Specific Receptor Tyrosine Kinase Research Articles

Live Cell Imaging of Human Liver Fibrosis using Hepatic Micro-Organoids.

Due to the limitations of available in vitro systems and animal models, we lack a detailed understanding of the pathogenetic mechanisms and have minimal treatment options for liver fibrosis. Therefore, we engineered a live cell imaging system that assesses fibrosis in a human multi-lineage hepatic organoid in a microwell (i.e., microHOs). Transcriptomic analysis revealed that TGFβ1 converted mesenchymal cells in microHOs into myofibroblast-like cells resembling those in fibrotic human liver tissue. When pro-fibrotic intracellular signaling pathways were examined, the anti-fibrotic effect of receptor-specific tyrosine kinase inhibitors was limited to the fibrosis induced by the corresponding growth factor, which indicates their anti-fibrotic efficacy would be limited to fibrotic diseases solely mediated by that growth factor. Based upon transcriptomic and transcription factor activation analyses in microHOs, GSK3β and p38 MAPK inhibitors were identified as potential new broad-spectrum therapies for liver fibrosis. Other new therapies could subsequently be identified using the microHO system.

Abstract A049: Collagen-driven kinome reprogramming reveals unique, actionable DDR1-signaling dependencies in pancreatic cancer cells

Abstract Introduction: Pancreatic ductal adenocarcinoma (PDA) is the 3rd most common cause of cancer death in the United States, with a 5-year survival rate of only 13%, in part due to late detection and metastatic dissemination at early stages of progression. Most PDA tumors exhibit a dense fibro-inflammatory stroma consisting of fibroblasts, immune cells, and a dense collagen-rich extracellular matrix (ECM) that regulate disease progression. How distinct collagens (COLs) influence PDA progression remains unclear. COLs signal via specific cell surface receptors, of which the Discoidin Domain Receptors (DDRs) constitute a unique family of collagen-binding receptor tyrosine kinases (RTKs). DDR1 is expressed by PDA cancer cells, while DDR2 is expressed by mesenchymal cells. DDR1 is activated by both basement membrane COL (e.g. COL4) and fibrillar COLs (e.g. COLs 1, 2, 11). Compared to most RTKs, relatively little is understood about differential ligand activation and signaling downstream of DDRs. Our working hypothesis is that switches in ECM collagen composition over the course of PDA progression induce changes in DDR1-intracellular signaling cascades, which may reveal unexplored therapeutic susceptibilities to target and eliminate PDA cancer cells. Methods and Recent Advances: Using genetically engineered mouse models of PDA, we previously found that genetic ablation of Ddr1 impedes tumor progression, blocking the transition from well-differentiated to poorly-differentiated adenocarcinoma and, as a result, metastasis. Moreover, we showed that xenografts of DDR1-expressing human PDA cell lines display enhanced tumor growth exclusively when implanted within a COL1 scaffold. Leveraging an innovative high-throughput kinase-activity mapping (HT-KAM) platform and kinase network resource database (PhosphoAtlas), we started investigating mechanisms of differential activation of DDR1 by distinct COLs, including COL1 and COL11, which is an understudied fibrillar collagen that is prominent in the stroma of late-stage, metastatic PDA. New, Unpublished Findings: Using several PDA cell line models with or without DDR1 expression, our results indicate that DDR1 activates two distinct signaling networks: (1) a conserved, coordinated response that is modestly activated by COL1 but is hyperactivated by COL11 (e.g., ERBB, AKT, MEK/ERK, SRC), and (2) a unique set of phospho-signaling nodes that are only induced by COL11 –and not COL1 (e.g., specific RTKs and PKCs). Several of these kinases are associated with cancer cell proliferation and survival, as well as EMT induction, in part illuminating the malignancy-promoting effects of DDR1 in late-stage PDA in response to changes in COL composition. Conclusion: Differential activation of DDR1 represents a new paradigm on how distinct fibrillar COLs within the TME may drive PDA cell signaling. We are actively exploring how distinct COLs differentially regulate PDA tumor growth and metastatic behavior via DDR1, and how specific kinase-targeting interventions may prevent malignant phenotypes or induce tumor cell death. Citation Format: Anjum Sohail, Yeonjoo Hwang, Denise P Munoz, Yoshihiro Ishikawa, Rafael Fridman, Howard Crawford, Jean-Philippe Coppe. Collagen-driven kinome reprogramming reveals unique, actionable DDR1-signaling dependencies in pancreatic cancer cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A049.

FGFR1-mediated enhancement of foot-and-mouth disease virus entry

Foot-and-mouth disease virus (FMDV), a member of picornavirus, can enter into host cell via macropinocytosis. Although it is known that receptor tyrosine kinases (RTKs) play a crucial role in FMDV macropinocytic entry, the specific RTK responsible for regulating this process and the intricacies of RTK-mediated downstream signaling remain to be elucidated. Here, we conducted a screening of RTK inhibitors to assess their efficacy against FMDV. Our findings revealed that two compounds specifically targeting fibroblast growth factor receptor 1 (FGFR1) and FMS-like tyrosine kinase 3 (FLT3) significantly disrupted FMDV entry. Furthermore, additional evaluation through gene knockdown and overexpression confirmed the promotion effect of FGFR1 and FLT3 on FMDV entry. Interestingly, we discovered that the increasement of FMDV entry facilitated by FGFR1 and FLT3 can be ascribed to increased macropinocytic uptake. Additionally, in-depth mechanistic study demonstrated that FGFR1 interacts with FMDV VP3 and undergoes phosphorylation during FMDV entry. Furthermore, the FGFR1 inhibitor inhibited FMDV-induced activation of p21-activated kinase 1 (PAK1) on Thr212 and Thr423 sites. Consistent with these findings, the ectopic expression of FGFR1 resulted in a concomitant increase in phosphorylation level of PAK1 on Thr212 and Thr423 sites. Taken together, our findings represent the initial exploration of FGFR1's involvement in FMDV macropinocytic entry, providing novel insights with potential implications for the development of antiviral strategies.

Atomic Force Microscopy Lifetime Analysis: An Intuitive Method for Evaluating Receptor Tyrosine Kinase Dimer-Targeting Inhibitors.

Overexpression of receptor tyrosine kinases (RTKs) or binding to ligands can lead to the formation of specific unliganded and liganded RTK dimers, and these two RTK dimers are potential targets for preventing tumor metastasis. Traditional RTK dimer inhibitor analysis was mostly based on end point assays, which required cumbersome cell handling and behavior monitoring. There are still challenges in developing intuitive process-based analytical methods to study RTK dimer inhibitors, especially those used to visually distinguish between unliganded and liganded RTK dimer inhibitors. Herein, taking the mesenchymal-epithelial transition factor (MET) receptor, an intuitive method for evaluating MET inhibitors has been developed based on atomic force microscopy (AFM) lifetime analysis. The time interval between the start of the force and the bond break point was regarded as the bond lifetime, which could reflect the stability of the MET dimer. The results showed that there was a significant difference in the lifetime (τ) of unliganded MET dimers (τ1 = 207.87 ± 4.69 ms) and liganded MET dimers (τ2 = 330.58 ± 15.60 ms) induced by the hepatocyte growth factor, and aptamer SL1 could decrease τ1 and τ2, suggesting that SL1 could inhibit both unliganded and liganded MET dimers. However, heparin only decreased τ2, suggesting that it could inhibit only the liganded MET dimer. AFM-based lifetime analysis methods could monitor RTK dimer status rather than provide overall average results, allowing for intuitive process-based analysis and evaluation of RTK dimers and related inhibitors at the single-molecule level. This study provides a novel complementary strategy for simple and intuitive RTK inhibitor research.

Abstract 952: Ex vivo drug testing identifies a potentially effective drug in 94% of cases for 403 patients in 42 tumor types

Abstract Objective: To determine whether patient derived tumor cells (PDTC) could be derived from a variety of solid tumors and used to select effective therapies, we developed a CLIA certified assay, the PARIS® test, to quantify drug sensitivities using PDTCs. Methods: Oncologists referred patients for the PARIS® test and patients had the option to consent to SEngine Precision Medicine’s IRB protocol. Samples were obtained from multiple cancer centers across the US and abroad. Patients were at all stages in their clinical journey ranging from treatment naïve to late stage, recurrent/refractory disease settings. Fresh specimens obtained from surgical resections, core biopsies, or body fluids arrived at our CLIA laboratory within 48 hrs from collection. Tumor origin and driver mutations were confirmed by IHC or DNA sequence in 88% of the cases. Results: PDTCs derived from 403 patients diagnosed with 42 different solid tumor types, including both common and rare tumors, were subjected to the PARIS® assay. An average of 67 oncology drugs (ranging from 6-307), including chemotherapies and targeted agents, were tested for each patient sample. A report ranking drug sensitivities was provided to the oncologist with an average turnaround time of less than 3 weeks. Drug sensitivity was classified as exceptional/good, moderate/low and no responses. Remarkably, 94.2% of the PDTCs exhibited selective exceptional/good responses to at least one, and typically several drugs, despite the majority of PDTCs being derived from patients with drug resistant, metastatic disease. The drug sensitivity profiles showed highly individualized responses as well as tumor type specificity. While known biomarkers/drug sensitivity associations were confirmed, many samples exhibited sensitivity to targeted agents in the absence of known biomarkers. For example, HER2+ breast cancers demonstrated sensitivity to HER2/EGFR inhibitor and a subset of luminal B and triple negative breast cancers demonstrated HER2/EGFRi responses without underlying genetic alterations. Functional testing was also useful in the rare tumor types. For example, low grade serous ovarian cancer (LGSOC) cells, differentiated from high grade by their response to specific receptor tyrosine kinase inhibitors and estrogen antagonists, but a poor response to standard of care, as is observed in the clinic. Three patients with LGSOC that were treated with the PARIS test top scoring drugs had a positive clinical response and cases from other tumor types will be presented. Conclusions: Functional testing of PDTCs from both common and rare tumor types is feasible, even for those that have failed standard of care. We provide an unprecedented view of patient-specific, actionable vulnerabilities to current oncology drugs. Personalization of cancer care will require improved access to off-label drugs. Citation Format: Rachele Rosati, Alex C. Rajevski, Payel Chatterjee, Lauren R. Appleyard, Ana Cristina Cordero Schmidt, Shalini Pereira, Robert L. Diaz, Brady Bernard, Brady Bernard, Carla Grandori, Christopher J. Kemp. Ex vivo drug testing identifies a potentially effective drug in 94% of cases for 403 patients in 42 tumor types [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 952.

Intracellular FGF1 protects cells from apoptosis through direct interaction with p53

Fibroblast growth factor 1 (FGF1) acts by activating specific tyrosine kinase receptors on the cell surface. In addition to this classical mode of action, FGF1 also exhibits intracellular activity. Recently, we found that FGF1 translocated into the cell interior exhibits anti-apoptotic activity independent of receptor activation and downstream signaling. Here, we show that expression of FGF1 increases the survival of cells treated with various apoptosis inducers, but only when wild-type p53 is present. The p53-negative cells were not protected by either ectopically expressed or translocated FGF1. We also confirmed the requirement of p53 for the anti-apoptotic intracellular activity of FGF1 by silencing p53, resulting in loss of the protective effect of FGF1. In contrast, in p53-negative cells, intracellular FGF1 regained its anti-apoptotic properties after transfection with wild-type p53. We also found that FGF1 directly interacts with p53 in cells and that the binding region is located in the DBD domain of p53. We therefore postulate that intracellular FGF1 protects cells from apoptosis by directly interacting with p53.

Personalized Medicine in Medullary Thyroid Carcinoma: A Broad Review of Emerging Treatments.

Medullary thyroid carcinoma (MTC) arises from parafollicular cells in the thyroid gland, and although rare, it represents an aggressive type of thyroid cancer. MTC is recognized for its low mutational burden, with point mutations in RET or RAS genes being the most common oncogenic events. MTC can be resistant to cytotoxic chemotherapy, and multitarget kinase inhibitors (MKIs) have been considered a treatment option. They act by inhibiting the activities of specific tyrosine kinase receptors involved in tumor growth and angiogenesis. Several tyrosine kinase inhibitors are approved in the treatment of advanced MTC, including vandetanib and cabozantinib. However, due to the significant number of adverse events, debatable efficiency and resistance, there is a need for novel RET-specific TKIs. Newer RET-specific TKIs are expected to overcome previous limitations and improve patient outcomes. Herein, we aim to review MTC signaling pathways, the most recent options for treatment and the applications for personalized medicine.

Multistep continuous flow synthesis of Erlotinib

Erlotinib is an orally administered, highly effective, specific epidermal growth factor receptor tyrosine kinase inhibitor, used to treat non-small cell lung cancer and pancreatic cancer. The traditional synthetic methods for Erlotinib exhibit long reaction time and safety concern. Herein, we describe a novel five-step route for the synthesis of Erlotinib in flow. These five steps comprise etherification, nitration, reduction, addition and cyclization reactions. All steps were optimized and converted to continuous flow process, which drastically reduces the reaction time and considerably improves the process safety as well as the total yield. Enabled by five continuous flow units, Erlotinib is efficiently afforded with an E-factor of 38, an overall yield of 83%, and a total residence time of 25.1 min. Majority steps in this process have been optimized for quantitative conversion, which offers the possibility of telescoping the entire process.

PYtags enable spatiotemporal measurements of receptor tyrosine kinase signaling in living cells.

Receptor tyrosine kinases (RTKs) are major signaling hubs in metazoans, playing crucial roles in cell proliferation, migration, and differentiation. However, few tools are available to measure the activity of a specific RTK in individual living cells. Here, we present pYtags, a modular approach for monitoring the activity of a user-defined RTK by live-cell microscopy. pYtags consist of an RTK modified with a tyrosine activation motif that, when phosphorylated, recruits a fluorescently labeled tandem SH2 domain with high specificity. We show that pYtags enable the monitoring of a specific RTK on seconds-to-minutes time scales and across subcellular and multicellular length scales. Using a pYtag biosensor for epidermal growth factor receptor (EGFR), we quantitatively characterize how signaling dynamics vary with the identity and dose of activating ligand. We show that orthogonal pYtags can be used to monitor the dynamics of EGFR and ErbB2 activity in the same cell, revealing distinct phases of activation for each RTK. The specificity and modularity of pYtags open the door to robust biosensors of multiple tyrosine kinases and may enable engineering of synthetic receptors with orthogonal response programs.

Advances in the Diagnosis and Treatment of a Driving Target: RET Rearrangements in non-Small-Cell Lung Cancer (NSCLC) Especially in China.

In the era of precision medicine, with the deepening of the research on malignant tumor driving genes, clinical oncology has fully entered the era of targeted therapy. For non-small-cell lung cancer (NSCLC), the development of targeted drugs targeting driver genes, such as epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK), has successfully opened up a new model of targeted therapy. At present, proto-oncogene rearranged during transfection (RET) fusion gene is an important novel oncogenic driving target, and specific receptor tyrosine kinase inhibitors (TKIs) targeting RET fusion have been approved. This article will review the latest research about the molecular characteristics, pathogenesis, detection, and clinical treatment strategies of RET rearrangements especially in China.

Vibrance-mg: Clinical Trial of Nipocalimab in Pediatric Myasthenia Gravis

Objective We describe an open-label study of nipocalimab to determine the effect of nipocalimab in pediatric participants with gMG. Background Nipocalimab is a high affinity, fully human, aglycosylated, effectorless IgG1 anti FcRn monoclonal antibody that targets the neonatal Fc receptor (FcRn) with high affinity, thereby lowering IgG pathogenic antibodies in autoimmune disease. Data from Vivacity-MG, a Phase 2, multicenter, randomized, double-blind, placebo-controlled study of nipocalimab demonstrated safety, tolerability, and efficacy of nipocalimab in adult generalized myasthenia gravis (gMG) (clinicaltrials.gov NCT03772587). Design/Methods This global study will enroll at least 12 participants, aged 2 to <18, with a diagnosis of gMG and an insufficient clinical response to ongoing, stable standard-of-care therapy, as reflected by a Myasthenia Gravis Foundation of America (MGFA) Class of IIa/b through IVa at screening. Participants must have a positive serologic test for either acetylcholine receptor or Muscle Specific Tyrosine Kinase pathogenic autoantibody. The study will consist of a screening period of up to 4 weeks, a 24-week open-label Active Treatment Phase where participants will receive nipocalimab intravenously every two weeks, and a Long-term Extension phase; after last dose, a safety follow-up assessment will be conducted at 8 weeks. The primary outcome is the effect of nipocalimab on total serum IgG, safety and tolerability, and PK in pediatric participants with gMG. Results Study enrollment will begin in 2022. Conclusions The vibrance-mg study will assess the PK/PD, safety and activity of Nipocalimab in pediatric gMG.

AXL and MET Tyrosine Kinase Receptors Co-Expression as a Potential Therapeutic Target in Malignant Pleural Mesothelioma.

Malignant pleural mesothelioma (MPM) is a highly lethal malignancy that unfortunately cannot benefit from molecularly targeted therapies. Although previous results showed the pivotal role of various receptor tyrosine kinases (RTKs) in MPM tumorigenesis, the treatment with a single inhibitor targeting one specific RTK has been shown to be ineffective in MPM patients. The main aim of the present study was to investigate the potential role of AXL and MET receptors in MPM and the possible efficacy of treatment with AXL and MET multitarget inhibitors. Immunohistochemical and FISH analyses were performed in a wide series of formalin-fixed paraffin-embedded MPM samples to detect the expression of two receptors and the potential gene amplification. In vitro studies were performed to evaluate putative correlations between the target's expression and the cell sensitivity to AXL-MET multitarget inhibitors. In our series, 10.4% of cases showed a co-expression of AXL and MET, regardless of their ligand expression, and the gene amplification. Furthermore, our in vitro results suggest that the concomitant pharmacological inhibition of AXL and MET may affect the proliferative and aggressiveness of MPM cells. In conclusion, the subset of MPM patients with AXL-MET co-activation could benefit from treatment with specific multitarget inhibitors.

NCAPG2 Maintains Cancer Stemness and Promotes Erlotinib Resistance in Lung Adenocarcinoma.

Simple SummaryThis study investigated the relationship between erlotinib resistance and stemness in lung adenocarcinoma. NCAPG2 was identified as an erlotinib resistance gene and maintained the stemness of lung adenocarcinoma.Erlotinib is a highly specific and reversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), but resistance inevitably develops as the disease progresses. Erlotinib resistance and cancer stem cells (CSCs) are poor factors hindering the prognosis of patients with lung adenocarcinoma (LUAD). Although studies have shown that erlotinib resistance and CSCs can jointly promote cancer development, the mechanism is currently unclear. Here, we investigated the potential biomarker and molecular mechanism of erlotinib resistance and cancer stemness in LUAD. An erlotinib resistance model based on four genes was constructed from The Cancer Genome Atlas (TCGA), the GEO database, the Cancer Cell Line Encyclopedia (CCLE), and the Genomics of Drug Sensitivity in Cancer (GDSC). Through multiple bioinformatic analyses, NCAPG2 was identified as a key gene for erlotinib resistance and stemness in LUAD. Further in vitro experiments demonstrated that NCAPG2 maintains stemness and contributes to erlotinib resistance in LUAD. In summary, NCAPG2 plays a vital role in stemness and erlotinib resistance in LUAD.

Design, synthesis and biological evaluation of erlotinib-based IDO1 inhibitors.

Erlotinib is a highly specific and reversible epidermal growth factor receptor tyrosine kinase inhibitor for the targeted therapy of non-small-cell lung cancer (NSCLC) However, the efficacy of erlotinib is limited because the development of drug resistance during chemotherapy. Indoleamine 2,3-dioxygenase-1 (IDO1) is a rate-limiting tryptophan catabolic enzyme that is activated in many human cancers. In this study, we designed a series of erlotinib-based 1,2,3-triazole compounds by combining erlotinib with phenyl or benzyl azide. Attentive FP prediction model was used to predict the bioactivity of those compounds. We discovered that most of the erlotinib-based 1,2,3-triazole compounds are capable of suppressing IDO1 activities in vitro experiments. Among them, compound 14b (IC50 = 0.59 ± 0.05 μM) had the strongest inhibitory effect on IDO1. In addition, compound 14b significantly inhibited tumor growth comparable to the antitumor activity of erlotinib and the IDO1 inhibitor epacadostat in murine tumor models.

βIII-tubulin suppression enhances the activity of Amuvatinib to inhibit cell proliferation in c-Met positive non-small cell lung cancer cells.

Non-Small Cell Lung Carcinoma (NSCLC) remains a leading cause of cancer death. Resistance to therapy is a significant problem, highlighting the need to find new ways of sensitising tumour cells to therapeutic agents. βIII-tubulin is associated with aggressive tumours and chemotherapy resistance in a range of cancers including NSCLC. βIII-tubulin expression has been shown to impact kinase signalling in NSCLC cells. Here, we sought to exploit this interaction by identifying co-activity between βIII-tubulin suppression and small-molecule kinase inhibitors. To achieve this, a forced-genetics approach combined with a high-throughput drug screen was used. We show that activity of the multi-kinase inhibitor Amuvatinib (MP-470) is enhanced by βIII-tubulin suppression in independent NSCLC cell lines. We also show that this compound significantly inhibits cell proliferation among βIII-tubulin knockdown cells expressing the receptor tyrosine kinase c-Met. Together, our results highlight that βIII-tubulin suppression combined with targeting specific receptor tyrosine kinases may represent a novel therapeutic approach for otherwise difficult-to-treat lung carcinomas.

Study on the mechanism of visual aging in cats’ primary visual cortex based on BDNF-TrkB signal pathway

To explore the expression of brain-derived neurotrophic factor (BDNF) and specific receptor tyrosine kinase receptor B (TrkB) in the primary visual cortex of young and old cats, especially to reveal the age-related differences in the mediating mechanism of BDNF-TrkB signaling pathway in cats’ visual cortex and their possible effects on synaptic plasticity, Nissl staining was used to display neurons in each layer of cats’ primary visual cortex, and immunohistochemical ABC method was used to label BDNF and TrkB immunopositive cells in each layer of cats’ primary visual cortex. The BDNF and TrkB receptor immunoreactive neurons and non-neurons were observed and photographed. Their density and immunoreactive intensity were measured. Results showed that BDNF and TrkB were widely expressed in all layers of visual cortex in young and old cats. Compared with the young group, the density and intensity of BDNF and TrkB positive cells in each layer of primary visual cortex in the old group decreased significantly (P < 0.01). The findings indicate that the expression levels of BDNF and TrkB in the primary visual cortex of cats decrease with age, suggesting that the change of BDNF-TrkB signal pathway caused by the weakening of brain-derived neurotrophic factor activity may be one of the important reasons for the decline of visual function.

HGG-04. Intramedullary spinal high grade glioma with ALK fusion and excellent response to targeted treatment with alectinib: case report

INTRODUCTION: Intramedullary spinal cord high grade gliomas are rare pediatric tumors , with a grim prognosis. Current therapeutical strategies include a surgical resection if feasible, and radiotherapy. Additional treatments with various chemotherapy agents have had a minor effect and did not change the course of the disease. New molecular targets are a source of hope. Recent molecular evidence regarding high grade infantile hemispheric gliomas describe specific tyrosine kinase receptor fusions or mutations in ALK, ROS, NTRK and MET domains which may lead to therapeutical targets. There is no data regarding these molecular changes in infantile intramedullary high grade gliomas. We present a two year old girl with a cervical high grade glioma with an ALK mutation which received targeted therapy. CASE REPORT: A two year old girl presented with progressive torticollis and hemiparesis. An intramedullary cervical tumor with ill -defined borders was diagnosed. A limited partial excision was performed and the pathological diagnosis was high grade glioma. Within weeks she developed progressive clinical and radiological deterioration. Molecular studies (Oncomine) revealed an ALK fusion (KIF5B) which was confirmed by immunohistochemistry. Treatment with ALK inhibitor alectinib at 150mg daily was initiated. Torticollis resolved within a week, and MRI after 3 months showed outstanding tumor shrinkage with a small residual mass. There were no adverse events to treatment. DISCUSSION: ALK fusion positive high grade glioma has recently been recognized in infants with hemispheric tumors, and a preliminary recent case report demonstrated excellent response to ALK inhibitors. Intramedullary spinal cord high grade gliomas are rare and harbor poor prognosis. This is the first case of ALK fusion glioma of the spine with excellent preliminary response to alectinib. The duration of treatment and long term prognosis is unknown. Molecular investigations can change the approach to pediatric rare CNS tumors.

Human Epidermal Growth Factor Receptor 2-Targeting Approaches for Colorectal Cancer: Clinical Implications of Novel Treatments and Future Therapeutic Avenues.

The treatment paradigm for colorectal cancer (CRC) has changed significantly over the past decade with targeted therapeutics. Human epidermal growth factor receptor 2 (HER2) amplification is seen among 3%-4% of patients with metastatic CRC (mCRC). The biological discovery of HER2 amplification in cancer cells has led to practice-changing drug development for several solid tumors, including breast, gastric, and esophageal cancers. HER2 amplification is now highly actionable in CRC with distinct therapeutic combinations, including the combination of monoclonal antibodies and HER2 receptor-specific tyrosine kinase inhibitors, as well as antibody-drug conjugates, that delivers targeted cytotoxic agents. However, it is essential to define the therapeutic role and sequence of these different combinations, some of which are already part of standard clinical practice. In this review article, we discuss recent clinical studies demonstrating the clinical benefits of each distinct therapeutic approach and their impacts on the current management of HER2-amplified mCRC. We also review ongoing clinical trials targeting the HER2 pathway in mCRC and elaborate on novel therapeutic opportunities in this space that may further define the changing paradigm of HER2-targeted therapy for CRC.

Update Overview of the Role of Angiopoietins in Lung Cancer.

Angiogenesis is a biological process that involves the formation of new blood vessels from the existing vasculature, and it plays a fundamental role in the development and progression of several types of cancer, including lung cancer. The angiopoietin/Tie2 ligand/receptor system orchestrates vascular integrity. In particular, Angiopoietin-1 activates the endothelial cell (EC)-specific receptor tyrosine kinase, Tie2, which is essential for preserving endothelial quiescence. On the other hand, Angiopoietin-2 acts as an inhibitor of the Angiopoietin-1/Tie2 signaling pathways, thus facilitating the destabilization of quiescent endothelium in cases of inflammation and cancer. Clinical studies have proven that high levels of Angiopoietin-2 indicate the development of non-small-cell lung carcinomas (NSCLC), while high levels of Angiopoietin-2 are strongly related to tumor angiogenesis, lymphangiogenesis, metastasis, and poor prognosis. Interestingly, the association of Angiopoietin-2 levels with the type of surgical approach makes Angiopoietin-2 a valuable factor in selecting the most suitable therapeutic strategy for lung cancer patients. The role of the Angiopoietin-1 and Angiopoietin-4 levels in NSCLC development requires further investigation. The present review focuses on the clinical impact of the Angiopoietin-1, Angiopoietin-2, and Angiopoietin-4 levels in patients diagnosed with NSCLC, emphasizing the interaction between them, and how they affect the development, progression, and metastasis of lung disease. Finally, it estimates the role of angiopoietins levels in the effective therapy of lung cancer patients.

2: Genetic- and Mobilization-Based Alterations in Matrix Alignment to Mitigate Aberrant Cell Fate Determination

Purpose:Cells recognize mechanical cues from the extracellular environment through interactions with matrix proteins, such as collagen. Following injury, fibrotic deposition of collagen can lead to aberrant cell differentiation and failed healing. Aligned collagen matrices can drive PDGFRα+ mesenchymal progenitor cells (MPCs) towards osteochondral lineages, leading to heterotopic ossification (HO). Previous work has shown that reducing mechanical strain by immobilizing a limb prevents the formation of an aligned extracellular matrix (ECM), leading to altered MPC differentiation, however, the cellular mechanisms of matrix reorganization following injury remain unclear. Using novel bioinformatics approach, we identified discoidin domain receptor 2 (DDR2) as a key MPC specific tyrosine kinase receptor that interacts with the fibrillar collagen matrix. We hypothesized that DDR2 activation leads to regulation of ECM alignment and therefore serves as a novel upstream regulator of mechanotransductive signaling following musculoskeletal repair.Methods:Heterotopic ossification was induced using a proven mouse model of 30% total body surface area burn with concurrent Achilles’ transection in Ddr2 deletion (Ddr2slie/slie) and littermate control mice on the C57/BL6J background. In separate experiments, ankle joint immobilizers were placed on injured mice for 1, 2 or 3 weeks after burn/tenotomy. Tissue from Ddr2 deleted, immobilized and mobile control mice were harvested for immunofluorescence histology, second harmonic generation of collagen fiber histology at 1, 3 and 9 weeks after injury (SHG) (n=4/group). HO site tissue was also harvested prior to injury and at 1 and 6 weeks after burn/tenotomy and processed for Single-Cell RNA sequencing (scRNA seq) and single nucleus assay for transposase-accessible chromatin (snATAC) using 10X Sequencing and downstream analysis using Seurat 4.0.1 and Signac 3.1.5.Results:Single-cell RNA sequencing showed that genes for collagen type 1 and 3 and Ddr2 are highly upregulated in MPCs following injury. SnATAC showed increased open chromatin reads in the promoter of MPCs following injury (not shown). Utilizing SHG, we found that the collagen matrix is aligned at three-weeks following injury, but one week of limb immobilization was enough to prevent aligned collagen. The active phosphorylated form of DDR2 (pDDR2) was decreased in PDGFRα+ MPCs within immobilized samples, suggesting that DDR2 may affect matrix alignment. Ddr2slie/slie had more disorganized collagen matrix nine weeks following injury and significantly reduced HO.Conclusions:This is the first work to alter collagen matrix organization by genetic modification and mobilization protocols and identifies DDR2 as a critical upstream receptor in matrix organization and aberrant progenitor differentiation following injury. DDR2 antagonism could have therapeutic potential in preventing heterotopic ossification following traumatic injury.