RAF1 Gene Research Articles

Targeting RAF1 gene fusions with MEK inhibition in metastatic melanoma

Abstract The biological and clinical relevance of gene fusions in melanoma is unknown. Reports and preclinical data have suggested that tumor cells with specific rearrangements such as RAF1 gene fusions could be therapeutically targeted. To investigate the relevance of targeted therapy in patients with melanoma harboring RAF1 gene fusions, we reviewed records of 1268 melanoma patients with targeted sequencing data at the Dana-Farber Cancer Institute. We identified 9 cases and report here on their clinicopathologic characteristics. We describe the favorable outcome of 2 patients who received MEK inhibitor therapy, including 1 patient with a durable response. We coalesced our data with published reports of patients with RAF1 gene fusions who were treated with targeted therapy. We find that single-agent MEK inhibition has anti-tumor activity in melanoma patients harboring an RAF1 gene fusion, and we propose that patients with RAF1 gene fusions should be considered for single-agent MEK inhibitor therapy.

Exploring the Dynamic Interplay of Deleterious Variants on the RAF1-RAP1A Binding in Cancer: Conformational Analysis, Binding Free Energy, and Essential Dynamics.

The RAF1-RAP1A interaction activates the MAPK/ERK pathway which is very crucial in the carcinogenesis process. This protein complex influences tumor formation, proliferation, and metastasis. Understanding aberrant interactions driven by clinical mutations is vital for targeted therapies. Hence, the current study focuses on the screening of clinically reported substitutions in the RAF1 and RAP1A genes using predictive algorithms integrated with all-atoms simulation, essential dynamics, and binding free energy methods. Survival analysis results revealed a strong association between RAF1 and RAP1A expression levels and diminished survival rates in cancer patients across different cancer types. Integrated machine learning algorithms showed that among the 134 mutations reported for these 2 proteins, only 13 and 35 were classified as deleterious mutations in RAF1 and RAP1P, respectively. Moreover, one mutation in RAF1 reported elevated levels of binding between RAF1 and RAP1P while in RAP1A, 7 mutations were reported to increase the binding affinity. The high-binding mutations, P34Q and V60F, were subjected to protein-protein coupling which confirmed the increase in the binding affinity. Wild-type and mutant RAF1-RAP1P bound complexes were subjected to molecular simulation investigation, revealing enhanced structural stability, increased compactness, and stabilized residue fluctuations of the mutant systems in contrast to the wild-type. In addition, hydrogen bonding analysis revealed a variation in the binding paradigm which further underscores the impact of these substitutions on the coupling of RAF1 and RAP1A. Principal component analysis (PCA) and free energy landscape (FEL) evaluation further determined dynamical variations in the wild-type and mutant complexes. Finally, the Gibbs free energy for each complex was estimated and found to be -71.94 ± 0.38 kcal/mol for the wild-type, -95.57 ± 0.37 kcal/mol for the V60F, and -85.76 ± 0.72 kcal/mol for P34Q complex. These findings confirm the effect of these variants on increasing the binding affinity of RAF1 to RAP1P. These mutations can therefore be targeted for cancer therapy to modulate the activity of the MAPK/ERK signaling pathway.

Identification of Bioactive and Anticancer Properties of Bidens Pilosa in-vitro Evidence.

Bidens pilosa and Trianthema portulacastrum are noteworthy weeds with a series of bioactive flavonoid constituents, hence, they can be utilized as potential health supplements and readily available sources of natural antioxidants, as well as effective constituents in medicinal applications. The current study aims to assess the anti-proliferative activity of B. pilosa and T. portulacastrum extracts using the HepG2 cell line. Methods The prepared extracts were evaluated for their cytotoxic influence and their potential CC50 in HepG2 cell lines and normal hepatocytes using the MTT assay. Using quantitative real-time polymerase chain reaction (qRT-PCR), the relative gene expression of Raf-1, MEK-1, LC3B, and Atg12 was quantified in treated cells to detect the expression levels of cell proliferation factors and autophagy-related genes. The quantification analysis of the released interleukin-1beta (IL-1β) and interleukin-1alpha (IL-1α) was also done using an ELISA assay. The activities of B. pilosa extract showed an anti-proliferative influence on HepG2 cell lines upon treatment as compared to normal cells. It was assessed for cytotoxicity using molecular studies against both Raf-1 and MEK-1 as proposed anticancer mechanisms and showed promising inhibitory activity against Raf-1 and MEK-1 gene expression. Likewise, the reduction of autophagy-related genes, Atg12 and LC3B, in HepG2 cells pre-treated with B. pilosa extract, further confirmed its influence in the induction of programmed cell death (PCD). The ELISA assay revealed a substantial elevation of the pro-inflammatory cytokines IL-1α and IL-1β upon treatment. This study found that B. pilosa extract, without any detectable cytotoxic effects, had potential inhibitory activities against both Raf-1 and MEK-1 gene expression, and a significant reduction in autophagic machinery upon treatment.<br /><br />.

Rare Oncogenic Fusions in Pediatric Central Nervous System Tumors: A Case Series and Literature Review

Background and Objectives: Central Nervous System (CNS) pediatric tumors represent the most common solid tumors in children with a wide variability in terms of survival and therapeutic response. By contrast to their adult counterpart, the mutational landscape of pediatric CNS tumors is characterized by oncogenic fusions rather than multiple mutated genes. CNS pediatric tumors associated with oncogenic fusions represent a complex landscape of tumors with wide radiological, morphological and clinical heterogeneity. In the fifth CNS WHO classification, there are few pediatric CNS tumors for which diagnosis is based on a single oncogenic fusion. This work aims to provide an overview of the impact of rare oncogenic fusions (NTRK, ROS, ALK, MET, FGFR, RAF, MN1, BCOR and CIC genes) on pathogenesis, histological phenotype, diagnostics and theranostics in pediatric CNS tumors. We report four cases of pediatric CNS tumors associated with NTRK (n = 2), ROS (n = 1) and FGFR3 (n = 1) oncogenic fusion genes as a proof of concept. Cases presentation and literature review: The literature review and the cohort that we described here underline that most of these rare oncogenic fusions are not specific to a single morpho-molecular entity. Even within tumors harboring the same oncogenic fusions, a wide range of morphological, molecular and epigenetic entities can be observed. Conclusions: These findings highlight the need for caution when applying the fifth CNS WHO classification, as the vast majority of these fusions are not yet incorporated in the diagnosis, including grade evaluation and DNA methylation classification.

RAF1 gene fusions are recurrent driver events in infantile fibrosarcoma-like mesenchymal tumors.

Infantile fibrosarcomas (IFS) and congenital mesoblastic nephroma (CMN) are rare myofibroblastic tumors of infancy and early childhood commonly harboring the ETV6::NTRK3 gene fusion. IFS/CMN are considered as tumors with an 'intermediate prognosis' as they are locally aggressive, but rarely metastasize, and generally have a favorable outcome. A fraction of IFS/CMN-related neoplasms are negative for the ETV6::NTRK3 gene rearrangement and are characterized by other chimeric proteins promoting MAPK signaling upregulation. In a large proportion of these tumors, which are classified as IFS-like mesenchymal neoplasms, the contributing molecular events remain to be identified. Here, we report three distinct rearrangements involving RAF1 among eight ETV6::NTRK3 gene fusion-negative tumors with an original histological diagnosis of IFS/CMN. The three fusion proteins retain the entire catalytic domain of the kinase. Two chimeric products, GOLGA4::RAF1 and LRRFIP2::RAF1, had previously been reported as driver events in different cancers, whereas the third, CLIP1::RAF1, represents a novel fusion protein. We demonstrate that CLIP1::RAF1 acts as a bona fide oncoprotein promoting cell proliferation and migration through constitutive upregulation of MAPK signaling. We show that the CLIP1::RAF1 hyperactive behavior does not require RAS activation and is mediated by constitutive 14-3-3 protein-independent dimerization of the chimeric protein. As previously reported for the ETV6::NTRK3 fusion protein, CLIP1::RAF1 similarly upregulates PI3K-AKT signaling. Our findings document that RAF1 gene rearrangements represent a recurrent event in ETV6::NTRK3-negative IFS/CMN and provide a rationale for the use of inhibitors directed to suppress MAPK and PI3K-AKT signaling in these cancers. © 2024 The Pathological Society of Great Britain and Ireland.

Abstract LB451: Targeting oncogenic transcription and signaling crosstalk fueling drug resistance in lung cancer

Abstract Lung cancer is the leading cause of all cancer-related mortality worldwide. The RAS-RAF-MEK-ERK (RAS-MAPK) signaling pathway is critical for maintaining cell survival and proliferation. Somatic mutations in the RAS or RAF genes are associated with frequent hyper-activation of RAS-MAPK pathway in non-small cell lung cancer or NSCLC. While direct inhibitors of KRAS G12C are emerging with promising efficacy, resistance to these agents as well as to inhibitors of RAF and MEK remains an obstacle to long-term patient survival. Therefore, it is essential to understand how drug resistance emerges in lung cancer and to identify bypass survival pathways or compensatory mechanisms that limit the response to RAS-MAPK targeted therapies in lung cancer. Emerging literature indicates a critical role of bromodomain and extra-terminal domain (BET) family of bromodomain proteins (BRD4, BRD3, BRD2) in various human malignancies and provides the rational for targeting BET proteins as a strategy for the development of new anticancer drugs. Using combinatorial drug screens in a panel of NSCLC cell lines, we found that BET proteins act in parallel to the RAS-MAPK pathway to promote drug resistance in lung cancer. Combination of BET and RAS-MAPK inhibitors caused pronounced cell death and potent tumor regression/stasis in several KRAS or BRAF mutant models of NSCLC with synergistic apoptosis induction and downregulation of MYC, a transcriptional target of BET proteins. However, concurrent loss of the tumor suppressor STK11 (aka LKB1) in NSCLC cells induced activation of the Hippo pathway effector and transcriptional co-activator, YAP and conferred resistance to the BET and RAS-MAPK inhibitors combination in NSCLC cells and tumors.These findings suggest an unprecedented functional interplay between BET chromatin regulators, Hippo-YAP and RAS-MAPK signaling in lung cancer and therapy resistance. Further, this study identified STK11 as a modifier of sensitivity to the BET and RAS-MAPK inhibitors combination in NSCLC cells and tumors. Citation Format: Nilanjana Chatterjee, Victor Olivas, Wei Wu, Tracy Tang, Ben Powell, Trever Bivona. Targeting oncogenic transcription and signaling crosstalk fueling drug resistance in lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB451.

Pilocytic astrocytoma: The paradigmatic entity in low‑grade gliomas (Review).

Among low-grade gliomas, representing 10-20% of all primary brain tumours, the paradigmatic entity is constituted by pilocytic astrocytoma (PA), considered a grade 1 tumour by the World Health Organization. Generally, this tumour requires surgical treatment with an infrequent progression towards malignant gliomas. The present review focuses on clinicopathological characteristics, and reports imaging, neurosurgical and molecular features using a multidisciplinary approach. Macroscopically, PA is a slow-growing soft grey tissue, characteristically presenting in association with a cyst and forming a small mural nodule, typically located in the cerebellum, but sometimes occurring in the spinal cord, basal ganglia or cerebral hemisphere. Microscopically, it may appear as densely fibrillated areas composed of elongated pilocytic cells with bipolar 'hairlike' processes or densely fibrillated areas composed of elongated pilocytic cells with Rosenthal fibres alternating with loosely fibrillated areas with a varied degree of myxoid component. A wide range of molecular alterations have been encountered in PA, mostly affecting the MAPK signalling pathway. In detail, the most frequent alteration is a rearrangement of the BRAF gene, although other alterations include neurofibromatosis type-1 mutations, BRAFV600E mutations, KRAS mutations, fibroblast growth factor receptor-1 mutations of fusions, neurotrophic receptor tyrosine kinase family receptor tyrosine kinase fusions and RAF1 gene fusions. The gold standard of PA treatment is surgical excision with complete margin resection, achieving minimal neurological damage. Conventional radiotherapy is not required; the more appropriate treatment appears to be serial follow-up. Chemotherapy should only be applied in younger children to avoid the risk of long-term growth and developmental issues associated with radiation. Finally, if PA recurs, a new surgical approach should be performed. At present, novel therapy involving agents targeting MAPK signalling pathway dysregulation is in development, defining BRAF and MEK inhibitors as target therapeutical agents.

Clinical outcomes and molecular characteristics of patients with pancreatic acinar cell carcinoma.

688 Background: PACC is a rare malignancy originating from the exocrine pancreas, accounting for less than 1% of all pancreatic cancers. Due to the rarity of the disease entity, there is a paucity of data to guide treatment decisions. This retrospective study aims to provide additional clinical characteristics and outcomes to aid in future treatment decisions. Methods: Pathology records from Mayo Clinic (AZ, FL, MN) patients (pts) denoting acinar or mixed-acinar cell carcinoma were searched between 2002 to 2023 and selected for retrospective review. Pt demographics, treatment courses, and next generation sequencing (NGS) were collected. Results: A total of 62 pts (74% male, n = 46) were identified with median age 64 years old. Histologic subtypes were 67% pure acinar cell carcinoma (42/62), 24% mixed acinar-neuroendocrine (15/62), and 8% mixed acinar-adenocarcinoma (5/62). AJCC stages at diagnosis were 34% stage I/II (21/62), 16% stage III (10/62), and 50% stage IV (31/62). Early-stage disease was treated with upfront surgical resection (81%, 17/21). Locally advanced disease received neoadjuvant therapy (NAT) followed by surgical resection (80%, 8/10). FOLFIRINOX was most often chosen as NAT (65%, 11/17), while others received gemcitabine-based NAT. The R0 resection rate was 86%. The 3 and 5-year survival estimates for stage III were 90.9% (95% CI: 75.4 – 100%) and 67.3% (95% CI: 42.3 – 100%), respectively. The 3 and 5-year survival estimates for stage IV were 36.6% (95% CI: 18.6 – 71.9%) and 29.3% (95% CI: 13.1 – 65.5%), respectively. Median survival time for stage IV was 3 years. Somatic NGS testing was done in 24 pts with alterations found in: homologous recombination (HR) in 42% (10/24); RAF alterations in 25% (6/24); mismatch repair (MMR) in 13% (3/24; none of them with MMR germline mutations), 1 ETV6-NTRK3 fusion, and 1 FGFR mutation. Germline NGS testing was done in 21 pts and alterations in HR were seen in 33% (7/21) of pts. This led to additional therapeutic options in 46% (11/24) of pts. Conclusions: Unlike PDAC, PACC is a genomically diverse disease, with potentially targetable alterations in RAF, HRD, and MMR genes, offering additional therapeutic options for significant number of pts. In addition, more than one-third of the pts harbored germline mutations in HR genes. Therefore, somatic and germline testing should be considered for any pt diagnosed with PACC.

Network pharmacology analysis and experimental validation to explore the effect and mechanism of tetramethylpyrazine for spinal cord injury

ObjectiveTo investigate the effect and mechanism of Tetramethylpyrazine (TMP) in treating Spinal Cord Injury (SCI) using network pharmacology analysis and animal experiments. MethodsThis study was based on public databases, including PharmMapper, BATMAN-TCM, and STRING, as well as KEGG pathway analysis and other methods of network pharmacology were used to preliminarily explore the molecular mechanism of TMP in the treatment of SCI. Using a mouse SCI compression injury model, the efficacy of TMP was evaluated, and the expression of predictive targets on the PI3K/AKT and MAPK signaling pathways was measured using Western blotting and q-PCR. ResultsNetwork pharmacology analysis showed that TMP may exert therapeutic effects through the MAPK and PI3K/AKT signaling pathways. In animal experimental validation studies, it was shown that after treatment with TMP, the hind limb motor function scores and ramp test scores of the TMP-treated mice improved significantly. HE staining showed that after treatment with TMP, cavities decreased, fewer glial cells proliferated, and fewer inflammatory cells infiltrated; Nielsen staining showed less neuronal loss. Western blot studies showed that compared with the model group, expression of RAS, ERK1/2, RAF1, PI3K, and p-AKT proteins in the spinal cord tissue of mice treated with high-dose TMP was significantly lower. Accordingly, q-PCR studies showed that compared with the model group, the expression levels of RAS, ERK1/2, RAF1, PI3K, and p-AKT genes in the spinal cords of mice in the high-dose TMP group were significantly lower. ConclusionTMP exhibits a good neuroprotective effect after SCI, which may be related to inhibition of the MAPK and PI3K/AKT signaling pathways.

REVIEWING ADVANCES IN UNDERSTANDING AND TARGETING THE MAPK SIGNALING PATHWAY IN HEPATOCELLULAR CARCINOMA PROGRESSION AND THERAPEUTICS

Hepatocellular carcinoma (HCC) is a severe and increasingly prevalent health issue affecting individuals globally. Recent research endeavors in the clinical domains have lately focused more on the MAPK signaling pathway in HCC. Activating mutations in the RAS and RAF genes, which greatly activate the MAPK pathway in malignancies, are rare in HCC patients, yet over 50% of them have activated the pathway. This suggests that other factors may be responsible for the activation of the signaling pathway in HCC. MAPK signaling is important to carcinogenesis, and it is often altered in human cancers. The drug resistance in targeted therapy against RTKs in HCC may arise from mutations in downstream components (RAS, RAF, MEK, ERK), resistant mutations within RTKs, and additional alternative pathways like PI3K and YAP may also develop the resistance. Epigenetic processes and chromatin remodeling are crucial to pharmacological tolerance to MAPK regulation. This review will focus on the latest developments in our knowledge of the cellular and molecular processes to activate the MAPK signaling pathway, as well as possible treatment approaches that specifically target this pathway in relation to HCC. The study also investigates the clinical efficacy of molecular-targeted treatments, including tyrosine kinase inhibitors and immunological checkpoint inhibitors and highlights the use of combination therapy for HCC.

Exploiting BRAF Mutation for Treatment of Malignant Melanoma: A Literature Review

Malignant melanoma, a deadly type of skin cancer, presents considerable challenges in clinical management. However, the advent of targeted therapies capitalizing on BRAF mutations has ushered in a new era of optimism for treating melanomas. This investigation delves into the utilization of BRAF mutations as a focused approach in addressing malignant melanoma. Anomalously activated RAS-RAF-MEK-ERK signaling, particularly through the prevalent V600E mutation, instigates uncontrolled cell proliferation and survival in melanocytes. Melanoma arises de novo from melanocytes carrying genetic alterations, with RAF mutations being the most common. Mutated RAF genes, notably the V600E mutation, induce dysregulated cell cycle progression, fueling unchecked proliferation. Given that RAF is a pivotal component of the RAS-MAPK pathway, manipulating this pathway emerges as a promising strategy to impede cancer growth. However, not all melanoma cases exhibit RAS mutations, necessitating molecular testing to identify BRAF mutations before initiating targeted therapy. Detecting typically somatic BRAF mutations mandates melanoma tissue as a specimen. The presence of V600E BRAF mutations becomes a crucial factor for employing BRAF inhibitor therapy. This review article underscores the imperative nature of RAF mutation testing in melanoma patients, serving as a predictive tool to determine the cancer's responsiveness to RAF inhibitor treatment. The identification of BRAF mutations offers a targeted therapeutic avenue, instilling fresh hope for personalized and effective interventions in the management of malignant melanoma. Keywords: skin cancer; melanoma; braf mutation

1,3-Dichloroadamantyl-Containing Ureas as Potential Triple Inhibitors of Soluble Epoxide Hydrolase, p38 MAPK and c-Raf.

Soluble epoxide hydrolase (sEH) is an enzyme involved in the metabolism of bioactive lipid signaling molecules. sEH converts epoxyeicosatrienoic acids (EET) to virtually inactive dihydroxyeicosatrienoic acids (DHET). The first acids are "medicinal" molecules, the second increase the inflammatory infiltration of cells. Mitogen-activated protein kinases (p38 MAPKs) are key protein kinases involved in the production of inflammatory mediators, including tumor necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2). p38 MAPK signaling plays an important role in the regulation of cellular processes, especially inflammation. The proto-oncogenic serine/threonine protein kinase Raf (c-Raf) is a major component of the mitogen-activated protein kinase (MAPK) pathway: ERK1/2 signaling. Normal cellular Raf genes can also mutate and become oncogenes, overloading the activity of MEK1/2 and ERK1/2. The development of multitarget inhibitors is a promising strategy for the treatment of socially dangerous diseases. We synthesized 1,3-disubstituted ureas and diureas containing a dichloroadamantyl moiety. The results of computational methods show that soluble epoxide hydrolase inhibitors can act on two more targets in different signaling pathways of mitogen-activated protein kinases p38 MAPK and c-Raf. The two chlorine atoms in the adamantyl moiety may provide additional Cl-π interactions in the active site of human sEH. Molecular dynamics studies have shown that the stability of ligand-protein complexes largely depends on the "spacer effect." The compound containing a bridge between the chloroadamantyl fragment and the ureide group forms more stable ligand-protein complexes with sEH and p38 MAPK, which indicates a better conformational ability of the molecule in the active sites of these targets. In turn, a compound containing two chlorine atoms forms a more stable complex with c-Raf, probably due to the presence of additional halogen bonds of chlorine atoms with amino acid residues.

Characterization of the genomic alterations in poorly differentiated thyroid cancer

Poorly differentiated thyroid carcinoma (PDTC) is a subtype of thyroid cancer that has a high rate of metastasis or recurrence and a relatively poor prognosis. However, there are few studies that have been conducted on PDTC at the whole protein-coding gene scale. Here, we performed genomic profiling of 15 patients with PDTC originated from follicular thyroid carcinoma using whole exome sequencing and also performed gene functional enrichment analysis of differentially expressed genes (DEGs) for three patients. Further, we investigated genetic variants associated with PDTC progression and the characteristics of clinical pathology. We revealed somatic genomic alterations in the RAF1, MAP2K2, and AKT2 genes that were not reported in previous studies. We confirmed frequent occurrences in the RAS gene in patients with PDTC; the genetic alterations were associated with the RAS-RAF-MEK-ERK/JNK, PI3K-AKT-mTOR signaling pathways, and the cell cycle. DEG analysis showed that immune response was lower in cancer tissues than in normal tissues. Through the association analysis of somatic mutations and the characteristics of clinical pathology from patients with PDTC, the somatic mutations of ABCA12, CLIP1, and ATP13A3 were significantly associated with a vascular invasion phenotype. By providing molecular genetic insight on PDTC, this study may contribute to the discovery of novel therapeutic target candidates.

Induction of Caspase-dependent Apoptosis in Rat Bone Marrow Mesenchymal Stem Cells Due to Di-2-Ethylhexyl Phthalate Toxicity was Found to Arrest the Cell Cycle at the G1 Stage.

Di-(2-ethylhexyl) phthalate (DEHP) is used as a plasticizer in polyvinyl chloride products which is widely utilized. Previously we found, DEHP reduced the viability and proliferation ability of bone marrow mesenchymal stem cells (BMSCs). In the present study, the mechanism of DEHP toxicity was investigated. Rat BMSCs were cultured up to 3rd passage and their viability was determined after treatment with 100 and 500 μM of DEHP for 24 and 48 hours. The levels of sodium, potassium, and calcium as well as induction of apoptosis were investigated. Using flow cytometry, cell cycle analysis was performed and the expression of genes involved in the cell cycle was evaluated using reverse transcriptase-PCR. Data were analyzed and p < 0.05 was taken as the level of significance. Although the viability and electrolyte level of BMSCs were not affected with 100 μM of DEHP, this environmental pollution induced caspase-dependent apoptosis in a concentration-dependent manner. In both of the concentrations, DEHP arrests the cell cycle at the G0/G1 phase, and the expression of Cdk2 and Cdk4 was significantly reduced whereas an over-expression of P53 was observed. However, the expression of the raf1 gene remained unchanged. DEHP induces caspase-dependent apoptosis in BMSCs and arrests the cell cycle due to the reduction of Cdk2 and Cdk4 expression via over-expression of P53.

RAF1 mutation leading to hypertrophic cardiomyopathy in a Chinese family with a history of sudden cardiac death: A diagnostic insight into Noonan syndrome.

Hypertrophic cardiomyopathy (HCM) is predominantly caused by mutations in sarcomeric genes. However, a subset of cases is attributed to genetic disorders unrelated to sarcomeric genes, such as Noonan syndrome (NS) and other RASopathies. In this study, we present a family with a history of sudden cardiac death (SCD) and focus on two adults with syndromic left ventricular hypertrophy (LVH). Clinical evaluations, including echocardiography, were conducted to assess cardiac manifestations. Whole-exome sequencing was performed to identify potential genetic variants underlying syndromic LVH in the study participants. Whole-exome sequencing revealed a missense variant in the RAF1 gene, c.782C>T (p.Pro261Leu). This variant confirmed the diagnosis of NS in the affected individuals. The findings of this study underscore the importance of family history investigation and genetic testing in diagnosing syndromic LVH. By identifying the underlying genetic cause, clinicians can better understand the etiology of RAS-HCM and its association with SCD in young adults.

Molecular insights into the lipid-carbohydrates metabolism switch under the endurance effort in Arabian horses.

Recent studies have shown that in Arabian horse muscle, long-term exercise-induced expression of genes related to fatty acid degradation and the downregulation of genes belonging to the glycolysis/gluconeogenesis and insulin signalling pathways. Long-lasting physical exertion may trigger the metabolism to switch the main energy source from carbohydrates to lipids due to higher caloric content. To describe the metabolism adaptation at the whole transcriptome of blood to endurance effort in Arabian horses. In vivo experiment. Venous blood samples from 10 Arabian horses were taken before and after a 120 km long endurance ride to isolate the RNA and perform the high-throughput NGS transcriptome sequencing. The results, including KEGG (Kyoto Encyclopaedia of Genes and Genomes) and GO (Gene Ontology) analyses, allowed us to describe the most significantly upregulated-ARV1, DGAT2, LIPE, APOA2, MOGAT1, MOGAT2, GYS1, GYS2 and downregulated-ACACA, ACACB, FADS1, FADS2 genes involved in carbohydrate and lipid metabolism. Also, the increased expression of RAF1, KRAS and NRAS genes involved in the Insulin pathway and PI3K-Akt was shown. Limited sample size, Arabians used for endurance racing were not compared to Arabians from other equestrian disciplines. This general insight into the processes described supports the thesis of the lipid-carbohydrates metabolism switch in endurance Arabian horses and provides the basis for further research.

Differential expression of hsa_circ_0064357 and hsa_circ_0064358 between oral squamous cell carcinoma and oral lichen planus

"Background/aims: Reliable biomarkers with high specificity and sensitivity and the potential to discriminate precancerous or early lesions from oral cancer improve scientific assessment and early detection. Dysregulated circRNAs play a critical role in the occurrence and progression of malignant biological behaviors of OSCC. The study of potential diagnostic roles of hsa_circ_0064357 and hsa_circ_0064358 in early diagnostic of precancerous lesions such as OLP to OSCC as the most common type of head-and-neck squamous cell carcinoma (HNSCC) was the focus of present research. Methods: The differential expression of hsa_circ_0064357, hsa_circ_0064358, and RAF1 target gene predicted using CircInteractome and Circbase databases between OSCC (n=30), OLP (n=10) tissues and their adjacent normal tissues were evaluated by qRT-PCR. The potential diagnostic value of circRNAs was identified by receiver operating characteristic (ROC) curve analysis. Results: hsa_circ_0064357 and hsa_circ_0064358 were identified to be lowly expressed, while RAF1 was upregulated in OSCC and OLP tissues more than adjacent normal tissues. Low expression of circRNAs was markedly correlated with TNM stages of OSCC patients. ROC analysis revealed AUC of 0.962 and 0.965 for hsa_circ_0064357 and hsa_circ_0064358, respectively, suggesting that circRNAs can serve as novel diagnostic biomarkers for early detection of OSCC. Conclusion: hsa_circ_0064357 and hsa_circ_0064358 might be involved in the progression and metastasis of OSCC and could be used as promising novel biomarkers for early diagnosis and the clinical monitoring of the malignant transformation of OLP into OSCC. Keywords: hsa_circ_0064357, hsa_circ_0064358, OSCC, OLP, RAF1 gene"

The spectrum of RAF1 fusion positive solid tumors in children and young adults.

e22013 Background: The RAF1 gene encodes a kinase protein in the MAPK signaling pathway. Fusions involving RAF1 have been reported in solid tumors with a higher prevalence in melanoma, breast cancer, non-small cell lung cancer, and brain tumors. The fusions typically replace the N-terminal autoinhibitory domain with the 5’ partner genes leading to autonomous activation of RAF1 kinase. The efficacy of MEK inhibitors as a potential treatment for RAF1 fusion positive tumors is under investigation. Here we present a cohort of 8 RAF1 fusions involved in a spectrum of tumors in children and young adults. Methods: A retrospective search for tumors harboring RAF1 fusion was performed using our clinical database from 2016 to date. The RNA fusion analysis targets &gt;700 exons of 117 genes for known and novel fusions. Additional genomic alterations, tumor type, and patient demographics were also collected. Results: A total of 8 cases positive for RAF1 fusion were identified from 2526 solid tumors including 6 brain tumors, 1 sarcoma, and 1 hepatoblastoma. Histologic diagnoses of the brain tumors were mostly low grade gliomas with no other driver mutations. Two pilocytic astrocytomas harbored RAF1 fusions without the pathognomonic KIAA1549: BRAF fusions. Although RAF1 fusions have been reported in rhabdomyosarcomas, it is the first time that a RAF1 fusion is associated with hepatoblastoma. 4 of the 8 RAF1 fusions identified are novel (noted with * in the table). The break points in RAF1 were at exon 7, 8, or 10, demonstrating the retention of the kinase domain. Conclusions: We report 8 RAF1 fusion positive solid tumors in children and young adults, mainly in low-grade gliomas. Although rare, the presence of a RAF1 fusion not only facilitates the tumor diagnosis but also provides genomic evidence for potential targeted therapies.

MiR‐643 suppresses cell invasion and radioresistant of lung cancer through RAF1

AbstractRAF1 (c‐raf) has been known as an important tumor‐promoter in many cancers. However, the regulatory mechanisms affecting RAF1 expressions are rarely reported. This study aimed to predict the candidate miRNAs of RAF1 gene and verify their functions in the progression of lung cancer. The expression of miR‐643 was detected by reverse transcription polymerase chain reaction (RT‐PCR). A dual‐luciferase report system was used to verify the relationship between miR‐643 and RAF1. RT‐PCR and Western blot were used to analyze the regulatory relationship between miR‐643 and RAF1. Transwell chamber, scratch, and monoclonal tests showed that miR‐643 affected the proliferation, migration, and radiosensitivity of H1299 and A549 cells by targeting the RAF1 gene. The expression of miR‐643 in lung cancer cells was lower than that in the bronchial epithelioid cells (CRL‐2741), and luciferase reporter experiment confirmed that miR‐643 targeted RAF1. MiR‐643 overexpression decreased the RAF1 expression, thereby decreasing cell migration, proliferation, and radiation resistance through the AKT/nuclear factor‐κB pathway. miR‐643 in lung cancer cells could inhibit cell proliferation, invasion, and metastasis and increase the radiosensitivity by downregulating RAF1.

Abstract #1400018: Genetic Alterations in NRAS, TERT, PIK3CA and SPEN Genes Leading to an Aggressive Metastatic RAI Refractory Follicular Thyroid Cancer

Follicular thyroid cancer (FTC) is a well-differentiated thyroid tumor and the second most common type after papillary thyroid cancer (PTC) with higher incidence of distant metastases, more aggressive behavior, and poorer outcome than PTC Patient is 43-year-old female with 6.2 cm TR4 left thyroid nodule on Neck US. On Exam, Cricoid is deviated to the right with left thyroid firm nodule. FNA showed Follicular neoplasm. TSH level was 1.59 (0.45-4.70 mIU/L) and Free T4 level: 1.19 (0.78-2.20 ng/dl) CT scan of neck with contrast and MRI thoracic spine: Large, solid heterogenous mass in left thyroid lobe causing lateral displacement and mild narrowing of the trachea with retrosternal extension, Osteolytic lesion of T4 vertebral body and right sided pleura-based mass at the level of T7-T8 with No enlarged cervical lymph nodes. IR biopsy of vertebra: thyroid Origin Metastatic Carcinoma, Patient underwent total thyroidectomy with central neck dissection. Follicular thyroid cancer (STAGE II pT3A,pN1B,pM1) Mutational Testing: Negative BRAF and KRAS with Positive NRAS, PIK3CA, SPEN and TERT. Patient started on TSH suppression therapy. 1 month Later: Thyroglobulin: 2443.4 ng/ml (1.3-31.8), Thyroglobulin Ab< 0.9 (0.0-4.0 IU/ml), TSH 0.02 with Free T4 2.53 FDG PET: Multifocal osseous metastatic disease, predominantly in the axial skeleton Thyrogen stimulated WBS I-123 showed No evidence of residual or metastatic disease. Patient recieved 214 mCi of iodine-131. Post treatment MN scan showed accumulation of iodine in the metastatic bone lesions with small focal activity in the thyroidectomy bed. Post RAI treatment: TG trended to 1102.7 then 1307 Patient Completed 10 fractions of external beam radiation on T4 spine Ultrasound thyroid: No residual thyroid tissue or suspicious lymph nodes Oncology started Bone directed therapy with zoledronate with consideration of PIK3CA mutation targeted therapy with Everolimus or Temsirolimus FTC is more aggressive with poorer prognosis than PTC that is more likely to hematogenously disseminate, with mortality rate of 50%. The neoplastic proliferation of thyroid follicular cells develops by altering multiple molecular pathways such as the PI3K/AKT pathway involving the RAS, RAF, RET, and NTRK1 genes. RAS is a dual activator of the mitogen activated protein kinase and PI3K/AKT pathways TERT is a catalytic subunit of the telomerase complex. Reported in 11–17% of FTC. TERT promoter mutations associated with tumor aggressiveness and mortality PIK3CA encodes p110-alpha, is a catalytic subunit of phosphatidylinositol 3-kinase (PI3K) involves in thyroid cancer tumorigenesis and progression, reported in 7.7% of FTC with sensitivity to therapies targeting PI3K49-56, AKT57-58, or mTOR59-66. In our patient, pretreatment MN scan failed to show RAI avid lesions but PET showed increase FDG uptake and since receiving RAI treatment helped in lowering TG that indicate a possibility of mixture of RAI avid and non-RAI avid lesions existing at same time so RAI treatment is still recommended despite negative Diagnostic Scan for persistent elevated TG.