Dataset Information

Melatonin synergizes BRAF-targeting agent vemurafenib in melanoma treatment by inhibiting iNOS/hTERT signaling and cancer-stem cell traits.

ABSTRACT: BACKGROUND:As the selective inhibitor of BRAF kinase, vemurafenib exhibits effective antitumor activities in patients with V600 BRAF mutant melanomas. However, acquired drug resistance invariably develops after its initial treatment. METHODS:Immunohistochemical staining was performed to detect the expression of iNOS and hTERT, p-p65, Epcam, CD44, PCNA in mice with melanoma xenografts. The proliferation and migration of melanoma cells were detected by MTT, tumorsphere culture, cell cycle, cell apoptosis, AO/EB assay and colony formation, transwell assay and scratch assay in vitro, and tumor growth differences were observed in xenograft nude mice. Changes in the expression of key molecules in the iNOS/hTERT signaling pathways were detected by western blot. Nucleus-cytoplasm separation, and immunofluorescence analyses were conducted to explore the location of p50/p65 in melanoma cell lines. Flow cytometry assay were performed to determine the expression of CD44. Pull down assay and ChIP assay were performed to detect the binding ability of p65 at iNOS and hTERT promoters. Additionally, hTERT promoter-driven luciferase plasmids were transfected in to melanoma cells with indicated treatment to determine luciferase activity of hTERT. RESULTS:Melatonin significantly and synergistically enhanced vemurafenib-mediated inhibitions of proliferation, colony formation, migration and invasion and promoted vemurafenib-induced apoptosis, cell cycle arresting and stemness weakening in melanoma cells. Further mechanism study revealed that melatonin enhanced the antitumor effect of vemurafenib by abrogating nucleus translocation of NF-?B p50/p65 and their binding at iNOS and hTERT promoters, thereby suppressing the expression of iNOS and hTERT. The elevated anti-tumor capacity of vemurafenib upon co-treatment with melatonin was also evaluated and confirmed in mice with melanoma xenografts. CONCLUSIONS:Collectively, our results demonstrate melatonin synergizes the antitumor effect of vemurafenib in human melanoma by inhibiting cell proliferation and cancer-stem cell traits via targeting NF-?B/iNOS/hTERT signaling pathway, and suggest the potential of melatonin in antagonizing the toxicity of vemurafenib and augmenting its sensitivities in melanoma treatment.

SUBMITTER: Hao J

PROVIDER: S-EPMC6360719 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Melatonin synergizes BRAF-targeting agent vemurafenib in melanoma treatment by inhibiting iNOS/hTERT signaling and cancer-stem cell traits.

Hao Jiaojiao J Fan Wenhua W Li Yizhuo Y Tang Ranran R Tian Chunfang C Yang Qian Q Zhu Tianhua T Diao Chaoliang C Hu Sheng S Chen Manyu M Guo Ping P Long Qian Q Zhang Changlin C Qin Ge G Yu Wendan W Chen Miao M Li Liren L Qin Lijun L Wang Jingshu J Zhang Xiuping X Ren Yandong Y Zhou Penghui P Zou Lijuan L Jiang Kui K Guo Wei W Deng Wuguo W

Journal of experimental & clinical cancer research : CR 20190204 1

<h4>Background</h4>As the selective inhibitor of BRAF kinase, vemurafenib exhibits effective antitumor activities in patients with V600 BRAF mutant melanomas. However, acquired drug resistance invariably develops after its initial treatment.<h4>Methods</h4>Immunohistochemical staining was performed to detect the expression of iNOS and hTERT, p-p65, Epcam, CD44, PCNA in mice with melanoma xenografts. The proliferation and migration of melanoma cells were detected by MTT, tumorsphere culture, cell ...[more]

PMID: 30717768

Similar Datasets

Project description:BackgroundRAF inhibitors are an effective therapy for patients with BRAF-mutant melanoma and brain metastasis. Efficacy data are derived from clinical studies enriched with physiologically fit patients; therefore, it is of interest to assess the real-world experience of vemurafenib in this population. Tumor-specific genetic variants that influence sensitivity to RAF kinase inhibitors also require investigation.MethodsRecords of patients with BRAF-mutant melanoma and brain metastases who were treated with vemurafenib were reviewed. Clinical data were extracted to determine extracranial and intracranial objective response rates, progression-free survival (PFS), overall survival (OS), and safety. A bait-capture, next-generation sequencing assay was used to identify mutations in pretreatment tumors that could explain primary resistance to vemurafenib.ResultsAmong patients with intracranial disease treated with vemurafenib, 27 were included in survival analyses and 22 patients were assessable for response. The extracranial and intracranial objective response rates were 71% and 50%, respectively. Discordant responses were observed between extracranial and intracranial metastatic sites in 4 of 19 evaluable patients. Median PFS was 4.1 months (95% confidence interval [CI]: 2.6-7.9); median intracranial PFS was 4.6 months (95% CI: 2.7-7.9), median OS was 7.5 months (95% CI: 4.3-not reached), with a 30.4% 1-year OS rate. Outcomes were influenced by performance status. Vemurafenib was tolerable, although radiation-induced dermatitis occurred in some patients who received whole-brain radiotherapy. Adequate samples for next-generation sequencing analysis were available for seven patients. Melanomas categorized as "poorly sensitive" (?20% tumor growth, new lesions, or ?50% shrinkage for <4 months) harbored co-occurring mutations in genes predicted to activate the phosphatidylinositol 3-kinase-AKT (PI3K-AKT) pathway.ConclusionVemurafenib is highly active in BRAF-mutant melanoma brain metastases but has limited activity in patients with poor performance status. The safety and efficacy of concurrent radiotherapy and RAF inhibition requires careful clinical evaluation. Combination strategies blocking the MAPK and PI3K-AKT pathway may be warranted in a subset of patients.Implications for practiceVemurafenib is active for BRAF-mutant intracranial melanoma metastases in an unselected patient population typical of routine oncologic practice. Patients with poor performance status appear to have poor outcomes despite vemurafenib therapy. Preliminary data indicate that co-occurring or secondary alterations in the phosphatidylinositol 3-kinase-AKT (PI3K-AKT) pathway are involved in resistance to RAF inhibition, thus providing a rationale for dual MAPK and PI3K-AKT pathway inhibition in this patient population.

Dataset Information

Melatonin synergizes BRAF-targeting agent vemurafenib in melanoma treatment by inhibiting iNOS/hTERT signaling and cancer-stem cell traits.

Publications

Melatonin synergizes BRAF-targeting agent vemurafenib in melanoma treatment by inhibiting iNOS/hTERT signaling and cancer-stem cell traits.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets