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Eyelid nystagmus in a child with cardiofaciocutaneous syndrome associated with BRAF mutation.

Eyelid nystagmus, thought to reflect midbrain or hindbrain disease, is a rare condition that typically occurs in association with neurologic and neuroophthalmic abnormalities. Cardiofaciocutaneous (CFC) syndrome associated with B-raf protooncogene serine/threonine kinase (BRAF) mutation is a complex syndrome that is associated with neurologic and neuroophthalmologic abnormalities. We report the case of a 4-year-old girl with CFC syndrome with global developmental delay who was referred for evaluation of alternating exotropia, right-sided dissociated vertical deviation, bilateral upgaze nystagm

Molecular alterations in hepatocellular carcinoma associated with hepatitis B and hepatitis C infections.

Chronic infections with hepatitis B (HBV) and hepatitis C viruses (HCV) are the leading cause of cirrhosis and hepatocellular carcinoma (HCC) worldwide. Both viruses encode multifunctional regulatory proteins activating several oncogenic pathways, which induce accumulation of multiple genetic alterations in the infected hepatocytes. Gene mutations in HBV- and HCV-induced HCCs frequently impair the TP53, Wnt/b-catenin, RAS/RAF/MAPK kinase and AKT/mTOR pathways, which represent important anti-cancer targets. In this review, we highlight the molecular mechanisms underlying the pathogenesis of pri

SUR-8, a conserved Ras-binding protein with leucine-rich repeats, positively regulates Ras-mediated signaling in C. elegans.

We describe the identification and characterization of a novel gene, sur-8, that positively regulates Ras-mediated signal transduction during C. elegans vulval development. Reduction of sur-8 function suppresses an activated ras mutation and dramatically enhances phenotypes of mpk-1 MAP kinase and ksr-1 mutations, while increase of sur-8 dosage enhances an activated ras mutation. sur-8 appears to act downstream of or in parallel to ras but upstream of raf. sur-8 encodes a conserved protein that is composed predominantly of leucine-rich repeats. The SUR-8 protein interacts directly with Ras but

Inhibition of Haspin Kinase Promotes Cell-Intrinsic and Extrinsic Antitumor Activity.

Patients with melanoma resistant to RAF/MEK inhibitors (RMi) are frequently resistant to other therapies, such as immune checkpoint inhibitors (ICI), and individuals succumb to their disease. New drugs that control tumor growth and favorably modulate the immune environment are therefore needed. We report that the small-molecule CX-6258 has potent activity against both RMi-sensitive (RMS) and -resistant (RMR) melanoma cell lines. Haspin kinase (HASPIN) was identified as a target of CX-6258. HASPIN inhibition resulted in reduced proliferation, frequent formation of micronuclei, recruitment of cG

Secretory phospholipase A2 plays an essential role in microglial inflammatory responses to Mycobacterium tuberculosis.

In previous studies, we have shown that reactive oxygen species (ROS)-mediated inflammatory signaling is essential for microglial proinflammatory responses to Mycobacterium tuberculosis (Mtb). To further investigate the molecular mechanisms governing these processes, we sought to describe the role of phospholipase A(2) (PLA(2)) in Mtb-induced ROS generation and inflammatory mediator release by microglia. Inhibition of secretory PLA(2) (sPLA(2)), but not cytosolic PLA(2) (cPLA(2)), profoundly abrogated Mtb-mediated ROS release, the generation of various inflammatory mediators (tumor necrosis fa

Synergistic induction of apoptosis in human leukemia cells (U937) exposed to bryostatin 1 and the proteasome inhibitor lactacystin involves dysregulation of the PKC/MAPK cascade.

Cotreatment with a minimally toxic concentration of the protein kinase C (PKC) activator (and down-regulator) bryostatin 1 (BRY) induced a marked increase in mitochondrial dysfunction and apoptosis in U937 monocytic leukemia cells exposed to the proteasome inhibitor lactacystin (LC). This effect was blocked by cycloheximide, but not by alpha-amanitin or actinomycin D. Qualitatively similar interactions were observed with other PKC activators (eg, phorbol 12-myristate 13-acetate and mezerein), but not phospholipase C, which does not down-regulate the enzyme. These events were examined in relati

Detection of the BRAF V600E mutation in melanocytic lesions using the ligase detection reaction.

BACKGROUND: BRAF is a member of the RAF kinase family, and it promotes signaling through the RAS-MAP kinase signal transduction cascade. Research has shown that a majority of melanomas and nevi exhibit an activating V600E (T1799A) mutation in BRAF exon 15. Additional studies of BRAF have demonstrated that the T1799A mutation is absent in uveal melanomas and Spitz nevi. METHODS: The ligase detection reaction (LDR) is a sensitive technique that can identify specific DNA mutations occurring at very low frequency within heterogeneous clinical samples, and it has previously been used to analyze mu

Secretory carrier membrane protein 3 modulates nuclear ERK1/2 signaling and drug response in triple-negative breast cancer.

INTRODUCTION: Triple-negative breast cancer (TNBC) frequently displays hyperactive mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinases 1/2 (ERK1/2) signaling but lacks tractable targets to sustain durable pathway inhibition. Identifying modulators that shape ERK1/2 output and influence responses to ERK1/2 inhibitors is therefore needed. The endosomal trafficking protein secretory carrier membrane protein 3 (SCAMP3) is a positive regulator of epidermal growth factor receptor (EGFR) signaling and ERK1/2-dependent phosphoproteomics programs in TNBC. However, the mechani

Molecularly Targeted Therapies in Oncology: Mechanisms, Resistance, and Combination Strategies.

Targeted therapies are reshaping oncology by enabling treatment selection based on actionable molecular alterations, improving precision, and reducing unnecessary toxicity. This review provides an up-to-date overview of current targeted treatment modalities and the medicinal chemistry principles that support their discovery and optimization. We synthesize evidence on small-molecule and biologic strategies spanning receptor and non-receptor kinases and their major signaling axes (PI3K-AKT-mTOR and RAS-RAF-MEK-ERK), apoptosis regulation (BCL-2 family), DNA repair via poly(ADP-ribose) polymerase

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… It comprises RAS proteins, RAF kinases (ARAF, BRAF, and RAF1/CRAF), MEK1/2, and ERK1/2. This cascade controls cell proliferation, differentiation, and survival, and aberrant activation is observed in a substantial fraction of human cancers. …

Melanoma With RNF11::BRAF Fusion: A Novel Fusion Previously Undescribed in Melanoma.

B-Raf Proto-Oncogene ( BRAF ) fusions are rare in melanomas. We present a case of cutaneous melanoma with a Ring Finger Protein 11 ( RNF11 ) ::BRAF fusion in a 63-year-old man with a history of stage IB melanoma on the right upper back (pT2apN0cM0; nonulcerated with a Breslow thickness of 1.2 mm). Despite initial treatment, the melanoma progressed to multiple metastases. Histopathologically, the tumor cells exhibited epithelioid and rhabdoid morphologies, with occasional giant pleomorphic cells and multinucleation, and were positive for antimelanocytic cocktail (HMB45, Melan-A, tyrosinase) and

[Schwannoma:Update on Molecular Profiling and Therapeutic Advances].

Schwannoma is a tumor that develops from the Schwann cells in the peripheral nervous system or cranial nerves. Gamma Knife radiosurgery has become an accepted treatment for schwannoma, with a high rate of tumor control. For sporadic or neurofibromatosis type 2-associated schwannoma resistant to radiotherapy, vascular endothelial growth factor(VEGF)-A/VEGF receptor(VEGFR)-targeted therapy(e.g., bevacizumab)may become the first-line therapy. However, some aspects of treatment with bevacizumab are problematic, such as the need for frequent parenteral administration, side effects, apparent drug re

Cellular senescence signaling in cancer: A novel therapeutic target to combat human malignancies.

Senescence is a special state of tumor suppression induced by cell cycle arrest. However, releasing senescence-associated secretory phenotypes by senescent cells could provide tumorigenic conditions and epigenetic changes in neighboring cells. The conventional anticancer drugs activate therapy-induced senescence by several mechanisms which include an increase in mitochondrial biogenesis and reactive oxygen species, up-regulation of tumor suppressor proteins (e.g., p53, p21, p38, and p16) and modulation of dysregulated signaling mediators, including senescence-associated β-galactosidase, ataxia

Capitalizing on paradoxical activation of the mitogen-activated protein kinase pathway for treatment of Imatinib-resistant mast cell leukemia.

Prevention of fatal side effects during cancer therapy of cancer patients with high-dosed pharmacological inhibitors is to date a major challenge. Moreover, the development of drug resistance poses severe problems for the treatment of patients with leukemia or solid tumors. Particularly drug-mediated dimerization of RAF kinases can be the cause of acquired resistance, also called "paradoxical activation." In the present work we re-analyzed the effects of different tyrosine kinase inhibitors (TKIs) on the proliferation, metabolic activity, and survival of the Imatinib-resistant, KIT V560G, D816…

Arctigenin induced gallbladder cancer senescence through modulating epidermal growth factor receptor pathway.

Gallbladder cancer has poor prognosis and limited therapeutic options. Arctigenin, a representative dibenzylbutyrolactone lignan, occurs in a variety of plants. However, the molecular mechanisms involved in the antitumor effect of arctigenin on gallbladder cancer have not been fully elucidated. The expression levels of epidermal growth factor receptor were examined in 100 matched pairs of gallbladder cancer tissues. A positive correlation between high epidermal growth factor receptor expression levels and poor prognosis was observed in gallbladder cancer tissues. Pharmacological inhibition or

The AhR agonist VAF347 augments retinoic acid-induced differentiation in leukemia cells.

In binary cell-fate decisions, driving one lineage and suppressing the other are conjoined. We have previously reported that aryl hydrocarbon receptor (AhR) promotes retinoic acid (RA)-induced granulocytic differentiation of lineage bipotent HL-60 myeloblastic leukemia cells. VAF347, an AhR agonist, impairs the development of CD14(+)CD11b(+) monocytes from granulo-monocytic (GM) stage precursors. We thus hypothesized that VAF347 propels RA-induced granulocytic differentiation and impairs D3-induced monocytic differentiation of HL-60 cells. Our results show that VAF347 enhanced RA-induced cell

The NM23-H1/H2 homolog NDK-1 is required for full activation of Ras signaling in C. elegans.

The group I members of the Nm23 (non-metastatic) gene family encode nucleoside diphosphate kinases (NDPKs) that have been implicated in the regulation of cell migration, proliferation and differentiation. Despite their developmental and medical significance, the molecular functions of these NDPKs remain ill defined. To minimize confounding effects of functional compensation between closely related Nm23 family members, we studied ndk-1, the sole Caenorhabditis elegans ortholog of group I NDPKs, and focused on its role in Ras/mitogen-activated protein kinase (MAPK)-mediated signaling events duri

Heat shock protein 90 inhibition in lung cancer.

The heat shock protein 90 (Hsp90) chaperone is required for the conformational maturation and stability of multiple oncogenic kinases that drive signal transduction and proliferation of lung cancer cells. The recent demonstration that mutant epidermal growth factor receptor is an Hsp90 client, irrespective of the presence of the secondary threonine-to-methionine amino acid substitution mutation at position 790 mediating anilinoquinazoline resistance, suggests Hsp90 inhibition as a novel strategy against this group of lung cancers. The rarer epidermal growth factor receptors harboring exon 20 i

Pro-survival signal inhibition by CDK inhibitor dinaciclib in Chronic Lymphocytic Leukaemia.

Dinaciclib is a cyclin-dependent kinase inhibitor with clinical potential in different cancers, including chronic lymphocytic leukaemia (CLL). In order to better understand its cytotoxic action, we characterized its effects on signalling pathways important for the survival of CLL cells. We found that dinaciclib induced apoptosis through the activation of caspases 8 and 9, which was independent of the presence of cytokines to mimic the environment of proliferation centres or IGVH mutation status. Moreover, treatment with dinaciclib led to the inhibition of oncogenic pathways normally activated

The influence of methylmercury on the nitric oxide production of alveolar macrophages.

Mercury is a global pollutant considered to be a persistent bioaccumulative and toxic chemical. Humans may be exposed to organic forms of mercury by either inhalation, oral, or dermal routes. Methylmercury is more toxic to living organisms than the inorganic forms. In this study, we attempted to elucidate the altered functions of alveolar macrophage including nitric oxide production after methylmercury exposure. Treatment of 7 muM methylmercury for 24 h inhibited lipopolysaccharide-induced nitric oxide and nitric oxide synthase production of alveolar macrophages. The addition of H-89 (PKA inhi

Properties of FDA-approved small molecule protein kinase inhibitors: A 2020 update.

Because genetic alterations including mutations, overexpression, translocations, and dysregulation of protein kinases are involved in the pathogenesis of many illnesses, this enzyme family is currently the subject of many drug discovery programs in the pharmaceutical industry. The US FDA approved four small molecule protein kinase antagonists in 2019; these include entrectinib, erdafitinib, pexidartinib, and fedratinib. Entrectinib binds to TRKA/B/C and ROS1 and is prescribed for the treatment of solid tumors with NTRK fusion proteins and for ROS1-postive non-small cell lung cancers. Erdafitin