Therapeutic targeting of KSP in preclinical models of high-risk neuroblastoma

Organoids as a new approach for improving pediatric cancer research

A key challenge in cancer research is the meticulous development of models that faithfully emulates the intricacies of the patient scenario, with emphasis on preserving intra-tumoral heterogeneity and the dynamic milieu of the tumor microenvironment (TME). Organoids emerge as promising tool in new drug development, drug screening and precision medicine. Despite advances in the diagnoses and treatment of pediatric cancers, certain tumor subtypes persist in yielding unfavorable prognoses. Moreover, the prognosis for a significant portion of children experiencing disease relapse is dismal. To improve pediatric outcome many groups are focusing on the development of precision medicine approach. In this review, we summarize the current knowledge about using organoid system as model in preclinical and clinical solid-pediatric cancer. Since organoids retain the pivotal characteristics of primary parent tumors, they exert great potential in discovering novel tumor biomarkers, exploring drug-resistance mechanism and predicting tumor responses to chemotherapy, targeted therapy and immunotherapies. We also examine both the potential opportunities and existing challenges inherent organoids, hoping to point out the direction for future organoid development.

KIF11 serves as a cell cycle mediator in childhood acute lymphoblastic leukemia

OBJECTIVE

To identify key gene in childhood acute lymphoblastic leukemia (ALL) through weighted gene co-expression network analysis (WGCNA), and their enriched biological functions and signaling pathways.

METHODS

Array data of the GSE73578 dataset, involving 46 childhood ALL samples, were acquired from the Gene Expression Omnibus (GEO) database. Hub modules associated with childhood ALL were screened out by WGCNA. Enriched biological functions and signaling pathways were then identified by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Hub genes were selected by overlapping those between down-regulated genes in GSE73578, GSE4698 and the hub module. Guilt by association (GBA) was adopted to verify the function of the identified KIF11 gene and to predict its target genes. Regulatory effects of KIF11 on the proliferation and cell cycle progression of ALL in vitro were determined by cytological experiments.

RESULTS

WGCNA showed that the yellow module was the most relevant to childhood ALL treatment, containing 698 genes that were enriched in cell division, mitotic nuclear division, DNA replication and DNA repair, cell cycle, DNA replication and the P53 signaling pathway. The KIF11 gene was screened out and predicted as a cell cycle mediator in childhood ALL. Knockdown of KIF11 in ALL cells inhibited cell proliferation and arrested cell cycle progression in G2/M phase.

CONCLUSIONS

The KIF11 gene is critical in the treatment process of childhood ALL, which is a promising therapeutic target for childhood ALL.

Design, Synthesis, and Evaluation of Biological Activity of Ferrocene-Ispinesib Hybrids: Impact of a Ferrocenyl Group on the Antiproliferative and Kinesin Spindle Protein Inhibitory Activity

With the aim to combine more than one biologically-active component in a single molecule, derivatives of ispinesib and its (S) analogue were prepared that featured ferrocenyl moieties or bulky organic substituents. Inspired by the strong kinesin spindle protein (KSP) inhibitory activity of ispinesib, the compounds were investigated for their antiproliferative activity. Among these compounds, several derivatives demonstrated significantly higher antiproliferative activity than ispinesib with nanomolar IC50 values against cell lines. Further evaluation indicated that the antiproliferative activity is not directly correlated with their KSP inhibitory activity while docking suggested that several of the derivatives may bind in a manner similar to ispinesib. In order to investigate the mode of action further, cell cycle analysis and reactive oxygen species formation were investigated. The improved antiproliferative activity of the most active compounds may be assigned to synergic effects of various factors such as KSP inhibitory activity due to the ispinesib core and ability to generate ROS and induce mitotic arrest.

Design, synthesis, molecular dynamics simulation, MM/GBSA studies and kinesin spindle protein inhibitory evaluation of some 4-aminoquinoline hybrids

The discovery of novel chemotherapeutic agents is always challenging for researchers in industry and academia. Among the recent promising anticancer therapeutic targets, an important modulatory factor in mitosis is the expression of the kinesin family motor protein (Eg5). In terms of chemotherapy treatment, mitosis has gained significant attention due to its role as one of the biological processes that can be intervened in it. This study was undertaken to design, synthesise and evaluation of 4-aminoquinoline hybrid compounds as potential Eg5 inhibitors. Based on data collected from Malachite green and steady state ATPase assays, it has been determined that compounds such as 6c, 6d, 6g, and 6h are sensitive to Eg5 inhibition. In special mention, compounds 4 and 6c showed promising inhibitory activity in Malachite green assay with IC₅₀ values of 2.32 ± 0.23 µM and 1.97 ± 0.23 µM respectively. Compound 4 showed favourable inhibitory potential Steady state ATPase Assay with IC₅₀ value of 5.39 ± 1.39 µM. We performed molecular docking, MM/GBSA calculations, and molecular dynamic simulations to evaluate the interactions between ligands and the binding site of the kinesin spindle protein to evaluate the functional consequences of these interactions. As a result of these findings, it can be concluded that these 4-amioquinoline Schiff's base hybrids may prove to be promising candidates for development as novel inhibitors of Eg5. Further in-vivo research in this area is required.

Lights and Shadows on the Cancer Multi-Target Inhibitor Rigosertib (ON-01910.Na)

Rigosertib (ON-01910.Na) is a small-molecule member of the novel synthetic benzyl-styryl-sulfonate family. It is currently in phase III clinical trials for several myelodysplastic syndromes and leukemias and is therefore close to clinical translation. The clinical progress of rigosertib has been hampered by a lack of understanding of its mechanism of action, as it is currently considered a multi-target inhibitor. Rigosertib was first described as an inhibitor of the mitotic master regulator Polo-like kinase 1 (Plk1). However, in recent years, some studies have shown that rigosertib may also interact with the PI3K/Akt pathway, act as a Ras-Raf binding mimetic (altering the Ras signaling pathway), as a microtubule destabilizing agent, or as an activator of a stress-induced phospho-regulatory circuit that ultimately hyperphosphorylates and inactivates Ras signaling effectors. Understanding the mechanism of action of rigosertib has potential clinical implications worth exploring, as it may help to tailor cancer therapies and improve patient outcomes.

Patient-derived models: Advanced tools for precision medicine in neuroblastoma

Neuroblastoma is a childhood cancer derived from the sympathetic nervous system. High-risk neuroblastoma patients have a poor overall survival and account for ~15% of childhood cancer deaths. There is thus a need for clinically relevant and authentic models of neuroblastoma that closely resemble the human disease to further interrogate underlying mechanisms and to develop novel therapeutic strategies. Here we review recent developments in patient-derived neuroblastoma xenograft models and in vitro cultures. These models can be used to decipher mechanisms of metastasis and treatment resistance, for drug screening, and preclinical drug testing. Patient-derived neuroblastoma models may also provide useful information about clonal evolution, phenotypic plasticity, and cell states in relation to neuroblastoma progression. We summarize current opportunities for, but also barriers to, future model development and application. Integration of patient-derived models with patient data holds promise for the development of precision medicine treatment strategies for children with high-risk neuroblastoma.

Adaptive risk-aware sharable and individual subspace learning for cancer survival analysis with multi-modality data

Biomedical multi-modality data (also named multi-omics data) refer to data that span different types and derive from multiple sources in clinical practices (e.g. gene sequences, proteomics and histopathological images), which can provide comprehensive perspectives for cancers and generally improve the performance of survival models. However, the performance improvement of multi-modality survival models may be hindered by two key issues as follows: (1) how to learn and fuse modality-sharable and modality-individual representations from multi-modality data; (2) how to explore the potential risk-aware characteristics in each risk subgroup, which is beneficial to risk stratification and prognosis evaluation. Additionally, learning-based survival models generally refer to numerous hyper-parameters, which requires time-consuming parameter setting and might result in a suboptimal solution. In this paper, we propose an adaptive risk-aware sharable and individual subspace learning method for cancer survival analysis. The proposed method jointly learns sharable and individual subspaces from multi-modality data, whereas two auxiliary terms (i.e. intra-modality complementarity and inter-modality incoherence) are developed to preserve the complementary and distinctive properties of each modality. Moreover, it equips with a grouping co-expression constraint for obtaining risk-aware representation and preserving local consistency. Furthermore, an adaptive-weighted strategy is employed to efficiently estimate crucial parameters during the training stage. Experimental results on three public datasets demonstrate the superiority of our proposed model.

Engineering human mini-bones for the standardized modeling of healthy hematopoiesis, leukemia, and solid tumor metastasis

The bone marrow microenvironment provides indispensable factors to sustain blood production throughout life. It is also a hotspot for the progression of hematologic disorders and the most frequent site of solid tumor metastasis. Preclinical research relies on xenograft mouse models, but these models preclude the human-specific functional interactions of stem cells with their bone marrow microenvironment. Instead, human mesenchymal cells can be exploited for the in vivo engineering of humanized niches, which confer robust engraftment of human healthy and malignant blood samples. However, mesenchymal cells are associated with major reproducibility issues in tissue formation. Here, we report the fast and standardized generation of human mini-bones by a custom-designed human mesenchymal cell line. These resulting humanized ossicles (hOss) consist of fully mature bone and bone marrow structures hosting a human mesenchymal niche with retained stem cell properties. As compared to mouse bones, we demonstrate superior engraftment of human cord blood hematopoietic cells and primary acute myeloid leukemia samples and also validate hOss as a metastatic site for breast cancer cells. We further report the engraftment of neuroblastoma patient-derived xenograft cells in a humanized model, recapitulating clinically described osteolytic lesions. Collectively, our human mini-bones constitute a powerful preclinical platform to model bone-developing tumors using patient-derived materials.

Kinesin Eg5 Selective Inhibition by Newly Synthesized Molecules as an Alternative Approach to Counteract Breast Cancer Progression: An In Vitro Study

Breast cancer (BC) is one of the most diagnosed cancers in women. Recently, a promising target for BC treatment was found in kinesin Eg5, a mitotic motor protein that allows bipolar spindle formation and cell replication. Thus, the aim of this work was to evaluate the effects of novel thiadiazoline-based Eg5 inhibitors, analogs of K858, in an in vitro model of BC (MCF7 cell line). Compounds 2 and 41 were selected for their better profile as they reduce MCF7 viability at lower concentrations and with minimal effect on non-tumoral cells with respect to K858. Compounds 2 and 41 counteract MCF7 migration by negatively modulating the NF-kB/MMP-9 pathway. The expression of HIF-1α and VEGF appeared also reduced by 2 and 41 administration, thus preventing the recruitment of the molecular cascade involved in angiogenesis promotion. In addition, 2 provokes an increased caspase-3 activation thus triggering the MCF7 apoptotic event, while 41 and K858 seem to induce the necrosis axis, as disclosed by the increased expression of PARP. These results allow us to argue that 2 and 41 are able to simultaneously intervene on pivotal molecular signaling involved in breast cancer progression, leading to the assumption that Eg5 inhibition can represent a valid approach to counteract BC progression.

The therapeutic effect of KSP inhibitors in preclinical models of cholangiocarcinoma

Cholangiocarcinoma (CCA) is an epithelial malignancy with a dismal prognosis owing to limited treatment options. Here, we identified several compound candidates against CCA using a high-throughput drug screen with approved or emerging oncology drugs, among which kinesin spindle protein (KSP) inhibitors showed potent cytotoxic effects on CCA cells. Treatment with KSP inhibitors SB743921 and ARRY520 caused significant tumor suppression in CCA xenograft models in vivo. Mechanistically, KSP inhibitors led to the formation of abnormal monopolar spindles, which further resulted in the mitotic arrest and cell death of CCA cells both in vivo and in vitro. KEGG pathway analysis of transcriptional data confirmed this finding. Moreover, our clinical data as well as the TCGA database showed KIF11 expression was abundant in most CCA tumor specimens and associated with poor outcomes of CCA patients. Our results demonstrate that the therapeutic regimen of KSP inhibitors could be a promising treatment strategy in CCA.

Kinesin spindle protein inhibitors in cancer: from high throughput screening to novel therapeutic strategies

Bringing to a halt the cell cycle in mitosis and interfering with its normal progression is one of the most successful anti-cancer strategies used nowadays. Classically, several kinds of anti-cancer drugs like taxanes and vinca alkaloids directly inhibit microtubules during cell division. These drugs exhibit serious side effects, most importantly, severe peripheral neuropathies. Alternatively, KSP inhibitors are grasping a lot of research attention as less toxic mitotic inhibitors. In this review, we track the medicinal chemistry developmental stages of KSP inhibitors. Moreover, we address the challenges that are faced during the development of KSP inhibitor therapy for cancer and future insights for the latest advances in research that are directed to find active KSP inhibitor drugs.

Scientists have recognized the importance of selective KSP inhibitors in the early 2000s and so various KSP protein inhibitors have been investigated. Only ten of these have been clinically evaluated for cancer treatment. Ispinesib (SB-715992) and filanesib (Arry-520) were the most promising small molecules in clinical trials against the KSP protein. Many challenges are faced during the development of an active anti-KSP drug; most importantly are the unsatisfactory clinical trial results. Designing dual inhibitors, antibody–drug conjugates, combination therapy and gene therapy approach are among the main strategies that are being investigated nowadays to find new effective KSP inhibitors. The scientific research efforts are still devoted to find an effective and tolerable KSP inhibitor drug that can gain US FDA approval.

High-throughput ex vivo drug testing identifies potential drugs and drug combinations for NRAS-positive malignant melanoma

Therapy options for patients with metastatic melanoma (MM) have considerably improved over the past decade. However, many patients still need effective therapy after unsuccessful immunotherapy, especially patients with BRAF-negative tumors who lack the option of targeted treatment second line. Therefore, the elucidation of efficient and personalized therapy options for these patients is required. In this study, three patient-derived cancer cells (PDCs) were established from NRAS Q61-positive MM patients. The response of PDCs and five established melanoma cell lines (two NRAS-positive, one wild type, and two BRAF V600-positive) was evaluated toward a panel of 527 oncology drugs using high-throughput drug sensitivity and resistance testing. The PDCs and cell lines displayed strong responses to MAPK inhibitors, as expected. Additionally, the PDCs and cell lines were responsive to PI3K/mTOR, mTOR, and PLK1 inhibitors among other effective drugs currently undergoing clinical trials. Combinations with a MEK inhibitor were tested with other targeted agents to identify effective synergies. MEK inhibitor showed synergy with multikinase inhibitor ponatinib, ABL inhibitor nilotinib, PI3K/mTOR inhibitor pictilisib, and pan-RAF inhibitor LY3009120. The application of the patients' cancer cells for functional drug testing ex vivo is one step further in the process of identifying potential agents and agent combinations to personalize treatment for patients with MM. Our preliminary study results suggest that this approach has the potential for larger-scale drug testing and personalized treatment applications in our expansion trial. Our results show that drug sensitivity and resistance testing may be implementable in the treatment planning of patients with MM.

3D Culture of Primary Patient-Derived Hepatoblastoma Tumoroids

Hepatoblastoma, the most common primary liver malignancy in children, remains poorly understood due in part to a relative lack of methods to expand tumor cells in culture and a paucity of robust experimental models. Here, we describe a method to obtain primary tumor cells from patients with hepatoblastoma and to propagate the cells in 3D culture as tumor organoids, or "tumoroids". We further detail methods to prepare the tumoroids for whole-mount and cross-sectional imaging as well as to perform lentiviral transduction.

Methodological advances in the discovery of novel neuroblastoma therapeutics

INTRODUCTION

Neuroblastoma is a cancer of the sympathetic nervous system that causes up to 15% of cancer-related deaths among children. Among the ~1,000 newly diagnosed cases per year in Europe, more than half are classified as high-risk, with a 5-year survival rate <50%. Current multimodal treatments have improved survival among these patients, but relapsed and refractory tumors remain a major therapeutic challenge. A number of new methodologies are paving the way for the development of more effective and safer therapies to ultimately improve outcomes for high-risk patients.

AREAS COVERED

The authors provide a critical review on methodological advances aimed at providing new therapeutic opportunities for neuroblastoma patients, including preclinical models of human disease, generation of omics data to discover new therapeutic targets, and artificial intelligence-based technologies to implement personalized treatments.

EXPERT OPINION

While survival of childhood cancer has improved over the past decades, progress has been uneven. Still, survival is dismal for some cancers, including high-risk neuroblastoma. Embracing new technologies (e.g. molecular profiling of tumors, 3D in vitro models, etc.), international collaborative efforts and the incorporation of new therapies (e.g. RNA-based therapies, epigenetic therapies, immunotherapy) will ultimately lead to more effective and safer therapies for these subgroups of neuroblastoma patients.

Anti-tumor effects of rigosertib in high-risk neuroblastoma

High-risk neuroblastoma has a poor prognosis despite intense treatment, demonstrating the need for new therapeutic strategies. Here we evaluated the effects of rigosertib (ON-01910.Na) in preclinical models of high-risk neuroblastoma. Among several hundred cancer cell lines representing 24 tumor types, neuroblastoma was the most sensitive to rigosertib. Treatment of MYCN-amplified neuroblastoma organoids resulted in organoid disintegration, decreased cell viability, and increased apoptotic cell death. Neuroblastoma response to rigosertib involved G2M cell cycle arrest and decreased phosphorylation of AKT (Ser473) and ERK1/2 (Thr202/Tyr204). Rigosertib delayed tumor growth and prolonged survival of mice carrying neuroblastoma MYCN-amplified PDX tumors (median survival: 31 days, treated; 22 days, vehicle) accompanied with increased apoptosis in treated tumors. We further identified vincristine and rigosertib as a potential promising drug combination treatment. Our results show that rigosertib might be a useful therapeutic agent for MYCN-amplified neuroblastomas, especially in combination with existing agents.

The Promise of Patient-Derived Preclinical Models to Accelerate the Implementation of Personalised Medicine for Children with Neuroblastoma

Patient-derived preclinical models are now a core component of cancer research and have the ability to drastically improve the predictive power of preclinical therapeutic studies. However, their development and maintenance can be challenging, time consuming, and expensive. For neuroblastoma, a developmental malignancy of the neural crest, it is possible to establish patient-derived models as xenografts in mice and zebrafish, and as spheroids and organoids in vitro. These varied approaches have contributed to comprehensive packages of preclinical evidence in support of new therapeutics for neuroblastoma. We discuss here the ethical and technical considerations for the creation of patient-derived models of neuroblastoma and how their use can be optimized for the study of tumour evolution and preclinical therapies. We also discuss how neuroblastoma patient-derived models might become avatars for personalised medicine for children with this devastating disease.

Molecular Mechanisms of MYCN Dysregulation in Cancers

MYCN, a member of MYC proto-oncogene family, encodes a basic helix-loop-helix transcription factor N-MYC. Abnormal expression of N-MYC is correlated with high-risk cancers and poor prognosis. Initially identified as an amplified oncogene in neuroblastoma in 1983, the oncogenic effect of N-MYC is expanded to multiple neuronal and nonneuronal tumors. Direct targeting N-MYC remains challenge due to its "undruggable" features. Therefore, alternative therapeutic approaches for targeting MYCN-driven tumors have been focused on the disruption of transcription, translation, protein stability as well as synthetic lethality of MYCN. In this review, we summarize the latest advances in understanding the molecular mechanisms of MYCN dysregulation in cancers.