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Cancer Discovery Jul 2024In this issue, Ryan and colleagues describe the preclinical development of a pan-RAF:MEK molecular glue with superior efficacy, brain penetrance, and tolerability in...
In this issue, Ryan and colleagues describe the preclinical development of a pan-RAF:MEK molecular glue with superior efficacy, brain penetrance, and tolerability in xenograft models of Ras/Raf/MAPK pathway-driven tumors. See related article by Ryan et al., p. 1190 (1).
Topics: Humans; Animals; Protein Kinase Inhibitors; raf Kinases; Mice; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase Kinases; Neoplasms
PubMed: 38946324
DOI: 10.1158/2159-8290.CD-24-0539 -
Acta Dermatovenerologica Croatica : ADC Mar 2024Mutation of the BRAF oncogene is one of the most common mutations detected in human neoplasia, occurring in 40-60% of all cutaneous melanoma. BRAF is a serine/threonine...
Mutation of the BRAF oncogene is one of the most common mutations detected in human neoplasia, occurring in 40-60% of all cutaneous melanoma. BRAF is a serine/threonine protein kinase which is an essential part of the mitogen-activated protein kinase (MAPK) pathway. It is physiologically activated by RAS, but in mutated form, due to molecular conformational change, BRAF becomes constitutively active with subsequent persistent activation of downstream cytoplasmic and nuclear proteins (MEK, ERK, ETS), which finally leads to gene expression that promotes cell growth and survival. Inhibition of the altered MAPK pathway by BRAF inhibitors and combined BRAF/MEK inhibitors in BRAF mutated melanoma has become a standard therapeutic approach (1,2). We recently reported the frequency and clinicopathological features of BRAF V600E mutated melanomas in the Dalmatian region of Croatia. This report included 80 cutaneous melanomas with BRAF analyses performed at our institution until the second half of 2017, using a kit which detected only BRAF V600E mutation (3). From the second half of 2017, we started using a kit which detects several types of BRAF mutations along with NRAS mutation. The aim of this report was to determine the spectrum and frequency of different BRAF mutations in a group of skin melanomas in the Dalmatian region of Croatia and to comment on the relationship between type of BRAF mutation and therapeutic response to MAPK pathway inhibition. The analysis included 179 patients with stage 3 and stage 4 cutaneous melanoma with known BRAF/NRAS mutational status. The paraffin blocks were forwarded from four Dalmatian hospitals (Split: 139 cases, Zadar: 17 cases, Šibenik: 13 cases, Dubrovnik: 10 cases). BRAF/NRAS mutation analysis was performed at the Institute of Pathology, Clinical Hospital Center Split, Croatia, in the period from the second half of 2017 to the end of 2022. For DNA extraction analysis, hematoxylin and eosin stained slides from each submitted sample were reviewed by a pathologist, and tumor tissue was identified for analysis. For all tissue specimens, DNA was extracted from sections (10 mm thick) using the cobas® DNA Sample Preparation Kit (Roche Molecular Diagnostics), following the manufacturer's protocol. The amount of genomic DNA was quantified using the Qubit® 2.0 Fluorometer (Life Technologies) and adjusted to a fixed concentration to be added to the amplification/detection mixture. For mutation analysis, the target DNA was amplified and detected on the cobas z 480 analyzer using the amplification and detection reagents provided in the Roche BRAF/NRAS mutation test (LSR) kit, according to the manufacturer's protocol. The test results were reported as follows: BRAF exon 11 mutation detected, BRAF V600E/E2/D mutation detected, BRAF V600K mutation detected, BRAF V600R mutation detected, BRAF K601E mutation detected, NRAS (G12X, G13X, A18T, Q61X, other NRAS Ex3/4) mutation detected, mutation not detected, or invalid result (no result was obtained on the cobas test). BRAF mutation was observed in 87 patients (48.6%), NRAS mutation was found in 27 patients (15.1%), while 65 patients (36.3%) were without BRAF/NRAS mutation (Table 1). In the group of BRAF mutated melanomas, 61 cases (70.1%) had V600E/E2/D mutation, 20 cases (23%) had V600K mutation, 3 cases (3.4%) had exon 11 mutation, 2 cases (2.3%) had V600R mutation, and 1 case (1.2%) had K601E mutation (Table 2). The observed frequency of BRAF mutated melanomas in this study was similar to the frequency reported in our previous study (48.6% and 47.5%, respectively) (3). The vast majority were BRAF V600 mutations, while BRAF non-V600 mutations were rare (95.4% and 4.6%, respectively). In the group of BRAF V600 mutations, V600E/E2/D mutations predominated, followed by V600K mutations, while V600R mutations were rare. Greaves et al. reported similar frequency of BRAF V600 mutations in a group of 499 BRAF-mutated cutaneous melanomas, with V600E/E2/D mutations observed in 77.2% cases, followed by V600K mutations observed in 17.2% cases, and V600R mutations observed in 2.6% cases (4). BRAF non-V600 mutations (exon 11 and K601E mutations) were rarely observed in this study, confirming the findings of other authors (4,5). A three-class system of BRAF mutations was recently proposed that takes into account the differences in their kinase activity, with class I containing mutants with high kinase activity and high response rate to BRAF and BRAF/MEK inhibitors. Class II BRAF mutations have lower kinase activity than class I mutants, but higher than wild-type BRAF, showing resistance to BRAF inhibitor monotherapy and sensitivity to MEK and BRAF/MEK inhibitors. Finally, class III BRAF mutations are characterized by low kinase activity and low response rate to targeted therapy (6). BRAF V600 mutations belong to class I mutations, which means that the large majority of BRAF-positive melanomas in this study (95.4%) were sensitive to targeted therapy. However, the sensitivity to targeted therapy is different among different class I BRAF mutations. While large randomized controlled trials on combined BRAF/MEK inhibition showed good overall response (63-68%) and improvement of progression-free survival (PFS) and overall survival (OS) for the melanomas with most prevalent V600E and V600K mutations, Menzer et al. showed lower response rate to MAPK pathway inhibition (45%) in the group of metastatic melanomas with BRAF V600 mutations other than V600E/K. The overall response rate to MAPK pathway inhibition in the same group of melanomas with BRAF non-V600 mutations (class II and III mutations) was only 18% (7). In our group of BRAF mutated skin metastatic melanomas, we found only 6 cases (6.9%) with expected lower response rate to MAPK pathway inhibition: 2 cases with V600R mutation (class I non-V600E/K mutation), 1 case with K601E mutation (class II mutation), and 3 cases with exon 11 mutation (class II and III mutations).
Topics: Humans; Proto-Oncogene Proteins B-raf; Melanoma; Skin Neoplasms; Croatia; Mutation; Female; Male; Middle Aged; Aged; Adult; Aged, 80 and over
PubMed: 38946192
DOI: No ID Found -
Acta Dermatovenerologica Croatica : ADC Mar 2024A 39-year-old Caucasian woman affected by Noonan Syndrome (NS) mutated in RAF1 was referred to us with itchy lesions on her limbs that had appeared two months earlier....
A 39-year-old Caucasian woman affected by Noonan Syndrome (NS) mutated in RAF1 was referred to us with itchy lesions on her limbs that had appeared two months earlier. Clinically, there were multiple umbilicated papules with a hyperkeratotic central plug, localized on the upper and lower limbs (Figure 1, a-b). The patient had no personal history of diabetes mellitus and no chronic renal failure, but suffered from hypertrophic cardiomyopathy. Blood tests showed no abnormalities. On histological examination of a skin lesion, an ectatic hair follicle with hyperkeratotic ostium was observed with fragments of hair, inflammatory cells, and epidermal perforation. A final diagnosis of Kyrle's disease (KD) was established. The patient underwent narrowband UVB (NB-UVB) phototherapy with residual atrophic scars (Figure 1, c-d) but with complete and long-lasting resolution of symptoms as well. KD belongs to perforating dermatoses (PD), a heterogeneous group of skin diseases characterized by the transepidermal elimination of dermal components. Despite the classification of PD being debated, four primary forms are traditionally recognized: reactive perforating collagenosis, elastosis perforans serpiginosum, perforating folliculitis, and KD (1). The typical skin manifestation of KD is an eruption of dome-shaped papules and nodules with a whitish central keratotic plug, mainly localized on the extremities and the buttocks. Described by Kyrle in 1916, KD is frequently associated with systemic diseases, especially chronic renal failure and diabetes mellitus. Other associated conditions include chronic hepatic disease, internal malignancies, and congestive heart disease (1). Despite the absence of a consensus, the control of the underlying disease remains the first therapeutic target. Both topical (keratolytics, retinoids, and corticosteroids) and systemic treatments (corticosteroid, retinoids, antibiotics, and phototherapy) have been reported to control skin manifestations (2). In our experience, NB-UVB is an effective option as first-line therapy in case of diffuse lesions, both in KD and in other PDs (3). NS is a relatively common RASopathy, an heterogenous group of genetic disease characterized by a defect of the Ras-mitogen-activated protein kinase (Ras-MAPK) pathway, with an estimated prevalence of 1/1000-2500. PTPN11 is the most frequent mutated gene, accounting for 50% of cases, but more than ten genes were identified as causing NS (4). Classical features include a distinctive facial dysmorphism, short stature, pulmonic stenosis, and other anomalies of different organs. The skin is commonly involved. Keratinization disorders and hair abnormalities such as keratosis pilaris, ulerythema ophryogenes, wavy or curly hair, and scarce scalp hair are often described. Other cutaneous signs include easy bruising, skin hyperlaxity, multiple lentigines, and café-au-lait spots (5). To the best of our knowledge, no cases of KD in patients with NS have been previously reported to date. The exact etiopathogenesis of KD is not clear, but it was hypothesized that systemic diseases, such as diabetes and chronic renal failure, can cause a deposit of substances or dermis alterations, which triggers the inflammatory process with subsequent transepidermal extrusion (1). In our patient, we ruled out all the causes commonly associated with KD. It is however possible that this manifestation could be a direct result of our patient's illness. Our patient suffered from diffuse keratosis pilaris, and one of the possible pathogenetic mechanisms of KD was theorized to be an abnormal epidermal keratinization with a secondary inflammatory dermic response (1). On the other hand, the hyperlaxity and fragility of the skin typical of NS suggest the presence of altered connective tissue, which could trigger an abnormal keratinization and, subsequently, the transepidermal extrusion, as well as perforating elastosis, and is associated with genetic connective tissue diseases (1). Moreover, our patient suffered from a cardiac disease, another condition associated with KD (5). Although these explanations have their appeal, there is currently insufficient evidence of a link between KD and NS, and it will be necessary to collect additional data to confirm this hypothesis.
Topics: Humans; Female; Noonan Syndrome; Adult; Ultraviolet Therapy; Darier Disease
PubMed: 38946190
DOI: No ID Found -
European Journal of Pharmacology Jun 2024Depression is a serious medical illness characterized by persistent feelings of sadness, hopelessness, and lack of interest in daily activities. It can interfere with...
Etanercept ameliorates chronic mild stress-induced depressive-like behavior in rats: crosstalk between MAPK and STAT3 pathways and norepinephrine and serotonin transporters.
Depression is a serious medical illness characterized by persistent feelings of sadness, hopelessness, and lack of interest in daily activities. It can interfere with daily functioning and quality of life. Despite decades of research, the pathophysiology of depression remains incompletely understood. The correlation between depression and inflammation has recently attracted considerable attention. This study investigated the potential antidepressant effect of etanercept, a tumor necrosis factor-alpha (TNF-α) inhibitor, utilizing a chronic mild stress (CMS) model in rats. Male Wistar rats were divided into two groups; one following a non-stressed protocol and the other a stressed protocol for 5 weeks. From the beginning of the third week, rats were treated either with saline daily or with etanercept twice a week (0.3 mg/kg, i.p.) or with fluoxetine daily (10 mg/kg, i.p) as a reference. Etanercept exhibited comparable effects to those of fluoxetine in counteracting CMS-induced behavioral manifestation in the forced swimming and splash tests. Etanercept also restored serotonin and norepinephrine levels to control values in the prefrontal cortex (PFC). Moreover, the current study verified the antioxidant and anti-inflammatory effects of etanercept. Interestingly, etanercept halted the expression of both norepinephrine and serotonin transporters in stressed rats. This could be attributed to abrogation of the p38 mitogen-activated protein kinase (p38 MAPK) and signal transducer and activator of transcription 3 (STAT-3) pathways in the PFC. The findings of the present study contribute to the understanding of the potential of etanercept as an antidepressant and provide insights into the neurobiological mechanisms underlying its therapeutic effects.
PubMed: 38945285
DOI: 10.1016/j.ejphar.2024.176801 -
Biomedicine & Pharmacotherapy =... Jun 2024Inflammation and immune responses are intricately intertwined processes crucial for maintaining homeostasis and combating against pathogens. These processes involve...
Inflammation and immune responses are intricately intertwined processes crucial for maintaining homeostasis and combating against pathogens. These processes involve complex signaling pathways, notably the Nuclear Factor kappa-light-chain-enhancer of activated B-cells (NF-κB) and Mitogen-Activated Protein Kinase (MAPK) pathways, which play crucial roles. Sulforaphane (SFN), a nutraceutic, has emerged as a potential regulator of NF-κB and MAPK signaling pathways, exhibiting anti-inflammatory properties. However, limited knowledge exists regarding SFN's effects on immune cell modulation. This study aimed to assess the immunomodulatory capacity of SFN pretreatment in human dendritic cells (DCs), followed by exposure to a chronic inflammatory environment induced by lipopolysaccharide. SFN pretreatment was found to inhibit the NF-κB and MAPK signaling pathways, resulting in phenotypic changes in DCs characterized by a slight reduction in the expression of surface markers, as well as a decrease of TNF-α/IL-10 ratio. Additionally, SFN pretreatment enhanced the proliferation of Treg-cells and promoted the production of IL-10 by B-cells before exposure to the chronic inflammatory environment. Furthermore, these changes in DCs were found to be influenced by the inhibition of NF-κB and MAPK pathways (specifically p38 MAPK and JNK), suggesting that these pathways may play a role in the regulation of the differentiation of adaptive immune responses (proliferation of T- and IL-10-producing regulatory-cells), prior to SFN pretreatment. Our findings suggest that SFN pretreatment may induce a regulatory response by inhibiting NF-κB and MAPK signaling pathways in an inflammatory environment. SFN could be considered a promising strategy for utilizing functional foods to protect against inflammation and develop immunoregulatory interventions.
PubMed: 38945082
DOI: 10.1016/j.biopha.2024.117056 -
Nature Communications Jun 2024JNK signaling is a critical regulator of inflammation and regeneration, but how it is controlled in specific tissue contexts remains unclear. Here we show that, in the...
JNK signaling is a critical regulator of inflammation and regeneration, but how it is controlled in specific tissue contexts remains unclear. Here we show that, in the Drosophila intestine, the TNF-type ligand, Eiger (Egr), is expressed exclusively by intestinal stem cells (ISCs) and enteroblasts (EBs), where it is induced by stress and during aging. Egr preferentially activates JNK signaling in a paracrine fashion in differentiated enterocytes (ECs) via its receptor, Grindelwald (Grnd). N-glycosylation genes (Alg3, Alg9) restrain this activation, and stress-induced downregulation of Alg3 and Alg9 correlates with JNK activation, suggesting a regulatory switch. JNK activity in ECs induces expression of the intermembrane protease Rhomboid (Rho), driving secretion of EGFR ligands Keren (Krn) and Spitz (Spi), which in turn activate EGFR signaling in progenitor cells (ISCs and EBs) to stimulate their growth and division, as well as to produce more Egr. This study uncovers an N-glycosylation-controlled, paracrine JNK-EGFR-JNK feedforward loop that sustains ISC proliferation during stress-induced gut regeneration.
Topics: Animals; Drosophila Proteins; ErbB Receptors; Intestines; MAP Kinase Signaling System; Drosophila melanogaster; Enterocytes; Stem Cells; Intestinal Mucosa; Drosophila; Glycosylation; Receptors, Invertebrate Peptide; Cell Proliferation; JNK Mitogen-Activated Protein Kinases; Signal Transduction; Cell Communication; Cell Differentiation; Epidermal Growth Factor; Membrane Proteins
PubMed: 38944657
DOI: 10.1038/s41467-024-49786-w -
Journal of Pediatric Urology Jun 2024Many pediatric urology conditions affect putatively normal tissues or appear too commonly to be based solely on specific DNA mutations. Understanding epigenetic...
INTRODUCTION
Many pediatric urology conditions affect putatively normal tissues or appear too commonly to be based solely on specific DNA mutations. Understanding epigenetic mechanisms in pediatric urology, therefore, has many implications that can impact cell and tissue responses to settings, such as environmental and hormonal influences on urethral development, uropathogenic infections, obstructive stimuli, all of which originate externally or extracellularly. Indeed, the cell's response to external stimuli is often mediated epigenetically. In this commentary, we highlight work on the critical role that epigenetic machinery, such as DNA methyltransferases (DNMTs), Enhancer of Zeste Polycomb Repressive Complex 2 Subunit (EZH2), and others play in regulating gene expression and cellular functions in three urological contexts.
DESIGN
Animal and cellular constructs were used to model clinical pediatric uropathology. The hypertrophy, trabeculation, and fibrosis of the chronically obstructed bladder was explored using smooth muscle cell models employing disorganised vs. normal extracellular matrix (ECM), as well as a new animal model of chronic obstructive bladder disease (COBD) which retains its pathologic features even after bladder de-obstruction. Cell models from human and murine hypospadias or genital tubercles (GT) were used to illustrate developmental responses and epigenetic dependency of key developmental genes. Finally, using bladder urothelial and organoid culture systems, we examined activity of epigenetic machinery in response to non uropathogenic vs. uropathogenic E.coli (UPEC). DNMT and EZH2 expression and function were interrogated in these model systems.
RESULTS
Disordered ECM exerted a principal mitogenic and epigenetic role for on bladder smooth muscle both in vitro and in CODB in vivo. Key genes, e.g., BDNF and KCNB2 were under epigenetic regulation in actively evolving obstruction and COBD, though each condition showed distinct epigenetic responses. In models of hypospadias, estrogen strongly dysregulated WNT and Hox expression, which was normalized by epigenetic inhibition. Finally, DNA methylation machinery in the urothelium showed specific activation when challenged by uropathogenic E.coli. Similarly, UPEC induces hypermethylation and downregulation of the growth suppressor p16INK4A. Moreover, host cells exposed to UPEC produced secreted factors inducing epigenetic responses transmissible from one affected cell to another without ongoing bacterial presence.
DISCUSSION
Microenvironmental influences altered epigenetic activity in the three described urologic contexts. Considering that many obstructed bladders continue to display abnormal architecture and dysfunction despite relief of obstruction similar to after resection of posterior valves or BPH, the epigenetic mechanisms described highlight novel approaches for understanding the underlying smooth muscle myopathy of this crucial clinical problem. Similarly, there is evidence for an epigenetic basis of xenoestrogen on development of hypospadias, and UTI-induced pan-urothelial alteration of epigenetic marks and propensity for subsequent (recurrent) UTI. The impact of mechanical, hormonal, infectious triggers on genitourinary epigenetic machinery activity invite novel avenues for targeting epigenetic modifications associated with these non-cancer diseases in urology. This includes the use of deactivated CRISPR-based technologies for precise epigenome targeting and editing. Overall, we underscore the importance of understanding epigenetic regulation in pediatric urology for the development of innovative therapeutic and management strategies.
PubMed: 38944627
DOI: 10.1016/j.jpurol.2024.06.008 -
Virology Jun 2024Therapies targeting virus-host interactions are seen as promising strategies for treating gallid alphaherpesvirus 1 (ILTV) infection. Our study revealed a biphasic...
Therapies targeting virus-host interactions are seen as promising strategies for treating gallid alphaherpesvirus 1 (ILTV) infection. Our study revealed a biphasic activation of two MAPK cascade pathways, MEK/ERK and p38 MAPK, as a notably activated host molecular event in response to ILTV infection. It exhibits antiviral functions at different stages of infection. Initially, the MEK/ERK pathway is activated upon viral invasion, leading to a broad suppression of metabolic pathways crucial for ILTV replication, thereby inhibiting viral replication from the early stage of ILTV infection. As the viral replication progresses, the p38 MAPK pathway activates its downstream transcription factor, STAT1, further hindering viral replication. Interestingly, ILTV overcomes this biphasic antiviral barrier by hijacking host p38-AKT axis, which protects infected cells from the apoptosis induced by infection and establishes an intracellular equilibrium conducive to extensive ILTV replication. These insights could provide potential therapeutic targets for ILTV infection.
PubMed: 38943781
DOI: 10.1016/j.virol.2024.110159 -
Nutrition Research (New York, N.Y.) Jun 2024Canola meal, a by-product of processing canola into oil, reportedly contains high amounts of phenolic compounds and proteins. However, as canola meal is primarily used...
Canola meal, a by-product of processing canola into oil, reportedly contains high amounts of phenolic compounds and proteins. However, as canola meal is primarily used as feed for livestock, advances in multiple research fields are required to broaden its potential applications. Photoaging is caused by continuous exposure to ultraviolet (UV) radiation from sunlight. UV radiation generates reactive oxygen species and destroys collagen in the skin, thickening the epidermis, reducing elasticity, and causing wrinkles. We hypothesized that canola meal extract (CME) can mitigate the damage to skin associated with wrinkles induced by exposure to UVB radiation. To evaluate the anti-wrinkle effect, we administered CME orally to 40 female Hos:HR-1 hairless mice divided into 5 groups: (1) control mice, (2) a UVB group, and (3-5) CME-treated groups (CME-250, 500, and 1000 mg/kg body weight/day, respectively). All groups except the controls were irradiated with UVB 3 times a week to create wrinkles due to photoaging. CME administration inhibited the increase of the number, mean length, and mean depth of wrinkles induced by UVB radiation as assessed using a skin replica. Histopathological image analysis revealed that CME administration resulted in a decrease in epidermal thickness and an increase in collagen content, while increasing catalase activity and hydroxyproline content in skin tissues. CME administration inhibited the phosphorylation of mitogen-activated protein kinase and decreased the production of collagenase and gelatinase. These results suggest that CME, an upcycled material, has the potential to develop into a healthful and functional food ingredient with anti-wrinkling effects.
PubMed: 38943729
DOI: 10.1016/j.nutres.2024.06.002 -
Journal of Diabetes Investigation Jun 2024Regulatory T cells (Tregs) have protected against many cardiovascular diseases. This study was intended to explore the effect of Tregs on diabetic cardiomyopathy (DCM)...
AIMS/INTRODUCTION
Regulatory T cells (Tregs) have protected against many cardiovascular diseases. This study was intended to explore the effect of Tregs on diabetic cardiomyopathy (DCM) using a db/db mouse model.
MATERIALS AND METHODS
Eight-week-old male db/db mice were randomly divided into four groups: the control group, administered 200 μL phosphate-buffered saline; the small-dose Treg group, administered 10 Tregs; the large-dose Treg group, administered 10 Tregs; and the PC group, administered 100 μg anti-CD25 specific antibody (PC61) and 10 Tregs. After 12 weeks, mice were euthanized. Transthoracic echocardiography was carried out at the beginning and end of the experiment. Relevant basic experiments to evaluate the effects of Tregs on DCM were carried out.
RESULTS
Echocardiography showed that the impaired diastolic and systolic functions were significantly improved in mice administered large-dose Tregs. Large-dose Tregs significantly ameliorated myocardial hypertrophy and fibrosis, and decreased hypertrophic gene expression and collagen deposition. The protective effects of Tregs on diabetic hearts were associated with decreased oxidative stress, inflammatory response and apoptosis. In addition, Tregs promoted the activation of the phosphatidylinositol 3-kinase-protein kinase B signaling pathway, whereas they inhibited extracellular signal-regulated kinase 1/2 and Jun N-terminal kinase phosphorylation, which might be responsible for the cardioprotective role of Tregs against DCM.
CONCLUSIONS
Tregs ameliorated myocardial hypertrophy and fibrosis, improved cardiac dysfunction, and protected against DCM progression in db/db mice. The mechanisms involved a decrease of inflammatory response, oxidative stress and apoptosis, which might be mediated by phosphatidylinositol 3-kinase-protein kinase B and mitogen-activated protein kinase pathways. Hence, Tregs might serve as a promising therapeutic approach for DCM treatment.
PubMed: 38943657
DOI: 10.1111/jdi.14251