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Transcriptional regulation of autophagy-lysosomal function in BRAF-driven melanoma progression and chemoresistance.

Autophagy maintains homeostasis and is induced upon stress. Yet, its mechanistic interaction with oncogenic signaling remains elusive. Here, we show that in BRAFV600E-melanoma, autophagy is induced by BRAF inhibitor (BRAFi), as part of a transcriptional program coordinating lysosome biogenesis/function, mediated by the TFEB transcription factor. TFEB is phosphorylated and thus inactivated by BRAFV600E via its downstream ERK independently of mTORC1. BRAFi disrupts TFEB phosphorylation, allowing its nuclear translocation, which is synergized by increased phosphorylation/inactivation of the ZKSCA

Combination of vemurafenib and cobimetinib in patients with advanced BRAF(V600)-mutated melanoma: a phase 1b study.

BACKGROUND: Addition of a MEK inhibitor to a BRAF inhibitor enhances tumour growth inhibition, delays acquired resistance, and abrogates paradoxical activation of the MAPK pathway in preclinical models of BRAF-mutated melanoma. We assessed the safety and efficacy of combined BRAF inhibition with vemurafenib and MEK inhibition with cobimetinib in patients with advanced BRAF-mutated melanoma. METHODS: We undertook a phase 1b study in patients with advanced BRAF(V600)-mutated melanoma. We included individuals who had either recently progressed on vemurafenib or never received a BRAF inhibitor. I

[What's new in dermato-oncology?].

One of the major advance concerning skin carcinoma is the development of targeted therapy: anti-patch/sonic/hedgehog for basal cell carcinoma (BCC) and anti-EGFR for squamous cell carcinoma (SCC). These therapies are indicated for advanced non surgically removable tumors. Their anti-tumoral efficacy has been shown, their effect seems to be suspensive which raises the question of their tolerability for long term use. Laboratory work have shown that BCC and SCC stem cells locate in different cell compartments and follow distinct molecular events which explains their distinct behaviour. The role

Novel nitric oxide-releasing derivatives of farnesylthiosalicylic acid: synthesis and evaluation of antihepatocellular carcinoma activity.

Novel furoxan-based nitric oxide (NO) releasing derivatives (8a-p) of farnesylthiosalicylic acid (FTS) were synthesized. Compound 8l displayed the strongest inhibition on the proliferation of human hepatocellular carcinoma (HCC) cells in vitro, superior to FTS, sorafenib, and furoxan moiety, selectively induced high frequency of HCC cell apoptosis, and produced high levels of NO in HCC cells but not in nontumor liver cells. Furthermore, 8l exhibited low acute toxicity to mice and significantly inhibited the growth of HCC tumors in vivo and the Ras-related signaling in the tumors. Therefore, ou

Effects of angiotensin type I receptor blockade on the cardiac Raf/MEK/ERK cascade activated via adrenergic receptors.

A close interaction between adrenergic nerves and angiotensin systems has been documented. The present study was designed to investigate the mechanisms of angiotensin-receptor blocker (ARB) suppression of beta-adrenergic receptor stimulation-induced cardiac hypertrophy. Chronic isoproterenol (ISO)-induced cardiac hypertrophy was inhibited in wild-type mice and AT1aR(-/-) mice treated with the ARB Candesartan (CV11974). Acute ISO-induced increase in phosphorylation levels of ERK MAPK was completely inhibited and increases in phosphorylation levels of p38 and JNK MAPKs were partially suppressed

Binding of HLA-G to ITIM-bearing Ig-like transcript 2 receptor suppresses B cell responses.

Inhibition of B cells constitutes a rational approach for treating B cell-mediated disorders. We demonstrate in this article that the engagement of the surface Ig-like transcript 2 (ILT2) inhibitory receptor with its preferential ligand HLA-G is critical to inhibit B cell functions. Indeed, ILT2-HLA-G interaction impedes both naive and memory B cell functions in vitro and in vivo. Particularly, HLA-G inhibits B cell proliferation, differentiation, and Ig secretion in both T cell-dependent and -independent models of B cell activation. HLA-G mediates phenotypic and functional downregulation of C

Identification of kinase fusion oncogenes in post-Chernobyl radiation-induced thyroid cancers.

Exposure to ionizing radiation during childhood markedly increases the risk of developing papillary thyroid cancer. We examined tissues from 26 Ukrainian patients with thyroid cancer who were younger than 10 years of age and living in contaminated areas during the time of the Chernobyl nuclear reactor accident. We identified nonoverlapping somatic driver mutations in all 26 cases through candidate gene assays and next-generation RNA sequencing. We found that 22 tumors harbored fusion oncogenes that arose primarily through intrachromosomal rearrangements. Altogether, 23 of the oncogenic drivers

miR-550a-3-5p acts as a tumor suppressor and reverses BRAF inhibitor resistance through the direct targeting of YAP.

Although evidence has emerged to suggest that YAP overexpression is a crucial factor for tumor progression and resistance to targeted drugs in multiple cancers, the miRNA-mediated YAP regulation is still unclear. Here we show that the novel miR-550a-3-5p acts as a tumor suppressor and reverses BRAF inhibitor resistance through the direct targeting of YAP. Our data showed that the miR-550a-3-5p suppressed cell proliferation, metastasis, and tumor sphere formation through the direct inhibition of YAP and its oncogenic pathway in various cancer cell types. In addition, we showed that the YAP sign

What to Do When Anti-PD-1 Therapy Fails in Patients With Melanoma.

Monotherapy with immune checkpoint inhibitors, specifically those targeting programmed death 1 (PD-1), has revolutionized the treatment of metastatic melanoma: approximately 40% of patients achieve a partial or complete response, many of which are durable. However, a subset of patients who initially respond to therapy will progress, leaving the majority of patients in need of an effective second-line approach. While some standard therapies exist, there has been robust interest in utilizing targeted immunotherapy combinations in this population to overcome primary or acquired resistance. Other

Persistent mTORC1 signaling in cell senescence results from defects in amino acid and growth factor sensing.

Mammalian target of rapamycin complex 1 (mTORC1) and cell senescence are intimately linked to each other and to organismal aging. Inhibition of mTORC1 is the best-known intervention to extend lifespan, and recent evidence suggests that clearance of senescent cells can also improve health and lifespan. Enhanced mTORC1 activity drives characteristic phenotypes of senescence, although the underlying mechanisms responsible for increased activity are not well understood. We have identified that in human fibroblasts rendered senescent by stress, replicative exhaustion, or oncogene activation, mTORC1

Investigation of the Relationship Between Radiation Dose and Gene Mutations and Fusions in Post-Chernobyl Thyroid Cancer.

BACKGROUND: Exposure to ionizing radiation during childhood is a well-established risk factor for thyroid cancer. However, the genetic mechanisms of radiation-associated carcinogenesis remain not fully understood. METHODS: In this study, we used targeted next-generation sequencing and RNA-Seq to study 65 papillary thyroid cancers (PTCs) from patients in the Ukrainian-American cohort with measurement-based iodine-131 (I-131) thyroid doses received as a result of the Chernobyl accident. We fitted linear regression models to evaluate differences in distribution of risk factors for PTC according

BRN2 is a non-canonical melanoma tumor-suppressor.

While the major drivers of melanoma initiation, including activation of NRAS/BRAF and loss of PTEN or CDKN2A, have been identified, the role of key transcription factors that impose altered transcriptional states in response to deregulated signaling is not well understood. The POU domain transcription factor BRN2 is a key regulator of melanoma invasion, yet its role in melanoma initiation remains unknown. Here, in a BrafV600E PtenF/+ context, we show that BRN2 haplo-insufficiency promotes melanoma initiation and metastasis. However, metastatic colonization is less efficient in the absence of B

Biomarkers for personalized oncology: recent advances and future challenges.

Cancer is a group of diseases characterized by the uncontrolled growth and spread of abnormal cells and oncology is a branch of medicine that deals with tumors. The last decade has seen significant advances in the development of biomarkers in oncology that play a critical role in understanding molecular and cellular mechanisms which drive tumor initiation, maintenance and progression. Clinical molecular diagnostics and biomarker discoveries in oncology are advancing rapidly as we begin to understand the complex mechanisms that transform a normal cell into an abnormal one. These discoveries hav

Axonal defects in mouse models of motoneuron disease.

Human motoneuron disease is characterized by loss of motor endplates, axonal degeneration, and cell death of motoneurons. The identification of the underlying gene defects for familial ALS, spinal muscular atrophy (SMA), and spinal muscular atrophy with respiratory distress (SMARD) has pointed to distinct pathophysiological mechanisms that are responsible for the various forms of the disease. Accumulating evidence from mouse models suggests that enhanced vulnerability and sensitivity to proapoptotic stimuli is only responsible for some but not all forms of motoneuron disease. Mechanisms that m

New developments in non-Hodgkin lymphoid malignancies.

The revised fourth edition of the World Health Organization (WHO) Classification of Tumours of Haematopoietic and Lymphoid Tissues (2017) reflects significant advances in understanding the biology, genetic basis and behaviour of haematopoietic neoplasms. This review focuses on some of the major changes in B-cell and T-cell non-Hodgkin lymphomas in the 2017 WHO and includes more recent updates. The 2017 WHO saw a shift towards conservatism in the classification of precursor lesions of small B-cell lymphomas such as monoclonal B-cell lymphocytosis, in situ follicular and in situ mantle cell neop

Loss of FBXW7-mediated degradation of BRAF elicits resistance to BET inhibitors in adult T cell leukemia cells.

BACKGROUND: Human T cell leukemia virus type 1 (HTLV-1)-associated adult T cell leukemia (ATL) has a very poor prognosis with a median survival of 8 months and a 4-year overall survival of 11% for acute ATL. Present treatment options are limited and there is no curative therapy for ATL. Ubiquitin ligase FBXW7 is commonly mutated or functionally inactivated in human cancers. Consistent with the notion that FBXW7 controls the degradation of many oncoproteins, loss of FBXW7 has been linked to increased drug resistance or sensitivity in cancer cells. METHOD: In this study, we have characterized F

Recurrent BRAF Gene Rearrangements in Myxoinflammatory Fibroblastic Sarcomas, but Not Hemosiderotic Fibrolipomatous Tumors.

Myxoinflammatory fibroblastic sarcoma (MIFS) is a low grade soft tissue sarcoma with a predilection for acral sites, being associated with a high rate of local recurrence but very infrequent distant metastases. Although a t(1;10) translocation resulting in TGFBR3-MGEA5 fusion has been reported as a recurrent genetic event in MIFS, this abnormality is seen only in a subset of cases. As no studies to date have investigated the spectrum of alternative genetic alterations in TGFBR3-MGEA5 fusion negative MIFS, we undertook a genetic analysis of this particular cohort for further molecular classific

Identification of molecular targets in vulvar cancers.

OBJECTIVES: To identify molecular alterations that contribute to vulvar cancer pathogenesis with the intent of identifying molecular targets for treatment. METHODS: After retrospective analysis of a database of molecularly-profiled gynecologic cancer patients, 149 vulvar cancer patients were included and tested centrally at a CLIA laboratory (Caris Life Sciences, Phoenix, AZ). Tests included one or more of the following: gene sequencing (Sanger or next generation sequencing [NGS]), protein expression (immunohistochemistry [IHC]), and gene amplification (C/FISH). A Fisher's exact test was used

Cardiac Monitoring for Patients Undergoing Treatment With MEK Inhibitor Monotherapy.

PURPOSE OF REVIEW: Aberrant activation of the RAS-RAF-MEK-ERK signaling pathway contributes to numerous malignancies, congenital syndromes, and cardiovascular disorders, establishing MEK inhibitors (MEKi) as crucial therapeutic agents. MEKi demonstrate substantial clinical benefit as monotherapy (e.g., NF1-associated tumors) or combination therapy (e.g., melanoma, glioma, congenital RASopathies). Cardiovascular adverse events, primarily asymptomatic reductions in left ventricular ejection fraction (LVEF), have prompted intensive echocardiographic monitoring. RECENT FINDINGS: Emerging evidence

Совпадение в полном тексте источника
… Pharmacotherapy and the RAS-RAF-MEK-ERK Pathway The RAS-RAF-MEK-ERK axis is initiated by ligand binding to membrane-bound receptor tyrosine kinases, which leads to the activation of RAS, followed by sequential phosphorylation of RAF kinases (CRAF-1, ARAF, BRAF), MEK1/2, and extracellular signal-regulated …

Anti-tumor activities of the new oral pan-RAF inhibitor, TAK-580, used as monotherapy or in combination with novel agents in multiple myeloma.

Many RAS pathway inhibitors, including pan-RAF inhibitors, have shown significant anti-tumor activities in both solid and hematological tumors. The pan-RAF inhibitor, TAK-580, is a representative of the novel RAF inhibitors that act by disrupting RAF homo- or heterodimerization. In this study, we examined the anti-tumor effects of TAK-580 used as monotherapy or in combination with bortezomib, lenalidomide, or other novel agents in multiple myeloma (MM) cells in vitro. TAK-580 monotherapy potently targeted proteins in the RAS-RAF-MEK-ERK signaling pathway and induced potent cytotoxicity and apo

Совпадение в полном тексте источника
… TAK-580 is a novel class II pan-RAF inhibitor, binds to the inactive, “DFG-out” conformation of BRAF, and potently inhibits both wild-type and mutant RAF kinases, possibly leading to a more effective blockade of the MAPK pathway with minimal paradoxical activation [ 13 , 31 ]. … A Novel RAF Kinase Inhibitor with DFG-Out-Binding Mode: High Efficacy in BRAF-Mutant Tumor Xenograft Models in the Absence of Normal Tissue Hyperproliferation. Mol Cancer Ther. 2016; 15:354–365. 10.1158/1535-7163.MCT-15-0617. 32. …