Effect of celastrol on temozolomide cytotoxicity in melanoma cells and inhibition of NF-kB signaling

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 9076-9076
Author(s):  
M. Chen ◽  
I. Osman ◽  
S. J. Orlow

9076 Background: Temozolomide (TMZ) exhibits clinical activity in the treatment of melanoma and glioblastoma, but response rates are low. Identification of agents that improve TMZ's efficacy and overcome resistance is of great interest. In this study, we have identified celastrol as a natural product that significantly enhances TMZ-induced cytotoxicity by testing a library of drugs and natural products for cytotoxic activity against glioma and melanoma cell lines and have examined its mechanism of action in melanoma cells. Methods: A preliminary screening of a library of 2000 drugs and natural products was performed and a short list of drugs was identified as able to enhance TMZ-induced cell killing in TMZ-resistant cancer cell lines. The effects of these compounds were further confirmed in five melanoma cell lines. A cell proliferation assay was used to compare growth inhibitory effects of single agent TMZ versus combination treatments. Synergy in inhibiting cell proliferation was assessed using combination-index methods. The expression of NF-kB, IkB, MAPK, and PARP were examined using Western blot analysis. The effect of treatments on the cell cycle was examined by flow cytometry. The localization of NF-kB in melanoma cells was evaluated through immunofluorescence microscopy. Results: Combining celastrol and TMZ synergistically inhibited cell proliferation, enhanced cell cycle arrest, and increased apoptosis in a series of melanoma cell lines, compared to treatment with TMZ alone. We further found that celastrol inhibited proteasome activity, TNF-α induced IkB phosphorylation and NF-kB translocation to the nucleus. Inhibition of NF-kB with siRNA mimicked the ability of celastrol to sensitize melanoma cells to TMZ-induced cell killing, suggesting inhibition of NF-kB was indeed involved in TMZ/celastrol-induced cytotoxicity. Furthermore, combination treatment induced phosphorylation of JNK. Conclusions: Our data suggest that combined use of TMZ with celastrol, a natural product derived from a vine extract that has been used orally in Chinese medicine for over a thousand years, may enhance the chemotherapeutic efficacy of TMZ in melanoma. No significant financial relationships to disclose.

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 12019-12019 ◽  
Author(s):  
S. Radulovic ◽  
S. Bjelogrlic ◽  
Z. Todorovic ◽  
M. Prostran

12019 Background: PARP-1 facilitates DNA strand brakes repair and PARP inhibitors were investigated as enhancers of chemoradiotherapy. We investigated whether 5-AIQ potentates the effect of doxorubicin (DOXO), cisplatin (CDDP) and paclitaxel (Ptx) on human (slow-growing) FemX and murine (fast-growing) B16 melanoma cell lines. Methods: Twenty-four hours after cells were seeded in 96 well plates, cytotoxic drugs and 5-AIQ were added to cell medium. For evaluation of single-agent activity, drugs were applied in concentration ranges as follows: CDDP (0.3–30 μM), DOXO (0.1–3 μM), Ptx (1–100 ηM), 5-AIQ (1–100 μM). 5-AIQ (3μM) was combined with CDDP (0.1, 0.3, 1 μM), DOXO (10, 3, 100 ηM), or Ptx (1, 3, 10 ηM). Incubation lasted for 72 hrs when SRB assay was utilized to determine individual and combine activity (interactions calculated with isobole method). For cell cycle analysis B16 cells were seeded on 6 well plates and treated with each drug alone and combinations, using the same concentrations as those for investigation of combine cytotoxic activity. Cell cycle was determined after 72 hrs, on FACS Calibur with propidium iodide dye. Results: 5-AIQ induced minimal changes in cell viability and cell cycle progression on both cell lines, compared to non-treated control. CDDP revealed high activity against FemX (IC50 = 2.85 μM) and B16 cells (IC50 = 8.84 μM), and G0/G1 arrest. In B16 cells 5-AIQ multiply enhanced CDDP’s activity with strong synergistic interaction and cells slightly driven to S phase. Synergism was also detected on B16 cells treated with combination of DOXO (IC50 = 0.2 μM on B16 and 0.89 μM on FemX) and 5-AIQ when DOXO was applied in low concentrations (10 and 30 ηM), while 5-AIQ did not interfere with cell cycle changes. Cytotoxicity of Ptx (IC50 = 6.16 ηM on B16 and <1 ηM on FemX) was stimulated only at higher concentrations. 5-AIQ stimulated G0/G1 and S phase arrest on B16 cells with Ptx of 3 and 10 ηM, respectively. In FemX cells, most of the interactions of 5-AIQ with CDDP, DOXO, and Ptx revealed as antagonistic. Conclusions: PARP-1 inhibitor 5-AIQ enhances cytotoxic activity of both DNA damaging and agents with different mechanism of action, but the effect varies between cell lines with different proliferation rate. No significant financial relationships to disclose.


2020 ◽  
Vol 3 (2) ◽  
pp. 194-209 ◽  
Author(s):  
Ana Carolina Ramos Moreno ◽  
Renata de Freitas Saito ◽  
Manoela Tiago ◽  
Renato Ramos Massaro ◽  
Roberta Liberato Pagni ◽  
...  

Among skin cancers, melanoma has the highest mortality rate. The heterogeneous genetic melanoma background leads to a tumor-propagating capacity particularly important in maintaining therapeutic resistance, and tumor recurrence. The identification of efficient molecules able to control melanoma progress represents an important opportunity for new therapeutic strategies, particularly in combination with the current standard-of-care treatments. In this context, several studies have reported the antitumor effects of melatonin against different types of cancer, including melanoma. Here, we describe the underlying mechanisms associated with melatonin’s activity in human melanoma cell lines, focusing on cell cycle and cytoskeleton remodeling. Interestingly, while melatonin induced melanocyte DNA replication, melanoma cells exhibited cell cycle arrest in the G1-phase. This phenomenon was associated with cyclin-D1 downregulation or p21 overexpression. The efficacy of melatonin on melanoma cells survival and proliferation was detected using the clonogenic assay, with a decrease in both the number and size of colonies. Additionally, melatonin induced a dramatic cytoskeleton remodeling in all melanoma cell lines, leading to a star-like morphology or cell swelling. The role of melatonin on melanoma cytoskeleton was associated with the actin disruption, with thinning and/or broken actin fibers, and weak and/or loss of paxillin along stress fibers. These data support the observed findings that melatonin impairs melanoma invasion in skin reconstructed models. Together, our results suggest that melatonin could be used to control melanoma growth and support basic and clinical studies on melatonin as a promising immunometabolic adjuvant for melanoma therapy.


Author(s):  
Ting La ◽  
Lei Jin ◽  
Xiao Ying Liu ◽  
Ze Hua Song ◽  
Margaret Farrelly ◽  
...  

The deubiquitinase cylindromatosis (CYLD) functions as a tumor suppressor inhibiting cell proliferation in many cancer types including melanoma. Here we present evidence that a proportion of melanoma cells are nonetheless addicted to CYLD for survival. The expression levels of CYLD varied widely in melanoma cell lines and melanomas in vivo, with a subset of melanoma cell lines and melanomas displaying even higher levels of CYLD than melanocyte lines and nevi, respectively. Strikingly, although short hairpin RNA (shRNA) knockdown of CYLD promoted, as anticipated, cell proliferation in some melanoma cell lines, it reduced cell viability in a fraction of melanoma cell lines with relatively high levels of CYLD expression and did not impinge on survival and proliferation in a third type of melanoma cell lines. The decrease in cell viability caused by CYLD knockdown was due to induction of apoptosis, as it was associated with activation of the caspase cascade and was abolished by treatment with a general caspase inhibitor. Mechanistic investigations demonstrated that induction of apoptosis by CYLD knockdown was caused by upregulation of receptor-interacting protein kinase 1 (RIPK1) that was associated with elevated K63-linked polyubiquitination of the protein, indicating that CYLD is critical for controlling RIPK1 expression in these cells. Of note, microRNA (miR) profiling showed that miR-99b-3p that was predicted to target the 3-untranslated region (3-UTR) of the CYLD mRNA was reduced in melanoma cell lines with high levels of CYLD compared with melanocyte lines. Further functional studies confirmed that the reduction in miR-99b-3p expression was responsible for the increased expression of CYLD in a highly cell line-specific manner. Taken together, these results reveal an unexpected role of CYLD in promoting survival of a subset of melanoma cells and uncover the heterogeneity of CYLD expression and its biological significance in melanoma.


2021 ◽  
Author(s):  
Iwona Piatkowska-Chmiel ◽  
Monika Gawronska-Grzywacz ◽  
Magdalena Iwan ◽  
Dorota Natorska-Chomicka ◽  
Mariola Herbet ◽  
...  

Abstract BackgroundThere is a lot of evidence which suggests that DPP IV level may correlate with a type of tumor cells, metastatic potential and prognosis for the patient. Bearing in mind that the melanomas are characterized by high heterogeneity and identification of specific phenotypes of cells allows for early and more effective therapy, the aim of our study was to check whether there is a correlation between the DPPIV and the metastatic potential of melanoma cell lines. Additionally, the aim of our research was to evaluate the anti-tumor potential of linagliptin and saxagliptin in melanoma cell lines as well as determining correlation between cytotoxicity of the drugs and DPP IV level. MethodsThe inhibitory effect of tested drugs on the cancer cell growth was assessed using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) while cell cycle analysis and apoptosis were performed using the NucleoCounter® NC-3000™ system (ChemoMetec, Denmark), following the instructions provided by the manufacturer. DPPIV release by cancer cells was measured by DPP4/CD26 ELISA assay kit for biological samples (Cloud-Clone Corp.,Wuhan,China). ResultsOur results showed that DPPIV overexpression promoted cell proliferation of melanoma cells. Our data showed that especially short term treatment with linagliptin is associated with not only decreased expression of DPPIV and inhibition of cell proliferation but also induction of cell cycle disruption and apoptosis in melanoma. ConclusionsThe routine identification of this glycoprotein in melanoma would be fundamental to assessing not only the risk of metastasis/disease progression but also selection of therapy and evaluation of its effectiveness.


2019 ◽  
Vol 12 (2) ◽  
pp. 50 ◽  
Author(s):  
Rehana L. Ahmed ◽  
Daniel P. Shaughnessy ◽  
Todd P. Knutson ◽  
Rachel I. Vogel ◽  
Khalil Ahmed ◽  
...  

Cyclin dependent kinase 11 (CDK11) is a protein kinase that regulates RNA transcription, pre-mRNA splicing, mitosis, and cell death. Targeting of CDK11 expression levels is effective in the experimental treatment of breast and other cancers, but these data are lacking in melanoma. To understand CDK11 function in melanoma, we evaluated protein and RNA levels of CDK11, Cyclin L1 and Cyclin L2 in benign melanocytes and BRAF- as well as NRAS-mutant melanoma cell lines. We investigated the effectiveness of reducing expression of this survival kinase using RNA interference on viability, clonal survival, and tumorsphere formation in melanoma cell lines. We examined the impact of CDK11 loss in BRAF-mutant melanoma on more than 700 genes important in cancer signaling pathways. Follow-up analysis evaluated how CDK11 loss alters cell cycle function in BRAF- and NRAS-mutant melanoma cells. We present data on CDK11, CCNL1 and CCNL2 mRNA expression in melanoma patients, including prognosis for survival. In sum, we found that CDK11 is necessary for melanoma cell survival, and a major impact of CDK11 loss in melanoma is to cause disruption of the cell cycle distribution with accumulation of G1- and loss of G2/M-phase cancer cells.


Cancers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 4781
Author(s):  
Abdelnaby Khalyfa ◽  
Wojciech Trzepizur ◽  
Alex Gileles-Hillel ◽  
Zhuanhong Qiao ◽  
David Sanz-Rubio ◽  
...  

Obstructive sleep apnea (OSA) is associated with increased cutaneous melanoma incidence and adverse outcomes. Exosomes are secreted by most cells, and play a role in OSA-associated tumor progression and metastasis. We aimed to study the effects of plasma exosomes from OSA patients before and after adherent treatment with continuous positive airway pressure (CPAP) on melanoma cells lines, and also to identify exosomal miRNAs from melanoma cells exposed to intermittent hypoxia (IH) or normoxia. Plasma-derived exosomes were isolated from moderate-to-severe OSA patients before (V1) and after (V2) adherent CPAP treatment for one year. Exosomes were co-incubated with three3 different melanoma cell lines (CRL 1424; CRL 1619; CRL 1675) that are characterized by genotypes involving different mutations in BRAF, STK11, CDKN2A, and PTEN genes to assess the effect of exosomes on cell proliferation and migration, as well as on pAMK activity in the presence or absence of a chemical activator. Subsequently, CRL-1424 and CRL-1675 cells were exposed to intermittent hypoxia (IH) and normoxia, and exosomal miRNAs were identified followed by GO and KEG pathways and gene networks. The exosomes from these IH-exposed melanoma cells were also administered to THP1 macrophages to examine changes in M1 and M2 polarity markers. Plasma exosomes from V1 increased CRL-1424 melanoma cell proliferation and migration compared to V2, but not the other two cell lines. Exposure to CRL-1424 exosomes reduced pAMPK/tAMPK in V1 compared to V2, and treatment with AMPK activator reversed the effects. Unique exosomal miRNAs profiles were identified for CRL-1424 and CRL-1675 in IH compared to normoxia, with six miRNAs being regulated and several KEGG pathways were identified. Two M1 markers (CXCL10 and IL6) were significantly increased in monocytes when treated with exosomes from IH-exposed CRL-1424 and CRL-1625 cells. Our findings suggest that exosomes from untreated OSA patients increase CRL-1424 melanoma malignant properties, an effect that is not observed in two other melanoma cell lines. Exosomal cargo from CRL-1424 cells showed a unique miRNA signature compared to CRL-1675 cells after IH exposures, suggesting that melanoma cells are differentially susceptible to IH, even if they retain similar effects on immune cell polarity. It is postulated that mutations in STK-11 gene encoding for the serine/threonine kinase family that acts as a tumor suppressor may underlie susceptibility to IH-induced metabolic dysfunction, as illustrated by CRL-1424 cells.


2021 ◽  
Vol 22 (2) ◽  
pp. 537
Author(s):  
Paula Wróblewska-Łuczka ◽  
Aneta Grabarska ◽  
Magdalena Florek-Łuszczki ◽  
Zbigniew Plewa ◽  
Jarogniew J. Łuszczki

(1) Cisplatin (CDDP) is used in melanoma chemotherapy, but it has many side effects. Hence, the search for natural substances that can reduce the dose of CDDP, and CDDP-related toxicity, is highly desired. Coumarins have many biological properties, including anticancer and antiproliferative effects. (2) An in vitro 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay on two human melanoma cell lines (FM55P and FM55M2) examined the antitumor properties of CDDP and five naturally occurring coumarins (osthole, xanthotoxin, xanthotoxol, isopimpinellin, and imperatorin). The antiproliferative effects produced by combinations of CDDP with the coumarins were assessed using type I isobolographic analysis. (3) The most potent anticancer properties of coumarins were presented by osthole and xanthotoxol. These compounds were characterized by the lowest median inhibitory concentration (IC50) values relative to the FM55P and FM55M2 melanoma cells. Isobolographic analysis showed that for both melanoma cell lines, the combination of CDDP and osthole exerted synergistic and additive interactions, while the combination of CDDP and xanthotoxol exerted additive interactions. Combinations of CDDP with xanthotoxin, isopimpinellin, and imperatorin showed antagonistic and additive interactions in two melanoma cell lines. (4) The combination of CDDP and osthole was characterized by the most desirable synergistic interaction. Isobolographic analysis allows the selection of potential candidates for cancer drugs among natural substances.


1998 ◽  
Vol 30 (3) ◽  
pp. 189-194 ◽  
Author(s):  
Volker Enzmann ◽  
Frank Faude ◽  
Leon Kohen ◽  
Peter Wiedemann

Blood ◽  
1991 ◽  
Vol 78 (3) ◽  
pp. 609-615 ◽  
Author(s):  
GC Baldwin ◽  
DW Golde ◽  
GF Widhopf ◽  
J Economou ◽  
JC Gasson

Abstract Hematopoietic growth factor receptors are present on cells of normal nonhematopoietic tissues such as endothelium and placenta. We previously demonstrated functional human granulocyte-macrophage colony- stimulating factor (GM-CSF) receptors on small cell carcinoma of the lung cell lines, and others have reported that certain solid tumor cell lines respond to GM-CSF in clonogenic assays. In the current study, we examine human melanoma cell lines and fresh specimens of melanoma to determine whether they have functional GM-CSF receptors. Scatchard analyses of 125I-GM-CSF equilibrium binding to melanoma cell lines showed a mean of 542 +/- 67 sites per cell with a kd of 0.72 +/- 0.14 nmol/L. Cross-linking studies in the melanoma cell line, M14, showed a major GM-CSF receptor species of 84,000 daltons. Under the conditions tested, the M14 cells did not have a proliferative response to GM-CSF in vitro, nor was any induction of primary response genes detected by Northern analysis in response to GM-CSF. Studies to determine internal translocation of the receptor-ligand complex indicated less than 10% of the 125I-GM-CSF internalized was specifically bound to receptors. Primary melanoma cells from five surgical specimens had GM-CSF receptors; Scatchard analysis was performed on one sample, showing 555 sites/cell with a kd of 0.23 nmol/L. These results indicate that human tumor cells may express a low-affinity GM-CSF receptor protein that localizes to the cell surface and binds ligand, but lacks functional components or accessory factors needed to transduce a signal.


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