Mechanisms of receptor tyrosine kinase activation in cancer

FGFR2 residence in primary cilia is necessary for epithelial cell signaling

Primary cilium projects from cells to provide a communication platform with neighboring cells and the surrounding environment. This is ensured by the selective entry of membrane receptors and signaling molecules, producing fine-tuned and effective responses to the extracellular cues. In this study, we focused on one family of signaling molecules, the fibroblast growth factor receptors (FGFRs), their residence within cilia, and its role in FGFR signaling. We show that FGFR1 and FGFR2, but not FGFR3 and FGFR4, localize to primary cilia of the developing mouse tissues and in vitro cells. For FGFR2, we demonstrate that the ciliary residence is necessary for its signaling and expression of target morphogenic genes. We also show that the pathogenic FGFR2 variants have minimal cilium presence, which can be rescued for the p.P253R variant associated with the Apert syndrome by using the RLY-4008 kinase inhibitor. Finally, we determine the molecular regulators of FGFR2 trafficking to cilia, including IFT144, BBS1, and the conserved T429V430 motif within FGFR2.

Design and Synthesis of New pyrazole Hybrids Linked to Oxime and Nitrate Moieties as COX-2, EGFRL858R/T790M Inhibitors and Nitric Oxide Donors with dual Anti-inflammatory/Anti-proliferative Activities

Two new series of pyrazole derivatives 14a-l and 17a-c with oxime/nitrate moieties as EGFRWT, mutant (EGFRL858R/T790M) and COX-2 inhibitors were synthesized and evaluated for anti-proliferative and anti-inflammatory activities. Compounds 14c, 14e, 14 g, 14i-l, 17b and 17c exhibited COX-2 selectivity in the range of (S.I. = 17-42) when compared to celecoxib (S.I. = 20.43). Concerning anti-neoplastic activity, screening was carried out against 60 human cancer cell lines by (NCI); Nine compounds (14c, 14e, 14 g, 14i-l, 17b and 17c) showed excellent inhibitory activity against all cancer cell lines especially non-small cell lung cancer (NSCLC). Further cytotoxicity testing of compounds 14c, 14e, 14 g, 14i-l, 17b and 17c was conducted on established EGFRT790M/L858R-resistant NSCLC (H1975), all tested compounds except 14 l exhibited potent activity (IC50 = 3.02-27.32 μM) which is higher than that of osimertinib (IC50 = 37.29 μM). It was noted that compound 17c, showed cell cycle arrest at G0/G1 phase of NSCLC (H1975) cells. In addition, compounds 14c, 14e, 14 g, 14i-l, 17b and 17c induced improved selective inhibitory activity against double mutant EGFRL858R/T790M tyrosine kinases with IC50 in the range of (0.031-0.076 μM, with selectivity index range S.I. of 2.5-14.58) which was comparable to that of osimertinib (IC50 = 0.037 μM, with S.I. of 1.89). The most potent anti-cancer compounds 14c, 14e, 14 g, 14i-l, 17b and 17c released NO in a slow rate of (1.45-3.37 %). Finally, applying covalent docking, we identified the covalent binding of 14 g, 14 k, and 17c with Cys797, providing insights into their potential as irreversible inhibitors targeting EGFRL858R/T790M protein.

Primary cilia and cancer: a tale of many faces

Cilia are microtubule-based sensory organelles which project from the cell surface, enabling detection of mechanical and chemical stimuli from the extracellular environment. It has been shown that cilia are lost in some cancers, while others depend on cilia or ciliary signaling. Several oncogenic molecules, including tyrosine kinases, G-protein coupled receptors, cytosolic kinases, and their downstream effectors localize to cilia. The Hedgehog pathway, one of the most studied ciliary-signaling pathways, is regulated at the cilium via an interplay between Smoothened (an oncogene) and Patched (a tumor suppressor), resulting in the activation of pro-survival programs. Interestingly, cilia loss can result in resistance to Smoothened-targeting drugs and increased cancer cell survival. On the other hand, kinase inhibitor-resistant and chemoresistant cancers have increased cilia and increased Hedgehog pathway activation, and suppressing cilia can overcome this resistance. How cilia regulate cancer is therefore context dependent. Defining the signaling output of cilia-localized oncogenic pathways could identify specific targets for cancer therapy, including the cilium itself. Increasing evidence implicates cilia in supporting several hallmarks of cancer, including migration, invasion, and metabolic rewiring. While cell cycle cues regulate the biogenesis of cilia, the absence of cilia has not been conclusively shown to affect the cell cycle. Thus, a complex interplay between molecular signals, phosphorylation events and spatial regulation renders this fascinating organelle an important new player in cancer through roles that we are only starting to uncover. In this review, we discuss recent advances in our understanding of cilia as signaling platforms in cancer and the influence this plays in tumor development.

Pearls and Updates on Pediatric Tyrosine Kinase-Altered Tumors

Receptor tyrosine kinases (RTKs) are crucial cell surface receptors that activate intracellular signaling pathways in response to external stimuli, regulating cell proliferation and survival. Under normal conditions, RTK activity is tightly regulated. In pediatric tumors, particularly mesenchymal neoplasms, chromosomal rearrangements are the primary mechanism of RTK-driven oncogenesis, involving genes like NTRK1/2/3, ALK, ROS1, RET, EGFR, and PDGFRB. This review highlights recent advances in understanding RTK-driven myofibroblastic tumors, focusing on the molecular characteristics that influence their classification and clinical behavior. Integration of morphologic, immunophenotypic, and molecular information is essential for accurate diagnosis, given the complex overlap among these tumors.

BRD4-targeted photodegradation nanoplatform for light activatable melanoma therapy

The targeted protein degradation (TPD) strategy modulates tumor growth pathways by degrading proteins of interest (POIs) and has reshaped anti-tumor drug research and development. Recently, the emergence of photodegradation-targeting chimeras (PDTACs) and laser irradiation at specific sites enables precise spatiotemporal controllability of TPD. Capitalizing on the advances of PDTACs, herein, we report a nanoplatform for efficiently delivering PDTAC molecule for photodegradation of bromodomain-containing protein 4 (BRD4) proteins, the key activators of oncogenic transcription. The PDTAC molecule, named as PPa-JQ1, is synthesized through the covalent attachment of the BRD4-targeting ligand JQ1-acid, to the photosensitizer pyropheophorbide-a (PPa), utilizing a 1,6-hexanediamine linker. The PPa-JQ1 is further encapsulated by human serum albumin (HSA) to obtain the HSA@PPa-JQ1 nanoplatform, which facilitates targeted and efficacious delivery to melanoma lesions. Both in vitro and in vivo therapeutic outcomes demonstrate that HSA@PPa-JQ1 can efficiently generate reactive oxygen species (ROS) to degrade BRD4 upon light irradiation, which eventually induces tumor death. Our study represents the first case to validate the anti-tumor therapeutic efficacy of PDTACs by systemic administration, providing the foundation for further application of PDTACs.

Identification and validation a novel kinase-related gene signature for predicting prognosis and responsiveness to immunotherapy in hepatocellular carcinoma

Liver cancer research highlights the kinome's critical role in disease initiation and progression. However, comprehensive data analysis on the kinome's impact on hepatocellular carcinoma (HCC) prognosis is limited. We used the TCGA-LIHC mRNA expression profiles, analyzing them with various R packages. Key methods included univariate Cox regression for prognostic gene identification, consensus clustering for subtype classification, Gene Set Enrichment Analysis (GSEA), and immune landscape evaluation. A prognostic model was developed using LASSO Cox regression, and chemotherapy drug sensitivity was assessed using the pRRophetic package. We identified 45 kinases-related differentially expressed genes (DEGs), with 27 linked to HCC prognosis. Cluster analysis divided these genes into two subtypes, with distinct prognoses. We discovered 157 DEGs between kinase-related subtypes, 120 of which were prognostically relevant. A kinase-related gene signature (KRS) was developed for prognostic prediction. The high-KRS group showed poorer survival in TCGA-LIHC and validation cohorts, with notable differences in immune cell infiltration and checkpoint gene expression. This group also showed varying sensitivity to common drugs and anti-PD-L1 treatment. In contrast, the low-KRS group might respond better to anti-PD-1 immunotherapy. Our study introduces a kinase-related gene signature as a novel tool for predicting HCC prognosis. This signature aids in tailoring personalized treatment strategies, potentially improving clinical outcomes in HCC patients.

Synergistic targeting strategies for prostate cancer

Prostate cancer is the second most commonly diagnosed cancer and the fifth leading cause of death among men worldwide. Androgen deprivation therapy is a common prostate cancer treatment, but its efficacy is often hindered by the development of resistance, which results in reducing survival benefits. Immunotherapy showed great promise in treating solid tumours; however, clinically significant improvements have not been demonstrated for patients with prostate cancer, highlighting specific drawbacks of this therapeutic modality. Hence, exploring novel strategies to synergistically enhance the efficacy of prostate cancer immunotherapy is imperative. Clinical investigations have focused on the combined use of targeted or gene therapy and immunotherapy for prostate cancer. Notably, tumour-specific antigens and inflammatory mediators are released from tumour cells after targeted or gene therapy, and the recruitment and infiltration of immune cells, including CD8+ T cells and natural killer cells activated by immunotherapy, are further augmented, markedly improving the efficacy and prognosis of prostate cancer. Thus, immunotherapy, targeted therapy and gene therapy could have reciprocal synergistic effects in prostate cancer in combination, resulting in a proposed synergistic model encompassing these three therapeutic modalities, presenting novel potential treatment strategies for prostate cancer.

Dermatomyofibromas harbor PDGFRB mutations - another tyrosine kinase-driven neoplasm

Platelet-derived growth factor receptor beta (PDGFRB) is one of the numerous members of the receptor tyrosine kinase protein family. When altered, it is known to be the driver mutation in different mesenchymal neoplasms, such as pericytic tumors, inflammatory myofibroblastic tumor, and sarcomas with myogenic differentiation. We investigated seven dermatomyofibromas for the presence of a PDGFRB mutation. Patients were 6 females and 1 male. Ages ranged from 2 to 59 years. Neoplasms were located in the shoulder (2), neck (2), upper arm (1), knee (1), and calf (1). Clinically, they appeared as ill-defined plaques. Complete excision was performed in four cases. In three cases, only a biopsy was taken. Histomorphologically, these dermal ill-defined tumors consisted of fascicles of slender myofibroblastic cells oriented often parallel to the epidermis. Their nuclei were monomorphic and elongated, and the cytoplasm was inconspicuous. Involvement of the superficial subcutis was seen in four cases. Immunohistochemically, neoplasms expressed SMA (5/7), focally desmin (1/5), and CD34 (4/6), while S100 was lacking (0/7). By DNA or RNA sequencing, PDGFRB activating mutations were identified in 6/7 tumors. Four neoplasms harbored a mutation in exon 12 encoding for the juxtamembrane domain and 2 neoplasms in exon 14 encoding for the tyrosine kinase domain. Sequencing analyses results highlight that these benign skin tumors belong to the broad spectrum of tyrosine kinase-driven neoplasms.

Invadopodia in cancer metastasis: dynamics, regulation, and targeted therapies

Pseudopodia and invadopodia are dynamic, actin-rich membrane structures extending from the cell surface. While pseudopodia are found in various cell types, invadopodia are exclusive to tumor cells and play a key role in cancer progression. These specialized structures enable tumor cells to degrade the extracellular matrix, breach tissue barriers, and invade surrounding tissues and blood vessels, thus facilitating metastasis. Extensive research has elucidated the distinct structure of invadopodia, the signaling pathways driving their formation, and their interaction with the tumor microenvironment. Integrin- and Src kinase-mediated signaling pathways regulate invadopodia dynamics. This review explores the mechanisms underlying invadopodia stabilization and highlights recent insights into their regulation by the tumor microenvironment. Particular emphasis is placed on the role of cell surface signaling in modulating invadopodia activity and the intracellular targeting of matrix metalloproteinases (MMPs) in enhancing invasive potential. A deeper understanding of invadopodia-driven cancer cell migration and metastasis provides valuable implications for therapeutic development. These findings support the potential for receptor-mediated and molecularly targeted therapies to inhibit tumor metastasis, improve clinical outcomes, and enhance the efficacy of existing cancer treatments.

Exploring the therapeutic potential of ligand-decorated nanostructured lipid carriers for targeted solid tumor therapy

Solid tumors present significant therapeutic challenges due to their complex pathophysiology, including poor vascularization, dense extracellular matrix, multidrug resistance, and immune evasion. Conventional treatment strategies, such as chemotherapy, radiotherapy, and surgical interventions, are often associated with systemic toxicity, suboptimal drug accumulation at the tumor site, and chemoresistance. Nanostructured lipid carriers (NLCs) have emerged as a promising approach to enhance anticancer therapy. NLCs offer several advantages, including high drug loading capacity, improved bioavailability, controlled release, and enhanced stability. Recent advancements in active targeting strategies have led to the development of ligand-decorated NLCs, which exhibit selective tumor targeting, improved cellular uptake, and reduced systemic toxicity. By functionalizing NLCs with different targeting ligands, site-specific drug delivery can be achieved for better therapeutic efficacy. This review comprehensively explores the potential of ligand-decorated NLCs in solid tumor therapy, highlights their design principles, and mechanisms of tumor targeting. Furthermore, it discusses various receptor-targeted NLCs for the effective treatment of solid tumors. The potential of ligand-decorated NLCs in combination therapy, gene therapy, photothermal therapy, and photodynamic therapy is also explored. Overall, ligand-decorated NLCs represent a versatile and effective strategy to achieve better therapeutic outcomes in solid tumor therapy.

The Molecular Basis of Pediatric Brain Tumors: A Review with Clinical Implications

Central nervous system (CNS) tumors are the most common solid malignancy in the pediatric population. These lesions are the result of the aberrant cell signaling step proteins, which normally regulate cell proliferation. Mitogen-activated protein kinase (MAPK) pathways and tyrosine kinase receptors are involved in tumorigenesis of low-grade gliomas. High-grade gliomas may carry similar mutations, but loss of epigenetic control is the dominant molecular event; it can occur either due to histone mutations or inappropriate binding or unbinding of DNA on histones. Therefore, despite the absence of genetic alteration in the classic oncogenes or tumor suppressor genes, uncontrolled transcription results in tumorigenesis. Isocitric dehydrogenase (IDH) mutations do not predominate compared to their adult counterpart. Embryonic tumors include medulloblastomas, which bear mutations of transcription-regulating pathways, such as wingless-related integration sites or sonic hedgehog pathways. They may also relate to high expression of Myc family genes. Atypical teratoid rhabdoid tumors harbor alterations of molecules that contribute to ATP hydrolysis of chromatin. Embryonic tumors with multilayered rosettes are associated with microRNA mutations and impaired translation. Ependymomas exhibit great variability. As far as supratentorial lesions are concerned, the major events are mutations either of NFkB or Hippo pathways. Posterior fossa tumors are further divided into two types with different prognoses. Type A group is associated with mutations of DNA damage repair molecules. Lastly, germ cell tumors are a heterogeneous group. Among them, germinomas manifest KIT receptor mutations, a subgroup of the tyrosine kinase receptor family.

Single-molecule localization microscopy as a tool to quantify di/oligomerization of receptor tyrosine kinases and G protein-coupled receptors

Dimerization and oligomerization of membrane receptors, including G protein-coupled receptors and receptor tyrosine kinases, are fundamental for regulating cell signaling and diversifying downstream responses to mediate a range of physiological processes. Receptor di/oligomers play roles in diverse facets of receptor function. Changes in receptor di/oligomers have been implicated in a range of diseases; therefore, better understanding of the specific composition and interactions between receptors in complexes is essential, especially for the development of di/oligomer-specific drugs. Previously, different optical microscopy approaches and proximity-based biophysical assays have been used to demonstrate di/oligomerization of membrane receptors. However, in recent years, single-molecule super-resolution microscopy techniques have allowed researchers to quantify and uncover the precise dynamics and stoichiometry of specific receptor complexes. This allows the organization of membrane protein receptors to be mapped across the plasma membrane to explore the effects of factors such as ligands, effectors, membrane environment, and therapeutic agents. Quantification of receptor complexes is required to better understand the intricate balance of distinct receptor complexes in cells. In this brief review, we provide an overview of single-molecule approaches for the quantification of receptor di/oligomerization. We will discuss the techniques commonly employed to study membrane receptor di/oligomerization and their relative advantages and limitations. SIGNIFICANCE STATEMENT: Receptor di/oligomerization plays an important role in their function. For some receptors, di/oligomerization is essential for functional signaling, whereas for others, it acts as a mechanism to achieve signaling pleiotropy. Aberrant receptor di/oligomerization has been implicated in a wide range of diseases. Single-molecule super-resolution microscopy techniques provide convincing methods to precisely quantify receptor complexes at the plasma membrane. Understanding receptor complex organization in disease models can also influence the targeting of specific monomeric or oligomeric complexes in therapeutic strategies.

Engineering aptamer-directed phosphatase recruiting chimeras: a strategy for modulating receptor function and overcoming drug resistance

Receptor tyrosine kinases (RTKs) play a crucial role in the regulation of intracellular signal transduction, underscoring their significance as targets for drug therapy. Despite the widespread clinical use of kinase inhibitors, the increasing occurrence of off-target effects and drug resistance makes it urgent to explore alternative approaches to modulate RTKs functions. Here, we propose an approach for attenuating cell-surface receptor signaling, termed Aptamer-directed Phosphatase Recruiting Chimeras (Apt-PRCs). The Apt-PRC is composed of an aptamer to recruit phosphatases and a binder to target receptors. As a proof-of-concept, we design and construct Apt-PRCs intended for direct dephosphorylation of tyrosine residues on the receptor targets, i.e., epidermal growth factor receptor and mesenchymal-epithelial transition factor, respectively. The as-developed Apt-PRCs manage to inhibit specifically and efficiently the reception and transmission of phosphorylation signals both in vitro and in vivo. Furthermore, it is discovered that the induced dephosphorylation could enhance the susceptibility to gefitinib in drug-resistant cancer cells and a xenograft mouse model, indicating the potential of Apt-PRCs to overcome drug resistance in cancer. This work offers a versatile methodology to design molecular mediators to modulate receptor phosphorylation so as to regulate the downstream signal transduction and overcome drug resistance.

Differential Response and Resistance to KRAS-Targeted Therapy

KRAS is the most frequently mutated oncogene. In epithelial malignancies such as lung, colorectal, and pancreatic tumors, KRAS is mutated in 25 to above 90% cases. KRAS was considered undruggable for over three decades until the recent development of covalent inhibitors targeting the KRAS G12C mutant. The recent approval of the KRAS G12C inhibitors sotorasib and adagrasib has ushered in a new era of KRAS-targeted therapy. Despite this success, a major challenge in KRAS-targeted therapy is intrinsic and acquired resistance to KRAS inhibitors. Clinical studies have shown that many patients with KRAS G12C cancers did not respond to sotorasib and adagrasib. Colorectal cancer, in particular, has a markedly lower response rate to KRAS G12C inhibitors compared to non-small cell lung cancer. Furthermore, the therapeutic response to KRAS G12C inhibition was short-lived, with quick emergence of acquired resistance. In this review, we summarize several major themes that have emerged from recent clinical and preclinical studies on the mechanisms of intrinsic and acquired resistance to KRAS-targeted therapy in colorectal, lung, and pancreatic cancers. We also discuss various combination strategies for targeting these mechanisms to overcome resistance to KRAS inhibitors.

BRAF Targeting Across Solid Tumors: Molecular Aspects and Clinical Applications

BRAF mutations are critical drivers in cancers such as melanoma, colorectal cancer, and non-small-cell lung cancer. The most common mutation, BRAF V600E, is a key therapeutic target. Targeted treatments with BRAF and MEK inhibitors have significantly improved progression-free and overall survival in melanoma patients. However, in cancers like metastatic colorectal cancer, BRAF mutations are associated with poor outcomes due to aggressive disease behavior and resistance to conventional chemotherapy. Despite progress, resistance to BRAF/MEK inhibitors remains a major challenge, often driven by secondary mutations in the mitogen-activated protein kinase (MAPK) pathway, activation of alternative pathways such as phosphoinositide 3-kinases (PI3Ks)/protein kinase B (AKT), or changes in the tumor microenvironment. These challenges have motivated ongoing research into combining BRAF inhibitors with immunotherapies to enhance and prolong treatment effectiveness. Future research must also account for the role of the cancer's tissue of origin, as the biological context significantly influences response to targeted therapies, highlighting the need for a deeper understanding of tumor biology, micro-environment, and genetics.

Kinase-Targeted Therapies for Glioblastoma

Protein phosphorylation and dephosphorylation are key mechanisms that regulate cellular activities. The addition or removal of phosphate groups by specific enzymes, known as kinases and phosphatases, activates or inhibits many enzymes and receptors involved in various cell signaling pathways. Dysregulated activity of these enzymes is associated with various diseases, predominantly cancers. Synthetic and natural single- and multiple-kinase inhibitors are currently being used as targeted therapies for different tumors, including glioblastoma. Glioblastoma IDH-wild-type is the most aggressive brain tumor in adults, with a median overall survival of 15 months. The great majority of glioblastoma patients present mutations in receptor tyrosine kinase (RTK) signaling pathways responsible for tumor initiation and/or progression. Despite this, the multi-kinase inhibitor regorafenib has only recently been approved for glioblastoma patients in some countries. In this review, we analyze the history of kinase inhibitor drugs in glioblastoma therapy.

The state of targeted therapeutic pharmacological approaches in pediatric neurosurgery: report from the European Society for Pediatric Neurosurgery (ESPN) Consensus Conference 2024

OBJECTIVE

The development of novel targeted therapies is opening new perspectives in the treatment of pediatric brain tumors. Their precise role in therapeutic protocols still needs still to be defined. Thus, these novel pharmacological approaches in pediatric neurosurgery were the topic of the European Society for Pediatric Neurosurgery (ESPN) Consensus Conference held in Lyon (France) in January 25-27, 2024.

METHOD

The paper reviews the current knowledge about targeted therapy as well as the current literature published on the topic. The conference aimed for an interdisciplinary consensus debate among pediatric oncologists and pediatric neurosurgeons on the following questions. Question 1: What is the current role for targeted therapies as neoadjuvant treatments before pediatric brain tumor removal? Question 2: What are the benefits, cost/efficiency, and long-term side effects of targeted therapies in the treatment of pediatric brain tumors? Question 3: Based on contemporary data, at which stage and in which pathologies do targeted therapies play a significant role?

RESULTS

Ninety-two participants answered consensus polls on the state of the art of targeted therapies, the ethical issues related to their use, and the evolving change in the role of pediatric neurosurgeons. The neoadjuvant role of targeted therapies is difficult to define as there are many different entities to consider. Despite the recently reported potential benefits, questions regarding the use of targeted therapies are manifold, in particular regarding sustainable benefits and long-term side effects. Additionally, challenging cost issues is a limiting factor for the broader availability of these drugs. Studies have demonstrated superiority of targeted therapy compared to chemotherapy both in randomized trials and compared to historical cohorts in the management of a subset of low-grade gliomas. The same drug combinations, BRAFi and MEKi, may be effective in HGG that have relapsed, progressed, or failed to respond to first-line therapy. Similar conclusions on efficacy may be drawn for mTORi in TSC and selumetinib in plexiform neurofibromas. For other tumors, the picture is still obscure due to the lack of data or even the lack of suitable targets. In conclusion, targeted treatment may not always be the best option even when a target has been identified. Safe surgery remains to be a favorable option in the majority of cases.

CONCLUSION

The constantly evolving drug technology and the absence of long-term safety and efficacy studies made it difficult to reach a consensus on the predefined questions. However, a report of the conference is summarizing the present debate and it might serve as a guideline for future perspectives and ongoing research.

The Research Progress of Neurotrophic Tyrosine Receptor Kinase (NTRK) Gene Fusions and Tropomyosin Receptor Kinase (TRK) Inhibitors: A Narrative Review

NTRK gene is responsible for encoding TRK, which consists of three family members: NTRK1, NTRK2, and NTRK3. These family members encode different proteins known as TRKA, TRKB, and TRKC, respectively. NTRK fusion genes are the clearest driving factor for carcinogenesis. NTRK gene fusion detection and TRK inhibitors are effective measures for the treatment of malignant tumors. The development of anti-tumor drugs targeting TRK proteins has been favored by various scientific research institutions and pharmaceutical companies. The first-generation TRK inhibitors, larotrectinib and entrectinib, have been approved for the treatment of pediatric and adult patients with metastatic or locally advanced solid tumors harboring NTRK fusion proteins, demonstrating remarkable anticancer efficacy in clinical settings. However, the issue of acquired resistance to TRK inhibitors has emerged. Currently, efforts are underway to develop next-generation TRK inhibitors based on sequence, structural, and kinetic methodologies, as well as to explore the intracellular signaling pathways of TRK and the mechanisms underlying resistance. The main focus of this review was to discuss the fusion of NTRK genes and the application of TRK inhibitor treatment.

Anti-EGFR therapy can overcome acquired resistance to the third-generation ALK-tyrosine kinase inhibitor lorlatinib mediated by activation of EGFR

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related mortality. Anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) are standard treatments for EML4-ALK-positive NSCLC, but resistance to these agents remains a challenge. This study aimed to determine the mechanisms of acquired resistance to the third-generation ALK-TKI lorlatinib. Lorlatinib-resistant cell lines were established by prolonged exposure to a high concentration of lorlatinib. Activation of epidermal growth factor receptor (EGFR) caused by a decrease in endocytosis and degradation of protein was demonstrated to play an essential role in acquired resistance to lorlatinib. The interaction between the EGFR and ALK was investigated to identify binding sites and conformational changes in ALK. We performed high-throughput compound screening using a small-molecule drugs library comprising 510 antitumor agents in an effort to discover small-molecule compounds that target EGFR in lorlatinib-resistant cells. Combination treatment with ALK-TKI and anti-EGFR agents suppressed acquired resistance to ALK-TKIs caused by activation of EGFR in vitro and in vivo, suggesting that the combination of lorlatinib and an anti-EGFR agent could be effective in patients with lorlatinib-resistant NSCLC. This research provides insights into the mechanism of resistance to lorlatinib and suggests that it can be overcome by anti-EGFR treatment, offering a promising approach for treating resistance to lorlatinib mediated by EGFR activation in patients with ALK-positive NSCLC.

A visualization analysis of global research trends in targeted therapies for thyroid carcinoma (2013-2023)

This study aims to analyze and identify primary research trends in targeted therapy for thyroid carcinoma (TC). It seeks to provide a factual foundation for researchers, as TC often presents with advanced stages and aggressive subtypes, leading to unfavorable clinical outcomes. The evolution of targeted therapies introduces promising treatment possibilities, necessitating a bibliometric analysis to better understand the current state and trends in this field. A comprehensive bibliometric analysis was conducted using data from the Web of Science Core Collection (WOSCC). Advanced search queries established a literature database, and the analysis was performed using tools such as VOSviewer, CiteSpace, Tableau, and Microsoft Excel. The study focused on publications from 2013 to 2023, examining patterns, geographical contributions, institutional output, and influential journals. The analysis identified 763 publications on TC targeted therapy during the study period, with significant contributions from the United States, China, and Italy, and the United States leading in output. Research activity peaked in 2021, showing overall fluctuating growth. Key contributing institutions included the University of Texas MD Anderson Cancer Center and the University of Pisa. Notable journals, such as Cancers and Thyroid, were among the most cited, underscoring their impact in the field. The study highlighted an increase in global research output and robust international collaborations, particularly among the leading contributing countries. This bibliometric analysis provides a comprehensive overview of significant contributions and trends in targeted therapy research for TC. It identifies key development processes and research hotspots, offering valuable insights to guide future research directions. The findings aim to stimulate further studies and foster advancements in this critical area of oncology.

CD105 blockade restores osimertinib sensitivity in drug-resistant EGFR-mutant non-small cell lung cancer

AIM

To investigate the role of CD105 in mediating drug resistance to EGFR-targeted therapy in non-small cell lung cancer (NSCLC).

METHODS

Imaging mass cytometry was conducted on 66 NSCLC tumors, 44 of which had EGFR mutations. We correlated clinical variables, including overall survival, with CD105 (endoglin) expression, a co-receptor for bone morphogenetic protein (BMP) signaling. Two osimertinib-resistant EGFR-mutant cell lines were developed to study the effects of EGFR and CD105 disruption. Single cell RNA sequencing of the isogenic parental and osimertinib resistant lines was performed. Additionally, ATAC sequencing and Single Cell ENergetIc metabolism by profiling Translation inHibition analysis (SCENITH) was used to assess promoter chromatin status and glycolytic state.

RESULTS

We found a negative correlation between CD105 expression and overall survival in patients. Treatment with osimertinib or EGFR knockdown significantly elevated CD105 expression in EGFR-mutant cell lines. Single-cell RNA sequencing identified a subset of cells with heightened endothelial characteristics and altered pyrimidine metabolism, associated with osimertinib resistance. These cells exhibited a slow-cycling behavior, characterized by elevated chromatin condensation and reduced glycolysis. Combining osimertinib with carotuximab, a CD105 neutralizing antibody, significantly reduced the slow-cycling transcriptomic signature, increased chromatin accessibility, and restored glycolysis compared to osimertinib treatment alone. Mass spectrometry confirmed that carotuximab re-engaged EGFR signaling by coupling it with CD105. Consequently, carotuximab re-sensitized resistant tumors to osimertinib by increasing their mitotic index and ERK signaling in mouse models.

CONCLUSION

Carotuximab effectively reduced the slow-cycling cell population and restored osimertinib sensitivity, offering a promising strategy for managing refractory NSCLC.

Old drugs, new challenges: reassigning drugs for cancer therapies

The "War on Cancer" began with the National Cancer Act of 1971 and despite more than 50 years of effort and numerous successes, there still remains much more work to be done. The major challenge remains the complexity and intrinsic polygenicity of neoplastic diseases. Furthermore, the safety of the antitumor therapies still remains a concern given their often off-target effects. Although the amount of money invested in research and development required to introduce a novel FDA-approved drug has continuously increased, the likelihood for a new cancer drug's approval remains limited. One interesting alternative approach, however, is the idea of repurposing of old drugs, which is both faster and less costly than developing new drugs. Repurposed drugs have the potential to address the shortage of new drugs with the added benefit that the safety concerns are already established. That being said, their interactions with other new drugs in combination therapies, however, should be tested. In this review, we discuss the history of repurposed drugs, some successes and failures, as well as the multiple challenges and obstacles that need to be addressed in order to enhance repurposed drugs' potential for new cancer therapies.

New Gain-of-Function Mutations Prioritize Mechanisms of HER2 Activation

ERBB2 (HER2) is a well-studied oncogene with several driver mutations apart from the well-known amplification defect in some breast cancers. We used the GigaAssay to test the functional effect of HER2 missense mutations on its receptor tyrosine kinase function. The GigaAssay is a modular high-throughput one-pot assay system for simultaneously measuring molecular function of thousands of genetic variants at very high accuracy. The activities of 5,886 mutations were classified, significantly more than mutants previously reported. These variants include 112 new in vitro, 10 known, and 9 new in vivo gain-of-function (GOF) mutations. Many of the GOFs spatially cluster in sequence and structure, supporting the activation mechanisms of heterodimerization with EGFR and release of kinase inhibition by the juxtamembrane domain. Retrospective analysis of patient outcomes from the Genomic Data Commons predicts increased survival with the newly identified HER2 GOF variants.

BRAF V600E in cancer: Exploring structural complexities, mutation profiles, and pathway dysregulation

BRAF, a fundamental component of cellular signaling pathways regulating growth and survival, is frequently mutated in cancer development. Among entire BRAF mutations, the V600E substitution stands out as a dominant alteration in various malignancies, including melanoma, colorectal cancer, and thyroid cancer. Understanding the structural differences between wild-type BRAF and BRAFV600E is crucial for elucidating the molecular mechanisms underpinnings tumorigenesis and identifying dysregulation associated with the same. V600E mutation results in a constitutively active kinase domain, leading to dysregulated downstream signaling independent of extracellular stimuli. This sustained activation promotes cell proliferation, survival, angiogenesis, and hallmark features of the cancer cells. The study describes three distinct classes of BRAF mutations where Class 1 mutations predominantly involve point mutations within the BRAF gene, while Class 2 encompasses in-frame insertions and deletions, and Class 3 comprises gene fusions with large-scale chromosomal rearrangements. Further, we have discussed dysregulated pathways associated with mutation of BRAFV600E, which includes MAPK/ERK, PI3K/AKT/mTOR, TP53, DNA damage response, and WNT/β-Catenin from schematic representation. In the current review, we have shown how these dysregulated pathways play pivotal roles in tumorigenesis, tumor progression in BRAF-mutant cancers and highlighted the critical role of BRAF dysregulation in cancer development followed by its therapeutic implications of targeting dysregulated pathways in BRAF-driven malignancies.

The radiogenomic and spatiogenomic landscapes of glioblastoma and their relationship to oncogenic drivers

BACKGROUND

Glioblastoma is a highly heterogeneous brain tumor, posing challenges for precision therapies and patient stratification in clinical trials. Understanding how genetic mutations influence tumor imaging may improve patient management and treatment outcomes. This study investigates the relationship between imaging features, spatial patterns of tumor location, and genetic alterations in IDH-wildtype glioblastoma, as well as the likely sequence of mutational events.

METHODS

We conducted a retrospective analysis of 357 IDH-wildtype glioblastomas with pre-operative multiparametric MRI and targeted genetic sequencing data. Radiogenomic signatures and spatial distribution maps were generated for key mutations in genes such as EGFR, PTEN, TP53, and NF1 and their corresponding pathways. Machine and deep learning models were used to identify imaging biomarkers and stratify tumors based on their genetic profiles and molecular heterogeneity.

RESULTS

Here, we show that glioblastoma mutations produce distinctive imaging signatures, which are more pronounced in tumors with less molecular heterogeneity. These signatures provide insights into how mutations affect tumor characteristics such as neovascularization, cell density, invasion, and vascular leakage. We also found that tumor location and spatial distribution correlate with genetic profiles, revealing associations between tumor regions and specific oncogenic drivers. Additionally, imaging features reflect the cross-sectionally inferred evolutionary trajectories of glioblastomas.

CONCLUSIONS

This study establishes clinically accessible imaging biomarkers that capture the molecular composition and oncogenic drivers of glioblastoma. These findings have potential implications for noninvasive tumor profiling, personalized therapies, and improved patient stratification in clinical trials.

Unveiling the Complexity of cis-Regulation Mechanisms in Kinases: A Comprehensive Analysis

Protein cis-regulatory elements (CREs) are regions that modulate the activity of a protein through intramolecular interactions. Kinases, pivotal enzymes in numerous biological processes, often undergo regulatory control via inhibitory interactions in cis. This study delves into the mechanisms of cis regulation in kinases mediated by CREs, employing a combined structural and sequence analysis. To accomplish this, we curated an extensive dataset of kinases featuring annotated CREs, organized into homolog families through multiple sequence alignments. Key molecular attributes, including disorder and secondary structure content, active and ATP-binding sites, post-translational modifications, and disease-associated mutations, were systematically mapped onto all sequences. Additionally, we explored the potential for conformational changes between active and inactive states. Finally, we explored the presence of these kinases within membraneless organelles and elucidated their functional roles therein. CREs display a continuum of structures, ranging from short disordered stretches to fully folded domains. The adaptability demonstrated by CREs in achieving the common goal of kinase inhibition spans from direct autoinhibitory interaction with the active site within the kinase domain, to CREs binding to an alternative site, inducing allosteric regulation revealing distinct types of inhibitory mechanisms, which we exemplify by archetypical representative systems. While this study provides a systematic approach to comprehend kinase CREs, further experimental investigations are imperative to unravel the complexity within distinct kinase families. The insights gleaned from this research lay the foundation for future studies aiming to decipher the molecular basis of kinase dysregulation, and explore potential therapeutic interventions.

Reciprocal regulation of MMP-28 and EGFR is required for sustaining proliferative signaling in PDAC

BACKGROUD

Sustaining proliferation signaling is the top hallmarks of cancer, driving continuous tumor growth and resistance to drug treatments. Blocking proliferation signaling has shown limited benefit in clinical treatment of pancreatic ductal adenocarcinoma, highlighting the urgent need to deeply understand proliferation signaling and develop new therapeutic strategies.

METHODS

By leveraging clinical data and data from the TCGA and GDSC datasets, we investigated the association between MMP-28 expression and the sensitivity to EGFR inhibitors as well as the prognosis of PDAC. Transcriptomic and biological experiments explore the regulatory role of MMP-28 on the EGFR signaling pathway. Additionally, in vitro and in vivo studies are employed to evaluate MMP-28 as a biomarker for sensitivity to EGFR inhibitors.

RESULTS

We found that MMP-28, a metalloproteinase, was significantly associated with the sensitivity to EGFR inhibitors. Furthermore, MMP-28 could promote PDAC growth and metastasis. Mechanistically, MMP-28 facilitated the maturation and release of the TGF-α precursor, thus promoting EGFR activation. In return, EGFR upregulated MMP-28 through AP-1-mediated transcription, forming a positive feedback loop that provided sustaining proliferation signaling for PDAC. Subsequently, MMP-28 was identified to predict the response to EGFR inhibitors and recognize responsive patients.

CONCLUSIONS

Our findings revealed the role of MMP-28 and EGFR in generation of sustaining proliferation signaling and provided a new therapy strategy for PDAC.

Progress in the discovery and development of anticancer agents from marine cyanobacteria

Covering 2010-April 2024There have been tremendous new discoveries and developments since 2010 in anticancer research based on marine cyanobacteria. Marine cyanobacteria are prolific sources of anticancer natural products, including the tubulin agents dolastatins 10 and 15 which were originally isolated from a mollusk that feeds on cyanobacteria. Decades of research have culminated in the approval of six antibody-drug conjugates (ADCs) and many ongoing clinical trials. Antibody conjugation has been enabling for several natural products, particularly cyanobacterial cytotoxins. Targeting tubulin dynamics has been a major strategy, leading to the discovery of the gatorbulin scaffold, acting on a new pharmacological site. Cyanobacterial compounds with different mechanisms of action (MOA), targeting novel or validated targets in a range of organelles, also show promise as anticancer agents. Important advances include the development of compounds with novel MOA, including apratoxin and coibamide A analogues, modulating cotranslational translocation at the level of Sec61 in the endoplasmic reticulum, largazole and santacruzamate A targeting class I histone deacetylases, and proteasome inhibitors based on carmaphycins, resembling the approved drug carfilzomib. The pipeline extends with SERCA inhibitors, mitochondrial cytotoxins and membrane-targeting agents, which have not yet advanced clinically since the biology is less understood and selectivity concerns remain to be addressed. In addition, efforts have also focused on the identification of chemosensitizing and antimetastatic agents. The review covers the state of current knowledge of marine cyanobacteria as anticancer agents with a focus on the mechanism, target identification and potential for drug development. We highlight the importance of solving the supply problem through chemical synthesis as well as illuminating the biological activity and in-depth mechanistic studies to increase the value of cyanobacterial natural products to catalyze their development.

Metformin inhibits the growth of SCLC cells by inducing autophagy and apoptosis via the suppression of EGFR and AKT signalling

Small cell lung cancer (SCLC) is a therapeutically challenging disease. Metformin, an effective agent for the treatment of type 2 diabetes, has been shown to have antitumour effects on many cancers, including non-small cell lung cancer (NSCLC) and breast cancer. Currently, the antitumour effects of metformin on SCLC and the underlying molecular mechanisms remain unclear. CCK-8, EdU, colony formation, flow cytometry, immunofluorescence, molecular docking, western blotting, nude mouse transplanted tumour model, and immunohistochemistry experiments were conducted to analyse gene functions and the underlying mechanism involved. In vitro experiments demonstrated that metformin inhibited the growth of SCLC cells (H446, H526, H446/DDP and H526/DDP), which was confirmed in xenograft mouse models in vivo. Additionally, metformin induced cell cycle arrest, apoptosis, and autophagy in these SCLC cells. The molecular docking results indicated that metformin has a certain binding affinity for EGFR. The western blotting results revealed that metformin decreased the expression of EGFR, p-EGFR, AKT, and p-AKT, which could be reversed by EGF and SC79. Moreover, metformin activated AMPK and inactivated mTOR, and compound C and SC79 increased the levels of p-mTOR. Metformin can not only enhance the antitumour effect of cisplatin but also alleviate the toxic effects of cisplatin on the organs of xenograft model animals. In summary, the current study revealed that metformin inhibits the growth of SCLC by inducing autophagy and apoptosis via suppression of the EGFR/AKT/AMPK/mTOR pathway. Metformin might be a promising candidate drug for combination therapy of SCLC.

EGF receptor in organ development, tissue homeostasis and regeneration

The epidermal growth factor receptor (EGFR) is a protein embedded in the outer membrane of epithelial and mesenchymal cells, bone cells, blood and immune cells, heart cells, glia and stem neural cells. It belongs to the ErbB family, which includes three other related proteins: HER2/ErbB2/c-neu, HER3/ErbB3, and HER4/ErbB4. EGFR binds to seven known signaling molecules, including epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-α). This binding triggers the formation of receptor pairs (dimers), self-phosphorylation of EGFR, and the activation of several signaling pathways within the cell. These pathways influence various cellular processes like proliferation, differentiation, migration, and survival. EGFR plays a critical role in both development and tissue homeostasis, including tissue repair and adult organ regeneration. Altered expression of EGFR is linked to disruption of tissue homeostasis and various diseases, among which cancer. This review focuses on how EGFR contributes to the development of different organs like the placenta, gut, liver, bone, skin, brain, T cell regulation, pancreas, kidneys, mammary glands and lungs along with their associated pathologies. The involvement of EGFR in organ-specific branching morphogenesis process is also discussed. The level of EGFR activity and its impact vary across different organs. Factors as the affinity of its ligands, recycling or degradation processes, and transactivation by other proteins or environmental factors (such as heat stress and smoking) play a role in regulating EGFR activity. Understanding EGFR's role and regulatory mechanisms holds promise for developing targeted therapeutic strategies.

Synthesis and Antitumor Activity of 6-(2-Aminobenzo[d]thiazol-5-yl) quinazolin-4(3H)-one Derivatives

Quinazolinones are key scaffolds in anticancer drug development. We previously identified the lead compound 16h from a series of 6-(1H-benzo[d]imidazol-6-yl) quinazolin-4(3H)-one derivatives. In this study, we optimized 16h to develop new 6-(2-aminobenzo[d]thiazol-5-yl) quinazolin-4(3H)-one derivatives, with compound 45 showing the best antiproliferative activity against A549 lung cancer cells (IC50: 0.44 μM) and good selectivity. Mechanistic studies revealed that compound 45 induced G1-phase arrest, inhibited ALK/PI3K/AKT signaling, disrupted mitochondrial membrane potential, and promoted apoptosis. It also significantly inhibited spheroid formation in a 3D cell culture model. In summary, the results suggest that compound 45 might have potential for the development of anticancer drugs.

Molecular biology of the novel anticancer medications: a focus on kinases inhibitors, biologics and CAR T-cell therapy

INTRODUCTION

Cancer treatment underwent significant changes in the last few years with the introduction of novel treatments targeting the immune system.

OBJECTIVES

The objective of this review is to discuss novel anticancer drugs including kinase inhibitors, biologics and cellular therapy with CAR-T cells.

METHODS

Most recent research articles were extracted from PubMed using keywords such as "kinases inhibitors", "CAR-T cell therapy".

RESULTS AND DISCUSSION

The number of kinase inhibitors is significantly increasing due to their demonstrated effectiveness in combination with biologics. CAR-T represented a major breakthrough in the field. Also, it focused on their mechanisms of action and the rational of their use either alone or in combination in relation to their modes of action.

Molecular principles underlying aggressive cancers

Aggressive tumors pose ultra-challenges to drug resistance. Anti-cancer treatments are often unsuccessful, and single-cell technologies to rein drug resistance mechanisms are still fruitless. The National Cancer Institute defines aggressive cancers at the tissue level, describing them as those that spread rapidly, despite severe treatment. At the molecular, foundational level, the quantitative biophysics discipline defines aggressive cancers as harboring a large number of (overexpressed, or mutated) crucial signaling proteins in major proliferation pathways populating their active conformations, primed for their signal transduction roles. This comprehensive review explores highly aggressive cancers on the foundational and cell signaling levels, focusing on the differences between highly aggressive cancers and the more treatable ones. It showcases aggressive tumors as harboring massive, cancer-promoting, catalysis-primed oncogenic proteins, especially through certain overexpression scenarios, as predisposed aggressive tumor candidates. Our examples narrate strong activation of ERK1/2, and other oncogenic proteins, through malfunctioning chromatin and crosslinked signaling, and how they activate multiple proliferation pathways. They show the increased cancer heterogeneity, plasticity, and drug resistance. Our review formulates the principles underlying cancer aggressiveness on the molecular level, discusses scenarios, and describes drug regimen (single drugs and drug combinations) for PDAC, NSCLC, CRC, HCC, breast and prostate cancers, glioblastoma, neuroblastoma, and leukemia as examples. All show overexpression scenarios of master transcription factors, transcription factors with gene fusions, copy number alterations, dysregulation of the epigenetic codes and epithelial-to-mesenchymal transitions in aggressive tumors, as well as high mutation loads of vital upstream signaling regulators, such as EGFR, c-MET, and K-Ras, befitting these principles.

Full-length transcriptome atlas of gallbladder cancer reveals trastuzumab resistance conferred by ERBB2 alternative splicing

Aberrant RNA alternative splicing in cancer generates varied novel isoforms and protein variants that facilitate cancer progression. Here, we employed the advanced long-read full-length transcriptome sequencing on gallbladder normal tissues, tumors, and cell lines to establish a comprehensive full-length gallbladder transcriptomic atlas. It is of note that receptor tyrosine kinases were one of the most dynamic components with highly variable transcript, with Erb-B2 receptor tyrosine kinase 2 (ERBB2) as a prime representative. A novel transcript, designated ERBB2 i14e, was identified for encoding a novel functional protein, and its protein expression was elevated in gallbladder cancer and strongly associated with worse prognosis. With the regulation of splicing factors ESRP1/2, ERBB2 i14e was alternatively spliced from intron 14 and the encoded i14e peptide was proved to facilitate the interaction with ERBB3 and downstream signaling activation of AKT. ERBB2 i14e was inducible and its expression attenuated anti-ERBB2 treatment efficacy in tumor xenografts. Further studies with patient derived xenografts models validated that ERBB2 i14e blockage with antisense oligonucleotide enhanced the tumor sensitivity to trastuzumab and its drug conjugates. Overall, this study provides a gallbladder specific long-read transcriptome profile and discovers a novel mechanism of trastuzumab resistance, thus ultimately devising strategies to improve trastuzumab therapy.

Enhancing non-viral DNA delivery systems: Recent advances in improving efficiency and target specificity

DNA-based therapies are often limited by challenges such as stability, long-term integration, low transfection efficiency, and insufficient targeted DNA delivery. This review focuses on recent progress in the design of non-viral delivery systems for enhancing targeted DNA delivery and modulation of therapeutic efficiency. Cellular uptake and intracellular trafficking mechanisms play a crucial role in optimizing gene delivery efficiency. There are two main strategies employed to improve the efficiency of gene delivery vectors: (i) explore different administration routes (e.g., mucosal, intravenous, intramuscular, subcutaneous, intradermal, intratumoural, and intraocular) that best facilitates optimal uptake into the targeted cells and organs and (ii) modify the delivery vectors with cell-specific ligands (e.g., natural ligands, antibodies, peptides, carbohydrates, or aptamers) that enable targeted uptake to specific cells with higher specificity and improved biodistribution. We describe how recent progress in employing these DNA delivery strategies is advancing the field and increasing the clinical translation and ultimate clinical application of DNA therapies.

Advances on the therapeutic potential of cell receptor activation in glioblastoma

Glioblastoma multiforme is the most common and aggressive malignant brain tumor. Current therapies have been unable to improve life expectancy in patients. This cancer is frequently accompanied by overexpression of receptors, such as EGFR, VEGFR and TLRs, involved in the regulation of inflammation, cell proliferation, differentiation, and survival. The present review summarizes current knowledge from preclinical and clinical studies investigating the role of pattern recognition and tyrosine kinase receptors in glioblastoma development and evolution, and their possible use to improve treatment outcomes and patient survival.

Implication of protein post translational modifications in gastric cancer

Gastric cancer (GC) is one of the most common and highly lethal malignant tumors worldwide, and its occurrence and development are regulated by multiple molecular mechanisms. Post-translational modifications (PTM) common forms include ubiquitylation, phosphorylation, acetylation and methylation. Emerging research has highlighted lactylation and glycosylation. The diverse realm of PTM and PTM crosstalk is linked to many critical signaling events involved in neoplastic transformation, carcinogenesis and metastasis. This review provides a comprehensive overview of the impact of PTM on the occurrence and progression of GC. Specifically, aberrant PTM have been shown to alter the proliferation, migration, and invasion capabilities of GC cells. Moreover, PTM are closely associated with resistance to chemotherapeutic agents in GC. Notably, this review also discusses the phenomenon of PTM crosstalk, highlighting the interactions among PTM and their roles in regulating signaling pathways and protein functions. Therefore, in-depth investigation into the mechanisms of PTM and the development of targeted therapeutic strategies hold promise for advancing early diagnosis, treatment, and prognostic evaluation of GC, offering novel insights and future research directions.

Current status and challenges in HER2 IHC assessment: scoring survey results in Japan

PURPOSE

This study aimed to assess the concordance of human epidermal growth factor receptor 2 (HER2) expression scoring by immunohistochemistry (IHC) among practicing pathologists in Japan, given the challenging nature of scoring and the critical role of HER2 status in breast cancer management.

METHODS

Whole slide images (WSI) from 20 invasive breast cancer cases (1 representative WSI per case) selected to represent a diverse IHC scores and staining patterns were used in an online survey involving seven reference pathologists who established consensus HER2 IHC scores (0 to 3 +) decided by majority interpretation. Participating pathologists nationwide scored the same 20 WSI cases online using the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) 2018 guidelines. Deidentified case metadata were registered in the uPath system.

RESULTS

A total of 144 participating pathologists responded. The scoring results of the participating pathologists most commonly agreed with the consensus IHC score, followed by a ± 1 point deviation and no survey responses with > 1 point deviation. The mean percentage of agreement with the consensus score for all 20 cases was 63.4%. In cases where the reference pathologists' scores were discordant, the participating pathologists also showed a lower concordance rate.

CONCLUSION

This study highlighted the current status of HER2 expression scoring by IHC for breast cancer among pathologists in Japan. These findings underscore the challenges in HER2 IHC scoring cases and emphasize the need for improved standardization and training, especially in the evolving landscape of HER2-targeted therapies.

New metal complexes of 1H-benzimidazole-2-yl hydrazones: Cytostatic, proapoptotic and modulatory activity on kinase signaling pathways

The copper complexes of two 1H-benzimidazole-2-yl hydrazones were obtained by complexation with copper chloride. The molecular structure of the complexes was studied by microchemical analysis, SEM-EDX, IR and micro-Raman spectroscopy and DFT calculations. It was found that both ligands form 1:1 complexes with the copper, where the Cu ions are coordinated by N-atom from the benzimidazole ring, N-atom of the azomethine bond, O-atom from the ortho-OH group of the aromatic ring and one chlorine atom. The coordination process significantly affected their cytotoxicity profile. The conversion of 2-(2-hydroxybenzylidene)-1-(1H-benzimidazol-2-yl)hydrazine 1.1. into a Cu complex 2.1. led to a 2.4-fold increase in its antileukemic activity against AR-230 cells and an 8-fold increase in the cytostatic activity against MCF-7 breast cancer cell line. The growth-inhibitory effect of the Cu complex of 2-(2-hydroxy-4-methoxybenzylidene)-1-(1H-benzimidazol-2-yl)hydrazine 2.2. on the MCF-7 cells was comparable to that of the respective ligand, however lacked towards the leukemic AR-230 cell population. Regarding their cytotoxic potential towards CCL-1 cells, both Cu complexes exhibited a weaker selectivity pattern as compared to their ligands. The proapoptotic and modulatory activity of 1.1 and 2.1. on key kinase signaling pathways was further studied in the ER + breast cancer (MCF-7) and bcr-abl + leukemic (AR-230) in vitro tumor models in a comparative manner to the reference drugs tamoxifen and imatinib, respectively. Inhibition of the JAK/STAT signaling pathway was outlined as a prominent mechanism in the antileukemic activity against the Ph + AR-230 in vitro model, whereas recruitment and activation of the extrinsic apoptotic pathway was established in the MCF-7 cells.

PAK2 as a therapeutic target in cancer: Mechanisms, challenges, and future perspectives

P21-activated kinases (PAKs) are crucial regulators within cellular signaling pathways and have been implicated in a range of human diseases, including cancer. Among the PAK family, PAK2 is widely expressed across various tissues and has emerged as a significant driver of cancer progression. However, systematic studies on PAK2 remain limited. This review provides a comprehensive overview of PAK2's role in cancer, focusing on its involvement in processes such as angiogenesis, metastasis, cell survival, metabolism, immune response, and drug resistance. We also explore its function in key cancer signaling pathways and the potential of small-molecule inhibitors targeting PAK2 for therapeutic purposes. Despite promising preclinical data, no PAK2 inhibitors have reached clinical practice, underscoring challenges related to their specificity and therapeutic application. This review highlights the biological significance of PAK2 in cancer and its interactions with critical signaling pathways, offering valuable insights for future research. We also discuss the major obstacles in developing PAK inhibitors and propose strategies to overcome these barriers, paving the way for their clinical translation.

Resistance to antibody-drug conjugates: A review

Antibody-drug conjugates (ADCs) are antitumor drugs composed of monoclonal antibodies and cytotoxic payload covalently coupled by a linker. Currently, 15 ADCs have been clinically approved worldwide. More than 100 clinical trials at different phases are underway to investigate the newly developed ADCs. ADCs represent one of the fastest growing classes of targeted antitumor drugs in oncology drug development. It takes advantage of the specific targeting of tumor-specific antigen by antibodies to deliver cytotoxic chemotherapeutic drugs precisely to tumor cells, thereby producing promising antitumor efficacy and favorable adverse effect profiles. However, emergence of drug resistance has severely hindered the clinical efficacy of ADCs. In this review, we introduce the structure and mechanism of ADCs, describe the development of ADCs, summarized the latest research about the mechanisms of ADC resistance, discussed the strategies to overcome ADCs resistance, and predicted biomarkers for treatment response to ADC, aiming to contribute to the development of ADCs in the future.

Molecular biology of cholangiocarcinoma and its implications for targeted therapy in patient management

Cholangiocarcinoma (CCA) remains a devastating malignancy and a significant challenge to treat. The majority of CCA patients are diagnosed at an advanced stage, making the disease incurable in most cases. The advent of high-throughput genetic sequencing has significantly improved our understanding of the molecular biology underpinning cancer. The identification of 'druggable' genetic aberrations and the development of novel targeted therapies against them is opening up new treatment strategies. Currently, 3 targeted therapies are approved for use in CCA; Ivosidenib in patients with IDH1 mutations and Infigratinib/Pemigatinib in those with FGFR2 fusions. As our understanding of the biology underpinning CCA continues to improve it is highly likely that additional targeted therapies will become available in the near future. This is important, as it is thought up to 40 % of CCA patients harbour a potentially actionable mutation. In this review we provide an overview of the molecular pathogenesis of CCA and highlight currently available and potential future targeted treatments.

Manipulating the EphB4-ephrinB2 axis to reduce metastasis in HNSCC

The EphB4-ephrinB2 signaling axis has been heavily implicated in metastasis across numerous cancer types. Our emerging understanding of the dichotomous roles that EphB4 and ephrinB2 play in head and neck squamous cell carcinoma (HNSCC) poses a significant challenge to rational drug design. We find that EphB4 knockdown in cancer cells enhances metastasis in preclinical HNSCC models by augmenting immunosuppressive cells like T regulatory cells (Tregs) within the tumor microenvironment. EphB4 inhibition in cancer cells also amplifies their ability to metastasize through increased expression of genes associated with hallmark pathways of metastasis along with classical and non-classical epithelial-mesenchymal transition. In contrast, vascular ephrinB2 knockout coupled with radiation therapy (RT) enhances anti-tumor immunity, reduces Treg accumulation into the tumor, and decreases metastasis. Notably, targeting the EphB4-ephrinB2 signaling axis with the engineered ligands ephrinB2-Fc-His and Fc-TNYL-RAW-GS reduces local tumor growth and distant metastasis in a preclinical model of HNSCC. Our data suggests that targeted inhibition of vascular ephrinB2 while avoiding inhibition of EphB4 in cancer cells could be a promising strategy to mitigate HNSCC metastasis.

AlphaFold Protein Structure Database and 3D-Beacons: New Data and Capabilities

The AlphaFold Protein Structure Database (https://alphafold.ebi.ac.uk/) has made significant strides in enhancing its utility and accessibility for the life science research community. The recent integration of AlphaMissense predictions enables access to the pathogenicity of human protein missense variants, with an innovative and interactive heatmap and 3D visualisation that display variant data at the residue level. Users can now toggle between structure model quality (pLDDT) and average pathogenicity scores, providing insights into the implications of specific residue changes. The Foldseek integration offers a rapid and accurate method for protein structure searches and comparisons. Bulk data download options further facilitate comprehensive data analysis and integration with other computational tools. The 3D-Beacons framework (https://www.ebi.ac.uk/pdbe/pdbe-kb/3dbeacons/) has also been enhanced with detailed annotation endpoints (such as AlphaMissense data) and integrates LevyLab's dataset of homomeric AlphaFold 2 models. These advancements significantly improve the functionality and accessibility of these resources, enabling discoveries using structure data.

Cell-free expression and SMA copolymer encapsulation of a functional receptor tyrosine kinase disease variant, FGFR3-TACC3

Despite their high clinical relevance, obtaining structural and biophysical data on transmembrane proteins has been hindered by challenges involved in their expression and extraction in a homogeneous, functionally-active form. The inherent enzymatic activity of receptor tyrosine kinases (RTKs) presents additional challenges. Oncogenic fusions of RTKs with heterologous partners represent a particularly difficult-to-express protein subtype due to their high flexibility, aggregation propensity and the lack of a known method for extraction within the native lipid environment. One such protein is the fibroblast growth factor receptor 3 fused with transforming acidic coiled-coil-containing protein 3 (FGFR3-TACC3), which has failed to express to sufficient quality or functionality in traditional expression systems. Cell-free protein expression (CFPE) is a burgeoning arm of synthetic biology, enabling the rapid and efficient generation of recombinant proteins. This platform is characterised by utilising an optimised solution of cellular machinery to facilitate protein synthesis in vitro. In doing so, CFPE can act as a surrogate system for a range of proteins that are otherwise difficult to express through traditional host cell-based approaches. Here, functional FGFR3-TACC3 was expressed through a novel cell-free expression system in under 48 h. The resultant protein was reconstituted using SMA copolymers with a specific yield of 300 µg/mL of lysate. Functionally, the protein demonstrated significant kinase domain phosphorylation (t < 0.0001). Currently, there is no published, high-resolution structure of any full-length RTK. These findings form a promising foundation for future research on oncogenic RTKs and the application of cell-free systems for synthesising functional membrane proteins.

Probing structural requirements for thiazole-based mimetics of sunitinib as potent VEGFR-2 inhibitors

Novel thiazole analogs 3a, 3b, 4, 5, 6a-g, 8a, 8b, 9a-c, 10a-d and 11 were designed and synthesized as molecular mimetics of sunitinib. In vitro antitumor activity of the obtained compounds was investigated against HepG2, HCT-116, MCF-7, HeP-2 and HeLa cancer cell lines. The obtained data showed that compounds 3b and 10c are the most potent members toward HepG2, HCT-116, MCF-7 and HeLa cells. Moreover, compounds 3a, 3b, 6g, 8a and 10c were assessed for their in vitro VEGFR-2 inhibitory activity. Results proved that compound 10c exhibited outstanding VEGFR-2 inhibition (IC50 = 0.104 μM) compared to sunitinib. Compound 10c paused the G0-G1 phase of the cell cycle in HCT-116 and MCF-7 cells and the S phase in HeLa cells. Additionally, compound 10c elevated caspase-3/9 levels in HCT-116 and HeLa cells, leading to cancer cell death via apoptosis. Furthermore, compound 10c showed a significant reduction in tumor volume in Swiss albino female mice as an in vivo breast cancer model. Docking results confirmed the tight binding interactions of compound 10c with the VEGFR-2 binding site, with its binding energy surpassing that of sunitinib. In silico PK studies predicted compound 10c to have good oral bioavailability and a good drug score with low human toxicity risks.

FLT3 is associated with dendritic cell infiltration, tertiary lymphoid structure construction, and predict response to checkpoint inhibitors immunotherapy in solid cancers

The crosstalk between cancers and the immune microenvironment plays a critical role in malignant progression. FMS-like tyrosine kinase 3 (FLT3) is a frequently mutated gene in acute myeloid leukemia (AML). However, its role in solid cancers remains poorly understood. We analyzed the frequency of FLT3 alterations, its mRNA expression levels, and its prognostic implications across multiple cancer types. Additionally, we explored genes co-expressed with FLT3 and performed gene ontology analysis to identify associated biological processes. We also examined the relationship between FLT3 expression and markers of various immune cells, tertiary lymphoid structures (TLSs), and epithelial-mesenchymal transition. Furthermore, we validated these findings in our own cohort of hepatocellular carcinoma (HCC) patients. We found that FLT3 alteration and expression were both significantly upregulated in AML and were associated with poor prognosis, which is opposite to its role in solid cancers. The genes co-expressed with FLT3 in solid cancers were correlated with the regulation of the immune microenvironment. FLT3 was positively correlated with the formation of TLSs in only solid cancers, which was especially relevant to central memory T cells. We also found that FLT3 was positively correlated with the infiltration of NK cells, B cells, and DCs. It also positively correlated with the occurrence of apoptosis in solid cancers, but exhibited opposite roles in AML. The structural factors of the TLSs were positively correlated with FLT3 in solid cancers, but exhibited a negative correlation in AML. Meanwhile, we further validated the above conclusions in our own HCC cohort and demonstrated that FLT3 could serve as a predictive indicator of PD-1 treatment efficacy in HCC. In summary, the role of FLT3 is different in AML and solid cancers. FLT3 is associated with dendritic cell infiltration, tertiary lymphoid structure construction, and predict response to checkpoint inhibitors immunotherapy in HCC.

Exploring the conformational space of ROS1 kinase domain and the impact of allosteric mutations

Chromosomal rearrangements are common oncogenic events in Non-Small Cell Lung Cancer. An example is the fusion of the ROS1 kinase domain with extracellular receptors. Although the fusion leads to a target that is druggable with multi-kinase inhibitors, several reports indicate the emergence of point mutations leading to drug resistance. Although these mutations are often located in the ATP binding pocket, a subset of them is neighboring the pocket without a direct effect on drug binding. Due to the clinical impact of these allosteric mutations, there is an urge to identify the mechanism of resistance and characterize the pocket for further drug design studies. This study aimed to unravel the resistance mechanism of L1982F and S1986F/Y mutations. The variants were modeled and simulated using classical Molecular Dynamics simulations and accessed for their conformational flexibility. Our results indicate a direct effect of these allosteric mutants in the binding pocket volume with an indication of the G-loop playing a central role.

Conditional requirement for dimerization of the membrane-binding module for BTK signaling in lymphocyte cell lines

Bruton's tyrosine kinase (BTK) is a major drug target in immune cells. The membrane-binding pleckstrin homology and tec homology (PH-TH) domains of BTK are required for signaling. Dimerization of the PH-TH module strongly stimulates the kinase activity of BTK in vitro. Here, we investigated whether BTK dimerizes in cells using the PH-TH module and whether this dimerization is necessary for signaling. To address this question, we developed high-throughput mutagenesis assays for BTK function in Ramos B cells and Jurkat T cells. We measured the fitness costs for thousands of point mutations in the PH-TH module and kinase domain to assess whether dimerization of the PH-TH module and BTK kinase activity were necessary for function. In Ramos cells, we found that neither PH-TH dimerization nor kinase activity was required for BTK signaling. Instead, in Ramos cells, BTK signaling was enhanced by PH-TH module mutations that increased membrane adsorption, even at the cost of reduced PH-TH dimerization. In contrast, in Jurkat cells, we found that BTK signaling depended on both PH-TH dimerization and kinase activity. Evolutionary analysis indicated that BTK proteins in organisms that evolved before the divergence of ray-finned fishes lacked PH-TH dimerization but had active kinase domains, similar to other Tec family kinases. Thus, PH-TH dimerization is a distinct feature of BTK that evolved to exert stricter regulatory control on kinase activity as adaptive immune systems gained increased complexity.

In vivo measurements of receptor tyrosine kinase activity reveal feedback regulation of a developmental gradient

A lack of tools for detecting receptor activity in vivo has limited our ability to fully explore receptor-level control of developmental patterning. Here, we extend a new class of biosensors for receptor tyrosine kinase (RTK) activity, the pYtag system, to visualize endogenous RTK activity in Drosophila. We build biosensors for three Drosophila RTKs that function across developmental stages and tissues. By characterizing Torso::pYtag during terminal patterning in the early embryo, we find that Torso activity differs from downstream ERK activity in two surprising ways: Torso activity is narrowly restricted to the poles but produces a broader gradient of ERK, and Torso activity decreases over developmental time while ERK activity is sustained. This decrease in Torso activity is driven by ERK pathway-dependent negative feedback. Our results suggest an updated model of terminal patterning where a narrow domain of Torso activity, tuned in amplitude by negative feedback, locally activates signaling effectors which diffuse through the syncytial embryo to form the ERK gradient. Altogether, this work highlights the usefulness of pYtags for investigating receptor-level regulation of developmental patterning.