrated that treating with CD40 and CSF1Ri individually caused largely non-overlapping changes in transcription, as indicated by their movement along orthogonal principal components (PC) relative to the control. Importantly, combination therapy was visualized as a systems-level combination of each individual treatment in PC space. We then examined the mRNAs most altered by either treatment alone or in combination relative to Controls (Log2FC>1.5, p<.01) by unsupervised hierarchical clustering. Five major gene patterns emerged from the clustering of genes. Cluster #1 comprises genes that are upregulated by CD40 and CSF1Ri+CD40 treatment but are mostly unaffected by CSF1Ri, suggesting that CD40 is the primary driver of this cluster in the combination treatment. Notable genes in this cluster include Tnfa, Ifng??Il12b and Cxcl9; interestingly, for Tnfa and Il12b, CSF1Ri+CD40 appears to have a synergistic effect on expression. In contrast to Cluster #1, Cluster #5 contains genes substantially downregulated by CSF1Ri and CSF1Ri+CD40 treatments, but are largely unaffected by CD40, suggesting that CSF1Ri is the driver of this cluster in the combination treatment. Cluster #5 genes include Cd36 and Fabp4, suggesting alterations in lipid homeostasis in the TAMs after treatment. Cluster #2 includes genes that are modestly upregulated by CD40 and CSF1Ri individually, leading to a stronger upregulation when combined. Finally, Clusters #3 and #4 include, for the most part, genes that are differentially affected by CD40 versus CSF1Ri and for which the combination treatment yields an intermediate response. In summary, these data show that CSF1Ri and CD40 agonism elicit predominantly distinct changes in gene expression in the CD11b+ cells, indicating they target different biological processes in myeloid cells. The net result of the changes in myeloid gene expression from the combination of CSF1Ri+CD40 treatment reveal additive effects by the individual treatments, but also synergy in the expression of several pro-inflammatory genes (e.g., Tnfa, Ifng, Il6 and Il12b). We further examined our dataset with Gene Set Enrichment Analysis (GSEA). Although CSF1Ri and CD40 treatments did not closely match any immunological signatures in the immunological database of MSigDb, combined CSF1Ri+CD40 had a strikingly similar signature to myeloid cells exposed to a variety of inflammatory stimulants, most closely reflected by BMDMs treated with lipopolysaccharide (LPS). This motivated us to look specifically at categories of NF-?B target genes that are significantly affected by LPS treatment, including transcription factors, cytokines and chemokines. Indeed, most of these NF-?B target genes associated with inflammation were strongly upregulated by CSF1Ri+CD40 treatment. Finally, Ingenuity Pathway Analysis identified TNFR1 and TNFR2 signaling and Acute phase response signaling among the top genetic signatures produced by the CSF1Ri+CD40 treatment combination, matching what we observed with GSEA. Thus, gene expression analysis not only revealed several biomarkers of response that may be relevant for assessing therapeutic activity in ongoing clinical trials using these drugs, but illuminated lead biological factors that may cause tumor regression. Conclusions: myeloid-targeted immunotherapies anti-CD40+CSF1R inhibition synergistically induce a pro-inflammatory microenviroment Overall design: mRNA profiles of tumor infiltrating lymphocytes (TILs) in mice were generated by deep sequencing, in triplicate, using Illumina.
Myeloid-targeted immunotherapies act in synergy to induce inflammation and antitumor immunity.
Specimen part, Cell line, Subject
View SamplesCharacterized by striking metastatic propensity and chemoresistance, melanoma is among the most lethal cutaneous malignancies. The transcription factor ATF2 was shown to elicit oncogenic activities in melanoma, and its inhibition attenuates melanoma development. Here, a mouse model engineered to express a transcriptionally inactive form of Atf2 (Atf2?8,9) was found to be sufficient to induce nevi formation and, when crossed with BrafV600E animals, to promote melanoma development. The cross of Atf2?8,9 with BrafV600E;Pten-/- mice augmented pigmentation, tumorigenicity, and metastasis. Similar to mouse Atf2?8,9, the human ATF2 splice variant 5 enhanced growth and migration capacity of cultured melanoma and immortalized melanocytes. Induced Melan-A, CXCL9, S100A8, CCR7 expression, seen in Atf2?8,9-driven tumors associate with their enhanced pigmentation, immune infiltration and propensity to metastasize. Notably, elevated ATF2SV5 expression in melanoma specimens coincided with poor prognosis. The gain-of-function activity elicited by the truncated ATF2 form offers unexpected insight into mechanisms underlying melanoma development and progression. Overall design: Compared silencing of ATF2SV5 in H3A cells vs. silencing of ATF2WT via Ampliseq whole transcriptome analysis on the Ion Proton
A Transcriptionally Inactive ATF2 Variant Drives Melanomagenesis.
Specimen part, Subject
View SamplesAnalysis of mouse primary natural killer (NK) cells and NK cells treated with DKK2 for 24 hours.Sequencing of the mRNAs from DKK2-treated primary NK cells in comparison of those from mock-treated cells suggest an alteration in STAT signaling. Overall design: Mouse primary NK cells were isolated from the spleens and cultured in the presence of 50 ng/ml recombinant murine IL-15 for 24 hours. And then NK cells were treated with mock or 200ng/ml DKK2 for another 24 hours before mRNA was isolated and purified by using RNeasy Plus Mini Kit (Qiagen). A total of two groups of Control NK cells and two groups of DKK2-treated NK cells were individually micromanipulated.
DKK2 imparts tumor immunity evasion through β-catenin-independent suppression of cytotoxic immune-cell activation.
Specimen part, Cell line, Treatment, Subject
View SamplesWe sought to identify genes and gene signatures which correlate with progression by sampling human melanomas from nevi, primary, and metastatic tumors. The large number of samples also permits analysis within groups.
Integrative genome comparison of primary and metastatic melanomas.
Sex, Specimen part, Disease, Race, Subject
View SamplesExpression profiling was performed using uncultured melanocytes and melanoma cell from various mouse models of BrafV600E induced melanocytic proliferation
mTORC1 activation blocks BrafV600E-induced growth arrest but is insufficient for melanoma formation.
Specimen part
View SamplesClinical and genomic evidence support the view that the metastatic potential of a primary tumor may be dictated by transforming events acquired early in the tumorigenic process. It has been proposed that the presence of such pro-metastatic events in early-stage tumors reflects their additional capability to function as oncogenes. Here, to test this deterministic hypothesis and identify potential pro-metastasis oncogenes, we adopted a comparative oncogenomics-guided functional genetic screening strategy involving (i) global transcriptomic data from two genetically engineered mouse models of melanoma with contrasting metastatic potential, (ii) genomic and transcriptomic profiles of human primary and metastatic melanoma and (iii) an invasion screen in TERT-immortalized human melanocytes and melanoma cells in vitro as well as (iv) evidence of expression selection in human melanoma tissues. This integrated effort led to the identification of 6 genes that are both potently pro-invasive and oncogenic. Further, we show that one such pro-invasion oncogene, ACP5, can confer spontaneous metastasis in vivo, engages a key pathway governing metastasis and is prognostic in human primary melanomas.
Proinvasion metastasis drivers in early-stage melanoma are oncogenes.
Specimen part, Disease, Disease stage
View SamplesBoth targeted inhibition of oncogenic driver mutations and immune-based therapies show efficacy in treatment of patients with metastatic cancer but responses are either short-lived or incompletely effective. Oncogene inhibition can augment the efficacy of immune-based therapy but mechanisms by which these two interventions might cooperate are incompletely resolved. Using a novel transplantable BRAFV600E-mutant murine melanoma model (SB-3123), we explore potential mechanisms of synergy between the selective BRAFV600E inhibitor vemurafenib and adoptive cell transfer (ACT)-based immunotherapy. We found that vemurafenib cooperated with ACT to delay melanoma progression but surprisingly did not enhance tumor infiltration or effector function of endogenous or adoptively transferred CD8+ T cells as previously observed. Instead, we found that the T cell cytokines IFN-gamma and TNF-alpha synergized with vemurafenib to induce cell cycle arrest of tumor cells in vitro. This was recapitulated in vivo as continuous vemurafenib administration was required to delay melanoma progression following ACT. The unexpected finding that immune cytokines synergize with oncogene inhibitors to induce growth arrest have major implications for understanding cancer biology at the intersection of oncogenic and immune signaling and provides a basis for design of combinatorial therapeutic approaches for patients with metastatic cancer.
Type I cytokines synergize with oncogene inhibition to induce tumor growth arrest.
Sex, Disease, Disease stage, Cell line
View Samples