scholarly journals Cabozantinib Is Effective in Melanoma Brain Metastasis Cell Lines and Affects Key Signaling Pathways

2021 ◽  
Vol 22 (22) ◽  
pp. 12296
Author(s):  
Trond Are Mannsåker ◽  
Tuyen Hoang ◽  
Synnøve Nymark Aasen ◽  
Ole Vidhammer Bjørnstad ◽  
Himalaya Parajuli ◽  
...  

Melanomas have a high potential to metastasize to the brain. Recent advances in targeted therapies and immunotherapies have changed the therapeutical landscape of extracranial melanomas. However, few patients with melanoma brain metastasis (MBM) respond effectively to these treatments and new therapeutic strategies are needed. Cabozantinib is a receptor tyrosine kinase (RTK) inhibitor, already approved for the treatment of non-skin-related cancers. The drug targets several of the proteins that are known to be dysregulated in melanomas. The anti-tumor activity of cabozantinib was investigated using three human MBM cell lines. Cabozantinib treatment decreased the viability of all cell lines both when grown in monolayer cultures and as tumor spheroids. The in vitro cell migration was also inhibited and apoptosis was induced by cabozantinib. The phosphorylated RTKs p-PDGF-Rα, p-IGF-1R, p-MERTK and p-DDR1 were found to be downregulated in the p-RTK array of the MBM cells after cabozantinib treatment. Western blot validated these results and showed that cabozantinib treatment inhibited p-Akt and p-MEK 1/2. Further investigations are warranted to elucidate the therapeutic potential of cabozantinib for patients with MBM.


2021 ◽  
Vol 3 (Supplement_3) ◽  
pp. iii3-iii3
Author(s):  
Jiwei Wang ◽  
Emma Rigg ◽  
Taral R Lunavat ◽  
Wenjing Zhou ◽  
Zichao Feng ◽  
...  

Abstract Background Melanoma has the highest propensity of any cancer to metastasize to the brain, with late-stage patients developing brain metastasis (MBM) in 40% of cases. Survival of patients with MBM is around 8 months with current therapies, illustrating the need for new treatments. MBM development is likely caused by molecular interactions between tumor cells and the brain, constituting the brain metastatic niche. miRNAs delivered by exosomes released by the primary tumor cells may play a role in niche establishment, yet the mechanisms are poorly understood. Here, the aim was to identify miRNAs released by exosomes from melanomas, which may be important in niche establishment and MBM progression. Materials and Methods miRNAs from exosomes collected from human astrocytes, melanocytes, and MBM cell lines were profiled to determine differential expression. Functional in vitro validation was performed by cell growth and migration assays, cytokine arrays, qPCR and Western blots. Functional in vivo studies were performed after miR knockdown in MBM cell lines. An in silico docking study was performed to determine drugs that potentially inhibit transcription of miR-146a to impede MBM development. Results miR-146a was the most upregulated miRNA in exosomes from MBM cells and was highly expressed in human and animal MBM samples. miR-146a mimics activated human astrocytes, shown by increased proliferation and migration, elevated expression of GFAP in vitro and in mouse brain tumor samples, and increased cytokine production. In animal studies, knockdown of miR-146a in MBM cells injected intracardially into mice reduced BM burden and increased animal survival. Based on the docking studies, deserpidine was found to be an effective inhibitor of MBM growth in vitro and in vivo. Conclusions MiR-146a may play an important role in MBM development, and deserpidine is a promising candidate for clinical use.



2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii57-ii57
Author(s):  
J Wang ◽  
E K Rigg ◽  
T R Lunavat ◽  
W Zhou ◽  
Z Feng ◽  
...  

Abstract BACKGROUND Melanoma has the highest propensity of any cancer to metastasize to the brain, with late-stage patients developing brain metastasis (MBM) in 40% of cases. Survival of patients with MBM is around 8 months with current therapies, illustrating the need for new treatments. MBM development is likely caused by molecular interactions between tumor cells and the brain, constituting the brain metastatic niche. miRNAs delivered by exosomes released from the primary tumor cells may play a role in niche establishment, yet the mechanisms are poorly understood. Here, the aim was to identify miRNAs released by exosomes from melanomas, which may be important in niche establishment and MBM progression. MATERIAL AND METHODS miRNAs in exosomes collected from human astrocytes, melanocytes, and MBM cell lines were profiled to determine differential expression. Functional in vitro validation was performed by cell growth and migration assays, cytokine arrays, qPCR and Western blots. Functional in vivo studies were performed after miR knockdown in MBM cell lines. An in silico docking study was performed to determine drugs that potentially inhibit transcription of miR-146a to impede MBM development. RESULTS miR-146a was the most upregulated miRNA in exosomes from MBM cells and was highly expressed in human and animal MBM samples. miR-146a mimics activated human astrocytes, shown by increased proliferation and migration, elevated expression of GFAP in vitro and in mouse brain tumor samples, and increased cytokine production. In animal studies, knockdown of miR-146 in MBM cells injected intracardially into mice reduced BM burden and increased animal survival. Based on the docking studies, deserpidine was found to be an effective inhibitor of MBM growth in vitro and in vivo. CONCLUSION miR-146a may play an important role in MBM development, and deserpidine is a promising candidate for clinical use.



Cancers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2838
Author(s):  
Shailendra K. Gautam ◽  
Ranjana K. Kanchan ◽  
Jawed A. Siddiqui ◽  
Shailendra K. Maurya ◽  
Sanchita Rauth ◽  
...  

Brain metastasis (BrM) remains a significant cause of cancer-related mortality in epidermal growth factor receptor 2-positive (ERBB2+) breast cancer (BC) patients. We proposed here that a combination treatment of irreversible tyrosine kinase inhibitor neratinib (NER) and the c-MET inhibitor cabozantinib (CBZ) could prevent brain metastasis. To address this, we first tested the combination treatment of NER and CBZ in the brain-seeking ERBB2+ cell lines SKBrM3 and JIMT-1-BR3, and in ERBB2+ organoids that expressed the c-MET/ERBB1 axis. Next, we developed and characterized an orthotopic mouse model of spontaneous BrM and evaluated the therapeutic effect of CBZ and NER in vivo. The combination treatment of NER and CBZ significantly inhibited proliferation and migration in ERBB2+ cell lines and reduced the organoid growth in vitro. Mechanistically, the combination treatment of NER and CBZ substantially inhibited ERK activation downstream of the c-MET/ERBB1 axis. Orthotopically implanted SKBrM3+ cells formed primary tumor in the mammary fat pad and spontaneously metastasized to the brain and other distant organs. Combination treatment with NER and CBZ inhibited primary tumor growth and predominantly prevented BrM. In conclusion, the orthotopic model of spontaneous BrM is clinically relevant, and the combination therapy of NER and CBZ might be a useful approach to prevent BrM in BC.



2020 ◽  
Vol 2 (Supplement_2) ◽  
pp. ii3-ii3
Author(s):  
Victor Oria ◽  
Hongyi Zhang ◽  
Huifang Zhu ◽  
Gang Deng ◽  
Christopher Zito ◽  
...  

Abstract Understanding the mechanisms behind melanoma brain metastasis, a disease that continues to portend a poor prognosis, will lead to the identification and development of novel drug targets. We previously identified PLEKHA5, a gene involved in brain development, as a novel molecule implicated in melanoma brain metastasis. Our aim was to further characterize the function of this protein in brain-tropic melanoma. We established stable loss- and gain-of-function cell lines to explore the underlying mechanisms of PLEKHA5-mediated tumor growth. The effect of PLEKHA5 expression silencing on proliferation and tumor growth was assessed using both in vitro systems and xenograft models of brain-tropic melanomas, respectively. The clinical relevance of PLEKHA5 dysregulation in brain metastasis was also investigated in two unique cohorts of melanoma patients with cerebrotropic disease and included analysis of matched cranial and extra-cranial specimens. Knock-down of PLEKHA5 in brain-tropic melanoma cells negatively regulated cell proliferation by inhibiting G1 to S cell cycle transition. This coincided with up-regulation of PDCD4, p21, and p27, as well as the downregulation of pRb protein, involved in the regulation of cell cycle. Conversely, the ectopic re-expression of PLEKHA5 had an inverse effect. Subcutaneous and direct cranial injections of PLEKHA5 knock-down cells in nude mice significantly inhibited tumor growth, while its overexpression upregulated the growth of tumors. This reduction in tumor growth in vivo might be attributed to decreased phosphorylation of Akt (S473) and mTOR (S2448), key mediators for tumor growth and survival. Our results demonstrate the role of PLEKHA5 as a mediator of melanoma brain metastasis. Our findings highlight the significance of PLEKHA5 as a possible regulator of cell cycle transition via crosstalk with the ubiquitin-proteasome and PI3K/AKT/mTOR signaling pathways, driving the proliferation and growth of brain-tropic melanomas. Our studies suggest that PLEKHA5 targeting should be further investigated for melanoma brain metastasis patient population.



Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2012
Author(s):  
Kathryn M. Appleton ◽  
Charuta C. Palsuledesai ◽  
Sean A. Misek ◽  
Maja Blake ◽  
Joseph Zagorski ◽  
...  

The Ras/MEK/ERK pathway has been the primary focus of targeted therapies in melanoma; it is aberrantly activated in almost 80% of human cutaneous melanomas (≈50% BRAFV600 mutations and ≈30% NRAS mutations). While drugs targeting the MAPK pathway have yielded success in BRAFV600 mutant melanoma patients, such therapies have been ineffective in patients with NRAS mutant melanomas in part due to their cytostatic effects and primary resistance. Here, we demonstrate that increased Rho/MRTF-pathway activation correlates with high intrinsic resistance to the MEK inhibitor, trametinib, in a panel of NRAS mutant melanoma cell lines. A combination of trametinib with the Rho/MRTF-pathway inhibitor, CCG-222740, synergistically reduced cell viability in NRAS mutant melanoma cell lines in vitro. Furthermore, the combination of CCG-222740 with trametinib induced apoptosis and reduced clonogenicity in SK-Mel-147 cells, which are highly resistant to trametinib. These findings suggest a role of the Rho/MRTF-pathway in intrinsic trametinib resistance in a subset of NRAS mutant melanoma cell lines and highlight the therapeutic potential of concurrently targeting the Rho/MRTF-pathway and MEK in NRAS mutant melanomas.





2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi222-vi222
Author(s):  
Breanna Mann ◽  
Noah Bell ◽  
Denise Dunn ◽  
Scott Floyd ◽  
Shawn Hingtgen ◽  
...  

Abstract Brain cancers remain one of the greatest medical challenges. The lack of experimentally tractable models that recapitulate brain structure/function represents a major impediment. Platforms that enable functional testing in high-fidelity models are urgently needed to accelerate the identification and translation of therapies to improve outcomes for patients suffering from brain cancer. In vitro assays are often too simple and artificial while in vivo studies can be time-intensive and complicated. Our live, organotypic brain slice platform can be used to seed and grow brain cancer cell lines, allowing us to bridge the existing gap in models. These tumors can rapidly establish within the brain slice microenvironment, and morphologic features of the tumor can be seen within a short period of time. The growth, migration, and treatment dynamics of tumors seen on the slices recapitulate what is observed in vivo yet is missed by in vitro models. Additionally, the brain slice platform allows for the dual seeding of different cell lines to simulate characteristics of heterogeneous tumors. Furthermore, live brain slices with embedded tumor can be generated from tumor-bearing mice. This method allows us to quantify tumor burden more effectively and allows for treatment and retreatment of the slices to understand treatment response and resistance that may occur in vivo. This brain slice platform lays the groundwork for a new clinically relevant preclinical model which provides physiologically relevant answers in a short amount of time leading to an acceleration of therapeutic translation.



2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e14544-e14544
Author(s):  
Son Tran ◽  
Satbir Thakur ◽  
Mohit Jain ◽  
Chunfen Zhang ◽  
Aru Narendran

e14544 Background: PV-10 (10% rose bengal disodium; 4,5,6,7-tetrachloro-2’,4’,5’,7’-tetraiodofluorescein) is a novel therapeutic agent previously shown to have potent anti-tumor activity following intratumoral injection in melanoma and refractory neuroblastoma, and currently is undergoing clinical testing as a single-agent for refractory metastatic neuroendocrine cancer (NCT02693067) and in combination with checkpoint inhibitors for metastatic melanoma (NCT02557321) and metastatic uveal melanoma (NCT00986661). Given the established clinical efficacy of PV-10 in adult melanoma and hepatic cancers via intratumoral injection, there is a need to evaluate the therapeutic potential of PV-10 in high-risk and refractory adult solid tumors via systemic administration. Our study aims to identify the clinical potential of systemically-delivered PV-10 by first generating prerequisite in vitro data for adult malignancies. Methods: Cytotoxicity assays were performed using the Alamar Blue assay to study the effects of PV-10 in vitro 96-hours post-treatment against a panel of adult solid tumor cell lines derived from breast (MCF-7, T-47D, MDA-MB-231), colorectal (HCT-116, LoVo, T-84), head and neck (CAL-27, Detroit-562, FaDu, UM-SCC-1), and testicular (NCC-IT, NTERA-2, TCAM-2) tissues. Light microscopy and Western blotting were used to investigate apoptosis induction and target modulation in tumor cells after PV-10 treatment. Results: In vitro results from our study demonstrate that PV-10 is cytotoxic at pharmacologically relevant concentrations across the indicated cell lines. Specifically, tumor cell lines originating from testicular tissues were highly sensitive to PV-10 treatment (Mean ± SD IC50: 37.5 ± 16.4 µM; n = 3) compared to breast (117.5 ± 71.0 µM; n = 3), colorectal (64.79 µM; n = 3), and head and neck (106.6 ± 29.2 µM; n = 4) cell lines. Western blot analyses showed dose- and time-dependent activation of pro-apoptotic protein markers in caspase-3 and PARP cleavage, indicating drug-induced apoptosis. Conclusions: This study provides the first pre-clinical results of PV-10 as a novel systemically-delivered therapeutic agent for a range of high-risk and refractory adult solid tumors. Data obtained from our in vitro experiments using a broad repertoire of cell lines that represent diverse molecular and phenotypic subtypes of solid tumors in adults can serve as prerequisite pre-clinical data to establish clinical testing in these populations.



2018 ◽  
Author(s):  
Soo-Hyun Kim ◽  
Richard P. Redvers ◽  
Lap Hing Chi ◽  
Xiawei Ling ◽  
Andrew J. Lucke ◽  
...  

ABSTRACTBreast cancer brain metastasis remains largely incurable. While several mouse models have been developed to investigate the genes and mechanisms regulating breast cancer brain metastasis, these models often lack clinical relevance since they require the use of immune-compromised mice and/or are poorly metastatic to brain from the mammary gland. We describe the development and characterisation of an aggressive brain metastatic variant of the 4T1 syngeneic model (4T1Br4) that spontaneously metastasises to multiple organs, but is selectively more metastatic to the brain from the mammary gland than parental 4T1 tumours. By immunohistochemistry, 4T1Br4 tumours and brain metastases display a triple negative phenotype, consistent with the high propensity of this breast cancer subtype to spread to brain. In vitro assays indicate that 4T1Br4 cells have an enhanced ability to adhere to or migrate across a brain-derived endothelial monolayer and greater invasive response to brain-derived soluble factors compared to 4T1 cells. These properties are likely to contribute to the brain-selectivity of 4T1Br4 tumours. Expression profiling and gene set enrichment analyses demonstrate the clinical relevance of the 4T1Br4 model at the transcriptomic level. Pathway analyses implicate tumour-intrinsic immune regulation and vascular interactions in successful brain colonisation, revealing potential therapeutic targets. Evaluation of two histone deacetylase inhibitors, SB939 and 1179.4b, shows partial efficacy against 4T1Br4 metastasis to brain and other sites in vivo and potent radio-sensitising properties in vitro. The 4T1Br4 model provides a clinically relevant tool for mechanistic studies and to evaluate novel therapies against brain metastasis.SUMMARY STATEMENTWe introduce a new syngeneic mouse model of spontaneous breast cancer brain metastasis, demonstrate its phenotypic, functional and transcriptomic relevance to human TNBC brain metastasis and test novel therapies.



2020 ◽  
Vol 4 (6) ◽  
Author(s):  
Lijuan Li ◽  
Lixia An ◽  
Lifang Li ◽  
Yongjuan Zhao

Sphingolipids are formed via the metabolism of sphingomyelin, aconstituent of the plasma membrane, or by denovosynthesis. Enzymatic pathways result in the formation of several different lipid mediators, which are known to have important roles in many cellular processes, including proliferation, apoptosis and migration. Several studies now suggest that these sphingolipid mediators, including ceramide, ceramide 1-phosphate and sphingosine 1-phosphate (S1P), are likely to have an integral role in in?ammation. This can involve, for example, activation of pro-in?ammatory transcription factors in different cell types and induction of cyclooxygenase-2, leading to production of pro-in?ammatory prostaglandins. The mode of action of each sphingolipid is different. Increased ceramide production leads to the formation of ceramide-rich areas of the membrane, which may assemble signalling complexes, whereas S1P acts via high-af?nity G-protein-coupled S1P receptors on the plasma membrane. Recent studies have demonstrated that in vitro effects of sphingolipids on in?ammation can translate into in vivo models. This review will highlight the areas of research where sphingolipids are involved in in?ammation and the mechanisms of action of each mediator. In addition, the therapeutic potential of drugs that alter sphingolipid actions will be examined with reference to disease states, such as asthma and in?ammatory bowel disease, which involve important in?ammatory components. A signi?cant body of research now indicates that sphingolipids are intimately involved in the in?ammatory process and recent studies have demonstrated that these lipids, together with associated enzymes and receptors, can provide effective drug targets for the treatment of pathological in?ammation.



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