PDGFRA Research Articles

Advances in Drug Therapy for Gastrointestinal Stromal Tumour.

Gastrointestinal stromal tumour (GIST) is a common gastrointestinal sarcoma located in the stromal cells of the digestive tract, and molecular studies have revealed the pathogenesis of mutations in KIT and PDGFRA genes. Since imatinib opened the era of targeted therapy for GIST, tyrosine kinase inhibitors (TKIs) that can treat GIST have been developed successively. However, the lack of new drugs with satisfactory therapeutic standards has made addressing resistance a significant challenge for TKIs in the face of the resistance to first-line and second-line drugs. Therefore, we need to find as many drugs and new treatments that block mutated genes as possible. We conducted a comprehensive collection of literature using databases, integrated and analysed the selected literature based on keywords and the comprehensive nature of the articles, and finally wrote articles based on the content of the studies. In this article, we first briefly explained the relationship between GIST and KIT/ PDGFRα and then introduced the related drug treatment. The research progress of TKIs was analyzed according to the resistance of the drugs. This article describes the research progress of some TKIs and briefly introduces the currently approved TKIs and some drugs under investigation that may have better therapeutic effects, hoping to provide clues to the research of new drugs.

BGB-A317-212: A multicenter, open-label, phase II study to evaluate the efficacy and safety of tislelizumab in combination with lenvatinib in patients with selected solid tumors.

2610 Background: Tislelizumab, an anti-programmed cell death protein 1 (PD-1) monoclonal antibody, has demonstrated promising efficacy in several advanced solid tumors. However, some patients (pts) do not respond or develop resistance to tislelizumab monotherapy. Lenvatinib, a receptor tyrosine kinase inhibitor targeting VEGFR 1-3, FGFR 1-4, PDGFR alpha, KIT, and RET, has shown a potential synergistic effect with anti-PD-1 therapy. Here, we report the primary results of a phase II study evaluating the combination of tislelizumab plus lenvatinib in pts with solid tumors (NCT05014828). Methods: Pts with histologically/cytologically confirmed selected solid tumors, naïve to lenvatinib and anti-programmed death-ligand 1 (PD-L1)/PD-1 therapies were enrolled. Part 1 (safety run-in) determined the recommended phase II dose (RP2D) of lenvatinib in combination with tislelizumab 400 mg IV every 6 weeks. In Part 2 (expansion), pts received lenvatinib at the RP2D from Part 1 (20 mg orally/day) plus tislelizumab per the Part 1 regimen until disease progression, withdrawal, or death. The primary endpoints were safety and RP2D determination (Part 1) and overall response rate (ORR; Part 2). Results: At data cutoff (Oct 20, 2023; median follow-up 12.1 months [mo; renal cell carcinoma, RCC]; 10.8 mo [head and neck squamous cell carcinoma, HNSCC]; 14.8 mo [gastric cancer, GC], and 22.0 mo [non-small cell lung cancer, NSCLC]), 58 pts were treated in Part 2 (RCC, n=23; HNSCC, n=27; GC, n=3; NSCLC, n=5), 6 of whom were also included in Part 1. The ORR was 66.7% in pts with RCC, 33.3% (HNSCC), 33.3% (GC), and 20.0% (NSCLC). Median duration of response (mDoR) was 18.5 mo and 9.6 mo in pts with NSCLC and HNSCC, respectively; not estimable (NE) for RCC and GC (Table). No new safety signals were identified; grade ≥3 treatment-related adverse events were reported in 78.3%, 59.3%, 33.3% and 60.0%, of pts with RCC, HNSCC, GC, and NSCLC, respectively (Table). Conclusions: Tislelizumab plus lenvatinib had a manageable safety profile and showed preliminary antitumor activity in pts with selected tumor types. Longer follow-up is needed to further investigate the potential of this combination to benefit pts with advanced solid tumors. Clinical trial information: NCT05014828 .[Table: see text]

Enrichment of oligodendrocyte precursor phenotypes in subsets of low-grade glioneuronal tumours.

Current histological classification of low-grade glioneuronal tumours does not adequately represent their underlying biology. The neural lineage(s) and differentiation stage(s) involved and the cell state(s) affected by the recurrent genomic alterations are unclear. Here, we describe dysregulated oligodendrocyte lineage developmental programmes in three low-grade glioneuronal tumour subtypes. Ten dysembryoplastic neuroepithelial tumours, four myxoid glioneuronal tumours and five rosette-forming glioneuronal tumours were collected. Besides a comprehensive characterization of clinical features, known diagnostic markers and genomic alterations, we used comprehensive immunohistochemical stainings to characterize activation of rat sarcoma/mitogen-activated protein kinase pathway, involvement of neuronal component, resemblance to glial lineages and differentiation blockage along the stages of oligodendrocyte lineage. The findings were further complemented by gene set enrichment analysis with transcriptome data of dysembryoplastic neuroepithelial tumours from the literature. Dysembryoplastic neuroepithelial tumours, myxoid glioneuronal tumours and rosette-forming glioneuronal tumours occur at different ages, with symptoms closely related to tumour location. Dysembryoplastic neuroepithelial tumours and myxoid glioneuronal tumours contain oligodendrocyte-like cells and neuronal component. Rosette-forming glioneuronal tumours contained regions of rosette-forming neurocytic and astrocytic features. Scattered neurons, identified by neuronal nuclei antigen and microtubule-associated protein-2 staining, were consistently observed in all dysembryoplastic neuroepithelial tumours and myxoid glioneuronal tumours examined, but only in one rosette-forming glioneuronal tumour. Pervasive neurofilament-positive axons were observed only in dysembryoplastic neuroepithelial tumour and myxoid glioneuronal tumour samples. Alterations in B-Raf proto-oncogene, serine/threonine kinase, fibroblast growth factor receptor 1, fibroblast growth factor receptor 3 and platelet-derived growth factor receptor alpha occurred in a mutually exclusive manner, coinciding with strong staining of phospho-p44/42 mitogen-activated protein kinase and low apoptotic signal. All dysembryoplastic neuroepithelial tumours, myxoid glioneuronal tumours and the neurocytic regions of rosette-forming glioneuronal tumours showed strong expression of neuron-glia antigen 2, platelet-derived growth factor receptor alpha (markers of oligodendrocyte precursor cells) and neurite outgrowth inhibitor-A (a marker of developing oligodendrocytes), but lacked the expression of oligodendrocyte markers ectonucleotide pyrophosphatase/phosphodiesterase family member 6 and myelin basic protein. Notably, transcriptomes of dysembryoplastic neuroepithelial tumours were enriched in oligodendrocyte precursor cell signature, but not in signatures of neural stem cells, myelinating oligodendrocytes and astrocytes. Dysembryoplastic neuroepithelial tumour, myxoid glioneuronal tumour and rosette-forming glioneuronal tumour resemble oligodendrocyte precursor cells, and their enrichment of oligodendrocyte precursor cell phenotypes is closely associated with the recurrent mutations in rat sarcoma/mitogen-activated protein kinase pathway.

Abstract PO5-28-01: Dynamics of Adipocyte Progenitors in the Mammary Gland during Obesity

Abstract Being overweight or obese is associated with a higher risk of breast cancer (BC) and worse disease-free and overall survival compared to normal-weight BC patients. The underlying biological basis for this association is attributed to alterations in the endocrine and inflammatory milieu of adipose tissue. However, existing chemotherapy and endocrine therapy are not effective in obese BC patients. There is a critical need to pin down adipose tissue cell types that may govern increased BC risk and adverse outcome in obesity. Adipocyte progenitors are immature mesenchymal cells in adipose tissue that have adipocyte differentiation potential and reported to be dysfunctional in obesity. In previous research, we first reported mammary adipocyte progenitors (MAPs) expressing Platelet-Derived Growth Factor Receptor alpha (PDGFRα) in the stromal microenvironment that transition into epithelial lineages during expansion of the murine mammary epithelium. The contribution of MAPs to shaping a pro-tumorigenic mammary tissue milieu in obesity is not known. Here, using diet-induced obesity MAP reporter and lineage tracing mouse models combined with single-cell RNA sequencing, we reveal elevated PDGFRα+ MAPs in the local mammary stroma in obesity. MAPs in the obese mammary gland manifest alterations in proliferation, cell state and molecular mechanisms, generating an inflammatory, cancer-prone tissue microenvironment. Our findings uncover the MAP lineage as a key contributor to forging an aberrant mammary gland in obesity, providing insight into the potential utility of targeting this cell population for eradicating BC risk related to augmented adiposity. Citation Format: Sharon Kwende, Prashant Nuthalapati, Dun Ning, Jacqulene Sunder Singh, Purna Joshi. Dynamics of Adipocyte Progenitors in the Mammary Gland during Obesity [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-28-01.

Clinical relevance of somatic mutations in Chinese lung adenocarcinoma and their prognostic implications for survival.

To comprehensively elucidate the genomic and mutational features of lung cancer cases, and lung adenocarcinoma (LUAD), it is imperative to conduct ongoing investigations into the genomic landscape. In this study, we aim to analyze the somatic mutation profile and assessed the significance of these informative genes utilizing a retrospective LUAD cohort. A total of 247 Chinese samples were analyzed to exhibit the tumor somatic genomic alterations in patients with LUAD. The Cox regression analysis was employed to identify prognosis-related genes and establish a predictive model for stratifying patients with LUAD. In the Dianjiang People's Hospital (DPH) cohort, the top five frequent mutated genes were (Epidermal growth factor receptor) EGFR (68%), TP53 (30%), RBM10 (13%), LRP1B (9%), and KRAS (9%). Of which, EGFR is a mostly altered driver gene, and most mutation sites are located in tyrosine kinase regions. Oncogene pathway alteration and mutation signature analysis demonstrated the RTK-RAS pathway alteration, and smoking was the main carcinogenic factor of the DPH cohort. Furthermore, we identified 34 driver genes in the DPH cohort, including EGFR (68%), TP53 (30.4%), RBM10 (12.6%), KRAS (8.5%), LRP1B (8.5%), and so on, and 45 Clinical Characteristic-Related Genes (CCRGs) were found to closely related to the clinical high-risk factors. We developed a Multiple Parameter Gene Mutation (MPGM) risk model by integrating critical genes and oncogenic pathway alterations in LUAD patients from the DPH cohort. Based on publicly available LUAD datasets, we identified five genes, including BRCA2, Anaplastic lymphoma kinase (ALK), BRAF, EGFR, and Platelet-Derived Growth Factor Receptor Alpha (PDGFRA), according to the multivariable Cox regression analysis. The MPGM-low group showed significantly better overall survival (OS) compared to the MPGM-high group (p < 0.0001, area under the curve (AUC) = 0.754). The robust performance was validated in 55 LUAD patients from the DPH cohort and another LUAD dataset. Immune characteristics analysis revealed a higher proportion of primarily DCs and mononuclear cells in the MPGM-low risk group, while the MPGM-high risk group showed lower immune cells and higher tumor cell infiltration. This study provides a comprehensive genomic landscape of Chinese LUAD patients and develops an MPGM risk model for LUAD prognosis stratification. Further follow-up will be performed for the patients in the DPH cohort consistently to explore the resistance and prognosis genetic features.

Estrogen Signaling Modulation Prevents and Even Reverses Skeletal Muscle Fibrosis

Background: Skeletal muscle fibrosis represents accumulation of extracellular matrix (ECM), often leading to muscle weakness and atrophy. Notably, lower abdominal muscle (LAM) fibrosis and atrophy cause inguinal herniation—a prevalent condition lacking pharmacological treatment. We developed a herniation mouse model, Aromhum, characterized by spontaneous scrotal hernias due to local estradiol (E2) production within LAM as well as hernia-associated fibroblasts (HAFs) that express platelet-derived growth factor alpha (PDGFRA) and estrogen receptor alpha (ESR1). Objectives &amp; Hypothesis: Our objective was to investigate the mechanism of ESR1 signaling on LAM HAFs and subsequent development of hernias. Methods: We manipulated estrogen signaling in two ways: first, we generated fibroblast-specific estrogen receptor alpha knockout mice (fEsr1−/−-Aromhum) capable of local E2 production but incapable of signaling through ESR1 (n = 5-10 mice/group). Second, we blocked E2 signaling pharmacologically using the potent ESR1 antagonist fulvestrant (0.15mg/kg, 90 days, n=10-15 mice/group). We conducted in vitro experiments on primary LAM HAFs exposed to 10nM E2 ± 100nM Fulvestrant (24-48h). These cells underwent analysis via ESR1 ChIP, ATAC, and RNA-seq in 3 technical replicates (3-5 mice each). Additionally, to demonstrate clinical relevance, we probed human herniated LAM tissues from patients (n=25 samples, 21-76 years). Results: All Aromhum mice develop scrotal hernias by 6 weeks. However, fEsr1−/−-Aromhum mice did not develop hernias, while littermate controls exhibited hernias. Thus, HAF ESR1 depletion mitigated LAM fibrosis and atrophy. Similarly, administering fulvestrant prior to hernia onset prevented hernia development. Remarkably, fulvestrant treatment in mice that had developed large scrotal hernias (&gt;200mm2) led to complete hernia regression with reversed muscle fibrosis and fiber atrophy (collagen levels comparable to wild-type mice). In vitro HAF culturing and subsequent multiomic analyses unveiled a core set of 58 genes directly influenced by E2/ESR1, including crucial ECM genes like fibulins ( Fbln5, Fbln7), metalloproteases ( Adamts3, Adamts6), and signaling molecules ( Ltbp1, Ncam1, Piezo2). Pathways such as TGFβ, WNT, and N-Glycan biosynthesis were significantly upregulated by E2. Human herniated LAM tissues exhibited substantial fibrosis, along with stromal HAF markers PDGFRA and ESR1. We also validated expression of the core E2-modulated genes in human LAM tissues ( NCAM1, LTBP1, ADAMTS6, PIEZO2). Collectively, these findings provide compelling evidence of ESR1 pathway activation and downstream gene involvement in both Aromhum scrotal hernias and human inguinal hernias. Conclusion: Our research underscores the central role of E2 in skeletal muscle fibrosis. Notably, we demonstrated that fibrosis can be entirely reversed by modulation of ESR1 signaling. Our study offers valuable insights into downstream genes and pathways that may serve as therapeutic targets for inguinal hernias and other fibrotic disorders. Funding: NIH: R01DK121529, Department of Veterans Affairs Research Career Scientist Award: IK6 RX003351. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Fusion of Platelet Derived Growth Factor Receptor Alpha (PDGFRA) With Ubiquitin Specific Peptidase 8 (USP8) in a Calcified Chondroid Mesenchymal Neoplasm Harboring t(4;15)(q12;q21) as a Sole Aberration.

The term "calcified chondroid mesenchymal neoplasm" was introduced in 2021 to describe a group of tumors characterized by various morphological features, including the formation of cartilage or chondroid matrix. These tumors frequently carry chimeric genes where the 5'-end partner gene is fibronectin 1 and the 3'-end partner gene codes for receptor tyrosine kinase. Our study explores fusion of the genes platelet-derived growth factor receptor alpha (PDGFRA) and ubiquitin-specific peptidase 8 (USP8) in calcified chondroid mesenchymal neoplasm. Genetic investigations were conducted on a tumor located in the leg of a 71-year-old woman. G-banding analysis of short-term cultured tumor cells revealed the karyotype 46,XX,t(4;15)(q12;q21)[6]/46,XX[4]. RNA sequencing detected in-frame PDGFRA::USP8 and USP8::PDGFRA chimeric transcripts, which were validated by RT-PCR/Sanger sequencing. The PDGFRA::USP8 chimeric protein is predicted to have cell membrane location and functions as a chimeric ubiquitinyl hydrolase. The USP8::PDGFRA protein was predicted to be nuclear and function as a positive regulator of cellular metabolic process. We report, for the first time, a calcified chondroid mesenchymal neoplasm carrying a balanced t(4;15)(q12;q21) chromosomal translocation, resulting in the generation of both PDGFRA::USP8 and USP8::PDGFRA chimeras. The PDGFRA::USP8 protein is located on the cell membrane and functions as a chimeric ubiquitinyl hydrolase, activated by PDGFs. Conversely, USP8::PDGFRA is a nuclear protein regulating metabolic processes.

Association between Platelet-Derived Growth Factor Receptor Alpha Gene Polymorphisms and Platelet-Rich Plasma's Efficiency in Treating Lateral Elbow Tendinopathy-A Prospective Cohort Study.

Individual differences in the response to platelet-rich plasma (PRP) therapy can be observed among patients. The genetic background may be the cause of this variability. The current study focused on the impact of genetic variants on the effectiveness of PRP. The aim of the present study was to analyze the impact of single nucleotide polymorphisms (SNP) of the platelet-derived growth factor receptor alpha (PDGFRA) gene on the effectiveness of treating lateral elbow tendinopathy (LET) with PRP. The treatment's efficacy was analyzed over time (2, 4, 8, 12, 24, 52 and 104 weeks after the PRP injection) on 107 patients using patient-reported outcome measures (PROM) and achievement of a minimal clinically important difference (MCID). Four SNPs of the PDGFRA gene (rs7668190, rs6554164, rs869978 and rs1316926) were genotyped using the TaqMan assay method. Patients with the AA genotypes of the rs7668190 and the rs1316926 polymorphisms, as well as carriers of the T allele of rs6554164 showed greater effectiveness of PRP therapy than carriers of other genotypes. Moreover, the studied SNPs influenced the platelets' parameters both in whole blood and in PRP. These results showed that PDGFRA gene polymorphisms affect the effectiveness of PRP treatment. Genotyping the rs6554164 and the rs1316926 SNPs may be considered for use in individualized patient selection for PRP therapy.

Abstract CT094: Targeting CSF1R with BLZ945 results in effective peripheral and tumor immune microenvironment modulation in advanced solid tumors and may be associated with limited efficacy in recurrent non-mesenchymal glioblastoma

Abstract Colony-stimulating factor 1 receptor (CSF-1R) signaling is involved in regulating monocyte differentiation, and the recruitment and survival of tumor-associated macrophages (TAMs). BLZ945 is a small molecule, highly selective, orally bioavailable, potent kinase inhibitor of CSF-1R that has shown the ability to reduce the recruitment of TAMs in animal models and promote infiltration of effector T cells into the tumor in preclinical models. Given the potential effects of BLZ945 on effector T-cell activity, a combination of BLZ945 with the programmed death 1 (PD-1) inhibitor spartalizumab was investigated in 1) a dose escalation phase I clinical trial with advanced solid tumor patients; and 2) an expansion phase II clinical trial in adult patients with relapsed/refractory glioblastoma (GBM) after standard of care and other lines of therapy (NCT02829723). The percentages of non-classical and intermediate monocytes in the PBMC fraction were decreased after treatment at multiple doses and schedules of treatment tested in the escalation phase. Screening and on-treatment paired tumor biopsy samples from the escalation phase were analyzed by RNA sequencing. Downregulated genes have been noted as macrophage-specific genes, suggesting that treatment with BLZ945 is downregulating macrophages in the tumor microenvironment. There appeared to be a trend for a reduction in TAM gene signatures and increase in T-cell inflammation signatures upon treatment with single-agent BLZ945 or BLZ945 + spartalizumab. RNA-sequencing analysis from archival surgical resection GBM samples from the expansion phase, revealed a potential correlation between PDGFRA gene expression and best percent change in tumor size. This suggests that non-mesenchymal GBM, for which PDGFRA is part of the defining signature, are more sensitive to the treatment. DNA-sequencing of these archival samples also revealed mutations in p53 in the tumors with partial responses but no mutations in EGFR or TERT. Citation Format: Carlos Rodrigo Gil Del Alcazar, Virginia Xu, Chia-chi Lin, Marta Gil-Martin, Aung Naing, Liqiong Fan, Fang Yang, David Quinn, Jincheng Wu, Cornelia Quadt, Jennifer Mataraza. Targeting CSF1R with BLZ945 results in effective peripheral and tumor immune microenvironment modulation in advanced solid tumors and may be associated with limited efficacy in recurrent non-mesenchymal glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT094.

Targeted DNA Sequencing Reveals Molecular Factors Associated with Clinical Outcomes in Recurrent Glioblastoma

INTRODUCTION: The prognostic significance of molecular alterations in recurrent glioblastoma (rGBM) remains unclear. METHODS: 121 consecutive glioblastoma (GBM) patients who underwent re-resection at a single institution from 2016-2021 were retrospectively reviewed. All patients underwent maximal safe resection followed by radiotherapy with concurrent and adjuvant temozolomide (TMZ) at time of initial diagnosis. DNA mutations from re-resection samples were assessed with a CLIA certified next-generation targeted DNA sequencing assay. Overall (OS) and progression-free survival (PFS) from re-resection were analyzed with the Kaplan-Meier method and Cox regression analyses. RESULTS: Median age at first recurrence was 57 years (range, 27-78), and median follow up from re-resection was 11 months. Salvage therapy comprised re-irradiation (n = 52, 43%), temozolomide (TMZ) (n = 39, 32%), lomustine (n = 47, 39%), and/or bevacizumab (n = 22, 18%). Median OS and PFS times were 12.1 and 4.4 months, respectively. Median tumor mutation burden (TMB) was 4 mut/Mb (range, 1-650), microsatellite instability (MSI) was 1.16% (range, 0-20), and MGMT methylation was present in 71 (59%) patients. Longer OS was found after postoperative TMZ (19.1 vs. 9.1), KPS &gt;70 (13.6 vs. 11.1), and/or re-irradiation (12.6 vs. 8.4) (p &lt; .05 for each). On multivariate analysis, TMZ (HR 0.2, 0.079-0.48), re-irradiation (HR 0.27, 0.12-0.58), and mutations in the PDGFRA (HR 0.24, 0.067-0.83) or PTEN (HR 2.3, 1.1-4.8) genes on targeted sequencing were associated with longer OS after re-resection (p &lt; .05). Multivariate predictors of re-irradiation response included MSI &gt; 1.16 (HR 0.25, 0.084-0.75), and mutations in PDGFRA (HR 0.04, 0.005-0.33), TERT (HR 0.16, 0.033-0.78), or PIK3R1 (HR 0.18, 0.041-0.8) genes. In the 46 matched primary/recurrent tumors, 40 (46%) had a longitudinal change in a mutation and 9 (24%) demonstrated hypermutation, of which 4 (57%) had simultaneous mismatch repair deficiencies. CONCLUSIONS: Our study identifies molecular factors associated with survival and response to re-irradiation in rGBM.

Exome Sequencing: the Search for Mutations Associated with Hereditary Breast and Ovarian Cancers in the Tuvan Ethnic Group (A Pilot Study).

Whole exome sequencing of peripheral blood samples from Tuvan females diagnosed with breast and ovarian cancers (BC/OC) was performed to search for new genes involved in BC/OC pathogenesis. Considering the high cost of whole exome sequencing and study material requirements, 9 samples were selected from 61 genomic DNA samples. A mutation in the LGR4 gene (rs34804482) involved in the tumor-mediated Wnt signaling pathway and a mutation in the BRWD1 gene (rs147211854) involved in chromatin remodeling were identified in BC patients. A mutation in the CITED2 gene (rs77963348) involved in the pathogenesis of primary ovarian insufficiency was identified in a patient with OC and a history of infertility. A mutation in the PDGFRA gene (rs2291591) was identified in two BC/OC patients. LRG4, BRWD1, PDGFRA, and CITED2 germline pathogenic mutations were discovered in Tuvan women diagnosed with BC/OC for the first time.

Molecular diversity in isocitrate dehydrogenase-wild-type glioblastoma.

In the dynamic landscape of glioblastoma, the 2021 World Health Organization Classification of Central Nervous System tumours endeavoured to establish biological homogeneity, yet isocitrate dehydrogenase-wild-type (IDH-wt) glioblastoma persists as a tapestry of clinical and molecular diversity. Intertumoural heterogeneity in IDH-wt glioblastoma presents a formidable challenge in treatment strategies. Recent strides in genetics and molecular biology have enhanced diagnostic precision, revealing distinct subtypes and invasive patterns that influence survival in patients with IDH-wt glioblastoma. Genetic and molecular biomarkers, such as the overexpression of neurofibromin 1, phosphatase and tensin homolog and/or cyclin-dependent kinase inhibitor 2A, along with specific immune cell abundance and neurotransmitters, correlate with favourable outcomes. Conversely, increased expression of epidermal growth factor receptor tyrosine kinase, platelet-derived growth factor receptor alpha and/or vascular endothelial growth factor receptor, coupled with the prevalence of glioma stem cells, tumour-associated myeloid cells, regulatory T cells and exhausted effector cells, signifies an unfavourable prognosis. The methylation status of O6-methylguanine-DNA methyltransferase and the influence of microenvironmental factors and neurotransmitters further shape treatment responses. Understanding intertumoural heterogeneity is complemented by insights into intratumoural dynamics and cellular interactions within the tumour microenvironment. Glioma stem cells and immune cell composition significantly impact progression and outcomes, emphasizing the need for personalized therapies targeting pro-tumoural signalling pathways and resistance mechanisms. A successful glioblastoma management demands biomarker identification, combination therapies and a nuanced approach considering intratumoural variability. These advancements herald a transformative era in glioblastoma comprehension and treatment.

PDGFRA K385 mutants in myxoid glioneuronal tumors promote receptor dimerization and oncogenic signaling

Myxoid glioneuronal tumors (MGNT) are low-grade glioneuronal neoplasms composed of oligodendrocyte-like cells in a mucin-rich stroma. These tumors feature a unique dinucleotide change at codon 385 in the platelet-derived growth factor receptor α (encoded by the PDGFRA gene), resulting in the substitution of lysine 385 into leucine or isoleucine. The functional consequences of these mutations remain largely unexplored. Here, we demonstrated their oncogenic potential in fibroblast and Ba/F3 transformation assays. We showed that the K385I and K385L mutants activate STAT and AKT signaling in the absence of ligand. Co-immunoprecipitations and BRET experiments suggested that the mutations stabilized the active dimeric conformation of the receptor, pointing to a new mechanism of oncogenic PDGF receptor activation. Furthermore, we evaluated the sensitivity of these mutants to three FDA-approved tyrosine kinase inhibitors: imatinib, dasatinib, and avapritinib, which effectively suppressed the constitutive activity of the mutant receptors. Finally, K385 substitution into another hydrophobic amino acid also activated the receptor. Interestingly, K385M was reported in a few cases of brain tumors but not in MGNT. Our results provide valuable insights into the molecular mechanism underlying the activation of PDGFRα by the K385I/L mutations, highlighting their potential as actionable targets in the treatment of myxoid glioneuronal tumors.

Progression-free survival after first recurrence in patients with glioblastoma.

Relevance. Despite all the treatment glioblastoma recurs as an aggressive and therapy-resistant tumor, and patients quickly die from these neoplasms. The study of glioblastoma recurrence processes and search for prognostic factors of the disease should lead to the improvement of survival rates of patients with this pathology. Purpose of the study. To study the influence of clinical and molecular-genetic factors on the median second recurrence-free period. Materials and methods. Progression-free survival after first recurrence in 34 patients aged 28 to 81 years with recurrent glioblastoma was analyzed. The diagnosis was established according to the WHO 2021 classification of CNS tumors. In each observation we studied such clinical parameters as patient’s age, functional status according to the Karnovsky scale pre- and postoperatively, peculiarities of neuroimaging picture (prevalence of tumor process, localization of recurrence, tumor volume), conducted treatment and molecular-genetic characteristics of the tumor (determination of mRNA expression level of genes: MGMT, VEGF, PDGFRA, β-tubulin III, ERCC-1, TOP2A). Results. Among the clinical and demographic characteristics, the median of the survival was influenced by the patients’ age and functional status after surgery. The median of the survival was more than 2 times higher in the group of patients under 50 years old, compared to patients over 50 years old (18.5 vs 8 weeks). The dependence of the median of the survival on the post- operative functional status (according to the Karnovsky scale) was determined (p = 0.001). The median of the survival in case of a single brain lobe lesion was more than 5 times higher than in case of widespread tumor process, though without statistical reliability (p = 0.09, 21.5 vs 4 weeks). Survival rates were higher when recurrence was localized within 2 cm of the area of removal of the primary neoplasm. After disease progression, the MGMT gene lost its predictive value. Patients with low expression of the TOR2A gene had a higher survival rate than those with medium and high expression (47.5 vs 3 weeks, p = 0.001; 47.5 vs 22.5 weeks, p = 0.06). The median of survival was higher than at high levels at low and medium PDGFRA gene expression levels (29 vs 0 weeks, p = 0.04; 21 vs 0 weeks; p = 0.05, respectively). Maximum survival rates were recorded in the group of patients after total and subtotal removal of tumor recurrence (22 and 18.5 weeks, p = 0.05). Administration of second-line chemotherapy with temozolomide statistically significantly increased the median of the second BRS (p = 0.01). Conclusion. Recurrent glioblastomas are characterized by an extremely aggressive course. Therefore, such prognostic factors as patient age, degree of tumor resection, tumor process prevalence, degree of tumor resection and 2nd line chemotherapy come to the forefront. It should be noted that the MGMT gene loses its predictive value during disease progression, while the TOR2A gene and PDGFRA gene become prognostic markers.

Advancing the Management of Skull Base Chondrosarcomas: A Systematic Review of Targeted Therapies.

Chondrosarcomas rank as the second most common primary bone malignancy. Characterized by the production of a cartilaginous matrix, these tumors typically exhibit resistance to both radiotherapy (RT) and chemotherapy (CT), resulting in overall poor outcomes: a high rate of mortality, especially among children and adolescents. Due to the considerable resistance to current conventional therapies such as surgery, CT, and RT, there is an urgent need to identify factors contributing to resistance and discover new strategies for optimal treatment. Over the past decade, researchers have delved into the dysregulation of genes associated with tumor development and therapy resistance to identify potential therapeutic targets for overcoming resistance. Recent studies have suggested several promising biomarkers and therapeutic targets for chondrosarcoma, including isocitrate dehydrogenase (IDH1/2) and COL2A1. Molecule-targeting agents and immunotherapies have demonstrated favorable antitumor activity in clinical studies involving patients with advanced chondrosarcomas. In this systematic review, we delineate the clinical features of chondrosarcoma and provide a summary of gene dysregulation and mutation associated with tumor development, as well as targeted therapies as a promising molecular approach. Finally, we analyze the probable role of the tumor microenvironment in chondrosarcoma drug resistance. A systematic search was conducted across major medical databases (PubMed, Embase, and Cochrane Library) up to 10 November 2023. The search strategy utilized relevant Medical Subject Heading (MeSH) terms and keywords related to "chondrosarcomas", "target therapies", "immunotherapies", and "outcomes". The studies included in this review consist of randomized controlled trials, non-randomized controlled trials, and cohort studies reporting on the use of target therapies for the treatment of chondrosarcoma in human subjects. Of the initial 279 articles identified, 40 articles were included in the article. The exclusion of 140 articles was due to reasons such as irrelevance, non-reporting of selected results, systematic literature review or meta-analysis, and lack of details on the method/results. Three tables highlighted clinical studies, preclinical studies, and ongoing clinical trials, encompassing 13, 7, and 20 studies, respectively. For the clinical study, a range of molecular targets, such as death receptors 4/5 (DR4 and DR5) (15%), platelet-derived growth factor receptor-alpha or -beta (PDGFR-α, PDGFR-β) (31%), were investigated. Adverse events were mainly constitutional symptoms emphasizing that to improve therapy tolerance, careful observation and tailored management are essential. Preclinical studies analyzed various molecular targets such as DR4/5 (28.6%) and COX-2 (28.6%). The prevalent indicator of antitumoral activity was the apoptotic rate of both a single agent (tumor necrosis factor-related apoptosis-inducing ligand: TRAIL) and double agents (TRAIL-DOX, TRAIL-MG132). Ongoing clinical trials, the majority in Phase II (53.9%), highlighted possible therapeutic strategies such as IDH1 inhibitors and PD-1/PD-L1 inhibitors (30.8%). The present review offers a comprehensive analysis of targeted therapeutics for skull base chondrosarcomas, highlighting a complex landscape characterized by a range of treatment approaches and new opportunities for tailored interventions. The combination of results from molecular research and clinical trials emphasizes the necessity for specialized treatment strategies and the complexity of chondrosarcoma biology.

Aspirin-exacerbated respiratory disease is associated with variants in filaggrin, epithelial integrity, and cellular interactions

BackgroundPrevious studies identified upto 6% of patients with Aspirin-Exacerbated Respiratory Disease (AERD) have family history of AERD indicating a possible link with genetic polymorphisms. However, whole exome sequencing (WES) studies of such associations are currently lacking. ObjectivesWe sought to examine whether WES can identify pathogenic variants associated with AERD. MethodsAERD diagnosis was confirmed in patients with nasal polyps and asthma. WES was performed using an Illumina sequencing platform. Human Phenotype Ontology (HPO) terms were used to define the patients’ phenotypes. Exomiser was used to annotate, filter, and prioritize possible disease-causing genetic variants. ResultsAmong thirty-nine patients with AERD, 41% reported a family history of asthma and 5% a family history of AERD. Pathogenic exome variants in the filaggrin gene (FLG) were found in two patients (5%). Other variants not known to be pathogenic were detected in an additional 16 patients (41%) in genes related to epithelial integrity and cellular interactions, including genes encoding desmoglein 3 (DSG3), dynein axonemal heavy chain 9 (DNAH9), collagen type VII alpha 1 chain (COL7A1), collagen type XVII alpha 1 chain (COL17A1), chromodomain helicase DNA binding protein-7 (CHD7), TSC complex subunit 2/tuberous sclerosis-2 protein (TSC2), P-selectin (SELP), and platelet-derived growth factor receptor-alpha (PDGFRA). ConclusionWES identified a monogenic susceptibility to AERD in 5% of patients with FLG pathogenic variants. Other variants, not previously identified as pathogenic, were found in genes relevant to epithelial integrity and cellular interactions and may further reveal genetic factors that contribute to this condition.

NTRK2 expression in gastrointestinal stromal tumors with a special emphasis on the clinicopathological and prognostic impacts

Gastrointestinal stromal tumors (GISTs) are typically characterized by activating mutations of the KIT proto-oncogene receptor tyrosine kinase (KIT) or platelet-derived growth factor receptor alpha (PDGFRA). Recently, the neurotrophic tyrosine receptor kinase (NTRK) fusion was reported in a small subset of wild-type GIST. We examined trk IHC and NTRK gene expressions in GIST. Pan-trk immunohistochemistry (IHC) was positive in 25 (all 16 duodenal and 9 out of 16 small intestinal GISTs) of 139 cases, and all pan-trk positive cases showed diffuse and strong expression of c-kit. Interestingly, all of these cases showed only trkB but not trkA/trkC expression. Cap analysis of gene expression (CAGE) analysis identified increased number of genes whose promoters were activated in pan-trk/trkB positive GISTs. Imbalanced expression of NTRK2, which suggests the presence of NTRK2 fusion, was not observed in any of trkB positive GISTs, despite higher mRNA expression. TrkB expression was found in duodenal GISTs and more than half of small intestinal GISTs, and this subset of cases showed poor prognosis. However, there was not clear difference in clinical outcomes according to the trkB expression status in small intestinal GISTs. These findings may provide a possible hypothesis for trkB overexpression contributing to the tumorigenesis and aggressive clinical outcome in GISTs of duodenal origin.

Reappraisals of biological behaviors of PDGFRA mutant gastrointestinal stromal tumor

Objective: To investigate the biological behavior spectrum of platelet-derived growth factor alpha receptor (PDGFRA)-mutant gastrointestinal stromal tumor (GIST), and to compare the clinical values of the Zhongshan method of benign and malignant evaluation with the modified National Institutes of Health (NIH) risk stratification. Methods: A total of 119 cases of GIST with PDGFRA mutation who underwent surgical resection at Zhongshan Hospital, Fudan University from 2009 to 2020 were collected. The clinicopathological data, follow-up records, and subsequent treatment were reviewed and analyzed statistically. Results: There were 79 males and 40 females. The patients ranged in age from 25 to 80 years, with a median age of 60 years. Among them, 115 patients were followed up for 1-154 months, and 13 patients progressed to disease. The 5-year disease-free survival (DFS) and overall survival (OS) were 90.1% and 94.1%, respectively. According to the modified NIH risk stratification, 8 cases, 32 cases, 38 cases, and 35 cases were very-low risk, low risk, intermediate risk, and high risk, and 5-year DFS were 100.0%, 95.6%, 94.3%, and 80.5%, respectively. There was no significant difference in prognosis among the non-high risk groups, only the difference between high risk and non-high risk groups was significant (P=0.029). However, the 5-year OS was 100.0%, 100.0%, 95.0% and 89.0%, and there was no difference (P=0.221). According to the benign and malignant evaluation Zhongshan method, 43 cases were non-malignant (37.4%), 56 cases were low-grade malignant (48.7%), 9 cases were moderately malignant (7.8%), and 7 cases were highly malignant (6.1%). The 5-year DFS were 100.0%, 91.7%, 77.8%, 38.1%, and the difference was significant (P<0.001). The 5-year OS were 100.0%, 97.5%, 77.8%, 66.7%, the difference was significant (P<0.001). Conclusions: GIST with PDGFRA gene mutation shows a broad range of biological behavior, ranging from benign to highly malignant. According to the Zhongshan method, non-malignant and low-grade malignant tumors are common, the prognosis after surgery is good, while the fewer medium-high malignant tumors showed poor prognosis after surgical resection. The overall biological behavior of this type of GIST is relatively inert, which is due to the low proportion of medium-high malignant GIST. The modified NIH risk stratification may not be effective in risk stratification for PDGFRA mutant GIST.

ESTABLISHING NOVEL MARKERS OF TENDON CELL POPULATIONS

Energy storing tendons such as the human Achilles and equine superficial digital flexor tendon (SDFT) are prone to age-related injury. Tendons have poor healing capacity and a lack of effective treatments can lead to ongoing pain, reduced function and re-injury. It is therefore important to identify the mechanisms underpinning age-related tendinous changes in order to develop more effective treatments. Our recent single cell sequencing data has shown that tendon cell populations have extensive heterogeneity and cells housed in the tendon interfascicular matrix (IFM) are preferentially affected by ageing. There is, however, a lack of established surface markers for cell populations in tendon, limiting the capacity to isolate distinct cell populations and study their contribution to age-related tendon degeneration. Here, we investigate the presence of the cell surface proteins MET proto-oncogene (MET), integrin subunit alpha 10 (ITGA10), fibroblast activation protein alpha (FAP) and platelet derived growth factor receptor alpha (PDGFRA) in the equine SDFT cell populations and their co-localisation with known markers.Using Western blot we validated the specificity of selected antibodies in equine tissue before performing immunohistochemistry to establish the location of the respective proteins in the SDFT. We subsequently used double labelling immunofluorescence with the established mural cell marker desmin (DES) to distinguish between tenocyte and mural cell populations.In situ, MET, ITGA10, and FAP presence was found in cells throughout the tendon whereas PDGFRA was present in cells within the IFM. Double labelling immunofluorescence with the mural cell marker DES showed lack of co-localisation between PDGFRA and DES suggesting PDGFRA is labelling an IFM cell population distinct from those associated with blood vessels.PDGFRA is a promising target for the specific cell sorting of IFM-localised tenocytes, enabling their isolation and subsequent characterisation.Acknowledgments: The authors acknowledge the Biotechnology and Biological Sciences Research Council (BB/W007282/1) for funding this work.

Pan-Canadian consensus recommendations for GIST management in high- and low-throughput centres across Canada.

Gastrointestinal stromal tumours (GISTs) are mesenchymal tumours that originate from the interstitial cells of Cajal. GISTs are mainly driven by gain-of-function mutations in receptor tyrosine kinase or platelet-derived growth factor receptor alpha. Surgical resection is the only curative treatment for localized tumours and all currently approved medical GIST treatments are based on orally available tyrosine kinase inhibitors. Recent discoveries in the molecular and clinical features of GISTs have greatly impacted GIST management. Due to the provincially rather than nationally administered Canadian healthcare system, there have been inconsistencies in the treatment of GISTs across the country. Therefore, guidance on the latest knowledge, clinical management and treatment of GIST is needed to standardize the approach to GIST management nationwide. To establish pan-Canadian guidance, provide up-to-date data and harmonize the clinical practice of GIST management in high- and low-throughput centres across Canada; a panel of 20 physicians with extensive clinical experience in GIST management reviewed relevant literature. This included radiologists, pathologists, interventional radiologists, surgeons and medical oncologists across Canada. The structured literature focused on seven key domains: molecular profiling, radiological techniques/reporting, targeted localized therapy, intricacies of systemic treatments, emerging tests, multidisciplinary care and patient advocacy. This literature review, along with clinical expertise and opinion, was used to develop this concise and clinically relevant consensus paper to harmonize the knowledge and clinical practice on GIST management across Canada. The content presented here will help guide healthcare providers, especially in Canada, in terms of approaching and managing GIST.