Project description:Interference with chemoresistance to enhance the efficacy of chemotherapeutics may be of great utility for cancer therapy. We have identified KINK-1 (Kinase Inhibitor of NF-ï«B-1), a highly selective small-molecule IKKï¢ inhibitor, as a potent suppressor of both constitutive and induced NF-ï«B activity in melanoma cells. While KINK-1 profoundly diminished various NF-ï«B-dependent gene products regulating proliferation, cytokine production or anti-apoptotic responses, the compound by itself showed little antiproliferative or pro-apoptotic activity on the cellular level. However, its combination with some cytostatics markedly enhanced their antitumoral activities in vitro, and doxorubicin-induced NF-ï«B activation, a mechanism implicated in chemoresistance, was abrogated by KINK-1. In addition, when KINK-1 was combined with doxorubicin in an in vivo melanoma model, experimental metastasis was significantly diminished as compared to either treatment alone. Induction of chemoresistance by KINK-1 in vivo was not observed. Thus, KINK-1 or related substances might increase the susceptibility of tumors to chemotherapy. Experiment Overall Design: one control and two time point (12hrs and 24hrs) are analyzed, with one replicate each (6 arrays total)
Project description:Interference with chemoresistance to enhance the efficacy of chemotherapeutics may be of great utility for cancer therapy. We have identified KINK-1 (Kinase Inhibitor of NF-kappaB-1), a highly selective small-molecule IKKkappa inhibitor, as a potent suppressor of both constitutive and induced NF-kappaB activity in melanoma cells. While KINK-1 profoundly diminished various NF-kappaB-dependent gene products regulating proliferation, cytokine production or anti-apoptotic responses, the compound by itself showed little antiproliferative or pro-apoptotic activity on the cellular level. However, its combination with some cytostatics markedly enhanced their antitumoral activities in vitro, and doxorubicin-induced NF-kappaB activation, a mechanism implicated in chemoresistance, was abrogated by KINK-1. In addition, when KINK-1 was combined with doxorubicin in an in vivo melanoma model, experimental metastasis was significantly diminished as compared to either treatment alone. Induction of chemoresistance by KINK-1 in vivo was not observed. Thus, KINK-1 or related substances might increase the susceptibility of tumors to chemotherapy. Keywords: time-course
Project description:Treatment of patients with triple-negative breast cancer (TNBC) has been challenging due to the absence of well-defined molecular targets and high invasive and proliferative capacities of these cells. Current treatments against TNBC have shown minimal activity due to the high recurrence rate in the patients. Therefore, a pressing need for novel and efficacious therapies against TNBC. Here, we found a novel small molecule inhibitor (NSC33353) with potent anti-tumor activity against TNBC cells. Anti-proliferative effects of NSC small molecule inhibitor were determined using 2D and 3D culture cell proliferation assays. Using proteomics, NGS and enrichment analysis, we globally investigated top regulatory pathways affected by this compound in TNBC cells. Subsequently, we validated the proteomics and NGS analysis data using seahorse and enzymatic assays. Finally, we showed the inhibitor anti-tumor effects and confirmed its potential mechanism in vivo. In this report, we showed that a novel NSC33353 small molecule inhibitor reduced the proliferation of TNBC cells. Proteomic analysis confirmed a significant metabolic reprograming including suppression of glycolysis and oxidative phosphorylation after treatment. Furthermore, we found that treatment with NSC33353 small molecule inhibitor impaired glycolysis and oxidative phosphorylation via modulating the activity of metabolic regulator enzymes. Altogether, our data indicate that NSC33353 small molecule inhibitor may exhibit anti-tumor activity in TNBC cells and provide a rationale for further investigation of the potential of NSC small molecule inhibitor as an attractive therapeutic drug for TNBC. Doxorubicin is one of the most effective agents in the treatment of TNBC and resistance to this drug is a major problem. We show that the combination of NSC33353 and doxorubicin synergistically suppressed the growth of TNBC cells suggesting the combination enhances the sensitivity to doxorubicin. Further in-depth investigations are required to evaluate the exact targets and mechanism of this potent small molecule inhibitor, and its anti-neoplasm effects on TNBC in vivo.
Project description:Immune checkpoint inhibitors (ICIs) are now the first line treatment for patients with advanced melanoma. Despite promising clinical results, many patients fail to respond to these therapies. BH3 mimetics, a novel class of small molecule inhibitors that bind and inhibit anti-apoptotic members of the BCL2 family proteins such as BCL2 or MCL1, have been very successful in treating hematologic malignancies. However, there are limited studies on the immunomodulatory role of the BH3 mimetics. Several factors contribute to ICI resistance including myeloid-derived suppressor cells (MDSCs) that exert immunosuppressive effects through direct and indirect inhibition of antitumor immunity. Thus, targeting MDSCs to enhance antitumor immunity has the potential to enhance the efficacy of ICIs. In this study, we show that the MCL1 inhibitor S64315 reduces melanoma tumor growth in an immune cell dependent manner in mice. Specifically, S64315 enhances antitumor immunity by reducing MDSC frequency and by promoting the activity of CD8+ T cells. Additionally, human MDSCs are 10 times more sensitive to S64315 than cutaneous melanoma lines. Further, we found that a higher expression of MCL1 is associated with poor survival for patients treated with anti-PD-1. Finally, combining S64315 and anti-PD-1 significantly slowed tumor growth compared to either agent alone. Together, this proof-of-concept study demonstrates the potential of combining MCL1 inhibitor with anti-PD-1 in the treatment of melanoma. It justifies the further development of next generation MCL1 inhibitors to improve efficacy of ICIs in treating malignant melanoma.
Project description:Epigenetic events, including covalent post-translational modification of histones, have frequently been demonstrated to play critical roles in tumor development and progression. The transcriptional coactivator, p300/CBP, possesses both histone acetyltransferase (HAT) activity as well as scaffolding properties that directly influence transcriptional activation of targeted genes. We have used a recently reported small molecule inhibitor of p300 HAT activity, C646, to explore the specific contribution of p300/CBP HAT activity to tumor development and progression. We find that C646 inhibits the growth of lineage-specific tumor cell lines including human melanomas through direct transcriptional regulation of cell cycle regulatory proteins. Further evaluation of the p300 HAT transcriptome in human melanoma cells using comprehensive gene expression profiling reveals that p300 HAT activity globally promotes cell cycle progression, nucleosome assembly, and the DNA damage checkpoint through direct transcriptional regulatory mechanisms. Additionally, C646 promotes sensitivity to DNA damaging agents leading to enhanced apoptosis of melanoma cells following combination treatment with cisplatin. Together our data suggest that p300 HAT activity regulates critical growth regulatory pathways in tumors and may serve as a novel therapeutic target for melanoma and other malignancies by promoting cellular responses to DNA damaging agents. Keywords: p300, small molecule inhibitor, melanoma WM35 cells grown under normal culture conditions were treated for 6 and 24 hours with compound C646 to block p300 HAT activity. A vehicle control (DMSO) was included at each time point. RNA was extracted from all 4 samples using the Qiagen RNeasy kit. RNA quality check, labeling, hybridization, initial data processing and analysis was performed by the JHMI Microarray Core Facility. Affymetrix GeneChip Human Exon 1.0 ST Array was used for this study.
Project description:Epigenetic events, including covalent post-translational modification of histones, have frequently been demonstrated to play critical roles in tumor development and progression. The transcriptional coactivator, p300/CBP, possesses both histone acetyltransferase (HAT) activity as well as scaffolding properties that directly influence transcriptional activation of targeted genes. We have used a recently reported small molecule inhibitor of p300 HAT activity, C646, to explore the specific contribution of p300/CBP HAT activity to tumor development and progression. We find that C646 inhibits the growth of lineage-specific tumor cell lines including human melanomas through direct transcriptional regulation of cell cycle regulatory proteins. Further evaluation of the p300 HAT transcriptome in human melanoma cells using comprehensive gene expression profiling reveals that p300 HAT activity globally promotes cell cycle progression, nucleosome assembly, and the DNA damage checkpoint through direct transcriptional regulatory mechanisms. Additionally, C646 promotes sensitivity to DNA damaging agents leading to enhanced apoptosis of melanoma cells following combination treatment with cisplatin. Together our data suggest that p300 HAT activity regulates critical growth regulatory pathways in tumors and may serve as a novel therapeutic target for melanoma and other malignancies by promoting cellular responses to DNA damaging agents. Keywords: p300, small molecule inhibitor, melanoma
Project description:Therapeutic approaches to treat melanoma include small molecule drugs that target activating protein mutations in pro-growth signaling pathways like the MAPK pathway. While beneficial to the approximately 50% of patients with activating BRAFV600 mutation, mono- and combination therapy with MAPK inhibitors is ultimately associated with acquired resistance. To better characterize the mechanisms of MAPK inhibitor resistance in melanoma, we utilize patient-derived xenografts and apply proteogenomic approaches leveraging genomic, transcriptomic, and proteomic technologies that permit the identification of resistance-specific alterations and therapeutic vulnerabilities. A specific challenge for proteogenomic applications comes at the level of data curation to enable multi-omics data integration. Here, we present a proteogenomic approach that uses custom curated databases to identify unique resistance-specific alternations in melanoma PDX models of acquired MAPK inhibitor resistance. We demonstrate this approach with a NRASQ61L melanoma PDX model from which resistant tumors were developed following treatment with a MEK inhibitor. Our multi-omics strategy addresses current challenges in bioinformatics by leveraging development of custom curated proteogenomics databases derived from individual resistant melanoma that evolves following MEK inhibitor treatment and is scalable to comprehensively characterize acquired MAPK inhibitor resistance across patient-specific models and genomic subtypes of melanoma.
Project description:The blossom of immunotherapy in melanoma highlights the need to delineate mechanisms of immune resistance. Recently, we have demonstrated that the RNA editing protein, adenosine deaminase acting on RNA-1 (ADAR1) is down-regulated during metastatic transition of melanoma, which enhances melanoma cell proliferation and tumorigenicity. Here we investigate the role of ADAR1 in melanoma immune resistance. Importantly, knockdown of ADAR1 in human melanoma cells induces resistance to tumor infiltrating lymphocytes in a cell contact-dependent mechanism. We show that ADAR1, in an editing-independent manner, regulates the biogenesis of miR-222 at the transcription level and thereby Intercellular Adhesion Molecule 1 (ICAM1) expression, which consequently affects melanoma immune resistance. ADAR1 thus has a novel, pivotal, role in cancer immune resistance. Corroborating with these results, the expression of miR-222 in melanoma tissue specimens was significantly higher in patients who had no clinical benefit from treatment with ipilimumab as compared to patients that responded clinically, suggesting that miR-222 could function as a biomarker for the prediction of response to ipilimumab. These results provide not only novel insights on melanoma immune resistance, but also pave the way to the development of innovative personalized tools to enable optimal drug selection and treatment. 13 formalin fixed paraffin embedded (FFPE) melanoma tissues were stained with hematoxilin and eosin for examination by an expert pathologist. Non-tumor tissue was removed. Total RNA was isolated using miRNeasy FFPE kit (Qiagen) according to the manufacture guidelines.
Project description:The A375, human BRAFV600E mutant melanoma, cell line (wildtype), two PTEN-null, BRAFV600E cell lines (KO5 and KO11), and PI3K overexpression cells (WT and PI3K H1047R mutant) were treated with small molecule inhibitors (dabrafenib, BRAF inhibitor; trametinib, MEK inhibitor alone and in combination for 0, 1 and 7 days