ROS production induced by BRAF inhibitor treatment rewires metabolic processes affecting cell growth of melanoma cells

Metabolic changes promoting cell survival are involved in metastatic melanoma progression and in the development of drug resistance. In BRAF-inhibitor resistant melanoma cells, we explored the role of FASN, an enzyme involved in lipogenesis overexpressed in metastatic melanoma. Resistant melanoma cells displaying enhanced migratory and pro-invasive abilities increased sensitivity to the BRAF inhibitor PLX4032 upon the molecular targeting of FASN and upon treatment with the FASN inhibitor orlistat. This behavior was associated with a marked apoptosis and caspase 3/7 activation observed for the drug combination. The expression of FASN was found to be inversely associated with drug resistance in BRAF-mutant cell lines, both in a set of six resistant/sensitive matched lines and in the Cancer Cell Line Encyclopedia. A favorable drug interaction in resistant cells was also observed with U18666 A inhibiting DHCR24, which increased upon FASN targeting. The simultaneous combination of the two inhibitors showed a synergistic interaction with PLX4032 in resistant cells. In conclusion, FASN plays a role in BRAF-mutated melanoma progression, thereby creating novel therapeutic opportunities for the treatment of melanoma.

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82 Methyl Donor Supplementation Alters Cytosine Methylation and Biological Processes of Cells Cultured in Divergent Glucose Media Reflecting Improvements in Mitochondrial Respiration and Cell Growth Rate

Journal of Animal Science ◽

10.1093/jas/skab054.178 ◽

2021 ◽

Vol 99 (Supplement_1) ◽

pp. 109-109

Author(s):

Matthew S Crouse ◽

Wellison Jarles Da Silva Diniz ◽

Joel Caton ◽

Carl R Dahlen ◽

Lawrence P Reynolds ◽

...

Keyword(s):

Growth Rate ◽

Cell Proliferation ◽

Cell Growth ◽

Vitamin B12 ◽

Mitochondrial Respiration ◽

Cytosine Methylation ◽

Biological Processes ◽

Cell Growth Rate ◽

Metabolic Processes ◽

Positive Regulation

Abstract We hypothesized that supplementation of one-carbon metabolites (OCM: methionine, folate, choline, and vitamin B12) to bovine embryonic tracheal fibroblasts in divergent glucose media would alter cytosine methylation, and alterations in cytosine methylation will reflect biological processes matching previously improved mitochondrial respiration, cell proliferation, and cell growth rate data. Cells were cultured with 1g/L glucose (Low) or 4.5g/L glucose (High). Control medium (CON) contained basal concentrations of folate (0.001g/L), choline (0.001g/L), vitamin B12 (4µg/L), and methionine (0.015g/L). The OCM were supplemented at 2.5 and 5 times (2.5X and 5X, respectively) the CON media, except methionine was limited to 2X across all supplemented treatments. Cells were passaged three times in their treatment media before DNA extraction. Reduced representation bisulfite sequencing was adopted to analyze and compare the genomic methylation patterns within and across treatments using edgeR. Biological processes (BP) were retrieved based on the nearest genes of differentially methylated cytosines (P < 0.01) for each comparison between treatments. In both Low and High treatments, greater OCM increased the proportion of hypomethylated vs. hypermethylated cytosines. Functional analyses pointed out positive regulation of BP related to energy metabolism, except for the contrasts within the High group. Among the BP, we can highlight positive regulation of: GTPase activity, catalytic activity, molecular function, protein modification processes, phosphorylation, protein phosphorylation, cellular protein metabolic processes, MAPK cascade, and metabolic processes. These data support previously reported results from this experiment that showed increased mitochondrial respiration, cell proliferation, and growth rates with increasing OCM levels. We interpret these data to imply that when energy and OCM requirements are met for growth and basal methylation levels, DNA methylation levels decrease which may allow for greater transcription. Thus, OCM can be utilized for other functions such as polyamine synthesis, nucleotide synthesis, energetic metabolites, and phosphatidylcholine synthesis. USDA is an equal opportunity provider and employer.

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Farnesyltransferase inhibition causes morphological reversion of ras-transformed cells by a complex mechanism that involves regulation of the actin cytoskeleton

Molecular and Cellular Biology ◽

10.1128/mcb.14.6.4193-4202.1994 ◽

1994 ◽

Vol 14 (6) ◽

pp. 4193-4202

Author(s):

G C Prendergast ◽

J P Davide ◽

S J deSolms ◽

E A Giuliani ◽

S L Graham ◽

...

Keyword(s):

Cell Growth ◽

Fiber Formation ◽

Transformed Cells ◽

Actin Stress Fiber ◽

Actin Organization ◽

Stress Fiber Formation ◽

Molecule Inhibitor ◽

Farnesyl Protein Transferase ◽

Actin Stress Fiber Formation ◽

Inhibitor Treatment

A potent and specific small molecule inhibitor of farnesyl-protein transferase, L-739,749, caused rapid morphological reversion and growth inhibition of ras-transformed fibroblasts (Rat1/ras cells). Morphological reversion occurred within 18 h of L-739,749 addition. The reverted phenotype was stable for several days in the absence of inhibitor before the transformed phenotype reappeared. Cell enlargement and actin stress fiber formation accompanied treatment of both Rat1/ras and normal Rat1 cells. Significantly, inhibition of Ras processing did not correlate with the initiation or maintenance of the reverted phenotype. While a single treatment with L-739,749 was sufficient to morphologically revert Rat1/ras cells, repetitive inhibitor treatment was required to significantly reduce cell growth rate. Thus, the effects of L-739,749 on transformed cell morphology and cytoskeletal actin organization could be separated from effects on cell growth, depending on whether exposure to a farnesyl-protein transferase inhibitor was transient or repetitive. In contrast, L-739,749 had no effect on the growth, morphology, or actin organization of v-raf-transformed cells. Taken together, the results suggest that the mechanism of morphological reversion is complex and may involve farnesylated proteins that control the organization of cytoskeletal actin.

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Combination therapy targeting the elevated interleukin‐6 level reduces invasive migration of BRAF inhibitor‐resistant melanoma cells

Molecular Oncology ◽

10.1002/1878-0261.12433 ◽

2019 ◽

Vol 13 (2) ◽

pp. 480-494 ◽

Cited By ~ 5

Author(s):

Purusottam Mohapatra ◽

Chandra Prakash Prasad ◽

Tommy Andersson

Keyword(s):

Combination Therapy ◽

Interleukin 6 ◽

Braf Inhibitor ◽

Melanoma Cells

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Modulation of cell growth and cisplatin sensitivity by membrane γ-glutamyltransferase in melanoma cells

European Journal of Cancer ◽

10.1016/j.ejca.2006.04.016 ◽

2006 ◽

Vol 42 (15) ◽

pp. 2623-2630 ◽

Cited By ~ 48

Author(s):

Maria Franzini ◽

Alessandro Corti ◽

Evelina Lorenzini ◽

Aldo Paolicchi ◽

Alfonso Pompella ◽

...

Keyword(s):

Cell Growth ◽

Melanoma Cells ◽

Cisplatin Sensitivity

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Senescence-associated secretory factors induced by cisplatin in melanoma cells promote non-senescent melanoma cell growth through activation of the ERK1/2-RSK1 pathway

Cell Death and Disease ◽

10.1038/s41419-018-0303-9 ◽

2018 ◽

Vol 9 (3) ◽

Cited By ~ 18

Author(s):

Xuerong Sun ◽

Benyan Shi ◽

Huiling Zheng ◽

Ling Min ◽

Jie Yang ◽

...

Keyword(s):

Cell Growth ◽

Melanoma Cell ◽

Melanoma Cells

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Abstract 263: Differential Effects of 17ß-Estradiol and 16a-Hydroxyestrone in Oxidative Stress and Proliferative Responses in Human Pulmonary Artery Smooth Muscle Cells - Implications in Pulmonary Arterial Hypertension

Hypertension ◽

10.1161/hyp.62.suppl_1.a263 ◽

2013 ◽

Vol 62 (suppl_1) ◽

Author(s):

Katie Y Hood ◽

Augusto C Montezano ◽

Margaret R MacLean ◽

Rhian M Touyz

Keyword(s):

Oxidative Stress ◽

Pulmonary Arterial Hypertension ◽

Cell Growth ◽

Arterial Hypertension ◽

Molecular Mechanisms ◽

Antioxidant Systems ◽

Ros Generation ◽

Ros Production ◽

Differential Effects ◽

Pulmonary Arterial

Women develop pulmonary arterial hypertension (PAH) more frequently than men. This may relate, in part, to metabolism of 17β-estradiol (E2), leading to formation of the deleterious metabolite, 16α-hydroxyestrone (16α OHE1), which plays a role in the remodelling of pulmonary arteries. Molecular mechanisms whereby 16αOHE1 influences PASMC remodelling are unclear but ROS may be important, since oxidative stress has been implicated in the pathogenesis of PAH. We hypothesised that E2 and 16αOHE1 leads to Nox-induced ROS production, which promotes PASMC damage. Cultured PASMCs were stimulated with either E2 (1nM) or 16αOHE1 (1nM) in the presence/absence of EHT1864 (100μM, Rac1 inhibitor) or tempol (antioxidant; 10μM). ROS production was assessed by chemiluminescence (O2-) and Amplex Red (H2O2). Antioxidants (thioredoxin, peroxiredoxin 1 and NQ01), regulators of Nrf2 (BACH1, Nrf2) and, marker of cell growth (PCNA) were determined by immunoblotting. E2 increased O2- production at 4h (219 ± 30% vs vehicle; p<0.05), an effect blocked by EHT1864 and tempol. E2 also increased H2O2 generation (152 ± 4%; p<0.05). Thioredoxin, NQ01 and peroxiredoxin1 (71 ± 6%; 78 ± 9%; 69 ± 8%; p<0.05 respectively) levels were decreased by E2 as was PCNA expression (72 ± 2%; p<0.05). 16αOHE1 exhibited a rapid (5 min) and exaggerated increase in ROS production (355 ± 41%; p<0.05), blocked by tempol and EHT1864. This was associated with an increase in Nox4 expression (139 ± 11% vs vehicle, p<0.05). 16αOHE1 increased BACH1, (129 ± 3%; p<0.05), a competitor of Nrf2, which was decreased (92 ± 2%). In contrast, thioredoxin expression was increased by 16aOHE1 (154 ± 22%; p<0.05). PCNA (150 ± 5%) expression was also increased after exposure to 16αOHE1. In conclusion, E2 and 16αOHE1 have differential effects on redox processes associated with PASMC growth. Whereas E2 stimulates ROS production in a slow and sustained manner without effect on cell growth, 16αOHE1 upregulates Nox4 with associated rapid increase in ROS generation and downregulation of antioxidant systems, affecting proliferation. Our findings suggest that E2 -derived metabolites may promote a pro-proliferative PASMC phenotype through Nox4-derived ROS generation. These deleterious effects may impact on vascular remodeling in PAH.

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BRAF-V600E–mutated Rosai-Dorfman-Destombes disease and Langerhans cell histiocytosis with response to BRAF inhibitor

Blood Advances ◽

10.1182/bloodadvances.2019000093 ◽

2019 ◽

Vol 3 (12) ◽

pp. 1848-1853 ◽

Cited By ~ 8

Author(s):

Rosemarie Mastropolo ◽

Allison Close ◽

Steven W. Allen ◽

Kenneth L. McClain ◽

Scott Maurer ◽

...

Keyword(s):

Langerhans Cell Histiocytosis ◽

Braf Inhibitor ◽

Langerhans Cell ◽

Braf V600e ◽

Disease Monitoring ◽

Blood Testing ◽

Molecular Assays ◽

Key Points ◽

Treatment Plans ◽

Inhibitor Treatment

Key Points Demonstration of BRAF-V600E in Rosai-Dorfman-Destombes disease requires sensitive molecular assays and molecular-based tissue immunostain. BRAF-V600E blood testing is important for disease-monitoring BRAF-mutated histiocytosis and can guide inhibitor treatment plans.

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