scholarly journals Critical role of miR-10b in BRafV600E dependent anchorage-independent growth and invasion of melanoma cells

2018 ◽  
Author(s):  
Ila Datar ◽  
Gardiyawasam Kalpana ◽  
Ivana de la Serna ◽  
Robert Trumbly ◽  
Jungmin Choi ◽  
...  
Keyword(s):  
Cell Invasion ◽  
High Throughput Sequencing ◽  
Genetic Locus ◽  
Critical Role ◽  
Melanoma Cells ◽  
Growth And Survival ◽  
Anchorage Independent Growth ◽  
Expression Of Genes ◽  
Kinase Cascade

AbstractRecent high-throughput-sequencing of cancer genomes has identified oncogenic mutations in the BRaf genetic locus as one of the critical events in melanomagenesis. BRaf encodes a serine/threonine kinase that regulates the MAPK/ERK kinase (MEK) and extracellular signal-regulated kinase (ERK) protein kinase cascade. In normal cells, the activity of BRaf is tightly regulated and is required for cell growth and survival. BRaf gain-of-function mutations in melanoma frequently lead to unrestrained growth, enhanced cell invasion and increased viability of cancer cells. Although it is clear that the invasive phenotypes of BRaf mutated melanoma cells are stringently dependent on BRaf-MEK-ERK activation, the downstream effector targets that are required for oncogenic BRaf-mediated melanomagenesis are not well defined. miRNAs have regulatory functions towards the expression of genes that are important in carcinogenesis. We observed that miR-10b expression correlates with the presence of the oncogenic BRaf (BRafV600E) mutation in melanoma cells. While expression of miR-10b enhances anchorage-independent growth of BRaf wild-type melanoma cells, miR-10b silencing decreases BRafV600E cancer cell invasion in vitro. Importantly, the expression of miR-10b is required for BRafV600E-mediated anchorage-independent growth and invasion of melanoma cells in vitro. Taken together our results suggest that miR-10b is an important mediator of oncogenic BRafV600E activity in melanoma.

scholarly journals The Same Receptor, G Protein, and Mitogen-activated Protein Kinase Pathway Activate Different Downstream Regulators in the Alternative White and Opaque Pheromone Responses ofCandida albicans

2008 ◽  
Vol 19 (3) ◽  
pp. 957-970 ◽  
Author(s):  
Song Yi ◽  
Nidhi Sahni ◽  
Karla J. Daniels ◽  
Claude Pujol ◽  
Thyagarajan Srikantha ◽  
...  
Keyword(s):  
Protein Kinase ◽  
G Protein ◽  
Basal Layer ◽  
Mitogen Activated Protein Kinase ◽  
Expression Of Genes ◽  
Ofcandida Albicans ◽  
Mitogen Activated Protein ◽  
Kinase Cascade ◽  
Alternative Responses

Candida albicans must undergo a switch from white to opaque to mate. Opaque cells then release mating type-specific pheromones that induce mating responses in opaque cells. Uniquely in C. albicans, the same pheromones induce mating-incompetent white cells to become cohesive, form an adhesive basal layer of cells on a surface, and then generate a thicker biofilm that, in vitro, facilitates mating between minority opaque cells. Through mutant analysis, it is demonstrated that the pathways regulating the white and opaque cell responses to the same pheromone share the same upstream components, including receptors, heterotrimeric G protein, and mitogen-activated protein kinase cascade, but they use different downstream transcription factors that regulate the expression of genes specific to the alternative responses. This configuration, although common in higher, multicellular systems, is not common in fungi, and it has not been reported in Saccharomyces cerevisiae. The implications in the evolution of multicellularity in higher eukaryotes are discussed.

Inhibition of p38α MAPK Reduces Tumor Burden, Prevents the Development of Myeloma Bone Disease, and Increases Survival in the 5T2 and 5T33 Murine Models of Myeloma.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3436-3436 ◽  
Author(s):  
Karin Vanderkerken ◽  
Satya Medicherla ◽  
Les Coulton ◽  
Benjamin Van Camp ◽  
Andy Protter ◽  
...  
Keyword(s):  
Bone Disease ◽  
Critical Role ◽  
Disease Free Survival ◽  
Myeloma Cell ◽  
Bone Lesions ◽  
Myeloma Cells ◽  
Growth And Survival ◽  
Myeloma Bone Disease ◽  
Osteolytic Bone Disease

Abstract The bone microenvironment plays a critical role in supporting the growth and survival of myeloma cells and the development of osteolytic bone disease. Signalling through p38 α MAPK mediates synthesis of myeloma cell survival factors by stromal cells; whereas, inhibiting p38 α MAPK reduces myeloma cell proliferation and inhibits osteoclast formation in vitro. However, it is unclear whether p38 α MAPK inhibition will prevent the growth and survival of myeloma cells and the bone disease in vivo. The aim of this study was to determine whether SCIO-469, a selective p38 α MAPK inhibitor, would inhibit myeloma growth and prevent the development of bone disease in the 5TMM syngeneic models of myeloma. Treatment of 5TMM cells, in vitro, with SCIO-469 resulted in a clear inhibition of p38 phosphorylation, as assessed by Western blotting and an inhibition up to 35% of stromal cell induced 5T33MM proliferation. Injection of 5T2MM murine myeloma cells into C57Bl/KaLwRij mice resulted in the growth of myeloma in bone and the development of bone disease characterized by increased osteoclast surface (p<0.05), a reduction in cancellous bone (p<0.01) and the presence of osteolytic bone lesions on x-ray (p<0.01). Treatment of 5T2MM-bearing mice with SCIO-469 (150mg/kg in the diet, therapeutical treatment from paraprotein detection) resulted in a 42% decrease in serum paraprotein and prevented development of osteolytic lesions (p<0.01). Injection of 5T33MM cells into C57Bl/KaLwRij mice also resulted in the development of myeloma but not associated bone disease. Treatment of 5T33MM-bearing mice from the time of tumor cell injection with SCIO-469 resulted in a decrease in serum paraprotein (8.8+/−1.4g/dl to 0.04+/− 0.03g/dl, p<0.001) and a reduction in the proportion of tumor cells in the bone marrow (67 +/− 8.1% to 1.09 +/− 0.58%, p<0.001). Kaplan-Meier analysis demonstrated an increase in disease-free survival (veh=27.5 days vs 96 days, p<0.001) after treatment of the mice with SCIO-469. These data demonstrate that targeting p38 α MAPK with SCIO-469 is associated with an anti-myeloma effect, which indirectly prevents the development of myeloma bone disease.

Preclinical and correlative studies of cabozantinib (XL184) in urothelial cancer (UC).

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 4543-4543
Author(s):  
Andrea Borghese Apolo ◽  
Young H. Lee ◽  
Fabiola Cecchi ◽  
Piyush K. Agarwal ◽  
Howard L. Parnes ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cell Invasion ◽  
Urothelial Cancer ◽  
Invasive Disease ◽  
Soft Agar ◽  
Visceral Metastasis ◽  
Anchorage Independent Growth ◽  
Median Serum ◽  
Muscle Invasive

4543 Background: Mounting evidence supports Met as a therapeutic target in urothelial cancer (UC). Activated Met can promote angiogenesis and tumor growth by upregulating VEGF and may play a role in UC pathogenesis. Cabozantinib inhibits VEGFR2 and Met pathways. In this study, we assessed shed Met (sMet) levels in the urine and serum of UC patients (pts) and cabozantinib’s effects on HGF-driven UC cell growth and invasion. Methods: sMet levels in serum and urine samples from 31 pts with UC (23 metastatic, 8 muscle-invasive) were correlated with stage, presence of visceral metastases and urinary source. The effects of cabozantinib on 4 human UC-derived cell lines were studied in vitro. Intact RT4, TCC-SUP, T24M2 and T24M3 cells at 80% confluence were serum deprived 16 h, then left untreated or treated with hepatocyte growth factor (HGF) and/or cabozantinib prior to analysis of Met, phospho- (p)Met, pAkt, Akt, pMAPK and MAPK by immunoassay or immunoblotting. Cabozantinib effects on basal and HGF-induced UC cell invasion, proliferation and soft agar growth were measured. Results: Median serum Met levels were modestly higher in pts with metastatic versus muscle-invasive disease. Urinary Met levels were clearly higher in pts with visceral metastasis (P=0.0111) and in urine from ileal conduits and neobladders compared to normally voided urine, regardless of stage (P=0.0489). Met content in UC cell lines was low in RT4 and higher in T24M2, T24M3 and TCC-SUP. Basal pMet content was universally low, increased significantly by HGF and this was reversed by cabozantinib. HGF-driven increases in pAkt/Akt and pMAPK/MAPK in all 4 cell lines were reversed by cabozantinib, as were HGF-enhanced UC cell invasion, proliferation and anchorage independent growth. Conclusions: Median urinary sMet is significantly higher in pts with visceral metastasis and in specimens from ileal conduits and neobladders relative to normally voided urine. UC cell Met content in culture increased with disease grade; HGF stimulated activation of Met and known effectors, and enhanced invasion, growth rate and anchorage-independent growth; cabozantinib effectively reversed these HGF-driven effects. These data support evaluation of cabozantinib in pts with metastatic UC.

scholarly journals Energy metabolism adaptations and gene expression reprogramming in a cellular MAFLD model

2021 ◽  
Author(s):  
Tian-Ran Zhou ◽  
Cagla Cömert ◽  
Xiaoyu Zhou ◽  
Lin Lin ◽  
Lars Bolund ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Energy Metabolism ◽  
Cell Model ◽  
Critical Role ◽  
Huh7 Cell ◽  
Mitochondrial Superoxide ◽  
Expression Of Genes ◽  
Bioenergetic Analysis ◽  
Vitro Model

Mitochondrial dysfunction plays a critical role in metabolic associated fatty liver disease (MAFLD). This study aims to characterize mitochondrial dysfunctions in a human MAFLD Huh7 cell model triggered by free fatty acid (FFA) (palmitate and oleate) overload for 24 hours. We investigate its impact on cellular energy metabolism and identify potential targets for MAFLD treatment. FFA-treated cells displayed an accumulation of lipid droplets and slightly decreased viability but no significant changes in mitochondrial superoxide levels. Bioenergetic analysis showed a shift to more respiration and less glycolytic fermentation. Comprehensive transcriptomics and proteomics analyses identified changes in the expression of genes prominently involved in fatty acid handling and metabolism. The expressions of seven genes were consistently and significantly (p<0.05) altered (4 upregulated and 3 downregulated genes) in both proteomics and transcriptomics. The FFA-treated Huh7 cell model is an appropriate in vitro model to study fatty acid metabolism and suitable to investigate the role of mitochondria, glycolysis, and multiple metabolic pathways in MAFLD. Our comprehensive analyses form a basis for drug discovery and screening using this model.

scholarly journals Microneme Rhomboid Protease TgROM1 Is Required for Efficient Intracellular Growth of Toxoplasma gondii

2008 ◽  
Vol 7 (4) ◽  
pp. 664-674 ◽  
Author(s):  
Fabien Brossier ◽  
G. Lucas Starnes ◽  
Wandy L. Beatty ◽  
L. David Sibley
Keyword(s):  
Toxoplasma Gondii ◽  
Cell Invasion ◽  
Secretory Pathway ◽  
Transmembrane Domain ◽  
Critical Role ◽  
Host Cells ◽  
Wild Type ◽  
Intracellular Growth ◽  
Adhesive Proteins

ABSTRACT Rhomboids are serine proteases that cleave their substrates within the transmembrane domain. Toxoplasma gondii contains six rhomboids that are expressed in different life cycle stages and localized to different cellular compartments. Toxoplasma rhomboid protein 1 (TgROM1) has previously been shown to be active in vitro, and the orthologue in Plasmodium falciparum processes the essential microneme protein AMA1 in a heterologous system. We investigated the role of TgROM1 to determine its role during in vitro growth of T. gondii. TgROM1 was localized in the secretory pathway of the parasite, including the Golgi apparatus and micronemes, which contain adhesive proteins involved in invasion of host cells. However, unlike other micronemal proteins, TgROM1 was not released onto the parasite surface during cell invasion, suggesting it does not play a critical role in cell invasion. Suppression of TgROM1 using the tetracycline-regulatable system revealed that ROM1-deficient parasites were outcompeted by wild-type T. gondii. ROM1-deficient parasites showed only modest decrease in invasion but replicated more slowly than wild-type cells. Collectively, these results indicate that ROM1 is required for efficient intracellular growth by T. gondii.

scholarly journals Targeting Rad51 as a strategy for the treatment of melanoma cells resistant to MAPK pathway inhibition

2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Elena Makino ◽  
Lisa Marie Fröhlich ◽  
Tobias Sinnberg ◽  
Corinna Kosnopfel ◽  
Birgit Sauer ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Metastatic Melanoma ◽  
Mapk Pathway ◽  
Critical Role ◽  
Melanoma Cells ◽  
Mapk Signaling ◽  
Transcriptional Level ◽  
Mapk Inhibitor

Abstract Rad51 is an essential factor of the homologous recombination DNA repair pathway and therefore plays an important role in maintaining genomic stability. We show that RAD51 and other homologous recombination repair genes are overexpressed in metastatic melanoma cell lines and in melanoma patient samples, which correlates with reduced survival of melanoma patients. In addition, Rad51 expression in melanoma cells was regulated on a transcriptional level by the MAPK signaling pathway with Elk1 as the main downstream transcriptional effector. Most strikingly, melanoma cells which developed resistance towards MAPK inhibitors could be efficiently targeted by Rad51 inhibitors similar to their sensitive counterparts, leading to DNA damage, G2/M arrest and apoptosis. Furthermore, the treatment of MAPK inhibitor resistant cells with Rad51 inhibitors enhances the susceptibility of these cells for MAPK inhibitor treatment in vitro and in vivo. These data indicate that Rad51 plays a critical role in the survival of metastatic melanoma cells and is a promising target for the therapy of melanoma irrespective of its MAPK inhibitor resistance status.

scholarly journals Elucidating the Role of the Maternal Embryonic Leucine Zipper Kinase in Adrenocortical Carcinoma

Endocrinology ◽  
2018 ◽  
Vol 159 (7) ◽  
pp. 2532-2544 ◽  
Author(s):  
Katja Kiseljak-Vassiliades ◽  
Yu Zhang ◽  
Adwitiya Kar ◽  
Raud Razzaghi ◽  
Mei Xu ◽  
...  
Keyword(s):  
Adrenocortical Carcinoma ◽  
Colony Formation ◽  
Leucine Zipper ◽  
Relative Sensitivity ◽  
Soft Agar ◽  
Growth And Survival ◽  
Expression Of Genes ◽  
H295r Cells ◽  
Antitumorigenic Effect

Abstract Adrenocortical carcinoma (ACC) is an aggressive cancer with a 5-year survival rate <35%. Mortality remains high due to lack of targeted therapies. Using bioinformatic analyses, we identified maternal embryonic leucine zipper kinase (MELK) as 4.1-fold overexpressed in ACC compared with normal adrenal samples. High MELK expression in human tumors correlated with shorter survival and with increased expression of genes involved in cell division and growth. We investigated the functional effects of MELK inhibition using newly developed ACC cell lines with variable MELK expression, CU-ACC1 and CU-ACC2, compared with H295R cells. In vitro treatment with the MELK inhibitor, OTSSP167, resulted in a dose-dependent decrease in rates of cell proliferation, colony formation, and cell survival, with relative sensitivity of each ACC cell line based upon the level of MELK overexpression. To confirm a MELK-specific antitumorigenic effect, MELK was inhibited in H295R cells via multiple short hairpin RNAs. MELK silencing resulted in 1.9-fold decrease in proliferation, and 3- to 10-fold decrease in colony formation in soft agar and clonogenicity assays, respectively. In addition, although MELK silencing had no effect on survival in normoxia, exposure to a hypoxia resulted in a sixfold and eightfold increase in apoptosis as assessed by caspase-3 activation and TUNEL, respectively. Together these data suggest that MELK is a modulator of tumor cell growth and survival in a hypoxic microenvironment in adrenal cancer cells and support future investigation of its role as a therapeutic kinase target in patients with ACC.

scholarly journals Corosolic acid reduces NSCLC cell proliferation, invasion, and chemoresistance via inducing mitochondrial and liposomal oxidative stress

2021 ◽  
Author(s):  
Mingming Jin ◽  
Yue Wu ◽  
Yuqing Lou ◽  
Xiyu Liu ◽  
Yitian Dai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Invasion ◽  
High Throughput Sequencing ◽  
Redox System ◽  
Cell Types ◽  
Nsclc Cell ◽  
M Cell ◽  
Corosolic Acid

Abstract Background: Corosolic acid is a pentacyclic triterpenoid isolated from Lagerstroemia speciosa, which is known to inhibit cancer cell proliferations. Whereas, it is unclear whether this compound has any effect on non-small cell lung cancer (NSCLC) cells. Methods: Here, we cultured A549 and PC9 cells in increasing corosolic acid concentrations, as well as treated mice with a physiologically relevant concentration of the compound, and used metabolomics analysis and high-throughput sequencing to examine its influences on cell invasion and proliferation, chemoresistance, and metastasis. Results: We found that corosolic acid inhibited cell invasion and proliferation in vivo and in vitro, as well as increase the chemosensitivity of both cell types to cisplatin. Furthermore, we found that corosolic acid destabilized the glutathione peroxidase 2-mediated redox system, which increased mitochondrial and liposomal oxidative stress. Corosolic acid also decreased the targeting protein for Xklp2 level, which inhibited PI3K/AKT signaling and induced apoptosis. In addition, the accumulation of reactive oxygen species dissociated the CCNB1/CDK1 complex and induced G2/M cell cycle arrest. Conclusion: Taken collectively, the data indicate that corosolic acid reduces NSCLC cell invasion and proliferation, as well as chemoresistance, by inducing mitochondrial and liposomal oxidative stress.

scholarly journals Functional Implication of Netrin Expression in Malignant Melanoma

2009 ◽  
Vol 31 (6) ◽  
pp. 415-422
Author(s):  
Simone Kaufmann ◽  
Silke Kuphal ◽  
Thomas Schubert ◽  
Anja K. Bosserhoff
Keyword(s):  
Malignant Melanoma ◽  
Melanoma Cells ◽  
Transcriptional Level ◽  
Altered Expression ◽  
Invasion And Migration ◽  
Expression Of Genes ◽  
Functional Relevance ◽  
And Migration

Background: Malignant melanoma cells are known to have altered expression of genes supporting proliferation and invasion, however, the expression of molecules of the Netrin family of repellent factors has not been analyzed in melanomas until now.Results: Here, we show that Netrin-1 expression is strongly induced in melanoma cells compared to melanocytes in vivo and in vitro controlled at the transcriptional level via ETS-1. In addition, the expression of the netrin receptor UNC5B was induced and that of UNC5C was reduced in the tumor cells. In order to determine the functional relevance of Netrin-1 expression in malignant melanoma, Netrin expression in melanoma cells was reduced by siRNA attempts and primary human melanocytes were treated with recombinant Netrin-1. The cells showed no changes in proliferation or apoptosis, however, a strong reduction of migratory properties was observed in the melanoma cells after reduction of Netrin expression whereas melanocyte migration was strongly induced by treatment with Netrin.Conclusions: Our study suggests that Netrin-1 promotes melanoma cell invasion and migration and therefore has an important role in the progression of malignant melanoma.

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