scholarly journals E3 ubiquitin ligase PARK2, an inhibitor of melanoma cell growth, is repressed by the oncogenic ERK1/2-ELK1 transcriptional axis

2020 ◽  
Vol 295 (47) ◽  
pp. 16058-16071
Author(s):  
Valentina Montagnani ◽  
Luisa Maresca ◽  
Alessandro Apollo ◽  
Sara Pepe ◽  
Ryan M. Carr ◽  
...  
Keyword(s):  
Cell Growth ◽  
Malignant Melanoma ◽  
Melanoma Cell ◽  
Ubiquitin Ligase ◽  
E3 Ubiquitin Ligase ◽  
Melanoma Cells ◽  
Mapk Signaling ◽  
Braf V600e ◽  
Promising Therapeutic Approach ◽  
Melanoma Growth

Malignant melanoma, the most aggressive form of skin cancer, is characterized by high prevalence of BRAF/NRAS mutations and hyperactivation of extracellular signal-regulated kinase 1 and 2 (ERK1/2), mitogen-activated protein kinases (MAPK), leading to uncontrolled melanoma growth. Efficacy of current targeted therapies against mutant BRAF or MEK1/2 have been hindered by existence of innate or development of acquired resistance. Therefore, a better understanding of the mechanisms controlled by MAPK pathway driving melanogenesis will help develop new treatment approaches targeting this oncogenic cascade. Here, we identify E3 ubiquitin ligase PARK2 as a direct target of ELK1, a known transcriptional effector of MAPK signaling in melanoma cells. We show that pharmacological inhibition of BRAF-V600E or ERK1/2 in melanoma cells increases PARK2 expression. PARK2 overexpression reduces melanoma cell growth in vitro and in vivo and induces apoptosis. Conversely, its genetic silencing increases melanoma cell proliferation and reduces cell death. Further, we demonstrate that ELK1 is required by the BRAF-ERK1/2 pathway to repress PARK2 expression and promoter activity in melanoma cells. Clinically, PARK2 is highly expressed in WT BRAF and NRAS melanomas, but it is expressed at low levels in melanomas carrying BRAF/NRAS mutations. Overall, our data provide new insights into the tumor suppressive role of PARK2 in malignant melanoma and uncover a novel mechanism for the negative regulation of PARK2 via the ERK1/2-ELK1 axis. These findings suggest that reactivation of PARK2 may be a promising therapeutic approach to counteract melanoma growth.

Temozolomide combined with the PI3K inhibitor LY294002 or the mTOR inhibitor rapamycin inhibits melanoma cell growth, survival and invasion

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 8559-8559 ◽  
Author(s):  
F. E. Meier ◽  
K. Lasithiotakis ◽  
B. Schittek ◽  
T. Sinnberg ◽  
C. Garbe
Keyword(s):  
Cell Growth ◽  
Metastatic Melanoma ◽  
Signaling Pathways ◽  
Cell Lines ◽  
Melanoma Cell ◽  
Mtor Inhibitor ◽  
Melanoma Cells ◽  
Mapk Signaling ◽  
Pi3k Inhibitor ◽  
Mapk Signaling Pathways

8559 Background: Potential therapeutic targets in the treatment of metastatic melanoma have emerged, to which pharmacological inhibitors have been designed, which may enhance tumor chemosensitivity. In melanoma, dacarbazine is considered to be the most effective agent although total responses do not exceed 20% The clinical activity of temozolomide is similar to that of dacarbazine, but temozolomide has the advantages of being absorbed orally and of crossing the blood-brain barrier. Many clinical trials of targeted therapy and chemotherapy combinations lack rigorous preclinical evaluation and may neglect relevant mechanistic interactions. The PI3K-AKT-mTOR (AKT) and RAS-RAF- MEK-ERK (MAPK) signaling pathways are constitutively activated in melanoma, and appear to play a role in chemoresistance. Methods: In this study, a panel of pharmacological inhibitors was utilized in order to block the AKT and MAPK signaling pathways at different levels (AKT: PI3K, mTOR; MAPK: RAF, MEK) in 5 human metastatic melanoma cell lines. The effects on chemosensitivity to temozolomide and cisplatin was then investigated. Results: The effects of most inhibitors on chemosensitivity varied significantly between the different cell lines. However, LY294002, a PI3K inhibitor and rapamycin, an mTOR inhibitor, consistently enhanced chemosensitivity. Treatment of melanoma cells with temozolomide or cisplatin combined with LY294002 or rapamycin had a strong effect on melanoma cell growth and survival. Invasive melanoma growth in organotypic cultures of human skin was suppressed completely. The most pronounced potentiation of efficacy was seen with temozolomide in combination with rapamycin. Conclusions: These data suggest that LY294002 and rapamycin can render melanoma cells susceptible to apoptosis, induced by chemotherapeutic agents such as temozolomide and cisplatin. Since both temozolomide and rapamycin are used clinically, the combination of temozolomide with rapamycin might potentially be utilized as an approach in melanoma treatment. This combination merits clinical investigation. No significant financial relationships to disclose.

scholarly journals Inhibitory Effects of Trehalose on Malignant Melanoma Cell Growth: Implications for a Novel Topical Anticancer Agent on the Ocular Surface

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Takashi Kudo ◽  
Kimio Takeuchi ◽  
Yu-ichi Ebina ◽  
Mitsuru Nakazawa
Keyword(s):  
Cell Cycle ◽  
Flow Cytometry ◽  
Cell Growth ◽  
Malignant Melanoma ◽  
Melanoma Cell ◽  
Ocular Surface ◽  
Melanoma Cells ◽  
Apoptotic Cells ◽  
Inhibitory Effects ◽  
Malignant Melanoma Cell

Purpose. To investigate the inhibitory effects of trehalose on malignant melanoma cell growth. Methods. We cultured human malignant melanoma cells in a medium containing trehalose (control/2.5%/5.0%/7.5%/10.0%) and used the MTT assay to evaluate the growth activities. Subsequently, trehalose was topically instilled on subconjunctivally inoculated melanoma cells in F334/NJcl-rmu/rmu rats, followed by a histopathological evaluation of tumor growth. Using flow cytometry, we compared the distribution of the cell cycle, rate of apoptotic cells, and intracellular factors related to the cell cycle in cultured melanoma cells after trehalose treatment. Results. The MTT study showed that proliferation of melanoma cells was significantly inhibited by ≧ 5% of trehalose concentrations in the culture media. Subconjunctivally inoculated melanoma cell masses were significantly smaller in eyes administered trehalose as compared to controls. Flow cytometry analyses demonstrated that the trehalose groups had increased rates of G2/M phase cells and apoptotic cells in the cell culture. These cells also exhibited increased expressions of cell-cycle inhibitory factors. Conclusions. The current results show trehalose inhibits malignant melanoma cell growth by inducing G2/M cell cycle arrest and apoptosis, suggesting trehalose as a potential candidate for a topical agent to inhibit proliferation of malignant tumor cells of the ocular surface.

scholarly journals Genetic Target Modulation Employing CRISPR/Cas9 Identifies Glyoxalase 1 as a Novel Molecular Determinant of Invasion and Metastasis in A375 Human Malignant Melanoma Cells In Vitro and In Vivo

Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1369 ◽  
Author(s):  
Jana Jandova ◽  
Jessica Perer ◽  
Anh Hua ◽  
Jeremy A. Snell ◽  
Georg T. Wondrak
Keyword(s):  
Malignant Melanoma ◽  
Enzymatic Activity ◽  
Melanoma Cell ◽  
Melanoma Cells ◽  
Metabolic Reprogramming ◽  
Invasion And Metastasis ◽  
Genetic Rescue ◽  
Human Malignant Melanoma ◽  
Glyoxalase 1 ◽  
Molecular Determinant

Metabolic reprogramming is a molecular hallmark of cancer. Recently, we have reported the overexpression of glyoxalase 1 (encoded by GLO1), a glutathione-dependent enzyme involved in detoxification of the reactive glycolytic byproduct methylglyoxal, in human malignant melanoma cell culture models and clinical samples. However, the specific role of GLO1 in melanomagenesis remains largely unexplored. Here, using genetic target modulation, we report the identification of GLO1 as a novel molecular determinant of invasion and metastasis in malignant melanoma. First, A375 human malignant melanoma cells with GLO1 deletion (A375-GLO1_KO) were engineered using CRISPR/Cas9, and genetic rescue clones were generated by stable transfection of KO clones employing a CMV-driven GLO1 construct (A375-GLO1_R). After confirming GLO1 target modulation at the mRNA and protein levels (RT-qPCR, immunodetection, enzymatic activity), phenotypic characterization indicated that deletion of GLO1 does not impact proliferative capacity while causing significant sensitization to methylglyoxal-, chemotherapy-, and starvation-induced cytotoxic stress. Employing differential gene expression array analysis (A375-GLO1_KO versus A375-GLO1_WT), pronounced modulation of epithelial mesenchymal transition (EMT)-related genes [upregulated: CDH1, OCLN, IL1RN, PDGFRB, SNAI3; (downregulated): BMP1, CDH2, CTNNB1, FN1, FTH1, FZD7, MELTF, MMP2, MMP9, MYC, PTGS2, SNAI2, TFRC, TWIST1, VIM, WNT5A, ZEB1, and ZEB2 (up to tenfold; p < 0.05)] was observed—all of which are consistent with EMT suppression as a result of GLO1 deletion. Importantly, these expression changes were largely reversed upon genetic rescue employing A375-GLO1_R cells. Differential expression of MMP9 as a function of GLO1 status was further substantiated by enzymatic activity and ELISA analysis; phenotypic assessment revealed the pronounced attenuation of morphological potential, transwell migration, and matrigel 3D-invasion capacity displayed by A375-GLO1_KO cells, reversed again in genetic rescue clones. Strikingly, in a SCID mouse metastasis model, lung tumor burden imposed by A375-GLO1_KO cells was strongly attenuated as compared to A375-GLO1_WT cells. Taken together, these prototype data provide evidence in support of a novel function of GLO1 in melanoma cell invasiveness and metastasis, and ongoing investigations explore the function and therapeutic potential of GLO1 as a novel melanoma target.

scholarly journals Cinobufagin Suppresses Melanoma Cell Growth by Inhibiting LEF1

2020 ◽  
Vol 21 (18) ◽  
pp. 6706
Author(s):  
Geon-Hee Kim ◽  
Xue-Quan Fang ◽  
Woo-Jin Lim ◽  
Jooho Park ◽  
Tae-Bong Kang ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cell Growth ◽  
Tumor Growth ◽  
Cancer Cells ◽  
Melanoma Cell ◽  
Transcriptional Activity ◽  
Melanoma Cells ◽  
Lung Cancer Cells ◽  
Luciferase Assay ◽  
Dependent Manner

Constitutive activation of the β-catenin dependent canonical Wnt signaling pathway, which enhances tumor growth and progression in multiple types of cancer, is commonly observed in melanoma. LEF1 activates β-catenin/TCF4 transcriptional activity, promoting tumor growth and progression. Although several reports have shown that LEF1 is highly expressed in melanoma, the functional role of LEF1 in melanoma growth is not fully understood. While A375, A2058, and G361 melanoma cells exhibit abnormally high LEF1 expression, lung cancer cells express lower LEF1 levels. A luciferase assay-based high throughput screening (HTS) with a natural compound library showed that cinobufagin suppressed β-catenin/TCF4 transcriptional activity by inhibiting LEF1 expression. Cinobufagin decreases LEF1 expression in a dose-dependent manner and Wnt/β-catenin target genes such as Axin-2, cyclin D1, and c-Myc in melanoma cell lines. Cinobufagin sensitively attenuates cell viability and induces apoptosis in LEF1 expressing melanoma cells compared to LEF1-low expressing lung cancer cells. In addition, ectopic LEF1 expression is sufficient to attenuate cinobufagin-induced apoptosis and cell growth retardation in melanoma cells. Thus, we suggest that cinobufagin is a potential anti-melanoma drug that suppresses tumor-promoting Wnt/β-catenin signaling via LEF1 inhibition.

scholarly journals Tumour Progression Stage-Dependent Secretion of YB-1 Stimulates Melanoma Cell Migration and Invasion

Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2328 ◽  
Author(s):  
Corinna Kosnopfel ◽  
Tobias Sinnberg ◽  
Birgit Sauer ◽  
Heike Niessner ◽  
Alina Muenchow ◽  
...  
Keyword(s):  
Cell Migration ◽  
Malignant Melanoma ◽  
Melanoma Cell ◽  
Cell Biology ◽  
Secretory Pathway ◽  
Tumour Progression ◽  
Melanoma Cells ◽  
Migration And Invasion ◽  
Melanoma Progression ◽  
And Migration

Secreted factors play an important role in intercellular communication. Therefore, they are not only indispensable for the regulation of various physiological processes but can also decisively advance the development and progression of tumours. In the context of inflammatory disease, Y-box binding protein 1 (YB-1) is actively secreted and the extracellular protein promotes cell proliferation and migration. In malignant melanoma, intracellular YB-1 expression increases during melanoma progression and represents an unfavourable prognostic marker. Here, we show active secretion of YB-1 from melanoma cells as opposed to benign cells of the skin. Intriguingly, YB-1 secretion correlates with the stage of melanoma progression and depends on a calcium- and ATP-dependent non-classical secretory pathway leading to the occurrence of YB-1 in the extracellular space as a free protein. Along with an elevated YB-1 secretion of melanoma cells in the metastatic growth phase, extracellular YB-1 exerts a stimulating effect on melanoma cell migration, invasion, and tumourigenicity. Collectively, these data suggest that secreted YB-1 plays a functional role in melanoma cell biology, stimulating metastasis, and may serve as a novel biomarker in malignant melanoma that reflects tumour aggressiveness.

scholarly journals The micro RNA hsa-miR-377-3p inhibits tumor growth in malignant melanoma

RSC Advances ◽  
2019 ◽  
Vol 9 (33) ◽  
pp. 19057-19064
Author(s):  
Jian Yuan ◽  
Lei Jiang ◽  
Chaotang Guo
Keyword(s):  
Cell Growth ◽  
Malignant Melanoma ◽  
Tumor Growth ◽  
Cell Line ◽  
Melanoma Cell ◽  
Micro Rna ◽  
A375 Cell ◽  
Line P ◽  
A375 Cell Line

We have demonstrated that miR-377-3p inhibits melanoma cell growth by binding to the ARMC8 mRNA in the A375 cell line.

scholarly journals Long-Term Local Injection of RAGE-Aptamer Suppresses the Growth of Malignant Melanoma in Nude Mice

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Nobutaka Nakamura ◽  
Takanori Matsui ◽  
Yuri Nishino ◽  
Ami Sotokawauchi ◽  
Yuichiro Higashimoto ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Malignant Melanoma ◽  
Nude Mice ◽  
Melanoma Cells ◽  
Local Injection ◽  
Stress Generation ◽  
Mrna Levels ◽  
Melanoma Growth

Accumulating evidence has suggested the pathological role of advanced glycation end products (AGEs) and their receptor RAGE axis in aging-associated disorders, including cancers. In this study, we examined the effects of local injection of RAGE-aptamer adjacent to the tumor on G361 melanoma growth in nude mice. We further investigated the effects of RAGE-aptamer on oxidative stress generation, RAGE, vascular endothelial growth factor (VEGF), and monocyte chemoattractant protein-1 (MCP-1) gene expression in Nε-(carboxymethyl)lysine (CML)-exposed G361 melanoma cells in vitro. Local injection of RAGE-aptamer adjacent to the tumor dramatically decreased the growth of G361 melanoma in nude mice, which was associated with reduced expression of CML, RAGE, nitrotyrosine, VEGF, CD31, and von Willebrand factor, markers of endothelial cells in G361 tumors. Furthermore, RAGE-aptamer inhibited the binding of CML to V-domain of RAGE and blocked the CML-induced increases in oxidative stress generation, RAGE, VEGF, and MCP-1 mRNA levels in G361 melanoma cells. Our present findings suggest that long-term local injection of RAGE-aptamer adjacent to the tumor could inhibit melanoma growth in nude mice partly by suppressing tumor angiogenesis via blockade of the CML-RAGE interaction. Local injection of RAGE-aptamer may be a feasible therapeutic tool for the treatment of malignant melanoma.

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