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Drug resistance in melanoma

F Faião-Flores, D K Alves-Fernandes, P C Pennacchi, S Sandri, A L S A Vicente, C Scapulatempo-Neto, V L Vazquez, R M Reis, J Chauhan, C R Goding, K S Smalley, S S Maria-Engler
BRAF inhibitor (BRAFi) therapy for melanoma patients harboring the V600E mutation is initially highly effective, but almost all patients relapse within a few months. Understanding the molecular mechanisms underpinning BRAFi-based therapy is therefore an important issue. Here we identified a previously unsuspected mechanism of BRAFi resistance driven by elevated Hedgehog (Hh) pathway activation that is observed in a cohort of melanoma patients after vemurafenib treatment. Specifically, we demonstrate that melanoma cell lines, with acquired in vitro-induced vemurafenib resistance, show increased levels of glioma-associated oncogene homolog 1 and 2 (GLI1/GLI2) compared with naïve cells...
October 17, 2016: Oncogene
Markus V Heppt, Cecilia Dietrich, Saskia A Graf, Thomas Ruzicka, Julia K Tietze, Carola Berking
Melanoma is a common type of skin cancer with a high propensity to metastasize. Tyrosine kinase inhibitors targeting the mitogen-activated protein kinase (MAPK) pathway and immune checkpoint blockade have recently revolutionized the management of unresectable and metastatic disease. However, acquired resistance and primary non-response to therapy require novel treatment strategies and combinations. The purpose of this review is to provide a brief and up-to-date overview on the clinical management and current trial landscape in melanoma...
2016: Oncology Research and Treatment
Neville E Sanjana, Jason Wright, Kaijie Zheng, Ophir Shalem, Pierre Fontanillas, Julia Joung, Christine Cheng, Aviv Regev, Feng Zhang
The noncoding genome affects gene regulation and disease, yet we lack tools for rapid identification and manipulation of noncoding elements. We developed a CRISPR screen using ~18,000 single guide RNAs targeting >700 kilobases surrounding the genes NF1, NF2, and CUL3, which are involved in BRAF inhibitor resistance in melanoma. We find that noncoding locations that modulate drug resistance also harbor predictive hallmarks of noncoding function. With a subset of regions at the CUL3 locus, we demonstrate that engineered mutations alter transcription factor occupancy and long-range and local epigenetic environments, implicating these sites in gene regulation and chemotherapeutic resistance...
September 30, 2016: Science
Fernanda Antunes, Marco Corazzari, Gustavo Pereira, Gian Maria Fimia, Mauro Piacentini, Soraya Smaili
Melanoma is one of leading cause of tumor death worldwide. Anti-cancer strategy includes combination of different chemo-therapeutic agents as well as radiation; however these treatments have limited efficacy and induce significant toxic effects on healthy cells. One of most promising novel therapeutic approach to cancer therapy is the combination of anti-cancer drugs with calorie restriction. Here we investigated the effect Cisplatin (CDDP), one of the most potent chemotherapeutic agent used to treat tumors, in association with fasting in wild type and mutated BRAF(V600E) melanoma cell lines...
September 29, 2016: Biochemical and Biophysical Research Communications
Kei Kawaguchi, Takashi Murakami, Bartosz Chmielowski, Kentaro Igarashi, Tasuku Kiyuna, Michiaki Unno, Scott D Nelson, Tara A Russell, Sarah M Dry, Yunfeng Li, Fritz C Eilber, Robert M Hoffman
Melanoma is a recalcitrant disease. The present study used a patient-derived orthotopic xenograft (PDOX) model of melanoma to test sensitivity to three molecularly-targeted drugs and one standard chemotherapeutic. A BRAF-V600E-mutant melanoma obtained from the right chest wall of a patient was grown orthotopically in the right chest wall of nude mice to establish a PDOX model. Two weeks after implantation, 50 PDOX nude mice were divided into 5 groups: G1, control without treatment; G2, vemurafenib (VEM) (30 mg/kg); G3; temozolomide (TEM) (25 mg/kg); G4, trametinib (TRA) (0...
September 28, 2016: Oncotarget
Leona Rohrbeck, Jia-Nan Gong, Erinna F Lee, Andrew J Kueh, Andreas Behren, Lin Tai, Guillaume Lessene, David C S Huang, Walter D Fairlie, Andreas Strasser, Marco J Herold
A large proportion of melanomas harbour the activating BRAF(V600E) mutation that renders these cells dependent on MAPK signalling for their survival. Although the highly specific and clinically approved BRAF(V600E) kinase inhibitor, PLX4032, induces apoptosis of melanoma cells bearing this mutation, the underlying molecular mechanisms are not fully understood. Here, we reveal that PLX4032-induced apoptosis depends on the induction of the pro-apoptotic BH3-only protein PUMA with a minor contribution of its relative BIM...
September 30, 2016: Cell Death and Differentiation
J P Liu, H Wang
Prostate cancer, especially castration-resistant prostate cancer (CRPC) with its very poor prognosis, quite difficult treatments and urgent need of new theraputic strategies has become a serious problem of men's health in our country. Recent studies have shown that prostate cancer cells can stimulate the immune response; therefore, immunotherapy has become one of the hot spots in the treatment of CRPC. Cancer vaccines including polypeptide vaccines, nucleic acid vaccines, whole cell vaccines and autologous dendritic cell vaccines have been in stage Ⅱ or Ⅲ clinical trials, and will have good application prospects...
October 1, 2016: Zhonghua Wai Ke za Zhi [Chinese Journal of Surgery]
Eri Adachi, Katsuya Sakai, Takumi Nishiuchi, Ryu Imamura, Hiroki Sato, Kunio Matsumoto
A dynamic phenotypic change contributes to the metastatic progression and drug resistance in malignant melanoma. Nevertheless, mechanisms for a phenotypic change have remained to be addressed. Here, we show that Met receptor expression changes in a cell-autonomous manner and can distinguish phenotypical differences in growth, as well as in metastatic and drug-resistant characteristics. In metastatic melanoma, the cells are composed of Met-low and Met-high populations. Met-low populations have stem-like gene expression profiles, are resistant to chemotherapeutic agents, and have shown abundant angiogenesis and rapid tumor growth in subcutaneous inoculation...
September 23, 2016: Oncotarget
Reiko Satow, Tomomi Nakamura, Chiaki Kato, Miku Endo, Mana Tamura, Ryosuke Batori, Shiori Tomura, Yumi Murayama, Kiyoko Fukami
Insights into mechanisms of drug resistance could extend the efficacy of cancer therapy. To probe mechanisms in melanoma, we performed siRNA screening of genes which mediate the development of neural crest cells from which melanocytes are derived. Here we report the identification of ZIC5 as a mediator of melanoma drug resistance. ZIC5 is a transcriptional suppressor of E-cadherin expressed highly in human melanoma. ZIC5 enhanced melanoma cell proliferation, survival, drug resistance, in vivo growth and metastasis...
September 26, 2016: Cancer Research
Rita Dorantes-Heredia, José Manuel Ruiz-Morales, Fernando Cano-García
Lung cancer is the principal cause of cancer-related death worldwide. The use of targeted therapies, especially tyrosine kinase inhibitors (TKIs), in specific groups of patients has dramatically improved the prognosis of this disease, although inevitably some patients will develop resistance to these drugs during active treatment. The most common cancer-associated acquired mutation is the epidermal growth factor receptor (EGFR) Thr790Met (T790M) mutation. During active treatment with targeted therapies, histopathological transformation to small-cell lung carcinoma (SCLC) can occur in 3-15% of patients with non-small-cell lung carcinoma (NSCLC) tumors...
August 2016: Translational Lung Cancer Research
Elisabetta Catalani, Francesca Proietti Serafini, Silvia Zecchini, Simona Picchietti, Anna Maria Fausto, Enrico Marcantoni, Federico Buonanno, Claudio Ortenzi, Cristiana Perrotta, Davide Cervia
Several modern drugs, including those for cancer therapy, have been isolated from natural sources, are based on natural products and its derivatives, or mime natural products. Some of them are in clinical use, others in clinical trials. The success of natural products in drug discovery is related to their biochemical characteristics and to the technologic methods used to study their feature. Natural compounds may acts as chemo-preventive agents and as factors that increase therapeutic efficacy of existing drugs, thus overcoming cancer cell drug resistance that is the main factor determining the failure in conventional chemotherapy...
September 17, 2016: Pharmacological Research: the Official Journal of the Italian Pharmacological Society
Ruo-Yu Zhang, Zhi-Hong Yu, Lifan Zeng, Sheng Zhang, Yunpeng Bai, Jinmin Miao, Lan Chen, Jingwu Xie, Zhong-Yin Zhang
Melanoma ranks among the most aggressive and deadly human cancers. Although a number of targeted therapies are available, they are effective only in a subset of patients and the emergence of drug resistance often reduces durable responses. Thus there is an urgent need to identify new therapeutic targets and develop more potent pharmacological agents for melanoma treatment. Herein we report that SHP2 levels are frequently elevated in melanoma, and high SHP2 expression is significantly associated with more metastatic phenotype and poorer prognosis...
September 16, 2016: Oncotarget
Long-Wang Chen, Ze-Feng Wang, Bo Zhu, Ruo-Jun Man, Yan-Dong Liu, Yuan-Heng Zhang, Bao-Zhong Wang, Zhong-Chang Wang, Hai-Liang Zhu
The increasingly acquired resistance to vemurafenib and side effects of known inhibitors motivate the search for new and more effective anti-melanoma drugs. In this Letter, virtual screening and scaffold growth were combined together to achieve new molecules as BRAF(V600E) inhibitors. Along with docking simulation, a primary screen in vitro was performed to filter the modifications for the lead compound, which was then substituted, synthesized and evaluated for their inhibitory activity against BRAF(V600E) and several melanoma cell lines...
October 15, 2016: Bioorganic & Medicinal Chemistry Letters
Jean-Philip Lacroix, Beatrice Wang
BACKGROUND: Dabrafenib, a novel selective small-molecule inhibitor of BRAF, has been shown to increase overall survival in patients with unresectable metastatic melanoma harboring the BRAF V600E mutation. The development of resistance has led to combination therapy with selective MEK inhibitor trametinib. Compared with vemurafenib, dabrafenib is a more recent BRAF inhibitor approved by the Food and Drug Administration in May 2013 for metastatic melanoma; fewer data are available in the current literature regarding cutaneous toxicity...
September 13, 2016: Journal of Cutaneous Medicine and Surgery
Valeria Lucarini, Carla Buccione, Giovanna Ziccheddu, Francesca Peschiaroli, Paola Sestili, Rossella Puglisi, Gianfranco Mattia, Cristiana Zanetti, Isabella Parolini, Laura Bracci, Iole Macchia, Alessandra Rossi, Maria Teresa D'Urso, Daniele Macchia, Massimo Spada, Adele De Ninno, Annamaria Gerardino, Pamela Mozetic, Marcella Trombetta, Alberto Rainer, Luca Businaro, Giovanna Schiavoni, Fabrizio Mattei
Resistance to Type I IFN (IFN-I)-induced anti-neoplastic effects has been reported in many tumors and arise, in part, from epigenetic silencing of IFN-stimulated genes by DNA methylation. We hypothesized that restoration of IFN-stimulated genes by co-administration of the demethylating drug 5-Aza-2'-Deoxycitidine (Decitabine; DAC) may enhance the susceptibility to IFN-I-mediated anti-tumoral effects in melanoma. We show that combined administration of IFN-I and DAC significantly inhibits the growth of murine and human melanoma cells, both in vitro and in vivo...
September 10, 2016: Journal of Investigative Dermatology
Sirkku Peltonen, Roope A Kallionpää, Juha Peltonen
Neurofibromatosis 1 (NF1) occurs in 1:2000 births. The main diagnostic signs are visible on the skin and this opens several interesting aspects for dermatological point of view. The NF1 syndrome is caused by mutations in the NF1 gene which encodes the tumor suppressor protein neurofibromin. Neurofibromin functions as a Ras-GTPase activating protein (RasGAP), and NF1 mutations lead to over-activation of the Ras signaling pathway. The NF1 gene and neurofibromin have intriguing functions in keratinocytes and melanocytes...
September 13, 2016: Experimental Dermatology
Takuya Iyoda, Yumi Nagamine, Yoshitomi Nakane, Yuya Tokita, Shougo Akari, Kazuki Otsuka, Motomichi Fujita, Keisuke Itagaki, You-Ichi Takizawa, Hiroaki Orita, Toshiyuki Owaki, Jyunichi Taira, Ryo Hayashi, Hiroaki Kodama, Fumio Fukai
The acquisition of drug resistance mediated by the interaction of tumor cells with the extracellular matrix (ECM), commonly referred to as cell adhesion-mediated drug resistance (CAM-DR), has been observed not only in hematopoietic tumor cells but also in solid tumor cells. We have previously demonstrated that a 22-mer peptide derived from fibronectin, FNIII14, can inhibit cell adhesion through the inactivation of β1 integrin; when coadministered with cytarabine, FNIII14 completely eradicates acute myelogenous leukemia by suppressing CAM-DR...
2016: PloS One
Lukas Klumpp, Efe C Sezgin, Franziska Eckert, Stephan M Huber
Breast cancer, lung cancer and melanoma exhibit a high metastatic tropism to the brain. Development of brain metastases severely worsens the prognosis of cancer patients and constrains curative treatment options. Metastasizing to the brain by cancer cells can be dissected in consecutive processes including epithelial-mesenchymal transition, evasion from the primary tumor, intravasation and circulation in the blood, extravasation across the blood-brain barrier, formation of metastatic niches, and colonization in the brain...
2016: International Journal of Molecular Sciences
Annissa J Huhn, Rachel M Guerra, Edward P Harvey, Gregory H Bird, Loren D Walensky
Anti-apoptotic BCL-2 family proteins block cell death by trapping the critical α-helical BH3 domains of pro-apoptotic members in a surface groove. Cancer cells hijack this survival mechanism by overexpressing a spectrum of anti-apoptotic members, mounting formidable apoptotic blockades that resist chemotherapeutic treatment. Drugging the BH3-binding pockets of anti-apoptotic proteins has become a highest-priority goal, fueled by the clinical success of ABT-199, a selective BCL-2 inhibitor, in reactivating apoptosis in BCL-2-dependent cancers...
September 22, 2016: Cell Chemical Biology
Tsun-Wen Yao, Jie Zhang, Michael Prados, William A Weiss, C David James, Theodore Nicolaides
Activating mutation of BRAF is a common finding in pediatric gliomas. As many as 14% of high grade and up to 66% of certain subtypes of low grade pediatric glioma have the BRAFV600E mutation. Small molecule inhibitors that selectively target BRAFV600E are FDA approved for melanoma and have shown significant efficacy in treating BRAFV600E glioma in pre-clinical trials. Despite showing initial anti-tumor activity, acquired drug resistance significantly limits the benefit from being treated with BRAFV600E inhibitors...
September 7, 2016: Oncotarget
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