Project description:Uveal melanoma (UM) is the most prevalent cancer of the eye in adults, with a highly aggressive form of metastasis that is refractory to current therapies. UM is driven by aberrant activation of the Gαq pathway by hotspot activating mutation of GNAQ/GNA11, with few additional genetic aberrations. Despite this, there are limited effective targeted therapies currently available against the treatment of UM and mUM. Here, we performed a high-throughput chemogenetic drug screen in GNAQ-mutant UM contrasted with that of BRAF-mutant skin cutaneous melanoma, as a network chemical biology-based approach to identify therapeutic agents that target the mechanistic underpinnings driving UM. We observed strong genotype-driven drug sensitivities, and identified several drug classes with preferential activity against UM using a method termed Drug Set Enrichment Analysis (DSEA). Among them, we found an enrichment for PKC inhibitors, and identified one compound LXS-196, with the highest preferential activity against UM. Our investigation into the mechanism of action of LXS-196 revealed that in addition to inhibiting the Gq-ERK pathway, unlike other PKC inhibitors, this drug also reduced FAK activity, a recently identified mediator of non-canonical Gαq-driven oncogenic signaling. Kinome profiling revealed that LXS-196 acts as a multi-targeted kinase inhibitor, with high preference for PKC as well as PKN/PRK, the latter a poorly investigated AGC kinase that is activated directly by RhoA. This primes LXS-196 to target cell-essential pathways that drive tumor growth in UM by targeting both PKC, in addition to FAK. Moreover, we find that PKN is activated by GNAQ downstream from RhoA, thereby contributing to FAK stimulation. These findings expose a signaling vulnerability that can be targeted pharmacologically. Ultimately, dual PKC and PKN inhibition by LXS-196 acts synergistically with FAK inhibitors (FAKi) to halt UM growth and promote cytotoxic cell death in vitro and in preclinical metastatic mouse models, thus providing a highly translatable therapeutic multimodal precision strategy against mUM.
Project description:Despite advances in surgery and radiotherapy of uveal melanoma (UM), many patients develop distant metastases that poorly respond to therapy. Improved therapies for the metastatic disease are therefore urgently needed. Expression of the epidermal growth factor receptor (EGFR), a target of kinase inhibitors and humanized antibodies in use for several cancers, had been reported. 48 human UMs were analyzed by expression profiling. Evidence for signaling in tumors was obtained through the application of a UM-specific EGF signature. The EGFR specific kinase inhibitor, Gefitinib, and the humanized monoclonal antibody, Cetuximab, were tested for their effect on EGFR signaling. Natural killer cell mediated antibody-dependent cellular cytotoxicity (ADCC) and TNF-alpha release was analyzed for Cetuximab. EGFR appears suited as a novel molecular drug target for therapy of uveal melanoma. Gene expression profiles of 19 unique samples from uveal melanoma patients were measured.
Project description:Despite advances in surgery and radiotherapy of uveal melanoma (UM), many patients develop distant metastases that poorly respond to therapy. Improved therapies for the metastatic disease are therefore urgently needed. Expression of the epidermal growth factor receptor (EGFR), a target of kinase inhibitors and humanized antibodies in use for several cancers, had been reported. 48 human UMs were analyzed by expression profiling. Evidence for signaling in tumors was obtained through the application of a UM-specific EGF signature. The EGFR specific kinase inhibitor, Gefitinib, and the humanized monoclonal antibody, Cetuximab, were tested for their effect on EGFR signaling. Natural killer cell mediated antibody-dependent cellular cytotoxicity (ADCC) and TNF-alpha release was analyzed for Cetuximab. EGFR appears suited as a novel molecular drug target for therapy of uveal melanoma.
Project description:Uveal melanoma (UM) is a rare form of melanoma with a genetics and immunology that is different from skin melanoma. Previous studies have identified genetic driver events of early stage disease when the tumor is confined to the eye. In this study, we have characterized genomic events in UM metastases using whole-genome and RNA sequencing from thirty-two and twenty-eight patients, respectively, and profiled individual tumor infiltrating lymphocytes in a number of the metastases. We find that 91% of the patients have metastases carrying inactivating events in the tumor suppressor BAP1 and this coincided with somatic alterations in GNAQ, GNA11, CYSLTR2, PLCB4, SF3B1 and/or CDKN2A. Mutational signature analysis revealed a rare subset of tumors with prominent signs of UV damage, associated with outlier mutational burden. We study copy number variations (CNV) and find overrepresented events, some of which were not altered in matched primary eye tumors. A focused siRNA screen identified functionally significant genes of some of the segments recurrently gained. We reintroduced a functional copy of BAP1 into a patient-derived BAP1 deficient tumor cell line and found broad transcriptomic changes of genes associated with subtype distinction and prognosis in primary UM. Lastly, our analysis of the immune microenvironments of metastases revealed a presence of tumor-reactive T cells. However, a large fraction expressed the immune checkpoint receptors such as TIM-3, TIGIT and LAG3. These results provide an updated view of genomic events represented in metastatic UM and immune interactions in advanced lesions.
Project description:Metastatic uveal melanoma (UM) remains challenging to treat, with objective response rates to immune checkpoint blockade (ICB) much lower than in primary cutaneous melanoma (CM). Besides a lower mutational burden, the overall immune-excluded tumor microenvironment of UM might contribute to the poor response rate. We therefore aimed at targeting deficiency in argininosuccinate synthase 1, which is a key metabolic feature of UM. This study aimed at investigating safety and tolerability of a triple combination consisting of ipilimumab and nivolumab immunotherapy and the metabolic therapy ADI-PEG 20. 9 patients were enrolled in this pilot study. The combination therapy was safe and tolerable with absence of immune related adverse events (irAE) of special interest but with 4 of 9 patients experiencing a CTCAE grade 3 AE. No objective responses were observed. All except one patient developed anti-drug antibodies (ADA) within a month of treatment initiation and therefore did not maintain arginine depletion. Further, an IFNg-dependent inflammatory signature was observed in metastatic lesions in patients pre-treated with ICB compared with patients with no pretreatment. Multiplex immunohistochemistry demonstrated variable presence of tumor infiltrating CD8 lymphocytes and PD-L1 expression at baseline in metastases.
Project description:Epithelial to mesenchymal transition (EMT) is activated during cancer invasion and metastasis, enriches for cancer stem cells (CSCs), and contributes to therapeutic resistance and disease recurrence. Signal transduction kinases play a pivotal role as chromatin-anchored proteins in eukaryotes. Here we report for the first time that protein kinase C-theta (PKC-q) regulates EMT by acting as a critical chromatin-anchored switch for inducible genes via TGF-M-NM-2 and the key inflammatory regulatory protein, NFkB. Chromatinized PKC-q exists as an active transcription complex and is required to establish a permissive chromatin state at signature EMT genes. Genome-wide analysis identifies a unique cohort of inducible PKC-q-sensitive genes that are directly tethered to PKC-q in the mesenchymal state. Collectively, we show that crosstalk between signaling kinases and chromatin is critical for eliciting inducible transcriptional programs that drive mesenchymal differentiation and CSC formation, providing novel mechanisms to target using epigenetic therapy in breast cancer. 2 biological samples were analysed, Immunoprecipitated and total input samples were obtained from each biological treatment. 2 Technical replicates were performed (samples from the sample lib prep were run on two different lanes).
Project description:By selective and reversible inhibition of CDK4/CDK6, we have developed a strategy to both inhibit proliferation and enhance cytotoxic killing of cancer cells. Induction of prolonged early-G1 arrest (pG1) by CDK4/CDK6 inhibition halts gene expression in early-G1 and prevents expression of genes programmed for other cell cycle phases. S-phase synchronization upon removal of the early-G1 block (pG1-S) fails to completely restore scheduled gene expression. Consequently, coordinate loss of IRF4 and gain of Bim and Noxa expression sensitize myeloma tumor cells to bortezomib-induced apoptosis in pG1 and more profoundly in pG1-S in vitro. Induction of pG1 and pG1-S by CDK4/CDK6 inhibition augments tumor-specific bortezomib killing in myeloma xenografts. Inhibition of CDK4/CDK6 in combination therapy thus represents a novel mechanism-based cancer therapy. PD 0332991 (PD) is the only known specific and reversible CDK4/CDK6 inhibitor. Gene expression was measured in myeloma MM1.S cells treated with PD (0.25 uM) in triplicate for 12, 24 or 36 h, or in cells released from G1, induced by 24hPD, for 4 or 18 h.
Project description:Uveal melanoma (UM) is a rare tumor of the eye that leads to deadly metastases in about half of the patients. ADAM10 correlates with c-Met expression in UM and high levels of both molecules are related to the development of metastases. MiR122 and miR144 modulate ADAM10 and c-Met expression in di erent settings. We hypothesized a potential onco-suppressive role for miR122 and miR144 through modulation of ADAM10 and c-Met in UM. We analyzed the UM Cancer Genome Atlas data portal (TCGA) dataset, two other cohorts of primary tumors and five human UM cell lines for miR122 and miR144 expression by miR microarray, RT-qPCR, Western blotting, miR transfection and luciferase reporter assay. Our results indicate that miR122 and miR144 are expressed at low levels in the UM cell lines and in the TCGA UM dataset and were down-modulated in a cohort of seven UM samples, compared to normal choroid. Both miR122 and miR144 directly targeted ADAM10 and c-Met. Overexpression of miR122 and miR144 led to reduced expression of ADAM10 and c-Met in the UM cell lines and impaired cell proliferation, migration, cell cycle and shedding of c-Met ecto-domain. Our results show that miR122 and miR144 display an onco-suppressive role in UM through ADAM10 and c-Met modulation.
Project description:Targeting protein kinase C (PKC) isoforms by the small molecule inhibitor enzastaurin has shown promising pre-clinical activity in a wide range of tumor cells. In this study, we further delineated its mechanism of action in multiple myeloma (MM) cells and found a novel role of b-catenin in regulating growth and survival of tumor cells. Specifically, inhibition of PKC leads to rapid accumulation of b-catenin by preventing the phosphorylation required for its proteasomal degradation. Microarray analysis and siRNA-mediated gene silencing in MM cells revealed that accumulated b-catenin activates early ER stress signaling via eIF2a, CHOP and p21, leading to immediate growth inhibition. Furthermore, accumulated b-catenin contributes to enzastaurin-induced cell death. Both sequential knock-down of b-catenin, c-Jun, and p73, as well as overexpression of b-catenin or p73 confirmed that accumulated b-catenin triggers c-Jun-dependent induction of p73, thereby conferring MM cell apoptosis. In summary, our data reveal a novel role of b-catenin in ER stress-mediated growth inhibition, and a new pro-apoptotic mechanism triggered by b-catenin upon inhibition of PKC isoforms. Moreover, we identify p73 as a potential novel therapeutic target in MM. Based on these and previous data, enzastaurin is currently under clinical investigation in a variety of hematologic malignancies including MM. Keywords: time course
Project description:LC-MS/MS based investigation of protein abundance changes, induced by DZNep treatment in A549-ACE2 cell line (0.75 uM DZNep, vehicle PBS; 6h pre-treatment, harvested 24 h.p.i. with mock/SARS-CoV/SARS-CoV-2 at MOI 3) or primary human bronchial epithelial cells (NHBEs) (1.5 uM DZNep, vehicle PBS; 6h pre-treatment, harvested 36 h.p.i. with mock/SARS-CoV/SARS-CoV-2 at MOI 3), or by Tubercidin in A549-ACE2 cell line (1 uM Tubercidin, vehicle DMSO; 3h pre-treatment, harvested 24 h.p.i. with mock/SARS-CoV at MOI 0.01/SARS-CoV-2 at MOI 0.1).