Activated FGF2 signaling pathway in tumor vasculature is essential for acquired resistance to anti-VEGF therapy

Fibroblast Growth Factor 2 (FGF2) Activates Vascular Endothelial Growth Factor (VEGF) Signaling in Gastrointestinal Stromal Tumors (GIST): An Autocrine Mechanism Contributing to Imatinib Mesylate (IM) Resistance

We showed previously that the autocrine activation of the FGFR-mediated pathway in GIST lacking secondary KIT mutations was a result of the inhibition of KIT signaling. We show here that the FGF2/FGFR pathway regulates VEGF-A/VEGFR signaling in IM-resistant GIST cells. Indeed, recombinant FGF2 increased the production of VEGF-A by IM-naive and resistant GIST cells. VEGF-A production was also increased in KIT-inhibited GIST, whereas the neutralization of FGF2 by anti-FGF2 mAb attenuated VEGFR signaling. Of note, BGJ 398, pan FGFR inhibitor, effectively and time-dependently inhibited VEGFR signaling in IM-resistant GIST T-1R cells, thereby revealing the regulatory role of the FGFR pathway in VEGFR signaling for this particular GIST cell line. This also resulted in significant synergy between BGJ 398 and VEGFR inhibitors (i.e., sunitinib and regorafenib) by enhancing their pro-apoptotic and anti-proliferative activities. The high potency of the combined use of VEGFR and FGFR inhibitors in IM-resistant GISTs was revealed by the impressive synergy scores observed for regorafenib or sunitinib and BGJ 398. Moreover, FGFR1/2 and VEGFR1/2 were co-localized in IM-resistant GIST T-1R cells, and the direct interaction between the aforementioned RTKs was confirmed by co-immunoprecipitation. In contrast, IM-resistant GIST 430 cells expressed lower basal levels of FGF2 and VEGF-A. Despite the increased expression VEGFR1 and FGFR1/2 in GIST 430 cells, these RTKs were not co-localized and co-immunoprecipitated. Moreover, no synergy between FGFR and VEGFR inhibitors was observed for the IM-resistant GIST 430 cell line. Collectively, the dual targeting of FGFR and VEGFR pathways in IM-resistant GISTs is not limited to the synergistic anti-angiogenic treatment effects. The dual inhibition of FGFR and VEGFR pathways in IM-resistant GISTs potentiates the proapoptotic and anti-proliferative activities of the corresponding RTKi. Mechanistically, the FGF2-induced activation of the FGFR pathway turns on VEGFR signaling via the overproduction of VEGF-A, induces the interaction between FGFR1/2 and VEGFR1, and thereby renders cancer cells highly sensitive to the dual inhibition of the aforementioned RTKs. Thus, our data uncovers the novel mechanism of the cross-talk between the aforementioned RTKs in IM-resistant GISTs lacking secondary KIT mutations and suggests that the dual blockade of FGFR and VEGFR signaling might be an effective treatment strategy for patients with GIST-acquired IM resistance via KIT-independent mechanisms.

Fibroblast growth factor 2

Fibroblast Growth Factor 2 (FGF2), also known as basic fibroblast growth factor, is a potent stimulator of growth and differentiation in multiple tissues. Its discovery traces back over 50 years ago when it was first isolated from bovine pituitary extracts due to its ability to stimulate fibroblast proliferation. Subsequent studies investigating the genomic structure of FGF2 identified multiple protein isoforms, categorized as the low molecular weight and high molecular weight FGF2. These isoforms arise from alternative translation initiation events and exhibit unique molecular and cellular functions. In this concise review, we aim to provide an overview of what is currently known about the structure, expression, and functions of the FGF2 isoforms within the contexts of development, homeostasis, and disease.

A real-world drug safety surveillance study of lenvatinib from the FAERS database

BACKGROUND

There is a need to determine lenvatinib-associated real-world adverse events (AEs) as its adverse effects may result in its discontinuation.

RESEARCH DESIGN AND METHODS

Lenvatinib-associated AEs were analyzed and quantified and risk signals from the first quarter of 2015 to the fourth quarter of 2023 were detected through data mining. Potential targets for lenvatinib-associated cholecystitis, cholangitis, and hepatic encephalopathy were identified by data mining.

RESULT

68 Preferred Terms (PTs) with an important imbalance were kept. Unexpected AEs, such as immune-mediated hepatitis, portal vein thrombosis and adrenal insufficiency were associated with the use of lenvatinib use. Lenvatinib alone was more strongly associated with adrenal insufficiency than lenvatinib and pembrolizumab combination. Hepatic encephalopathy was more strongly correlated with drug use when Lenvatinib was administered to male patients with hepatocellular carcinoma. Most AEs occurred during the first month after treatment, with a median onset time of 41 days. FGFR4, PDGFRA, and KIT (Lenvatinib targets) are potentially linked to cholecystitis, cholangitis, and hepatic encephalopathy.

CONCLUSIONS

We identified Lenvatinib-associated AEs and discovered new AEs that will be useful for clinical monitoring and risk assessment.

Gli1-mediated tumor cell-derived bFGF promotes tumor angiogenesis and pericyte coverage in non-small cell lung cancer

BACKGROUND

Tumor angiogenesis inhibitors have been applied for non-small cell lung cancer (NSCLC) therapy. However, the drug resistance hinders their further development. Intercellular crosstalk between lung cancer cells and vascular cells was crucial for anti-angiogenenic resistance (AAD). However, the understanding of this crosstalk is still rudimentary. Our previous study showed that Glioma-associated oncogene 1 (Gli1) is a driver of NSCLC metastasis, but its role in lung cancer cell-vascular cell crosstalk remains unclear.

METHODS

Conditioned medium (CM) from Gli1-overexpressing or Gli1-knockdown NSCLC cells was used to educate endothelia cells and pericytes, and the effects of these media on angiogenesis and the maturation of new blood vessels were evaluated via wound healing assays, Transwell migration and invasion assays, tube formation assays and 3D coculture assays. The xenograft model was conducted to establish the effect of Gli1 on tumor angiogenesis and growth. Angiogenic antibody microarray analysis, ELISA, luciferase reporte, chromatin immunoprecipitation (ChIP), bFGF protein stability and ubiquitination assay were performed to explore how Gli1 regulate bFGF expression.

RESULTS

Gli1 overexpression in NSCLC cells enhanced the endothelial cell and pericyte motility required for angiogenesis required for angiogenesis. However, Gli1 knockout in NSCLC cells had opposite effect on this process. bFGF was critical for the enhancement effect on tumor angiogenesis. bFGF treatment reversed the Gli1 knockdown-mediated inhibition of angiogenesis. Mechanistically, Gli1 increased the bFGF protein level by promoting bFGF transcriptional activity and protein stability. Importantly, suppressing Gli1 with GANT-61 obviously inhibited angiogenesis.

CONCLUSION

The Gli1-bFGF axis is crucial for the crosstalk between lung cancer cells and vascular cells. Targeting Gli1 is a potential therapeutic approach for NSCLC angiogenesis.

Identification of key genes modules linking diabetic retinopathy and circadian rhythm

Background

Diabetic retinopathy (DR) is a leading cause of vision loss worldwide. Recent studies highlighted the crucial impact of circadian rhythms (CR) on normal retinopathy in response to the external light cues. However, the role of circadian rhythms in DR pathogenesis and potential investigational drugs remains unclear.

Methods

To investigate the weather CR affects DR, differential expression analysis was employed to identify differentially expressed genes (DEGs) from the GEO database (GSE160306). Functional enrichment analysis was conducted to identify relevant signaling pathways. LASSO regression was utilized to screen pivotal genes. Weighted gene co-expression network anlaysis (WGCNA) was applied to identify different modules. Additionally, we use the Comparative Toxicogenomics Database (CTD) database to search key genes related to drugs or molecular compounds. The diabetic mouse model received three consecutive intraperitoneal injections of streptozotocin (STZ) during 3 successive days.

Results

We initially identified six key genes associated with circadian rhythm in DR, including COL6A3, IGFBP2, IGHG4, KLHDC7A, RPL26P30, and MYL6P4. Compared to normal tissue, the expression levels of COL6A3 and IGFB2 were significantly increased in DR model. Furthermore, we identified several signaling pathways, including death domain binding, insulin-like growth factor I binding, and proteasome binding. We also observed that COL6A3 was positively correlated with macrophages (cor=0.628296895, p=9.96E-08) and Th17 cells (cor=0.665120835, p=9.14E-09), while IGFBP2 showed a negatively correlated with Tgd (cor=-0.459953045, p=0.000247284) and Th2 cells (cor=-0.442269719, p=0.000452875). Finally, we identified four drugs associated with key genes: Resveratrol, Vitamin E, Streptozocin, and Sulindac.

Conclusion

Our findings revealed several key genes related to circadian rhythms and several relevant drugs in DR, providing a novel insight into the mechanism of DR and potential implications for future DR treatment. This study contributes to a better understanding of CR in DR and its implications for future therapeutic interventions.

Neutrophil extracellular traps promote angiogenesis in gastric cancer

Although antiangiogenic therapy has been used in gastric cancer, disease progression due to drug resistance remains common. Neutrophils play an important role in the occurrence and progression of cancer via neutrophil extracellular traps (NETs). However, few studies have investigated angiogenic regulation in gastric cancer. We aimed to determine the role of NETs in promoting angiogenesis in gastric cancer. Multiple immunohistochemical staining was used to analyze the spatial distribution of NETs and microvessels in patient tissue samples. A mouse subcutaneous tumor model was established to determine the effect of NETs on tumor growth, and changes in microvessel density were observed via immunohistochemical staining. We screened differentially expressed proteins in HUVECs stimulated by NETs via proteomics. Cell Counting Kit-8, EdU labeling, and tubule formation assays were used to verify the effect of NETs on HUVEC proliferation, migration, and tubule formation. Blocking NETs, which was related to decreased microvessel density, significantly inhibited tumor growth in the murine subcutaneous tumor model. Compared with those of the control group, tumor volume and mass among mice in the inhibition group decreased by 61.3% and 77.9%, respectively. The NET-DNA receptor CCDC25 was expressed in HUVECs, providing a platform for NETs to promote HUVEC proliferation, migration, and tubulation. In an in vitro rat aortic explant model, NETs induced HUVEC proliferation, survival, and chemotaxis, which were not significantly different from those observed in the VEGF stimulation group. Our results confirm that NETs promote angiogenesis in gastric cancer, providing a theoretical basis for identifying new anti-vascular therapeutic targets. Video Abstract.

The FGF/FGFR signalling mediated anti-cancer drug resistance and therapeutic intervention

ABSTRACT Fibroblast Growth Factor (FGF) ligands and their receptors are crucial factors driving chemoresistance in several malignancies, challenging the efficacy of currently available anti-cancer drugs. The Fibroblast growth factor/receptor (FGF/FGFR) signalling malfunctions in tumor cells, resulting in a range of molecular pathways that may impact its drug effectiveness. Deregulation of cell signalling is critical since it can enhance tumor growth and metastasis. Overexpression and mutation of FGF/FGFR induce regulatory changes in the signalling pathways. Chromosomal translocation facilitating FGFR fusion production aggravates drug resistance. Apoptosis is inhibited by FGFR-activated signalling pathways, reducing multiple anti-cancer medications' destructive impacts. Angiogenesis and epithelial-mesenchymal transition (EMT) are facilitated by FGFRs-dependent signalling, which correlates with drug resistance and enhances metastasis. Further, lysosome-mediated drug sequestration is another prominent method of resistance. Inhibition of FGF/FGFR by following a plethora of therapeutic approaches such as covalent and multitarget inhibitors, ligand traps, monoclonal antibodies, recombinant FGFs, combination therapy, and targeting lysosomes and micro RNAs would be helpful. As a result, FGF/FGFR suppression treatment options are evolving nowadays. To increase positive impacts, the processes underpinning the FGF/FGFR axis' role in developing drug resistance need to be clarified, emphasizing the need for more studies to develop novel therapeutic options to address this significant problem. Communicated by Ramaswamy H. Sarma.

Exosomal cargos-mediated metabolic reprogramming in tumor microenvironment

Metabolic reprogramming is one of the hallmarks of cancer. As nutrients are scarce in the tumor microenvironment (TME), tumor cells adopt multiple metabolic adaptations to meet their growth requirements. Metabolic reprogramming is not only present in tumor cells, but exosomal cargos mediates intercellular communication between tumor cells and non-tumor cells in the TME, inducing metabolic remodeling to create an outpost of microvascular enrichment and immune escape. Here, we highlight the composition and characteristics of TME, meanwhile summarize the components of exosomal cargos and their corresponding sorting mode. Functionally, these exosomal cargos-mediated metabolic reprogramming improves the "soil" for tumor growth and metastasis. Moreover, we discuss the abnormal tumor metabolism targeted by exosomal cargos and its potential antitumor therapy. In conclusion, this review updates the current role of exosomal cargos in TME metabolic reprogramming and enriches the future application scenarios of exosomes.

Tumor Vasculature as an Emerging Pharmacological Target to Promote Anti-Tumor Immunity

Tumor vasculature abnormality creates a microenvironment that is not suitable for anti-tumor immune response and thereby induces resistance to immunotherapy. Remodeling of dysfunctional tumor blood vessels by anti-angiogenic approaches, known as vascular normalization, reshapes the tumor microenvironment toward an immune-favorable one and improves the effectiveness of immunotherapy. The tumor vasculature serves as a potential pharmacological target with the capacity of promoting an anti-tumor immune response. In this review, the molecular mechanisms involved in tumor vascular microenvironment-modulated immune reactions are summarized. In addition, the evidence of pre-clinical and clinical studies for the combined targeting of pro-angiogenic signaling and immune checkpoint molecules with therapeutic potential are highlighted. The heterogeneity of endothelial cells in tumors that regulate tissue-specific immune responses is also discussed. The crosstalk between tumor endothelial cells and immune cells in individual tissues is postulated to have a unique molecular signature and may be considered as a potential target for the development of new immunotherapeutic approaches.

Molecular Mechanisms and Future Implications of VEGF/VEGFR in Cancer Therapy

Angiogenesis, the sprouting of new blood vessels from existing vessels, is one of six known mechanisms employed by solid tumors to recruit blood vessels necessary for their initiation, growth, and metastatic spread. The vascular network within the tumor facilitates the transport of nutrients, oxygen, and immune cells and is regulated by pro- and anti-angiogenic factors. Nearly four decades ago, VEGF was identified as a critical factor promoting vascular permeability and angiogenesis, followed by identification of VEGF family ligands and their receptors (VEGFR). Since then, over a dozen drugs targeting the VEGF/VEGFR pathway have been approved for approximately 20 solid tumor types, usually in combination with other therapies. Initially designed to starve tumors, these agents transiently "normalize" tumor vessels in preclinical and clinical studies, and in the clinic, increased tumor blood perfusion or oxygenation in response to these agents is associated with improved outcomes. Nevertheless, the survival benefit has been modest in most tumor types, and there are currently no biomarkers in routine clinical use for identifying which patients are most likely to benefit from treatment. However, the ability of these agents to reprogram the immunosuppressive tumor microenvironment into an immunostimulatory milieu has rekindled interest and has led to the FDA approval of seven different combinations of VEGF/VEGFR pathway inhibitors with immune checkpoint blockers for many solid tumors in the past 3 years. In this review, we discuss our understanding of the mechanisms of response and resistance to blocking VEGF/VEGFR, and potential strategies to develop more effective therapeutic approaches.

Aberrant protein synthesis and cancer development: The role of canonical eukaryotic initiation, elongation and termination factors in tumorigenesis

In tumourigenesis, oncogenes or dysregulated tumour suppressor genes alter the canonical translation machinery leading to a reprogramming of the translatome that, in turn, promotes the translation of selected mRNAs encoding proteins involved in proliferation and metastasis. It is therefore unsurprising that abnormal expression levels and activities of eukaryotic initiation factors (eIFs), elongation factors (eEFs) or termination factors (eRFs) are associated with poor outcome for patients with a wide range of cancers. In this review we discuss how RNA binding proteins (RBPs) within the canonical translation factor machinery are dysregulated in cancers and how targeting such proteins is leading to new therapeutic avenues.

Integrin-specific hydrogels for growth factor-free vasculogenesis

Integrin-binding biomaterials have been extensively evaluated for their capacity to enable de novo formation of capillary-like structures/vessels, ultimately supporting neovascularization in vivo. Yet, the role of integrins as vascular initiators in engineered materials is still not well understood. Here, we show that αvβ3 integrin-specific 3D matrices were able to retain PECAM1⁺ cells from the stromal vascular fraction (SVF) of adipose tissue, triggering vasculogenesis in vitro in the absence of extrinsic growth factors. Our results suggest that αvβ3-RGD-driven signaling in the formation of capillary-like structures prevents the activation of the caspase 8 pathway and activates the FAK/paxillin pathway, both responsible for endothelial cells (ECs) survival and migration. We also show that prevascularized αvβ3 integrin-specific constructs inosculate with the host vascular system fostering in vivo neovascularization. Overall, this work demonstrates the ability of the biomaterial to trigger vasculogenesis in an integrin-specific manner, by activating essential pathways for EC survival and migration within a self-regulatory growth factor microenvironment. This strategy represents an improvement to current vascularization routes for Tissue Engineering constructs, potentially enhancing their clinical applicability.

Evaluation of the Effect of the Fibroblast Growth Factor Type 2 (FGF-2) Administration on Placental Gene Expression in a Murine Model of Preeclampsia Induced by L-NAME

The abnormal implantation of the trophoblast during the first trimester of pregnancy precedes the appearance of the clinical manifestations of preeclampsia (PE), which is a hypertensive disorder of pregnancy. In a previous study, which was carried out in a murine model of PE that was induced by NG-nitro-L-arginine methyl ester (L-NAME), we observed that the intravenous administration of fibroblast growth factor 2 (FGF2) had a hypotensive effect, improved the placental weight gain and attenuated the fetal growth restriction, and the morphological findings that were induced by L-NAME in the evaluated tissues were less severe. In this study, we aimed to determine the effect of FGF2 administration on the placental gene expression of the vascular endothelial growth factor (VEGFA), VEGF receptor 2 (VEGFR2), placental growth factor, endoglin (ENG), superoxide dismutase 1 (SOD1), catalase (CAT), thioredoxin (TXN), tumor protein P53 (P53), BCL2 apoptosis regulator, Fas cell surface death receptor (FAS), and caspase 3, in a Sprague Dawley rat PE model, which was induced by L-NAME. The gene expression was determined by a real-time polymerase chain reaction using SYBR green. Taking the vehicle or the L-NAME group as a reference, there was an under expression of placental VEGFA, VEGFR2, ENG, P53, FAS, SOD1, CAT, and TXN genes in the group of L-NAME + FGF2 (p < 0.05). The administration of FGF2 in the murine PE-like model that was induced by L-NAME reduced the effects that were generated by proteinuria and the increased BP, as well as the response of the expression of genes that participate in angiogenesis, apoptosis, and OS. These results have generated valuable information regarding the identification of molecular targets for PE and provide new insights for understanding PE pathogenesis.

Far beyond anti-angiogenesis: Benefits for anti-basicFGF therapy in cancer

Basic FGF (bFGF) was discovered as a typical inducer of angiogenesis and has already been studied for 3 decades. Recent evidence indicates that bFGF plays different roles and controls signaling pathways that participate in the hallmarks of cancer, underscoring bFGF an appealing target for anti-cancer therapy. However, the early clinical trials designed to block bFGF signaling showed safety without satisfiable benefits for cancer patients. In this review, we firstly discuss bFGF's canonical signaling pathways and later review newly identified bFGF's functions that contribute to the cancer hallmarks besides its typical role in angiogenesis. After, we summarize the role of bFGF as a therapeutic target in response to different cancer therapies including radiotherapy, chemotherapy, targeted therapy, immunotherapy, and highlight the difficulties we must solve regarding the design of drugs targeting specifically bFGF. We also emphasize the need, especially for natural bFGF traps, to deepen their molecular mechanisms of action considering the specific context of cancer with different FGFR status, as well as the urgence of stratifying patients for both anti-bFGF first line and second line anti-cancer therapy. Finally, a perspective on potential feed-forward oncogenic signaling pathways mediated by bFGF is made. We discuss the importance of developing additional robust biomarkers to select patients who will benefit from bFGF-targeted therapy, as well as the rationale of developing combinatory therapies targeting either bFGF and/or its intracellular (co)effectors. This would ultimately provide novel therapeutic strategies to fight cancer.

New insights into antiangiogenic therapy resistance in cancer: Mechanisms and therapeutic aspects

Angiogenesis is a hallmark of cancer and is required for tumor growth and progression. Antiangiogenic therapy has been revolutionarily developing and was approved for the treatment of various types of cancer for nearly two decades, among which bevacizumab and sorafenib continue to be the two most frequently used antiangiogenic drugs. Although antiangiogenic therapy has brought substantial survival benefits to many cancer patients, resistance to antiangiogenic drugs frequently occurs during clinical treatment, leading to poor outcomes and treatment failure. Cumulative evidence has demonstrated that the intricate interplay among tumor cells, bone marrow-derived cells, and local stromal cells critically allows for tumor escape from antiangiogenic therapy. Currently, drug resistance has become the main challenge that hinders the therapeutic efficacies of antiangiogenic therapy. In this review, we describe and summarize the cellular and molecular mechanisms conferring tumor drug resistance to antiangiogenic therapy, which was predominantly associated with redundancy in angiogenic signaling molecules (e.g., VEGFs, GM-CSF, G-CSF, and IL17), alterations in biological processes of tumor cells (e.g., tumor invasiveness and metastasis, stemness, autophagy, metabolic reprogramming, vessel co-option, and vasculogenic mimicry), increased recruitment of bone marrow-derived cells (e.g., myeloid-derived suppressive cells, tumor-associated macrophages, and tumor-associated neutrophils), and changes in the biological functions and features of local stromal cells (e.g., pericytes, cancer-associated fibroblasts, and endothelial cells). We also review potential biomarkers to predict the response to antiangiogenic therapy in cancer patients, which mainly consist of imaging biomarkers, cellular and extracellular proteins, a certain type of bone marrow-derived cells, local stromal cell content (e.g., pericyte coverage) as well as serum or plasma biomarkers (e.g., non-coding RNAs). Finally, we highlight the recent advances in combination strategies with the aim of enhancing the response to antiangiogenic therapy in cancer patients and mouse models. This review introduces a comprehensive understanding of the mechanisms and biomarkers associated with the evasion of antiangiogenic therapy in cancer, providing an outlook for developing more effective approaches to promote the therapeutic efficacy of antiangiogenic therapy.

Dynamic Interactions between Tumor Cells and Brain Microvascular Endothelial Cells in Glioblastoma

GBM is the most aggressive brain tumor among adults. It is characterized by extensive vascularization, and its further growth and recurrence depend on the formation of new blood vessels. In GBM, tumor angiogenesis is a multi-step process involving the proliferation, migration and differentiation of BMECs under the stimulation of specific signals derived from the cancer cells through a wide variety of communication routes. In this review, we discuss the dynamic interaction between BMECs and tumor cells by providing evidence of how tumor cells hijack the BMECs for the formation of new vessels. Tumor cell-BMECs interplay involves multiple routes of communication, including soluble factors, such as chemokines and cytokines, direct cell-cell contact and extracellular vesicles that participate in and fuel this cooperation. We also describe how this interaction is able to modify the BMECs structure, metabolism and physiology in a way that favors tumor growth and invasiveness. Finally, we briefly reviewed the recent advances and the potential future implications of some high-throughput 3D models to better understanding the complexity of BMECs-tumor cell interaction.

The Safety Profile of Hepatectomy Following Preoperative Systemic Therapy with Lenvatinib Plus Anti-PD-1 Antibodies Versus Hepatectomy Alone in Patients With Hepatocellular Carcinoma

Objective

To determine the safety of hepatectomy after combined lenvatinib and anti-PD-1 preoperative systemic therapy (PST) in patients with marginally resectable hepatocellular carcinoma (HCC).

Background

PST followed by hepatectomy (PSTH) is an emerging treatment for HCC. However, the impact of PST with lenvatinib plus anti-PD-1 antibodies on surgical safety is unknown.

Methods

Medical records from consecutive patients with marginally resectable advanced HCC who underwent hepatectomy after PST with lenvatinib and anti-PD-1 antibodies between January 2018 and August 2021 were retrieved from a prospectively designed database. Propensity score matching (1:2) was performed with a further 2318 HCC patients who underwent upfront hepatectomy (UH) without initial antitumor treatment during the same period.

Results

In total, 49 and 98 matched patients were included in the PSTH and UH groups, respectively. Compared to the UH group, individuals in the PSTH group experienced more intraoperative blood loss, blood transfusions, and longer postoperative hospital stays. Moreover, posthepatectomy liver failure was more common in the PSTH group, who also had worse albumin-bilirubin (ALBI) scores on postoperative days 1-7. A significantly greater amount of drainage was also required in the PSTH group. However, the 30-day morbidity and 90-day mortality were similar among the two groups. Additionally, the duration of surgery, use of hepatic inflow occlusion during surgery, and the levels of postoperative inflammation-based markers were not statistically different between the two groups.

Conclusions

Despite more intraoperative and postoperative adverse events, PSTH had comparable 30-day morbidity and 90-day mortality as UH. Thus, PSTH appears to be a viable treatment option for marginally resectable HCC patients with careful preoperative evaluation.

Inhibition of Fibroblast Growth Factor Receptor Attenuates Ultraviolet B-Induced Skin Carcinogenesis

Altered FGFR signaling has been shown to play a role in a number of cancers. However, the role of FGFR signaling in the development and progression of ultraviolet B-induced (UVB) induced cutaneous squamous cell carcinoma (cSCC) remains unclear. In the current study, the effect of UVB radiation on FGFR activation and its downstream signaling in mouse skin epidermis was examined. In addition, the impact of FGFR inhibition on UVB-induced signaling and skin carcinogenesis was also investigated. Exposure of mouse dorsal skin to UVB significantly increased phosphorylation of FGFRs in the epidermis as well as activation of downstream signaling pathways, including AKT/mTOR, STATs and MAPK. Topical application of the pan-FGFR inhibitor AZD4547 to mouse skin prior to exposure to UVB significantly inhibited FGFR phosphorylation as well as mTORC1, STAT3 and MAPK activation (i.e., phosphorylation). Moreover, AZD4547 pretreatment significantly inhibited UVB-induced epidermal hyperplasia and hyperproliferation and reduced infiltration of mast cells and macrophages into the dermis. AZD4547 treatment also significantly inhibited mRNA expression of inflammatory genes in the epidermis. Finally, mice treated topically with AZD4547 prior to UVB exposure showed decreased cSCC incidence and increased survival rate. Collectively, the current data supports the hypothesis that inhibition of FGFR in epidermis may provide a new strategy to prevent and/or treat UVB-induced cSCC.

Lenvatinib dose, efficacy, and safety in the treatment of multiple malignancies

INTRODUCTION

Lenvatinib is an oral multitargeted tyrosine kinase inhibitor that has shown efficacy and manageable safety across multiple cancer types. The recommended starting doses for lenvatinib differ across cancer types and indications based on whether it is used as monotherapy or as combination therapy.

AREAS COVERED

This review covers clinical trials that established the dosing paradigm and efficacy of lenvatinib and defined its adverse-event profile as a monotherapy; or in combination with the mTOR inhibitor, everolimus; or the anti-PD-1 antibody, pembrolizumab; and/or chemotherapy.

EXPERT OPINION

Lenvatinib has been established as standard-of-care either as a monotherapy or in combination with other anticancer agents for the treatment of radioiodine-refractory differentiated thyroid carcinoma, hepatocellular carcinoma, renal cell carcinoma, and endometrial carcinoma, and is being investigated further across several other tumor types. The dosing and adverse-event management strategies for lenvatinib have been developed through extensive clinical trial experience. Collectively, the data provide the rationale to start lenvatinib at the recommended doses and then interrupt or dose reduce as necessary to achieve required dose intensity for maximized patient benefit. The adverse-event profile of lenvatinib is consistent with that of other tyrosine kinase inhibitors, and clinicians are encouraged to review and adopt relevant symptom-management strategies.

Tumors Modulate the Systemic Vascular Response to Anti‐angiogenic Therapy

Toxicologic evaluation of new drug candidates routinely utilizes healthy animals. In oncology, there remains a limited understanding of the effects of novel test candidates in a diseased host. For vascular modulating agents (VMAs), an increased understanding of preclinical tumour–host interaction, and its potential to exacerbate or alleviate ‘off‐target’ effects of anti‐angiogenic administration, could aid in the prediction of adverse clinical outcomes in a defined cancer patient. We have previously reported that the implantation and growth of a range of human‐ and mouse‐derived tumours leads to structural vascular and, potentially, functional signalling changes within host mouse endocrine tissues, indicating possible roles for tumour‐ and host‐derived cytokines/growth factors and the liberation of myeloid‐derived suppressor cells in this phenomenon. Here, we further demonstrate that the growth of the Calu‐6 xenograft is associated with a resistance to VMA‐induced mouse peripheral endocrine vascular rarefaction (toxicity), with potential functional impact, notably with respect to mixed tyrosine kinase inhibition. The pathogenesis of these findings indicates a potential role for both tumour‐ and host‐derived basic fibroblast growth factor (bFGF), with associated upregulation in the intra‐tumoural autotaxin‐lysophosphatic acid signalling axis.

The growth of the Calu‐6 xenograft is associated with a resistance to vascular modulating agent‐induced mouse peripheral endocrine vascular rarefaction (toxicity), with potential functional impact, notably with respect to mixed tyrosine kinase inhibition. The pathogenesis of these findings indicates a potential role for basic fibroblast growth factor, with associated upregulation in the autotaxin‐lysophosphatic acid signalling axis.

Inhibition of FGFR Reactivates IFNγ Signaling in Tumor Cells to Enhance the Combined Antitumor Activity of Lenvatinib with Anti-PD-1 Antibodies

Combination therapies consisting of immune checkpoint inhibitors plus anti-VEGF therapy show enhanced antitumor activity and are approved treatments for patients with renal cell carcinoma (RCC). The immunosuppressive roles of VEGF in the tumor microenvironment are well studied, but those of FGF/FGFR signaling remain largely unknown. Lenvatinib is a receptor tyrosine kinase inhibitor that targets both VEGFR and FGFR. Here, we examine the antitumor activity of anti-PD-1 mAb combined with either lenvatinib or axitinib, a VEGFR-selective inhibitor, in RCC. Both combination treatments showed greater antitumor activity and longer survival in mouse models versus either single agent treatment, whereas anti-PD-1 mAb plus lenvatinib had enhanced antitumor activity compared with anti-PD-1 mAb plus axitinib. Flow cytometry analysis showed that lenvatinib decreased the population of tumor-associated macrophages and increased that of IFNγ-positive CD8⁺ T cells. Activation of FGFR signaling inhibited the IFNγ-stimulated JAK/STAT signaling pathway and decreased expression of its target genes, including B2M, CXCL10, and PD-L1. Furthermore, inhibition of FGFR signaling by lenvatinib restored the tumor response to IFNγ stimulation in mouse and human RCC cell lines. These preclinical results reveal novel roles of tumor FGFR signaling in the regulation of cancer immunity through inhibition of the IFNγ pathway, and the inhibitory activity of lenvatinib against FGFRs likely contributes to the enhanced antitumor activity of combination treatment comprising lenvatinib plus anti-PD-1 mAb. SIGNIFICANCE: FGFR pathway activation inhibits IFNγ signaling in tumor cells, and FGFR inhibition with lenvatinib enhances antitumor immunity and the activity of anti-PD-1 antibodies.

Is There Still a Place for Tyrosine Kinase Inhibitors for the Treatment of Hepatocellular Carcinoma at the Time of Immunotherapies? A Focus on Lenvatinib

The systemic treatment of hepatocellular carcinoma is changing rapidly. Three main classes of treatment are now available. Historically, multi-targeted tyrosine kinase inhibitors (TKIs) (sorafenib and lenvatinib as first-line; regorafenib and cabozantinib as second-line) were the first to show an improvement in overall survival (OS). Anti-vascular endothelial growth factor (anti-VEGF) antibodies can be used in first-line (bevacizumab) or second-line (ramucirumab) combination therapy. More recently, immuno-oncology (IO) has profoundly changed therapeutic algorithms, and the combination of atezolizumab-bevacizumab is now the first-line standard of care. Therefore, the place of TKIs needs to be redefined. The objective of this review was to define the place of TKIs in the therapeutic algorithm at the time of IO treatment in first-line therapy, with a special focus on lenvatinib that exhibits one of the higher anti-tumoral activity among TKI in HCC. We will discuss the place of lenvatinib in first line (especially if there is a contra-indication to IO) but also after failure of atezolizumab and bevacizumab. New opportunities for lenvatinib will also be presented, including the use at an earlier stage of the disease and combination with IOs.

FGF/FGFR-Dependent Molecular Mechanisms Underlying Anti-Cancer Drug Resistance

Simple Summary

Deregulation of the FGF/FGFR axis is associated with many types of cancer and contributes to the development of chemoresistance, limiting the effectiveness of current treatment strategies. There are several mechanisms involved in this phenomenon, including cross-talks with other signaling pathways, avoidance of apoptosis, stimulation of angiogenesis, and initiation of EMT. Here, we provide an overview of current research and approaches focusing on targeting components of the FGFR/FGF signaling module to overcome drug resistance during anti-cancer therapy.

Abstract

Increased expression of both FGF proteins and their receptors observed in many cancers is often associated with the development of chemoresistance, limiting the effectiveness of currently used anti-cancer therapies. Malfunctioning of the FGF/FGFR axis in cancer cells generates a number of molecular mechanisms that may affect the sensitivity of tumors to the applied drugs. Of key importance is the deregulation of cell signaling, which can lead to increased cell proliferation, survival, and motility, and ultimately to malignancy. Signaling pathways activated by FGFRs inhibit apoptosis, reducing the cytotoxic effect of some anti-cancer drugs. FGFRs-dependent signaling may also initiate angiogenesis and EMT, which facilitates metastasis and also correlates with drug resistance. Therefore, treatment strategies based on FGF/FGFR inhibition (using receptor inhibitors, ligand traps, monoclonal antibodies, or microRNAs) appear to be extremely promising. However, this approach may lead to further development of resistance through acquisition of specific mutations, metabolism switching, and molecular cross-talks. This review brings together information on the mechanisms underlying the involvement of the FGF/FGFR axis in the generation of drug resistance in cancer and highlights the need for further research to overcome this serious problem with novel therapeutic strategies.

OLIE, ITCC-082: a Phase II trial of lenvatinib plus ifosfamide and etoposide in relapsed/refractory osteosarcoma

While survival rates for patients with relapsed/refractory osteosarcoma are low, kinase inhibitors have shown efficacy in its treatment. The multikinase inhibitor lenvatinib, plus ifosfamide and etoposide, showed antitumor activity in a Phase II study in patients with relapsed/refractory osteosarcoma. This Phase II randomized controlled trial (OLIE) will assess whether the combination of lenvatinib + ifosfamide + etoposide is superior to ifosfamide + etoposide alone in children, adolescents and young adults with relapsed/refractory osteosarcoma. The primary end point is progression-free survival; secondary and exploratory end points include, but are not limited to, overall survival, objective response rate, safety and tolerability, pharmacokinetic characterization of lenvatinib in the combination treatment, quality of life and quantification of baseline unresectable lesions that are converted to resectable.

The Rapidly Evolving Landscape of First-Line Targeted Therapy in Metastatic Urothelial Cancer: A Systematic Review

BACKGROUND

Metastatic urothelial carcinoma (mUC) historically is treated with first-line platinum-based combination chemotherapy, preferably cisplatin plus gemcitabine whenever possible. In recent years, multiple classes of targeted therapy have demonstrated benefit, with some receiving approval in mUC. This review will summarize phase III efficacy and safety data for targeted agents, principally immune checkpoint inhibitors (ICIs), as either first-line or first-line switch-maintenance therapy for mUC and interpret these findings in the context of the current treatment landscape.

MATERIALS AND METHODS

Published and presented phase III data on targeted therapy for the first-line or first-line switch-maintenance treatment of mUC were identified using the key search terms "targeted therapy" AND "urothelial carcinoma" AND "advanced" OR respective aliases according to the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

RESULTS

Of the six eligible phase III targeted therapy trials, two assessing ICIs met their primary endpoints in platinum-eligible patients. First-line ICI plus chemotherapy combinations have not improved overall survival (OS), although final OS results of the IMVigor 130 trial are pending. Switch-maintenance using an ICI in patients achieving at least stable disease following platinum-based chemotherapy statistically significantly improved OS (21.4 vs. 14.3 months, hazard ratio, 0.69; 95% confidence interval, 0.56-0.86; p = .001). Current sequencing options for mUC include first-line platinum-based chemotherapy with a switch to ICI either immediately or upon disease progression.

CONCLUSION

Recent targeted therapy trials have expanded ICI sequencing options for mUC. The treatment landscape is likely to evolve rapidly, with results from multiple phase III trials expected in the next 5 years.

IMPLICATIONS FOR PRACTICE

Multiple classes of targeted agents are approved for use in metastatic urothelial carcinoma (mUC). Six phase III trials have recently provided insight on the benefit of these agents in the first-line setting. In platinum-eligible patients, immune checkpoint inhibitors (ICIs) combined with first-line platinum-based chemotherapy failed to demonstrate improved survival, although ICI monotherapy as switch-maintenance significantly improved overall survival in patients with mUC who had achieved at least stable disease following first-line platinum-based chemotherapy. In patients ineligible for any chemotherapy, pembrolizumab, atezolizumab, or pembrolizumab in combination with enfortumab vedotin may be options.

Fibroblast Growth Factor Receptors (FGFRs) and Noncanonical Partners in Cancer Signaling

Increasing evidence indicates that success of targeted therapies in the treatment of cancer is context-dependent and is influenced by a complex crosstalk between signaling pathways and between cell types in the tumor. The Fibroblast Growth Factor (FGF)/FGF receptor (FGFR) signaling axis highlights the importance of such context-dependent signaling in cancer. Aberrant FGFR signaling has been characterized in almost all cancer types, most commonly non-small cell lung cancer (NSCLC), breast cancer, glioblastoma, prostate cancer and gastrointestinal cancer. This occurs primarily through amplification and over-expression of FGFR1 and FGFR2 resulting in ligand-independent activation. Mutations and translocations of FGFR1-4 are also identified in cancer. Canonical FGF-FGFR signaling is tightly regulated by ligand-receptor combinations as well as direct interactions with the FGFR coreceptors heparan sulfate proteoglycans (HSPGs) and Klotho. Noncanonical FGFR signaling partners have been implicated in differential regulation of FGFR signaling. FGFR directly interacts with cell adhesion molecules (CAMs) and extracellular matrix (ECM) proteins, contributing to invasive and migratory properties of cancer cells, whereas interactions with other receptor tyrosine kinases (RTKs) regulate angiogenic, resistance to therapy, and metastatic potential of cancer cells. The diversity in FGFR signaling partners supports a role for FGFR signaling in cancer, independent of genetic aberration.

Role of FGF System in Neuroendocrine Neoplasms: Potential Therapeutic Applications

Neuroendocrine neoplasms (NENs) are a heterogeneous group of tumors originating from neuroendocrine cells dispersed in different organs. Receptor tyrosine kinases are a subclass of tyrosine kinases with a relevant role in several cellular processes including proliferation, differentiation, motility and metabolism. Dysregulation of these receptors is involved in neoplastic development and progression for several tumors, including NENs. In this review, we provide an overview concerning the role of the fibroblast growth factor (FGF)/fibroblast growth factor receptor (FGFR) system in the development and progression of NENs, the occurrence of fibrotic complications and the onset of drug-resistance. Although no specific FGFR kinase inhibitors have been evaluated in NENs, several clinical trials on multitarget tyrosine kinase inhibitors, acting also on FGF system, showed promising anti-tumor activity with an acceptable and manageable safety profile in patients with advanced NENs. Future studies will need to confirm these issues, particularly with the development of new tyrosine kinase inhibitors highly selective for FGFR.

Resistance to Molecularly Targeted Therapies in Melanoma

Malignant melanoma is the most aggressive type of skin cancer with invasive growth patterns. In 2021, 106,110 patients are projected to be diagnosed with melanoma, out of which 7180 are expected to die. Traditional methods like surgery, radiation therapy, and chemotherapy are not effective in the treatment of metastatic and advanced melanoma. Recent approaches to treat melanoma have focused on biomarkers that play significant roles in cell growth, proliferation, migration, and survival. Several FDA-approved molecular targeted therapies such as tyrosine kinase inhibitors (TKIs) have been developed against genetic biomarkers whose overexpression is implicated in tumorigenesis. The use of targeted therapies as an alternative or supplement to immunotherapy has revolutionized the management of metastatic melanoma. Although this treatment strategy is more efficacious and less toxic in comparison to traditional therapies, targeted therapies are less effective after prolonged treatment due to acquired resistance caused by mutations and activation of alternative mechanisms in melanoma tumors. Recent studies focus on understanding the mechanisms of acquired resistance to these current therapies. Further research is needed for the development of better approaches to improve prognosis in melanoma patients. In this article, various melanoma biomarkers including BRAF, MEK, RAS, c-KIT, VEGFR, c-MET and PI3K are described, and their potential mechanisms for drug resistance are discussed.

Roles of the Dynamic Tumor Immune Microenvironment in the Individualized Treatment of Advanced Clear Cell Renal Cell Carcinoma

Immune checkpoint inhibitors (ICIs) are currently a first-line treatment option for clear cell renal cell carcinoma (ccRCC). However, recent clinical studies have shown that a large number of patients do not respond to ICIs. Moreover, only a few patients achieve a stable and durable response even with combination therapy based on ICIs. Available studies have concluded that the response to immunotherapy and targeted therapy in patients with ccRCC is affected by the tumor immune microenvironment (TIME), which can be manipulated by targeted therapy and tumor genomic characteristics. Therefore, an in-depth understanding of the dynamic nature of the TIME is important for improving the efficacy of immunotherapy or combination therapy in patients with advanced ccRCC. Here, we explore the possible mechanisms by which the TIME affects the efficacy of immunotherapy and targeted therapy, as well as the factors that drive dynamic changes in the TIME in ccRCC, including the immunomodulatory effect of targeted therapy and genomic changes. We also describe the progress on novel therapeutic modalities for advanced ccRCC based on the TIME. Overall, this review provides valuable information on the optimization of combination therapy and development of individualized therapy for advanced ccRCC.

Inhibition of FGF-FGFR and VEGF-VEGFR signalling in cancer treatment

The sites of targeted therapy are limited and need to be expanded. The FGF‐FGFR signalling plays pivotal roles in the oncogenic process, and FGF/FGFR inhibitors are a promising method to treat FGFR‐altered tumours. The VEGF‐VEGFR signalling is the most crucial pathway to induce angiogenesis, and inhibiting this cascade has already got success in treating tumours. While both their efficacy and antitumour spectrum are limited, combining FGF/FGFR inhibitors with VEGF/VEGFR inhibitors are an excellent way to optimize the curative effect and expand the antitumour range because their combination can target both tumour cells and the tumour microenvironment. In addition, biomarkers need to be developed to predict the efficacy, and combination with immune checkpoint inhibitors is a promising direction in the future. The article will discuss the FGF‐FGFR signalling pathway, the VEGF‐VEGFR signalling pathway, the rationale of combining these two signalling pathways and recent small‐molecule FGFR/VEGFR inhibitors based on clinical trials.

Angiogenesis regulation by microRNAs and long non-coding RNAs in human breast cancer

MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are capable of regulating gene expression post-transcriptionally. Since the past decade, a number of in vitro, in vivo, and clinical studies reported the roles of these non-coding RNAs (ncRNAs) in regulating angiogenesis, an important cancer hallmark that is associated with metastases and poor prognosis. The specific roles of various miRNAs and lncRNAs in regulating angiogenesis in breast cancer, with particular focus on the downstream targets and signalling pathways regulated by these ncRNAs will be discussed in this review. In light of the recent trend in exploiting ncRNAs as cancer therapeutics, the potential use of miRNAs and lncRNAs as biomarkers and novel therapeutic agent against angiogenesis was also discussed.

Role of Extracellular Matrix in Gastrointestinal Cancer-Associated Angiogenesis

Gastrointestinal tumors are responsible for more cancer-related fatalities than any other type of tumors, and colorectal and gastric malignancies account for a large part of these diseases. Thus, there is an urgent need to develop new therapeutic approaches to improve the patients' outcome and the tumor microenvironment is a promising arena for the development of such treatments. In fact, the nature of the microenvironment in the different gastrointestinal tracts may significantly influence not only tumor development but also the therapy response. In particular, an important microenvironmental component and a potential therapeutic target is the vasculature. In this context, the extracellular matrix is a key component exerting an active effect in all the hallmarks of cancer, including angiogenesis. Here, we summarized the current knowledge on the role of extracellular matrix in affecting endothelial cell function and intratumoral vascularization in the context of colorectal and gastric cancer. The extracellular matrix acts both directly on endothelial cells and indirectly through its remodeling and the consequent release of growth factors. We envision that a deeper understanding of the role of extracellular matrix and of its remodeling during cancer progression is of chief importance for the development of new, more efficacious, targeted therapies.

From CENTRAL to SENTRAL (SErum aNgiogenesis cenTRAL): Circulating Predictive Biomarkers to Anti-VEGFR Therapy

Background: In the last decade, a series of analyses failed to identify predictive biomarkers of resistance/susceptibility for anti-angiogenic drugs in metastatic colorectal cancer (mCRC). We conducted an exploratory preplanned analysis of serum pro-angiogenic factors (SErum aNgiogenesis-cenTRAL) in 72 mCRC patients enrolled in the phase II CENTRAL (ColorEctalavastiNTRiAlLdh) trial, with the aim to identify potential predictive factors for sensitivity/resistance to first line folinic acid-fluorouracil-irinotecan regimen (FOLFIRI) plus bevacizumab. Methods: First-line FOLFIRI/bevacizumab patients were prospectively assessed for the following circulating pro-angiogenic factors, evaluated with ELISA (enzyme-linked immunosorbent assay)-based technique at baseline and at every cycle: Vascular endothelial growth factor A (VEGF-A), hepatocyte growth factor (HGF), stromal derived factor-1 (SDF-1), placental derived growth factor (PlGF), fibroblast growth factor-2 (FGF-2), monocyte chemotactic protein-3 (MCP-3), interleukin-8 (IL-8). Results: Changes in circulating FGF-2 levels among different blood samples seemed to correlate with clinical outcome. Patients who experienced an increase in FGF-2 levels at the second cycle of chemotherapy compared to baseline, had a median Progression Free Survival (mPFS) of 12.85 vs. 7.57 months (Hazard Ratio—HR: 0.73, 95% Confidence Interval—CI: 0.43-1.27, p = 0.23). Similar results were seen when comparing FGF-2 concentrations between baseline and eight-week time point (mPFS 12.98 vs. 8.00 months, HR: 0.78, 95% CI: 0.46–1.33, p = 0.35). Conclusions: Our pre-planned, prospective analysis suggests that circulating FGF-2 levels’ early increase could be used as a marker to identify patients who are more likely to gain benefit from FOLFIRI/bevacizumab first-line therapy.