Neurofibromin Research Articles

Abstract 2021: The RXR agonist MSU-42011 and the MEK inhibitor selumetinib reduce pERK levels in NF1-deficient cells and inhibit cytokine production in macrophages

Abstract Neurofibromatosis type 1 (NF1) is a common genetic disease that predisposes approximately 50% of affected individuals to develop plexiform neurofibromas (PNFs), which can progress to highly aggressive malignant peripheral nerve sheath tumors (MPNSTs) in approximately 10% of patients. NF1 is caused by mutations in the tumor suppressor gene NF1, which encodes for neurofibromin, a negative regulator of RAS activity. Selumetinib, a specific inhibitor of MEK1/2, is the only FDA-approved drug for NF1-associated PNFs. However, the anti-tumor effects of selumetinib are limited in MPNSTs and have dose-limiting side effects. Deficiency of the NF1 gene not only promotes tumorigenesis but also has broad effects on the immune cells and cytokine signaling driven by hyperactive RAS signaling. Because macrophages account for almost half of cells in NF1 lesions and their infiltration correlates with disease progression, we hypothesized that targeting tumor-promoting immune cells could be an alternative approach for treating NF1. The novel retinoid X receptor (RXR) agonist MSU-42011 reduces tumor growth in experimental Kras-driven cancers by decreasing pERK expression, reducing tumor-promoting immune cells like CD206+ macrophages and regulatory T cells, and increasing activated cytotoxic T cells. Here, we treated NF1-deficient cells and macrophages with MSU-42011 and selumetinib, either alone or in combination, using monoculture and conditioned media (CM) conditions. In human PNF cells and mouse MPNSTs, treatment with 200 nM MSU-40211 or 50 nM selumetinib for 3 hours reduced pERK protein levels compared with untreated controls, and the combination treatment enhanced this reduction in pERK protein levels. Additionally, there was a trend toward reduction in cell viability with increasing drug concentrations after 72 hours of the combination treatment. Moreover, CM from human and mouse PNF cells increased the mRNA expression of monocyte chemoattractant CCL2 (C-C motif chemokine ligand 2) and the secretion of IL-6 and TNFα in human THP1 monocytes/macrophages and bone marrow derived macrophages (BMDM). Notably, MSU-42011 and selumetinib alone inhibited CCL2 mRNA expression in THP1 macrophages and BMDM stimulated with CM from human and mouse PNF cells, respectively, and the inhibition of CCL2 mRNA expression was greatest with combination treatment. The combination of MSU42011 and selumetinib also significantly reduced tumor burden in a LL2 model of lung cancer driven by an activating Kras mutation. Based on the similarities in RAS activation and immune cell infiltration in NF1 and lung cancer, our next step is to confirm the immunomodulatory and anti-tumor effects of MSU-42011 and selumetinib in a syngeneic model of PNF and MPNST. Citation Format: Pei-Yu Hung, Jessica A. Moerland, Karen T. Liby. The RXR agonist MSU-42011 and the MEK inhibitor selumetinib reduce pERK levels in NF1-deficient cells and inhibit cytokine production in macrophages [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2021.

RNA-binding proteins potentially regulate the alternative splicing of apoptotic genes during knee osteoarthritis progression

BackgroundAlternative splicing (AS) is a principal mode of genetic regulation and one of the most widely used mechanisms to generate structurally and functionally distinct mRNA and protein variants. Dysregulation of AS may result in aberrant transcription and protein products, leading to the emergence of human diseases. Although considered important for regulating gene expression, genome-wide AS dysregulation, underlying mechanisms, and clinical relevance in knee osteoarthritis (OA) remain unelucidated. Therefore, in this study, we elucidated and validated AS events and their regulatory mechanisms during OA progression.ResultsIn this study, we identified differentially expressed genes between human OA and healthy meniscus samples. Among them, the OA-associated genes were primarily enriched in biological pathways such as extracellular matrix organization and ossification. The predominant OA-associated regulated AS (RAS) events were found to be involved in apoptosis during OA development. The expression of the apoptosis-related gene BCL2L13, XAF1, and NF2 were significantly different between OA and healthy meniscus samples. The construction of a covariation network of RNA-binding proteins (RBPs) and RAS genes revealed that differentially expressed RBP genes LAMA2 and CUL4B may regulate the apoptotic genes XAF1 and BCL2L13 to undergo AS events during OA progression. Finally, RT-qPCR revealed that CUL4B expression was significantly higher in OA meniscus samples than in normal controls and that the AS ratio of XAF1 was significantly different between control and OA samples; these findings were consistent with their expected expression and regulatory relationships.ConclusionsDifferentially expressed RBPs may regulate the AS of apoptotic genes during knee OA progression. XAF1 and its regulator, CUL4B, may serve as novel biomarkers and potential therapeutic targets for this disease.

High-Grade Astrocytoma with Piloid Features: A Dual Institutional Review of Imaging Findings of a Novel Entity.

High-grade astrocytoma with piloid features (HGAP) is a recently identified brain tumor characterized by a distinct DNA methylation profile. Predominantly located in the posterior fossa of adults, HGAP is notably prevalent in individuals with neurofibromatosis type 1. We present an image-centric review of HGAP and explore the association between HGAP and neurofibromatosis type 1. Data were collected from 8 HGAP patients treated at two tertiary care institutions between January 2020 and October 2023. Demographic details, clinical records, management, and tumor molecular profiles were analyzed. Tumor characteristics, including location and imaging features on MR imaging, were reviewed. Clinical or imaging features suggestive of neurofibromatosis 1 or the presence of NF1 gene alteration were documented. The mean age at presentation was 45.5 years (male/female = 5:3). Tumors were midline, localized in the posterior fossa (n = 4), diencephalic/thalamic (n = 2), and spinal cord (n = 2). HGAP lesions were T1 hypointense, T2-hyperintense, mostly without diffusion restriction, predominantly peripheral irregular enhancement with central necrosis (n = 3) followed by mixed heterogeneous enhancement (n = 2). Two NF1 mutation carriers showed signs of neurofibromatosis type 1 before HGAP diagnosis, with one diagnosed during HGAP evaluation, strengthening the HGAP-NF1 link, particularly in patients with posterior fossa masses. All tumors were IDH1 wild-type, often with ATRX, CDKN2A/B, and NF1 gene alteration. Six patients underwent surgical resection followed by adjuvant chemoradiation. Six patients were alive, and two died during the last follow-up. Histone H3 mutations were not detected in our cohort, such as the common H3K27M typically seen in diffuse midline gliomas, linked to aggressive clinical behavior and poor prognosis. HGAP lesions may involve the brain or spine and tend to be midline or paramedian in location. Underlying neurofibromatosis type 1 diagnosis or imaging findings are important diagnostic cues.

Unilateral Multifocal Inner Ear and Internal Auditory Canal or Cerebellopontine Angle Cochleovestibular Schwannomas-Genetic Analysis and Management by Surgical Resection and Cochlear Implantation.

To describe the genetic characteristics and the management of two very rare cases of unilateral multifocal inner ear and internal auditory canal or cerebellopontine angle cochleovestibular schwannomas not being associated to full neurofibromatosis type 2-related schwannomatosis. In a 29-year-old man and a 55-year-old woman with single-sided deafness multifocal unilateral cochleovestibular schwannomas were surgically resected, and hearing was rehabilitated with a cochlear implant (CI). Unaffected tissue was analyzed using next generation sequencing of the NF2 gene. Tumor tissue was analyzed using a 340-parallel sequencing gene panel. Mutations in the NF2 gene, word recognition score for monosyllables at 65 dB SPL (WRS 65 ) with CI. No disease-causing mutation was detected in the examined sequences in blood leucokytes. All tumor samples revealed, among others, somatic pathogenic NF2 mutations. While the anatomically separate tumors in case 1 were likely molecular identical, the tumors in case 2 showed different genetic patterns. WRS 65 was 55% at 6 years of follow-up and 60% at 4.5 years of follow-up, respectively. The occurrence of multifocal unilateral cochleovestibular schwannomas without pathogenic variants in NF2 in non-affected blood leucocytes can be associated with mosaic NF2 -related schwannomatosis (case 1), or with likely sporadic mutations (case 2) and may be overlooked due to their extreme rarity. Although challenging, successful hearing rehabilitation could be achieved through surgical resection of the tumors and cochlear implantation.

Patient Sex and Origin Influence Distribution of Driver Genes and Clinical Presentation of Paraganglioma.

Sexual and ancestral differences in driver gene prevalence have been described in many cancers but have not yet been investigated in pheochromocytoma and paraganglioma (PPGL). This study aims to assess whether sex and ancestry influence prevalence of PPGL driver genes and clinical presentation. We conducted a retrospective analysis of patients with PPGL considering studies from 2010 onwards that included minimal data of type of disease, sex, mutated gene, and country of origin. Additional features were recorded when available (age, tumor location, bilateral or multifocal, somatic or germline, and metastatic disease). We included 2162 patients: 877 in Europe and 757 in Asia. Males presented more often with germline pathogenic variants (PVs) in genes activating hypoxia pathways (P = .0006) and had more often sympathetic paragangliomas (P = .0005) and metastasis (P = .0039). On the other hand, females with PPGLs due to MAX PVs were diagnosed later than males (P = .0378) and more often developed metastasis (P = .0497). European but not Asian females presented more often with PPGLs due to PVs in genes related to kinase signaling (P = .0052), particularly RET and TMEM127. Contrary to experiences from Europe, Asian patients with PPGL due to PVs in kinase signaling genes NF1, HRAS, and FGFR1 showed a high proportion of sympathetic tumors, while European patients almost exclusively had adrenal tumors (P < .005). Personalized management of patients with PPGL might benefit from considering sexual and ancestral differences. Further studies with better clinically aligned cohorts from various origins are required to better dissect ancestral influences on PPGL development.

Treatment and prognostic implications of strong PD-L1 expression in primary hepatic sarcomatoid carcinoma.

Primary hepatic sarcomatoid carcinoma (HSC) is an extremely rare and aggressive subtype of primary liver cancer. HSC has uncertain pathogenesis and dismal prognosis with overall survival of only 8.3months. The molecular alterations of HSC are also not well understood. In this study, the authors describe a patient who presented with a large liver mass. The patient underwent complete surgical resection and histological examination demonstrated HSC, infiltrating the stomach. PD-L1 was strongly positive in the tumor cells. The patient was started on anti-PD-L1 immunotherapy postsurgery and is doing well 15 months after surgical resection. Tumor whole exome sequencing revealed genetic alterations in TP53, NF2 and MAGEC3 genes, indicating their potential role in tumor development.

The serine-threonine protein kinase Snf1 orchestrates the expression of plant cell wall-degrading enzymes and is required for full virulence of the maize pathogen Colletotrichum graminicola

Colletotrichum graminicola, the causal agent of maize leaf anthracnose and stalk rot, differentiates a pressurized infection cell called an appressorium in order to invade the epidermal cell, and subsequently forms biotrophic and necrotrophic hyphae to colonize the host tissue. While the role of force in appressorial penetration is established (Bechinger et al., 1999), the involvement of cell wall-degrading enzymes (CWDEs) in this process and in tissue colonization is poorly understood, due to the enormous number and functional redundancy of these enzymes. The serine/threonine protein kinase gene SNF1 identified in Sucrose Non-Fermenting yeast mutants mediates de-repression of catabolite-repressed genes, including many genes encoding CWDEs. In this study, we identified and functionally characterized the SNF1 homolog of C. graminicola. Δsnf1 mutants showed reduced vegetative growth and asexual sporulation rates on media containing polymeric carbon sources. Microscopy revealed reduced efficacies in appressorial penetration of cuticle and epidermal cell wall, and formation of unusual medusa-like biotrophic hyphae by Δsnf1 mutants. Severe and moderate virulence reductions were observed on intact and wounded leaves, respectively. Employing RNA-sequencing we show for the first time that more than 2,500 genes are directly or indirectly controlled by Snf1 in necrotrophic hyphae of a plant pathogenic fungus, many of which encode xylan- and cellulose-degrading enzymes. The data presented show that Snf1 is a global regulator of gene expression and is required for full virulence.

Multimodal Imaging of Choroidal Nodules in Neurofibromatosis Type I.

To clarify the possibilities and role of posterior segment imaging in patients with neurofibromatosis type I (NF1), and to show the prevalence of this disease in the pediatric population in Slovakia. Until recently, ophthalmologic consultations in patients with NF1 were limited mainly to the observation of Lisch nodules of the iris and the presence of optic nerve glioma. However, advances in imaging capabilities have made it possible to investigate and describe new f indings concerning the ocular manifestations of this disease. Between October 2020 and November 2021, we examined the anterior and posterior segment of 76 eyes (38 children – 12 boys and 26 girls) with genetically confirmed NF1 gene mutation at our clinic. The age of the patients ranged from 4 to 18 years. The anterior segment was checked for the presence of Lisch nodules biomicroscopically with a slit lamp. On the posterior segment, the presence of choroidal nodules was checked by various imaging methods – fundus camera, infrared confocal selective laser ophthalmoscopy, MultiColor imaging, OCT, and OCT angiography. All the patients had magnetic resonance imaging performed in order to detect potential optic nerve gliomas for the purpose of diagnosis. We observed the correlation between the patients’ age, presence of Lisch nodules and the presence of choroidal nodules. Eight patients also had other manifestations of the disease – optic nerve gliomas or microvascular changes (so-called “corkscrew” vessels). Out of 38 patients, Lisch iris nodules were present in 20 patients (53%) and choroidal nodules in 24 patients (63%). There was no positive correlation between the presence of these two manifestations within the same patient or eye, but there is a clear correlation between the presence of choroidal nodules and patient age. The results suggest that a previously unknown ocular manifestation of neurofibromatosis type I, namely choroidal nodules, has a higher prevalence than Lisch nodules also in the pediatric population and can be easily visualized using various imaging modalities. It will be important to include follow-up observation of this finding among the standard controls for ocular findings in NF1, and it will be very interesting to correlate this f inding with the exact NF1 mutation

Giant gluteal and vesical plexiform neurofibromas in a patient with neurofibromatosis type 1: a case report

BackgroundNeurofibromatosis type 1 is a neurocutaneous genetic disorder caused by mutations in the NF1 gene, resulting in the formation of benign tumors called neurofibromas. The most common type of tumor seen in patients with neurofibromatosis type 1 is the slow-growing and benign neurofibroma, with a subtype called plexiform neurofibroma being particularly common and causing pain, functional impairment, and cosmetic disfigurement.Case presentationWe report the case of a 20-year-old North African female patient with a history of neurofibromatosis type 1 who presented with a growing mass in her right gluteal region, which was later diagnosed as a giant cutaneous neurofibroma. Imaging studies revealed infiltration in several regions, including the urinary bladder wall, resulting in significant bilateral hydronephrosis. The patient is currently being monitored, and no excisional procedures are planned.ConclusionsNeurofibromatosis type 1 can cause a variety of clinical symptoms, including the development of large plexiform neurofibromas. It is important to closely monitor patients with neurofibromatosis type 1 for the early detection of neurofibromas. Early detection and prompt surgical intervention are essential for preventing complications.

Exploring Differentiation and TEAD Inhibition in NF2-Knockdown NES Cells

Background: The NF2 gene is a tumor suppressor encoding gene on chromosome 22 that is a known regulator of the Hippo pathway. When the mammalian version of the pathway is inactive, such as with a loss of NF2, downstream proteins YAP/TAZ remain unphosphorylated, enter the nucleus to form a complex with TEAD 1/2/3/4, and begin transcription. Hyperactivation of theYAP/TAZ-TEAD complex has been observed in many cancers, allowing for targeting with TEAD inhibitors. Here, we assess how the loss of NF2 in human neuroepithelial stem (NES) cells affect their differentiational development. We also seek to understand the effects of TEAD inhibition on wildtype (WT) and NF2-knockdown NES cells.&#x0D; Materials and Methods: Differentiation. WT and NF2-knockdown cells were grown in media without growth factors to differentiate them. TEAD Inhibition. Non-differentiating and differentiating WT and NF2-knockdown cells were treated with TEAD Inhibitor 690 (TEADi). During both conditions, cells were harvested at 5 points throughout the growth period.&#x0D; Results: Decreased NF2 in cells promoted retention of an earlier cell morphology compared to WT, which appeared to develop neuronal features, such as axons. WT cells exhibited elevated expression of genes characteristic of NES differentiation when compared to NF2-knockdown cells. Following the addition of TEADi, cell culture imaging revealed seemingly increased cell death in WT cell populations compared to NF2-knockdown cells. Interestingly, differentiating NF2-knockdown cells adhere to one another to form clusters, but with TEADi, these clusters are formed to a much lesser extent.&#x0D; Conclusion: Although more experimentation is needed, these are early steps in demonstrating how NF2 loss appears to halt the differentiation of NES cells. Additionally, TEAD inhibition seems to reduce the clustering seen in differentiating NF2-knockdown cells; however, experimental concentrations need to be explored in the future. Further work is needed to understand the effects of TEAD inhibition on NF2-knockdown cells.

Activation of the melanocortin-1 receptor attenuates neuronal apoptosis after traumatic brain injury by upregulating Merlin expression

Traumatic brain injury (TBI) is a common disease worldwide with high mortality and disability rates. Besides the primary mechanical injury, the secondary injury associated with TBI can also induce numerous pathological changes, such as brain edema, nerve apoptosis, and neuroinflammation, which further aggravates neurological dysfunction and even causes the death due to the primary injury. Among them, neuronal apoptosis is a key link in the injury. Melanocortin-1 receptor (MC1R) is a G protein coupled receptor, belonging to the melanocortin receptor family. Studies have shown that activation of MC1R inhibits oxidative stress and apoptosis, and confers neuroprotective effects against various neurological diseases. Merlin is a protein product of the NF2 gene, which is widely expressed in the central nervous system (CNS) of mice, rats, and humans. Studies have indicated that Merlin is associated with MC1R. In this study, we explored the anti-apoptotic effects and potential mechanisms of MC1R. A rat model of TBI was established through controlled cortical impact. The MC1R-specific agonist Nle4-D-Phe7-α-Melanocyte (NDP-MSH) and the inhibitor MSG-606 were employed to explore the effects of MC1R and Merlin following TBI and investigated the associated mechanisms. The results showed that the expression levels of MC1R and Merlin were upregulated after TBI, and activation of MC1R promoted Merlin expression. Further, we found that MC1R activation significantly improved neurological dysfunction and reduced brain edema and neuronal apoptosis induced by TBI in rats. Mechanistically, its neuroprotective function and anti-apoptotic were partly associated with MC1R activation. In conclusion, we demonstrated that MC1R activation after TBI may inhibit apoptosis and confer neuroprotection by upregulating the expression of Merlin.

Characterizing the Efficacy and Safety of Chemotherapy Plus Everolimus in HER2-Negative Metastatic Breast Cancer Harboring Altered PI3K/AKT/mTOR.

The clinical outcomes of chemotherapy (CT) for the treatment of metastatic triple-negative (TN) and hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (mBC) have proven to be disappointing. The phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway, a tumor-promoting signaling cascade frequently mutated in breast cancer (BC), has been implicated in chemoresistance. In this study, our objective is to investigate the efficacy and safety of combining everolimus with chemotherapy in mBC patients exhibiting mutations in the PI3K/AKT/mTOR pathway. We conducted a retrospective analysis to characterize the efficacy, safety, and their association with clinical and molecular characteristics of metastatic lesions in 14 patients with HER2- mBC. These patients harbored at least one altered member of the PI3K/AKT/mTOR signaling pathway and were treated with a combination of a chemotherapy agent and the mTOR inhibitor everolimus (CT+EVE). The majority of patients belonged to the triple-negative (TN) subtype (9/14, 64.3%), having already undergone 2 lines of chemotherapy (CT) in the metastatic setting (11, 78.6%). These patients carried altered phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) and were administered a vinorelbine-containing regimen (10, 71.4%). The objective response rate (ORR) was 42.9%, with a disease control rate of 92.9%. The median progression-free survival (PFS) and overall survival (OS) were 5.9 (95% confidence interval (CI): 4.9-13.6) months and 14.3 (95% CI: 8.5-not reached (NR)) months, respectively. Patients with fewer prior treatment lines tended to exhibit longer PFS. OS, PFS, and ORR were comparable between hormone receptor-positive (HR+) and triple-negative breast cancer (TNBC) patients, but numerical improvements were noted in patients with a single PI3K pathway alteration compared to those with more than one alteration. Genomic alterations that surfaced upon progression on CT+EVE included cyclin dependent kinase 4 (CDK4) and epidermal growth factor receptor (EGFR) amplification, as well as neurofibromin 1 (NF1) mutation, suggesting potential mechanisms of acquired resistance. An analysis of adverse events indicated manageable toxicities. The findings of this study suggest both activity and safety for the combination of chemotherapy and the mTOR inhibitor everolimus (CT+EVE) in patients with HER2- mBC who have alterations in the PI3K pathway, particularly those who have received fewer prior chemotherapy. However, it is crucial to note that large-scale, randomized control studies are warranted to more comprehensively characterize the efficacy and safety of this combination therapy.

The role of scoliosis on the comorbidity and demographics of neurofibromatosis type 1 patients: A retrospective analysis of the National Inpatient Sample database.

Neurofibromatosis type 1 (NF1) is the most common neurocutaneous syndrome in the United States, affecting every 1 in 3000 individuals. NF1 occurs due to non-functional mutations in the NF1 gene, which expresses neurofibromin, a protein involved in tumour suppression. As a result, NF1 typically presents with non-cancerous neoplasm masses called neurofibromas across the body. Out of all NF1 abnormalities, the most common skeletal abnormality seen in around 10%-30% of NF1 patients is scoliosis, an improver curvature of the spine. However, there is a lack of research on the effects of scoliosis on demographics and morbidities of NF1 patients. We performed a national analysis to investigate the complex relationship between NF1 and scoliosis on patients' demographics and comorbidities. We conducted a retrospective cross-sectional analysis of the 2017 US National Inpatient Sample database using univariable Chi-square analysis and multivariable binary logistic regression analysis to determine the interplay of NF1 and scoliosis on patients' demographics and comorbidities. Our query resulted in 4635 total NF1 patients, of which 475 (10.25%) had scoliosis and 4160 (89.75%) did not. Demographic analysis showed that NF1 patients with scoliosis were typically younger, female and white compared to NF1 patients without scoliosis. Comorbidity analysis showed that NF1 patients with scoliosis were more likely to develop malignant brain neoplasms, epilepsy, hydrocephalus, pigmentation disorders, hypothyroidism, diabetes with chronic complications and coagulopathy disorders. NF1 patients with scoliosis were less likely to develop congestive heart failure, pulmonary circulation disease, peripheral vascular disease, paralysis, chronic pulmonary disease, lymphoma and psychosis. NF1 patients with scoliosis were predominantly younger, female, white patients. The presence of scoliosis in NF1 patients increases the risks for certain brain neoplasms and disorders but serves a protective effect against some pulmonary and cardiac complications.

Neuroprotective role of FOXA1 in Parkinson's disease: Involvements of NF1 transcription activation and MAPK signaling pathway inhibition

Forkhead box A1 (FOXA1), a member of the forkhead family of transcription factors, plays a crucial role in the development of various organ systems and exhibits neuroprotective properties. This study aims to investigate the effect of FOXA1 on Parkinson's disease (PD) and unravel the underlying mechanism. Transcriptome analysis of PD was conducted using three GEO datasets to identify aberrantly expressed genes. A mouse model of PD was generated by injecting neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP), resulting in reduced FOXA1 expression. FOXA1 decline was also observed in 1-methyl-4-phenylpyridinium-treated SH-SY5Y cells. Artificial upregulation of FOXA1 improved motor abilities of mice according to rotarod and pole tests, and it mitigated tissue damage, cell loss, and neuronal damage in the mouse substantia nigra or in vitro. FOXA1 was found to bind to the neurofibromin 1 (NF1) promoter, thereby inducing its transcription and inactivating the mitogen-activated protein kinase (MAPK) signaling pathway. Further experimentation revealed that silencing NF1 in mice or SH-SY5Y cells counteracted the neuroprotective effects of FOXA1. In conclusion, this research suggests that FOXA1 activates NF1 transcription and inactivates the MAPK signaling pathway, ultimately ameliorating neuronal damage and motor disability in PD. The findings may offer novel ideas in the field of PD management.

Breast Cancer; Clinical Spectrum and Genetic Abnormalities in Women of Reproductive Age-Retrospective Study.

Objective: To examine the clinical spectrum of breast cancer, its symptoms, presentation, histologic types and different types of its genetic aberrations in the women of reproductive age.Methodology: This Retrospective study was conducted at the Heavy Industries Taxila (HIT) Hospital, Taxila Cantt, from March 2022 to December 2022. The Temporal sampling technique was used to collect the data. We looked at the data of patients with breast cancer that were treated at the HIT hospital Taxila. The retrospective data was collected from the files of the patients who visited HIT Hospital, dated back from January 2011 to December 2020. The study included women of reproductive age with breast cancer symptoms, regardless of whether they had a family history of the disease. The women with metastatic breast lesions and breast trauma were excluded from the study. Age, hormone receptor status, axillary lymph node status, histologic grade and subtype, tumor size margin status, menopausal status, human epidermal growth factor receptor-2 (HER2)/neu status, and the entire genetic spectrum were all included in the charts. The clinical spectrum, staging, and genetic spectrum are all described in tables. Results: The disease's genetic makeup was found to be quite diverse, with abnormalities in genes; ATM, BARD1, CDH1, and BRCA2 making up 2 (3%) each, 3 (4%) breast cancer gene 1 (BRCA1) and BRCA2 abnormalities making up 48 (67%) of the cases. Twelve (16%) of the patients had TP53 mutations, while two (2%) of the patients had NF1 and RECQL gene alterations.Conclusions: This study identifies multiple genes that contribute to the development of breast cancer, including BRCA1, BRCA2, TP53, BARD1 and Cadherin 1 (CDH1) genes.

Neurofibromatosis type 1: Clinical characteristics and mutation spectrum in a North Indian cohort

BackgroundNeurofibromatosis type 1 (NF1) is a unique, highly penetrant neuro-cutaneous disorder with a wide range of manifestations. Though the clinical diagnosis of NF1 is straight forward, there can be other disorders which mimic NF1, especially its cutaneous features. Here we describe the clinical and mutation spectrum of a series of individuals whose primary diagnosis was NF1 or NF1 related disorders. MethodsWe have screened 29 unrelated individuals who fulfilled the clinical criteria of NF1. Whole exome sequencing (WES) was done in all individuals except one with suspected microdeletion syndrome with NF1 in whom Cytogenetic microarray (CMA) was done. ResultsOut of 29 suspected patients, 25 had germline pathogenic/likely pathogenic variants involving NF1 gene. Five novel and 20 known variants in coding and non-coding regions were identified, among them 7 variants were deletions (28%), 7 nonsense (28%), 3 splice-site (12%), 4 missense (16%), 2 duplications (8%) and 2 (8%) were contiguous deletions. In those where NF1 variants were not detected, 3 had neurofibromatosis type 2 (NF2) and 1 rare autosomal recessive form of Elher Danlos syndrome. ConclusionWe hereby present the wide range of manifestations in different age groups and the mutation spectrum ranging from small scale variants to contiguous gene deletion syndromes involving NF1 gene. We highlight the usefulness of molecular testing and its importance in tumor surveillance and genetic counseling in this disorder.

Germline mutations in pediatric cancer cohort with mixed-ancestry Mexicans.

Childhood cancer is one of the primary causes of disease-related death in 5- to 14-year-old children and currently no prevention strategies exist to reduce the incidence of this disease. Childhood cancer has a larger hereditary component compared with cancer in adults. Few genetic studies have been conducted on children with cancer. Additionally, Latin American populations are underrepresented in genomic studies compared with other populations. Therefore, the aim of this study is to analyze germline mutations in a group of mixed-ancestry Mexican pediatric patients with solid and hematological cancers. We analyzed genetic variants from 40 Mexican childhood cancer patients and their relatives. DNA from saliva or blood samples was used for whole-exome sequencing. All variants were identified following GATK best practices. We found that six patients (15%) were carriers of germline mutations in CDKN2A, CHEK2, DICER1, FANCA, MSH6, MUTYH, NF1, and SBDS cancer predisposition genes, and additional new variants predicted to be deleterious by in silico algorithms. A population genetics analysis detected five components consistent with the demographic models assumed for modern mixed-ancestry Mexicans. This report identifies potential genetic risk factors and provides a better understanding of the underlying mechanisms of childhood cancer in this population.

Abstract A061: The LSD1 inhibitor iadademstat shows preclinical efficacy in malignant peripheral nerve sheath tumor cells and synergistic effects in combination

Abstract Background: Malignant peripheral nerve sheath tumors (MPNSTs) are highly aggressive and rare malignancies accounting for 10% of all tissue sarcomas. Around 50% develop in patients with neurofibromatosis type 1 carrying mutations in the NF1 gene and the other 50% occur sporadically. NF1 is a tumor suppressor gene and a negative regulator of RAS signaling pathway. However, mutation of the NF1 gene is not sufficient to drive MPNST and a series of further mutational events must accumulate in genes other than NF1, such as in CDKN2A and PRC2 complex components. Mutations in p53 or PTEN and/or mutations or copy number variations in oncogenes, such as EGFR or c-Met can also be detected in MPNST. Herein we explore the effects of LSD1 inhibition with iadademstat as a single agent in a panel of MPNST cell lines, both NF1-related and sporadic, and in combination with inhibitors of the MEK-ERK and PI3K/AKT signaling pathways. Materials and Methods: The cell viability in 12 MPNST cell lines, both commercial and derived from patients’ primary tumors, was assessed after 6 days of treatment with iadademstat as a single agent. Synergisms between iadademstat and the MEK inhibitor selumetinib or the PI3K inhibitor copanlisib were also evaluated after 6 days of treatment in three selected responsive cell lines and analyzed with Calcusyn and Combenefit software. Additionally, the effects of iadademstat in RAS pathways (pAKT and pERK levels) were also evaluated in these cell lines. Results: Iadademstat displayed sub-nanomolar activity as a single agent in 8 out of 12 cell lines tested, both NF1-related and sporadic, with different degrees of viability reduction. This was further confirmed with two additional LSD1 inhibitors, with iadademstat being the most potent inhibitor tested. Highly-responsive cell lines showed a decrease in pAKT levels while medium- and low-responsive cell lines displayed no significant differences. pERK levels were not affected. Moreover, the combination of iadademstat and selumetinib or copanlisib displayed strong synergy in cell viability assays in both commercial and patient-derived iadademstat-sensitive cell lines. Conclusions: The LSD1 inhibitor iadademstat is efficacious as single agent in nearly 70% of the MPNST cell lines tested, both NF1-related and sporadic and this efficacy increases synergistically in combination with selumetinib or copanlisib. Therefore, LSD1 inhibitors alone or in combination emerge as a potential treatment for MPNST, an indication with high unmet needs with no approved targeted therapies available. Citation Format: Natalia Sacilotto, Cristina Mascaró, Edgar Creus, Juana Fernández, Conxi Lázaro, Ana Limón, Robert Soliva, Jordi Xaus. The LSD1 inhibitor iadademstat shows preclinical efficacy in malignant peripheral nerve sheath tumor cells and synergistic effects in combination [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A061.

Oral Decitabine/Cedazuridine Is a Tolerable and Effective Ambulatory Regimen for Patients with Advanced Myeloproliferative Neoplasms

Background: Treatment options are limited for patients (pts) with advanced myeloproliferative neoplasms (MPNs). Most pts become refractory to JAK2 inhibitor (JAKi) therapy by 3 years with subsequent survival of only 11-16 months. Sequential treatment with chromatin-modifying agents including decitabine (D) can upregulate CXCR4 expression, correct abnormal trafficking of myelofibrosis (MF) stem cells, and eliminate JAK2V617F+ MF stem and progenitor cells in preclinical models ( Wang et al, Cancer Res 2019, Blood 2010). Combination therapy with intravenous D and ruxolitinib (Rux) had a favorable effect on overall survival (OS) in a phase 2 study of MPN-accelerated/blast phase pts ( Mascarenhas et al, Blood Adv 2020) and prolonged survival in a cohort of DIPSS-plus high-risk MF pts ( Bader et al, Leuk Res 2015). Oral decitabine/cedazuridine (DC), therefore, represents an attractive ambulatory treatment option for pts with advanced MPNs. Methods: We retrospectively reviewed the electronic health records of pts with advanced high-risk MF (AHR-MF) or MPN- accelerated phase (MPN-AP) seen at our institution that were treated with DC with or without a JAKi from 1/2021-7/2023. MPN-AP was defined by the presence of 10-19% blasts in peripheral blood/ bone marrow. AHR-MF was defined by the presence of 4-9% circulating blasts or 5-9% blasts in the bone marrow, and/or refractoriness to a JAKi. Results: A total of 14 pts, 7 each with MPN-AP and AHR-MF, respectively received DC therapy (Table 1). Most pts (8/14 or 57%) were older than 75 years. All pts were classified as high risk/very high-risk (MIPPS70 plus v.2). Ten (71%) pts had one or more high molecular risk mutations ( ASXL1, EZH2, SRSF2, IDH1/2, U2AF1), with the most prevalent being ASXL1 mutations in 8/14 (57%) pts. Other somatic mutations included NF1, KRAS, NRAS, BRAF, GATA2, STAG2, DNMT3A and TET2 genes. Eight of the 14 pts (57%) had either an unfavorable or very high-risk karyotype (MIPSS70 plus v.2). Thirteen pts had previously failed JAKi therapy. The median number of cycles of DC therapy was 2 (range,1-6) and 4 (range,1-26) for MPN-AP and AHR-MF pts, respectively and 4/7 pts received a concurrent JAKi in each group. Two pts in AHR-MF cohort were successfully bridged to transplant. Two pts in the MPN-AP group discontinued treatment after cycle 1 due to neutropenic sepsis and progression to blast phase, respectively. Among MPN-AP pts who received ≥ 2 cycles of DC, circulating blasts were reduced to ≤ 5% in 4/5 pts, normalization of thrombocytopenia and improvement in hemoglobin by ≥ 1.5 g/dl each occurred in 3/5 pts (Fig.1). In the AHR-MF cohort, 6/7 pts received ≥ 2 cycles of DC with elimination of circulating blasts in one pt. WBC and platelet count were effectively reduced in 4/4 and 2/2 pts with baseline WBC of &amp;gt;50x 10 3/uL and platelet count &amp;gt;1000 x 10 3/uL, respectively. Spleen size reduction was achieved in two pts with combination of DC + Rux who were previously refractory to a JAKi. One pt achieved complete resolution of palpable splenomegaly after 2 cycles of combination therapy. The predominant treatment-related adverse event was neutropenic fever in three pts requiring hospitalization. DC cycle length was reduced from 5 to 3/28 days in 7/14 pts, which reduced the degree of therapy related neutropenia and anemia. Pts remained ambulatory during treatment except for hospitalizations related to neutropenic fever. With a median follow-up of 109 days (range, 28 days - 29 months), median OS has not been reached. Three pts in the MPN-AP cohort progressed to MPN-blast phase (BP), including two pts who only received one cycle of DC. Two pts with MPN-BP died after 28 and 68 days of DC therapy, respectively. None of the AHR-MF pts progressed to MPN-AP/BP. The most durable response was observed in a pt who has received a total of 26 cycles of DC + Rux with stable disease for &amp;gt;2 years and loss of BRAF and KRAS mutations after 9 months of treatment. Conclusions: DC therapy appears to be a well-tolerated and effective oral ambulatory regimen with clinically meaningful responses in elderly, transplant ineligible pts as well as a bridge to transplant in high-risk pts with advanced MPNs. The ease of outpatient administration significantly reduces pt treatment burdens and positively impacts their quality of life. These data provide a rationale for studying oral decitabine/cedazuridine +/- JAKi in a prospective manner, especially in pts with AHR-MF refractory to JAKi prior to evolution MPN-AP/BP.

Updates in Management of Malignant Pleural Mesothelioma.

Malignant pleural mesothelioma (MPM) is an aggressive asbestos-associated thoracic malignancy that is usually incurable. As demonstrated in the landmark MARS2 trial, surgical resection does not improve survival outcomes and its role in managing MPM is limited. Whilst platinum-pemetrexed chemotherapy in combination with bevacizumab was the standard first-lineapproach for unresectable disease, landmark phase 3 trials have now established the role of immune checkpoint inhibitors (CPIs) in the upfront management of unresectable disease: either nivolumab-ipilimumab or carboplatin-pemetrexed-pembrolizumab. Patient selection for optimal strategy remains an ongoing question. For relapsed disease novel genomic-based therapies targeting a range of aberrations including losses of the tumour suppressor genes BAP1, CDKN2A and NF2, are being evaluated. Nonetheless, the future of MPM therapeutics holds promise. Here we overview current treatment strategies in the management of MPM.