BRAF and MEK inhibitor targeted therapy in papillary craniopharyngiomas: a cohort study.

OBJECTIVE: Targeted therapy (TT) with BRAF/MEK inhibitors has emerged as a potential treatment in papillary craniopharyngiomas (PCPs). However, standardized data on large cohorts are lacking. Our study aimed to assess real-life efficacy and safety of BRAF/MEK inhibition in patients with PCPs. DESIGN: Retrospective French multicenter study involving BRAF V600E-mutated PCP patients, treated with BRAF/MEK inhibitor combination dabrafenib and trametinib, from April 2019 to July 2023. METHODS: Objective response and clinical and safety outcomes were assessed after 3 months and at the last available follow-up during TT. RESULTS: Sixteen patients (8 females, mean age 50.5 ± 15.75 years), receiving either neoadjuvant therapy (NEO) for non-resectable tumors (n = 6), post-surgical adjuvant therapy (ADJ; n = 8), or palliative therapy (PAL) following failure of multimodal treatment (n = 2), were included.At the last follow-up (mean 7.6 ± 5.3 months), 12 patients showed subtotal response, 3 exhibited partial response, and 1 maintained stable disease. Mean volume reduction was 88.9 ± 4.4%, 73.3 ± 23.4%, and 91.8 ± 4.3% in the NEO, ADJ, and PAL groups, respectively.Targeted therapy resolved headaches in 5/5 patients and visual impairment in 6/9; 2/3 patients had improved neurological symptoms, 1/4 presented weight loss, and 2/14 recovered endocrine function.Targeted therapy was well-tolerated in 62.5% of cases; adverse events led to treatment discontinuation in 5 patients and definitive discontinuation in 3 cases. CONCLUSIONS: In this study, 94% of patients showed partial response or better to TT. Adverse events were acceptable. Further research is needed to establish standardized protocols; however, these results advocate for a NEO approach in invasive PCPs.

Advances in the Treatment of Pediatric Low-Grade Gliomas.

PURPOSE OF REVIEW: Pediatric low-grade gliomas (pLGGs) often result in significant long-term morbidities despite high overall survival rates. This review aims to consolidate the current understanding of pLGG biology and molecular features and provide an overview of current and emerging treatment strategies. RECENT FINDINGS: Surgical resection remains a primary treatment modality, supplemented by chemotherapy and radiotherapy in specific cases. However, recent advances have elucidated the molecular underpinnings of pLGGs, revealing key genetic abnormalities such as BRAF fusions and mutations and the involvement of the RAS/MAPK and mTOR pathways. Novel targeted therapies, including MEK, BRAF and pan-RAF inhibitors, have shown promise in clinical trials, demonstrating significant efficacy and manageable toxicity. Understanding of pLGGs has significantly improved, leading to more personalized treatment approaches. Targeted therapies have emerged as effective alternatives, potentially reducing long-term toxicities. Future research should focus on optimizing therapy sequences, understanding long-term impacts, and ensuring global accessibility to advanced treatments.

The Investigation of Hsp90 C-terminal inhibitors containing Amide bioisosteres.

Heat Shock Protein 90 (Hsp90) is responsible for the proper folding and maturation of ~400 client protein substrates, many of which are directly associated with the ten hallmarks of cancer. Hsp90 is a great target for cancer therapy including melanoma, since Hsp90 inhibition can disrupt multiple oncogenic pathways simultaneously. In this study, we report the synthesis and anti-proliferative activity manifested by a series of Hsp90 C-terminal inhibitors against mutant BRAF and wild-type BRAF melanoma cells. Furthermore, we explored structure-activity relationships (SAR) for the amide moiety of 6 (B1), a novel Hsp90 C-terminal inhibitor via introduction of amide bioisosteres. Compound 6 displayed an IC50 of 1.01 µM, 0.782 µM, 0.607 µM and 1.413 µM against SKMel173, SKMel103, SKMel19 and A375 cells, respectively.

Combination Atezolizumab, Cobimetinib, and Vemurafenib as a Treatment Option in BRAF V600 Mutation-Positive Melanoma: Patient Selection and Perspectives.

The treatment landscape for advanced and metastatic melanoma has drastically changed in recent years, with the advent of novel therapeutic options such as immune checkpoint inhibitors and targeted therapies offering remarkable efficacy and significantly improved patient outcomes compared to traditional approaches. Approximately 50% of melanomas harbor activating BRAF mutations, with over 90% resulting in BRAF V600E. Tumors treated with BRAF inhibitor monotherapy have a high rate of developing resistance within six months. Combination therapy with MEK inhibitors helped to mitigate this treatment resistance and led to improved outcomes. Due to the up-regulation of PD-1/PD-L1 receptors in tumors treated with BRAF/MEK inhibitor therapy, further studies included a third combination agent, anti-PD-1/PD-L1 inhibitors. This triple combination therapy may have superior efficacy and a manageable safety profile when compared with single or double agent therapy regimens.

Effective treatment of advanced and metastatic melanoma can be challenging. Newer treatment methods for patients with BRAF-mutated tumors include a combination of drugs with different complementary mechanisms. These drugs include BRAF-inhibitors, MEK-inhibitors, and PD-1/PD-L1 inhibitors. When these three medications are used in combination, patients may have better response rates and survival outcomes, when compared to using just one or two of these medications together. Toxicity rates are higher with a triple-medication regimen, so careful patient selection is important to consider.

IL-1ß-activated PI3K/AKT and MEK/ERK pathways coordinately promote induction of partial epithelial-mesenchymal transition.

Epithelial-mesenchymal transition (EMT) is a cellular process in embryonic development, wound healing, organ fibrosis, and cancer metastasis. Previously, we and others have reported that proinflammatory cytokine interleukin-1ß (IL-1ß) induces EMT. However, the exact mechanisms, especially the signal transduction pathways, underlying IL-1ß-mediated EMT are not yet completely understood. Here, we found that IL-1ß stimulation leads to the partial EMT-like phenotype in human lung epithelial A549 cells, including the gain of mesenchymal marker (vimentin) and high migratory potential, without the complete loss of epithelial marker (E-cadherin). IL-1ß-mediated partial EMT induction was repressed by PI3K inhibitor LY294002, indicating that the PI3K/AKT pathway plays a significant role in the induction. In addition, ERK1/2 inhibitor FR180204 markedly inhibited the IL-1ß-mediated partial EMT induction, demonstrating that the MEK/ERK pathway was also involved in the induction. Furthermore, we found that the activation of the PI3K/AKT and MEK/ERK pathways occurred downstream of the epidermal growth factor receptor (EGFR) pathway and the IL-1 receptor (IL-1R) pathway, respectively. Our findings suggest that the PI3K/AKT and MEK/ERK pathways coordinately promote the IL-1ß-mediated partial EMT induction. The inhibition of not one but both pathways is expected yield clinical benefits by preventing partial EMT-related disorders such as organ fibrosis and cancer metastasis.

Three-Year Analysis of Adjuvant Therapy in Postoperative Melanoma including Acral and Mucosal Subtypes.

BACKGROUND: Adjuvant therapy has improved the clinical prognosis for postoperative melanoma patients. However, the long-term efficacy of this therapy on the melanoma acral and mucosal subtypes has not been fully evaluated in previous trials. This study assessed the 3-year recurrence-free survival and overall survival of patients with melanoma, including the acral and mucosal subtypes, treated with anti-PD-1 antibody (Ab) or with the combination of the BRAF and MEK inhibitors dabrafenib and trametinib. METHODS: We retrospectively analyzed both the 3-year time to relapse (TTR) and overall survival (OS) of 120 patients treated with anti-PD-1 antibody (Ab), or with the combination of dabrafenib and trametinib. RESULTS: The overall median TTR was 18.4 months, with a range of 0.69 to 36 months. The 3-year TTR of the acral and mucosal types was 28.1% and 38.5%, respectively. Baseline tumor thickness (TT) and acral type were associated with the TTR in subgroup analysis. Moreover, we classified 104 acral and non-acral cutaneous patients into the anti-PD-1 Abs or dabrafenib plus trametinib combined therapies cohort in multiple analyses. The acral subtype and TT were detected as important prognostic factors. In the 3-year OS, only tumor ulceration was associated with the OS in both univariate and multiple analyses. There was no significant difference in baseline or treatment-related factors of the mucosal type (p > 0.05). CONCLUSION: This study suggests that adjuvant therapy is more effective with non-acral cutaneous melanoma than either the acral or mucosal types at the 3-year TTR endpoint.

Hydrolyzed conchiolin protein inhibits melanogenesis through PKA/CREB and MEK/ERK signalling pathways.

OBJECTIVE: Hydrolyzed conchiolin protein (HCP) derived from pearl and nacre extracts exerts skin-lightening effects; however, the underlying molecular mechanisms are not fully understood. Herein, we investigated the effect of HCP on melanogenesis and the signalling pathways involved. METHODS: B16F10 cells and PIG cells were treated with HCP to verify its ability to inhibit melanin. Western Blot, immunofluorescence, and flow cytometry methods were performed to investigate the effect of HCP on melanogenesis signalling pathway proteins. The inhibitors were used to further validate the effect of HCP on PKA/CREB and MEK/ERK signalling pathways. To further evaluate the whitening ability of HCP, changes in melanin were detected using 3D melanin skin model and zebrafish model. RESULTS: HCP was found to significantly inhibit melanin synthesis and decrease the expression of melanogenesis-related proteins, such as microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase-related protein-2, in a dose-dependent manner. Additionally, we revealed that HCP suppresses melanogenesis via the regulation of the PKA/cAMP response element-binding (CREB) and MEK/extracellular signalling-regulated kinase (ERK) signalling pathways. Using 3D melanin skin models, we demonstrated that HCP can achieve skin-lightening effects by improving apparent chroma, increasing apparent brightness, and inhibiting melanin synthesis. Furthermore, HCP exhibits skin-whitening effects in a zebrafish model. CONCLUSION: These results suggest that HCP suppresses the melanogenesis signalling cascade by inhibiting the PKA/CREB, MEK/ERK signalling pathway and downregulating MITF and its downstream signalling pathways, resulting in decreased melanin synthesis. In summary, HCP is a potential anti-pigmentation agent with promising applications in cosmetics and pharmaceutical products.

OBJECTIF: La protéine conchioline hydrolysée (HCP) dérivée des extraits de perle et de nacre exerce des effets éclaircissants sur la peau ; cependant, les mécanismes moléculaires sous­jacents ne sont pas entièrement compris. Dans cette étude, nous avons investigué l'effet de la HCP sur la mélanogenèse et les voies de signalisation impliquées. MÉTHODES: Les cellules B16F10 et PIG ont été traitées avec la HCP pour vérifier sa capacité à inhiber la mélanine. Des méthodes de Western Blot, d'immunofluorescence et de cytométrie en flux ont été réalisées pour étudier l'effet de la HCP sur les protéines des voies de signalisation de la mélanogenèse. Les inhibiteurs ont été utilisés pour valider davantage l'effet de la HCP sur les voies de signalisation PKA/CREB et MEK/ERK. Pour évaluer plus en détail la capacité éclaircissante de la HCP, les changements de mélanine ont été détectés en utilisant un modèle de peau en 3D de mélanine et un modèle de poisson­zèbre. RÉSULTATS: Il a été constaté que la HCP inhibe significativement la synthèse de la mélanine et diminue l'expression des protéines liées à la mélanogenèse, telles que le facteur de transcription associé à la microphthalmie (MITF), la tyrosinase et la protéine liée à la tyrosinase­2, de manière dose­dépendante. De plus, nous avons révélé que la HCP supprime la mélanogenèse via la régulation des voies de signalisation PKA/cAMP et MEK/ERK. En utilisant des modèles de peau en 3D de mélanine, nous avons démontré que la HCP peut atteindre des effets éclaircissants sur la peau en améliorant la chroma apparente, en augmentant la luminosité apparente et en inhibant la synthèse de la mélanine. En outre, la HCP présente des effets éclaircissants sur la peau dans un modèle de poisson­zèbre. CONCLUSION: Ces résultats suggèrent que la HCP supprime la cascade de signalisation de la mélanogenèse en inhibant les voies de signalisation PKA/CREB et MEK/ERK et en régulant à la baisse le MITF et ses voies de signalisation en aval, ce qui entraîne une diminution de la synthèse de la mélanine. En résumé, la HCP est un agent potentiel anti­pigmentation avec des applications prometteuses dans les produits cosmétiques et pharmaceutiques.

Mucocutaneous toxicities from MEK inhibitors: a scoping review of the literature.

BACKGROUND: MEK inhibitors cause a wide spectrum of mucocutaneous toxicities which can delay or interrupt life-saving therapy. PURPOSE: To summarize the morphology, incidence, and clinical presentation of mucocutaneous toxicities from MEK inhibitors via a scoping review of the literature. METHODS: We conducted a scoping review of the published literature, including clinical trials, retrospective and prospective studies, reviews, and case reports and series. All included literature was analyzed by a panel of pediatric and adult oncodermatologists. RESULTS: Of 1626 initial citations, 227 articles met final inclusion criteria. Our review identified follicular reactions, ocular toxicities, xerosis, eczematous dermatitis, edema, and paronychia as the most common mucocutaneous side effects from MEK inhibitor therapy. Grade 1 and 2 reactions were the most prevalent and were typically managed while continuing treatment; however, grade 3 toxicities requiring dose reductions or treatment interruptions were also reported. CONCLUSION: Mucocutaneous toxicities to MEK inhibitor therapy are common and most often mild in severity. Early recognition and treatment can mitigate disruptions in oncologic therapy.

Tretinoin synergistically enhances the antitumor effect of combined BRAF, MEK, and EGFR inhibition in BRAFV600E colorectal cancer.

Patients with BRAF-mutated colorectal cancer (BRAFV600E CRC) are currently treated with a combination of BRAF inhibitor and anti-EGFR antibody with or without MEK inhibitor. A fundamental problem in treating patients with BRAFV600E CRC is intrinsic and/or acquired resistance to this combination therapy. By screening 78 compounds, we identified tretinoin, a retinoid, as a compound that synergistically enhances the antiproliferative effect of a combination of BRAF inhibition and MEK inhibition with or without EGFR inhibition on BRAFV600E CRC cells. This synergistic effect was also exerted by other retinoids. Tretinoin, added to BRAF inhibitor and MEK inhibitor, upregulated PARP, BAK, and p-H2AX. When either RARα or RXRα was silenced, the increase in cleaved PARP expression by the addition of TRE to ENC/BIN or ENC/BIN/CET was canceled. Our results suggest that the mechanism of the synergistic antiproliferative effect involves modulation of the Bcl-2 family and the DNA damage response that affects apoptotic pathways, and this synergistic effect is induced by RARα- or RXRα-mediated apoptosis. Tretinoin also enhanced the antitumor effect of a combination of the BRAF inhibitor and anti-EGFR antibody with or without MEK inhibitor in a BRAFV600E CRC xenograft mouse model. Our data provide a rationale for developing retinoids as a new combination agent to overcome resistance to the combination therapy for patients with BRAFV600E CRC.

Inhibition of AIM2 expression enhance treatment effect of osimertinib in treatment of glioma.

INTRODUCTION: Glioma is one of the most commonly tumours which occurs in the central nervous system and accounts for nearly 80% of brain tumours, with a significantly high mortality and morbidity. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are used as EGFR targeted therapy in various types of solid tumours; however, effective treatment for glioma is still limited. Osimertinib is an irreversible, oral third-generation TKI that targets the mutation at T790M, which causes cancer cells to acquire resistance to drugs. Osimertinib could be effective in the treatment of EGFR mutations with minimal effects on the activity of wild-type EGFR. Absent in melanoma 2 (AIM2) is highly expressed in glioma cells, promoting the maturation of pro-cancer cytokines and contributing to progression of glioma. However, the secretion of pro-cancer cytokines of tumour cells has been regarded as the resistance mechanism to EGFR-TKIs, including osimertinib. A high level of these cytokines also indicates a shorter progression-free survival (PFS). As AIM2 regulates the secretion of pro-cancer cytokines, we thought inhibition of AIM2 may contribute to the therapeutic effect of EGFR-TKIs. MATERIAL AND METHODS: We first established AIM2 inhibition and overexpression in cells. Then, the viability rate of cells was calculated by cell counting kit-8 (CCK-8) method, and apoptotic ratio of cells were measured by flow cytometry. The expression of inflammatory-related genes was detected using quantitative polymerase chain reaction (qPCR), concentrations of inflammatory-related factors were measured using enzyme-linked immunosorbent assay (ELISA). The expression of Wnt/b-catenin and EGFR/Ras/Mitogen-activated protein kinase kinase 1 (MEK) signalling pathway components was detected using western blotting. RESULTS: We found that inhibition of AIM2 enlarged the effect of osimertinib on the upregulation of inflammatory gene expression and secretion of these genes, increasing apoptosis. In addition, we also found that AIM2 could enhance the effect of osimertinib on reducing the expression of the Wnt/b-catenin and EGFR/Ras/MEK signalling pathways, resulting in the inhibition of cellular proliferation, and exerting an anti-tumour effect. These effects were also observed using in vivo experiments. CONCLUSIONS: AIM2 presents a potential therapeutic target in treatment of glioma.

Molecular Susceptibility and Treatment Challenges in Melanoma.

Melanoma is the most aggressive subtype of cancer, with a higher propensity to spread compared to most solid tumors. The application of OMICS approaches has revolutionized the field of melanoma research by providing comprehensive insights into the molecular alterations and biological processes underlying melanoma development and progression. This review aims to offer an overview of melanoma biology, covering its transition from primary to malignant melanoma, as well as the key genes and pathways involved in the initiation and progression of this disease. Utilizing online databases, we extensively explored the general expression profile of genes, identified the most frequently altered genes and gene mutations, and examined genetic alterations responsible for drug resistance. Additionally, we studied the mechanisms responsible for immune checkpoint inhibitor resistance in melanoma.

Recurrent adamantinomatous craniopharyngiomas show MAPK pathway activation, clonal evolution and rare TP53-loss-mediated malignant progression.

The two types of craniopharyngioma, adamantinomatous (ACP) and papillary (PCP), are clinically relevant tumours in children and adults. Although the biology of primary craniopharyngioma is starting to be unravelled, little is known about the biology of recurrence. To fill this gap in knowledge, we have analysed through methylation array, RNA sequencing and pERK1/2 immunohistochemistry a cohort of paired primary and recurrent samples (32 samples from 14 cases of ACP and 4 cases of PCP). We show the presence of copy number alterations and clonal evolution across recurrence in 6 cases of ACP, and analysis of additional whole genome sequencing data from the Children's Brain Tumour Network confirms chromosomal arm copy number changes in at least 7/67 ACP cases. The activation of the MAPK/ERK pathway, a feature previously shown in primary ACP, is observed in all but one recurrent cases of ACP. The only ACP without MAPK activation is an aggressive case of recurrent malignant human craniopharyngioma harbouring a CTNNB1 mutation and loss of TP53. Providing support for a functional role of this TP53 mutation, we show that Trp53 loss in a murine model of ACP results in aggressive tumours and reduced mouse survival. Finally, we characterise the tumour immune infiltrate showing differences in the cellular composition and spatial distribution between ACP and PCP. Together, these analyses have revealed novel insights into recurrent craniopharyngioma and provided preclinical evidence supporting the evaluation of MAPK pathway inhibitors and immunomodulatory approaches in clinical trials in against recurrent ACP.

The safety and efficacy of binimetinib for lung cancer: a systematic review.

BACKGROUND: Lung cancer, accounting for a significant proportion of global cancer cases and deaths, poses a considerable health burden. Non-small cell lung cancer (NSCLC) patients have a poor prognosis and limited treatment options due to late-stage diagnosis and drug resistance. Dysregulated of the mitogen-activated protein kinase (MAPK) pathway, which is implicated in NSCLC pathogenesis, underscores the potential of MEK inhibitors such as binimetinib. Despite promising results in other cancers, comprehensive studies evaluating the safety and efficacy of binimetinib in lung cancer are lacking. This systematic review aimed to investigate the safety and efficacy of binimetinib for lung cancer treatment. METHODS: We searched PubMed, Scopus, Web of Science, and Google Scholar until September 2023. Clinical trials evaluating the efficacy or safety of binimetinib for lung cancer treatment were included. Studies were excluded if they included individuals with conditions unrelated to lung cancer, investigated other treatments, or had different types of designs. The quality assessment was conducted utilizing the National Institutes of Health tool. RESULTS: Seven studies with 228 participants overall were included. Four had good quality judgments, and three had fair quality judgments. The majority of patients experienced all-cause adverse events, with diarrhea, fatigue, and nausea being the most commonly reported adverse events of any grade. The objective response rate (ORR) was up to 75%, and the median progression-free survival (PFS) was up to 9.3 months. The disease control rate after 24 weeks varied from 41% to 64%. Overall survival (OS) ranged between 3.0 and 18.8 months. Notably, treatment-related adverse events were observed in more than 50% of patients, including serious adverse events such as colitis, febrile neutropenia, and pulmonary infection. Some adverse events led to dose limitation and drug discontinuation in five studies. Additionally, five studies reported cases of death, mostly due to disease progression. The median duration of treatment ranged from 14.8 weeks to 8.4 months. The most common dosage of binimetinib was 30 mg or 45 mg twice daily, sometimes used in combination with other agents like encorafenib or hydroxychloroquine. CONCLUSIONS: Only a few studies have shown binimetinib to be effective, in terms of improving OS, PFS, and ORR, while most of the studies found nonsignificant efficacy with increased toxicity for binimetinib compared with traditional chemotherapy in patients with lung cancer. Further large-scale randomized controlled trials are recommended.

Repurposing Anticancer Drugs Targeting the MAPK/ERK Signaling Pathway for the Treatment of Respiratory Virus Infections.

Respiratory virus infections remain a significant challenge to human health and the social economy. The symptoms range from mild rhinitis and nasal congestion to severe lower respiratory tract dysfunction and even mortality. The efficacy of therapeutic drugs targeting respiratory viruses varies, depending upon infection time and the drug resistance engendered by a high frequency of viral genome mutations, necessitating the development of new strategies. The MAPK/ERK pathway that was well delineated in the 1980s represents a classical signaling cascade, essential for cell proliferation, survival, and differentiation. Since this pathway is constitutively activated in many cancers by oncogenes, several drugs inhibiting Raf/MEK/ERK have been developed and currently used in anticancer treatment. Two decades ago, it was reported that viruses such as HIV and influenza viruses could exploit the host cellular MAPK/ERK pathway for their replication. Thus, it would be feasible to repurpose this category of the pathway inhibitors for the treatment of respiratory viral infections. The advantage is that the host genes are not easy to mutate such that the drug resistance rarely occurs during short-period treatment of viruses. Therefore, in this review we will summarize the research progress on the role of the MAPK/ERK pathway in respiratory virus amplification and discuss the potential of the pathway inhibitors (MEK inhibitors) in the treatment of respiratory viral infections.

Trametinib boosts palbociclib's efficacy in breast cancer via autophagy inhibition.

Breast cancer, a predominant global health issue, requires ongoing exploration of new therapeutic strategies. Palbociclib (PAL), a well-known cyclin-dependent kinase (CDK) inhibitor, plays a critical role in breast cancer treatment. While its efficacy is recognized, the interplay between PAL and cellular autophagy, particularly in the context of the RAF/MEK/ERK signaling pathway, remains insufficiently explored. This study investigates PAL's inhibitory effects on breast cancer using both in vitro (MCF7 and MDA-MB-468 cells) and in vivo (tumor-bearing nude mice) models. Aimed at elucidating the impact of PAL on autophagic processes and exploring the potential of combining it with trametinib (TRA), an MEK inhibitor, our research seeks to address the challenge of PAL-induced drug resistance. Our findings reveal that PAL significantly decreases the viability of MCF7 and MDA-MB-468 cells and reduces tumor size in mice while showing minimal cytotoxicity in MCF10A cells. However, PAL also induces protective autophagy, potentially leading to drug resistance via the RAF/MEK/ERK pathway activation. Introducing TRA effectively neutralized this autophagy, enhancing PAL's anti-tumor efficacy. A combination of PAL and TRA synergistically reduced cell viability and proliferation, and in vivo studies showed notable tumor size reduction. In conclusion, the PAL and TRA combination emerges as a promising strategy for overcoming PAL-induced resistance, offering a new horizon in breast cancer treatment.

Synergic activity of FGFR2 and MEK inhibitors in the treatment of FGFR2-amplified cancers of unknown primary.

Patients with cancer of unknown primary (CUP) carry the double burden of an aggressive disease and reduced access to therapies. Experimental models are pivotal for CUP biology investigation and drug testing. We derived two CUP cell lines (CUP#55 and #96) and corresponding patient-derived xenografts (PDXs), from ascites tumor cells. CUP cell lines and PDXs underwent histological, immune-phenotypical, molecular, and genomic characterization confirming the features of the original tumor. The tissue-of-origin prediction was obtained from the tumor microRNA expression profile and confirmed by single-cell transcriptomics. Genomic testing and fluorescence in situ hybridization analysis identified FGFR2 gene amplification in both models, in the form of homogeneously staining region (HSR) in CUP#55 and double minutes in CUP#96. FGFR2 was recognized as the main oncogenic driver and therapeutic target. FGFR2-targeting drug BGJ398 (infigratinib) in combination with the MEK inhibitor trametinib proved to be synergic and exceptionally active, both in vitro and in vivo. The effects of the combined treatment by single-cell gene expression analysis revealed a remarkable plasticity of tumor cells and the greater sensitivity of cells with epithelial phenotype. This study brings personalized therapy closer to CUP patients and provides the rationale for FGFR2 and MEK targeting in metastatic tumors with FGFR2 pathway activation.

Functional distinction in oncogenic Ras variant activity in Caenorhabditis elegans.

Ras genes are important oncogenes that are frequently mutated in cancer. Human oncogenic variants exhibit functional distinctions in terms of their representation in different cancer types, impact on cellular targets and sensitivity to pharmacological treatments. However, how these distinct variants influence and respond to the cellular networks in which they are embedded is poorly understood. To identify novel participants in the complex interplay between Ras genotype and cell interaction networks in vivo, we have developed and tested an experimental framework using a simple vulva-development assay in the nematode C. elegans. Using this system, we evaluated a set of Ras oncogenic substitution changes at G12, G13 and Q61. We found that these variants fall into distinct groups based on phenotypic differences, sensitivity to gene dosage and inhibition of the downstream kinase MEK and their response to genetic modulators that influence Ras activity in a non-autonomous manner. Together, our results demonstrated that oncogenic C. elegans Ras variants exhibit clear distinctions in how they interface with the vulva-development network and showed that extracellular modulators yield variant-restricted effects in vivo.

Mechanism of Abnormal Activation of MEK1 Induced by Dehydroalanine Modification.

Mitogen-activated protein kinase kinase 1 (MAPK kinase 1, MEK1) is a key kinase in the mitogen-activated protein kinase (MAPK) signaling pathway. MEK1 mutations have been reported to lead to abnormal activation that is closely related to the malignant growth and spread of various tumors, making it an important target for cancer treatment. Targeting MEK1, four small-molecular drugs have been approved by the FDA, including Trametinib, Cobimetinib, Binimetinib, and Selumetinib. Recently, a study showed that modification with dehydroalanine (Dha) can also lead to abnormal activation of MEK1, which has the potential to promote tumor development. In this study, we used molecular dynamics simulations and metadynamics to explore the mechanism of abnormal activation of MEK1 caused by the Dha modification and predicted the inhibitory effects of four FDA-approved MEK1 inhibitors on the Dha-modified MEK1. The results showed that the mechanism of abnormal activation of MEK1 caused by the Dha modification is due to the movement of the active segment, which opens the active pocket and exposes the catalytic site, leading to sustained abnormal activation of MEK1. Among four FDA-approved inhibitors, only Selumetinib clearly blocks the active site by changing the secondary structure of the active segment from α-helix to disordered loop. Our study will help to explain the mechanism of abnormal activation of MEK1 caused by the Dha modification and provide clues for the development of corresponding inhibitors.

NK-92 cells activated by IL-2 inhibit the progression of endometriosis in vitro.

BACKGROUND: Interleukin (IL)-2 is a key cytokine capable of modulating the immune response by activating natural killer (NK) cells. This study was recruited to explore the therapeutic potential of IL-2-activated NK-92 cells in endometriosis in vitro. METHODS: Ectopic endometrial stromal cells (EESCs) were isolated and co-cultured with IL-2-activated NK-92 cells at varying effector-to-target (E:T) ratios (1:0 [Control], 1:1, 1:3, and 1:9). The viability, cytotoxicity, and cell surface antigen expression of IL-2-activated NK-92 cells were assessed. The viability, apoptosis, invasion, and migration ability of EESCs co-cultured with NK-92 cells at different ratios were evaluated. The apoptosis-related proteins, invasion and migration-related proteins as well as MEK/ERK pathway were examined via western blot. Each experiment was repeated three times. RESULTS: IL-2 activation enhanced NK-92 cytotoxicity in a concentration-dependent manner. Co-culturing EESCs with IL-2-activated NK-92 cells at E:T ratios of 1:1, 1:3, and 1:9 reduced EESC viability by 20%, 45%, and 70%, respectively, compared to the control group. Apoptosis rates in EESCs increased in correlation with the NK-92 cell proportion, with the highest rate observed at a 1:9 ratio. Moreover, EESC invasion and migration were significantly inhibited by IL-2-activated NK-92 cells, with a 60% reduction in invasion and a 50% decrease in migration at the 1:9 ratio. Besides, the MEK/ERK signalling pathway was down-regulated in EESCs by IL-2-activated NK-92 cells. CONCLUSION: IL-2-activated NK-92 cells exhibit potent cytotoxic effects against EESCs. They promote EESC apoptosis and inhibit viability, invasion, and migration through modulating the MEK/ERK signalling pathway.

Endometriosis is a common chronic systemic disease affecting approximately 190 million women worldwide. However, clinical treatments for endometriosis remain challenging due to the scarcity of high-quality scientific evidence and conflicting available guidelines. This research was designed to explore whether interleukin (IL)-2 affected the progression of endometriosis by modulating endometrial stromal cell apoptosis and natural killer (NK) cell-mediated cytotoxicity, thereby providing new therapeutic methods for endometriosis.

Case report: Treatment response of NF-1-associated bladder ganglioneuroma to trametinib.

We present the clinical course of a 4-year-old girl with neurofibromatosis type 1-associated, unresectable, symptomatic urinary bladder ganglioneuroma. She was initially trialed on sirolimus without response and subsequently responded to MEK inhibitor trametinib, with improvement clinically and radiographically over 10 months. This report broadens the repertoire of therapeutic strategies for MEK inhibition in diseases related to the MAPK pathway.