Sonidegib: mechanism of action, pharmacology, and clinical utility for advanced basal cell carcinomas

A novel indole derivative, 2-{3-[1-(benzylsulfonyl)piperidin-4-yl]-2-methyl-1H-indol-1-yl}-1-(pyrrolidin-1-yl)ethenone, suppresses hedgehog signaling and drug-resistant tumor growth

The Hedgehog (Hh) signaling pathway plays important roles in various physiological functions. Several malignancies, such as basal cell carcinoma (BCC) and medulloblastoma (MB), have been linked to the aberrant activation of Hh signaling. Although therapeutic drugs have been developed to inhibit Hh pathway-dependent cancer growth, drug resistance remains a major obstacle in cancer treatment. Here, we show that the newly identified, 2-{3-[1-(benzylsulfonyl)-1,2,3,6-tetrahydropyridin-4-yl]-2-methyl-1H-indol-1-yl}-1-(pyrrolidin-1-yl)ethenone analog (LKD1214) exhibits comparable potency to vismodegib in suppressing the Hh pathway activation. LKD1214 represses Smoothened (SMO) activity by blocking its ciliary translocation. Interestingly, we also identified that it has a distinctive binding interface with SMO compared with other SMO-regulating chemicals. Notably, it maintains an inhibitory activity against the SmoD477H mutant, as observed in a patient with vismodegib-resistant BCC. Furthermore, LKD1214 inhibits tumor growth in the mouse model of MB. Collectively, these findings suggest that LKD1214 has the therapeutic potential to overcome drug-resistance in Hh-dependent cancers.

Potential role of immunotherapy and targeted therapy in the treatment of cancer: A contemporary nursing practice

Immunotherapy and targeted therapy have emerged as promising therapeutic options for cancer patients. Immunotherapies induce a host immune response that mediates long-lived tumor destruction, while targeted therapies suppress molecular mechanisms that are important for tumor maintenance and growth. In addition, cytotoxic agents and targeted therapies regulate immune responses, which increases the chances that these therapeutic approaches may be efficiently combined with immunotherapy to ameliorate clinical outcomes. Various studies have suggested that combinations of therapies that target different stages of anti-tumor immunity may be synergistic, which can lead to potent and more prolonged responses that can achieve long-lasting tumor destruction. Nurses associated with cancer patients should have a better understanding of the immunotherapies and targeted therapies, such as their efficacy profiles, mechanisms of action, as well as management and prophylaxis of adverse events. Indeed, this knowledge will be important in establishing care for cancer patients receiving immunotherapies and targeted therapies for cancer treatment. Moreover, nurses need a better understanding regarding targeted therapies and immunotherapies to ameliorate outcomes in patients receiving these therapies, as well as management and early detection of possible adverse effects, especially adverse events associated with checkpoint inhibitors and various other therapies that control T-cell activation causing autoimmune toxicity. Nurses practice in numerous settings, such as hospitals, home healthcare agencies, radiation therapy facilities, ambulatory care clinics, and community agencies. Therefore, as compared to other members of the healthcare team, nurses often have better opportunities to develop the essential rapport in providing effective nurse-led patient education, which is important for effective therapeutic outcomes and continuance of therapy. In this article, we have particularly focused on providing a detailed overview on targeted therapies and immunotherapies used in cancer treatment, management of their associated adverse events, and the impact as well as strategies of nurse-led patient education.

Pharmacology of Veratrum californicum Alkaloids as Hedgehog Pathway Antagonists

Veratrum californicum contains steroidal alkaloids that function as inhibitors of hedgehog (Hh) signaling, a pathway involved in the growth and differentiation of cells and normal tissue development. This same Hh pathway is abnormally active for cell proliferation in more than 20 types of cancer. In this current study, alkaloids have been extracted from the root and rhizome of V. californicum, followed by their separation into five fractions using high performance liquid chromatography. Mass spectrometry was used to identify the presence of twenty-five alkaloids, nine more than are commonly cited in literature reports, and the Bruker Compass Data Analysis software was used to predict the molecular formula for every detected alkaloid. The Gli activity of the raw extract and each fraction were compared to 0.1 µM cyclopamine, and fractions 1, 2, and 4 showed increased bioactivity through suppression of the Hh signaling pathway. Fractions 2 and 4 had enhanced bioactivity, but fraction 1 was most effective in inhibiting Hh signaling. The composition of fraction 1 consisted of veratrosine, cycloposine, and potential isomers of each.

Polymeric micelles for cutaneous delivery of the hedgehog pathway inhibitor TAK-441: Formulation development and cutaneous biodistribution in porcine and human skin

TAK-441 is a potent inhibitor of the hedgehog pathway (IC50 4.4 nM) developed for the treatment of basal cell carcinoma that is active against the vismodegib-resistant Smoothened receptor D473H mutant. The objective of this study was to develop a micelle-based formulation of TAK-441 using D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) and to investigate its cutaneous delivery and biodistribution. The micelles were prepared using solvent evaporation and incorporation of TAK-441 in the TPGS micelles increased aqueous solubility ∼40-fold. The optimal formulation, a 3% HPMC hydrogel of TAK-441 loaded TPGS micelles, retained ∼92% of the initial TAK-441 content (2.5 mgTAK-441/g) after storage at 4 °C for 6 months. Finite dose experiments using human skin demonstrated that this formulation resulted in significantly greater cutaneous deposition of TAK-441 after 12 h than a non-micelle control formulation, (0.40 ± 0.11 µg/cm2 and 0.05 ± 0.02 µg/cm2, respectively) - no transdermal permeation was observed. The cutaneous biodistribution profile demonstrated that TAK-441 was predominantly delivered to the viable epidermis and upper dermis. Delivery from the HPMC hydrogel formulation resulted in TAK-441 epidermal concentrations that were several thousand-fold higher than the IC50, with almost negligible transdermal permeation, thereby decreasing the risk of systemic side effects in vivo.

Targeted therapy and immunotherapy for orbital and periorbital tumors: a major review

Traditionally, for patients who are poor candidates for surgery and/or radiotherapy, palliative chemotherapy is often offered but with significant toxic side effects. However, recent advancements in our understanding of tumor biology and molecular genetics have brought new understanding to the molecular pathways of certain tumors and cancers. This has ushered in a new era of precision medicine specific to a tumor or cancer treatment pathway (targeted therapy) or directed to host-tumor responses (immunotherapy). This article will focus on recent updates in the application of available targeted and immunotherapy for managing orbital and periorbital tumors and tumor-like conditions, which include cutaneous basal cell carcinoma, cutaneous squamous cell carcinoma, cutaneous melanoma, Merkel cell carcinoma, sebaceous gland carcinoma, solitary fibrous tumor, dermatofibrosarcoma protuberans, orbital meningioma, neurofibromatosis, Langerhans cell histiocytosis, ocular adnexal lymphoma, orbital lymphatic malformation, and adenoid cystic carcinoma.

Hedgehog signaling in tissue homeostasis, cancers, and targeted therapies

The past decade has seen significant advances in our understanding of Hedgehog (HH) signaling pathway in various biological events. HH signaling pathway exerts its biological effects through a complex signaling cascade involved with primary cilium. HH signaling pathway has important functions in embryonic development and tissue homeostasis. It plays a central role in the regulation of the proliferation and differentiation of adult stem cells. Importantly, it has become increasingly clear that HH signaling pathway is associated with increased cancer prevalence, malignant progression, poor prognosis and even increased mortality. Understanding the integrative nature of HH signaling pathway has opened up the potential for new therapeutic targets for cancer. A variety of drugs have been developed, including small molecule inhibitors, natural compounds, and long non-coding RNA (LncRNA), some of which are approved for clinical use. This review outlines recent discoveries of HH signaling in tissue homeostasis and cancer and discusses how these advances are paving the way for the development of new biologically based therapies for cancer. Furthermore, we address status quo and limitations of targeted therapies of HH signaling pathway. Insights from this review will help readers understand the function of HH signaling in homeostasis and cancer, as well as opportunities and challenges of therapeutic targets for cancer.

Pharmacokinetics and pharmacodynamics of Hedgehog pathway inhibitors used in the treatment of advanced or treatment-refractory basal cell carcinoma

INTRODUCTION

Sonidegib and vismodegib are currently the only US Food and Drug Administration and European Medicines Agency-approved small-molecule Hedgehog pathway inhibitors (HHIs)for treating adults with advanced or refractory basal cell carcinoma (BCC) that is not amenable to conventional surgery or radiotherapy. At this time, there are no head-to-head clinical trials comparing these two HHIs for efficacy and safety to assist clinicians with determining which HHI may be best suited for their patients.

AREAS COVERED

This review briefly describes the pathogenesis of BCC, provides a detailed overview of the key pharmacokinetic profile differences between sonidegib and vismodegib, explains their pharmacodynamics, and highlights the therapeutic considerations when either HHI is used to treat special patient populations.

EXPERT OPINION

Although both HHIs act at the same molecular target in the Hedgehog pathway, there are significant differences in their pharmacokinetic profiles that may play a potential role in their efficacy and safety. Evidence-based recommendations serve to inform clinicians until direct comparative clinical trials of sonidegib versus vismodegib are conducted to determine the clinical relevance of the reported differences in their pharmacokinetic properties.

Activation mechanism of the human Smoothened receptor

Smoothened (SMO) is a membrane protein of the class F subfamily of G protein-coupled receptors (GPCRs) and maintains homeostasis of cellular differentiation. SMO undergoes conformational change during activation, transmitting the signal across the membrane, making it amenable to bind to its intracellular signaling partner. Receptor activation has been studied at length for class A receptors, but the mechanism of class F receptor activation remains unknown. Agonists and antagonists bound to SMO at sites in the transmembrane domain (TMD) and the cysteine-rich domain have been characterized, giving a static view of the various conformations SMO adopts. Although the structures of the inactive and active SMO outline the residue-level transitions, a kinetic view of the overall activation process remains unexplored for class F receptors. We describe SMO's activation process in atomistic detail by performing 300 μs of molecular dynamics simulations and combining it with Markov state model theory. A molecular switch, conserved across class F and analogous to the activation-mediating D-R-Y motif in class A receptors, is observed to break during activation. We also show that this transition occurs in a stage-wise movement of the transmembrane helices: TM6 first, followed by TM5. To see how modulators affect SMO activity, we simulated agonist and antagonist-bound SMO. We observed that agonist-bound SMO has an expanded hydrophobic tunnel in SMO's core TMD, whereas antagonist-bound SMO shrinks this tunnel, further supporting the hypothesis that cholesterol travels through a tunnel inside Smoothened to activate it. In summary, this study elucidates the distinct activation mechanism of class F GPCRs and shows that SMO's activation process rearranges the core TMD to open a hydrophobic conduit for cholesterol transport.

Cholesterol in the ciliary membrane as a therapeutic target against cancer

Primary cilium is a non-motile, antenna-like structure that develops in the quiescent G0 phase-cell surface. It is composed of an array of axonemal microtubules polymerized from the centrosome/basal body. The plasma membrane surrounding the primary cilium, which is called the ciliary membrane, contains a variety of receptors and ion channels, through which the cell receives extracellular chemical and physical stimuli to initiate signal transduction. In general, primary cilia disappear when cells receive the proliferative signals to re-enter the cell cycle. Primary cilia thus cannot be identified in many malignant and proliferative tumors. In contrast, some cancers, including basal cell carcinoma, medulloblastoma, gastrointestinal stromal tumor, and other malignancies, retain their primary cilia. Importantly, it has been reported that the primary cilia-mediated oncogenic signals of Hedgehog, Wnt, and Aurora kinase A are involved in the tumorigenesis and tumor progression of basal cell carcinoma and some types of medulloblastoma. It has also been demonstrated that cholesterol is significantly more enriched in the ciliary membrane than in the rest of the plasma membrane to ensure Sonic hedgehog signaling. A series of epidemiological studies on statin drugs (cholesterol-lowering medication) demonstrated that they prevent recurrence in a wide range of cancers. Taken together, ciliary cholesterol could be a potential therapeutic target in primary cilia-dependent progressive cancers.

The role of Hedgehog and Notch signaling pathway in cancer

Notch and Hedgehog signaling are involved in cancer biology and pathology, including the maintenance of tumor cell proliferation, cancer stem-like cells, and the tumor microenvironment. Given the complexity of Notch signaling in tumors, its role as both a tumor promoter and suppressor, and the crosstalk between pathways, the goal of developing clinically safe, effective, tumor-specific Notch-targeted drugs has remained intractable. Drugs developed against the Hedgehog signaling pathway have affirmed definitive therapeutic effects in basal cell carcinoma; however, in some contexts, the challenges of tumor resistance and recurrence leap to the forefront. The efficacy is very limited for other tumor types. In recent years, we have witnessed an exponential increase in the investigation and recognition of the critical roles of the Notch and Hedgehog signaling pathways in cancers, and the crosstalk between these pathways has vast space and value to explore. A series of clinical trials targeting signaling have been launched continually. In this review, we introduce current advances in the understanding of Notch and Hedgehog signaling and the crosstalk between pathways in specific tumor cell populations and microenvironments. Moreover, we also discuss the potential of targeting Notch and Hedgehog for cancer therapy, intending to promote the leap from bench to bedside.

Cancer-associated fibroblasts: Origin, function, imaging, and therapeutic targeting

The tumor microenvironment (TME) is emerging as one of the primary barriers in cancer therapy. Cancer-associated fibroblasts (CAF) are a common inhabitant of the TME in several tumor types and play a critical role in tumor progression and drug resistance via different mechanisms such as desmoplasia, angiogenesis, immune modulation, and cancer metabolism. Due to their abundance and significance in pro-tumorigenic mechanisms, CAF are gaining attention as a diagnostic target as well as to improve the efficacy of cancer therapy by their modulation. In this review, we highlight existing imaging techniques that are used for the visualization of CAF and CAF-induced fibrosis and provide an overview of compounds that are known to modulate CAF activity. Subsequently, we also discuss CAF-targeted and CAF-modulating nanocarriers. Finally, our review addresses ongoing challenges and provides a glimpse into the prospects that can spearhead the transition of CAF-targeted therapies from opportunity to reality.

Modulation of Hedgehog Signaling for the Treatment of Basal Cell Carcinoma and the Development of Preclinical Models

Basal Cell Carcinoma (BCC) is the most commonly diagnosed cancer worldwide. While the survivability of BCC is high, many patients are excluded from clinically available treatments due to health risks or personal choice. Further, patients with advanced or metastatic disease have severely limited treatment options. The dysregulation of the Hedgehog (Hh) signaling cascade drives onset and progression of BCC. As such, the modulation of this pathway has driven advancements in BCC research. In this review, we focus firstly on inhibitors that target the Hh pathway as chemotherapeutics against BCC. Two therapies targeting Hh signaling have been made clinically available for BCC patients, but these treatments suffer from limited initial efficacy and a high rate of chemoresistant tumor recurrence. Herein, we describe more recent developments of chemical scaffolds that have been designed to hopefully improve upon the available therapeutics. We secondly discuss the history and recent efforts involving modulation of the Hh genome as a method of producing in vivo models of BCC for preclinical research. While there are many advancements left to be made towards improving patient outcomes with BCC, it is clear that targeting the Hh pathway will remain at the forefront of research efforts in designing more effective chemotherapeutics as well as relevant preclinical models.

Adult Medulloblastoma: Updates on Current Management and Future Perspectives

Medulloblastoma (MB) is a malignant embryonal tumor of the posterior fossa belonging to the family of primitive neuro-ectodermic tumors (PNET). MB generally occurs in pediatric age, but in 14–30% of cases, it affects the adults, mostly below the age of 40, with an incidence of 0.6 per million per year, representing about 0.4–1% of tumors of the nervous system in adults. Unlike pediatric MB, robust prospective trials are scarce for the post-puberal population, due to the low incidence of MB in adolescent and young adults. Thus, current MB treatments for older patients are largely extrapolated from the pediatric experience, but the transferability and applicability of these paradigms to adults remain an open question. Adult MB is distinct from MB in children from a molecular and clinical perspective. Here, we review the management of adult MB, reporting the recent published literature focusing on the effectiveness of upfront chemotherapy, the development of targeted therapies, and the potential role of a reduced dose of radiotherapy in treating this disease.

Bayesian Optimization of Computer-Proposed Multistep Synthetic Routes on an Automated Robotic Flow Platform

Computer-aided synthesis planning (CASP) tools can propose retrosynthetic pathways and forward reaction conditions for the synthesis of organic compounds, but the limited availability of context-specific data currently necessitates experimental development to fully specify process details. We plan and optimize a CASP-proposed and human-refined multistep synthesis route toward an exemplary small molecule, sonidegib, on a modular, robotic flow synthesis platform with integrated process analytical technology (PAT) for data-rich experimentation. Human insights address catalyst deactivation and improve yield by strategic choices of order of addition. Multi-objective Bayesian optimization identifies optimal values for categorical and continuous process variables in the multistep route involving 3 reactions (including heterogeneous hydrogenation) and 1 separation. The platform's modularity, robotic reconfigurability, and flexibility for convergent synthesis are shown to be essential for allowing variation of downstream residence time in multistep flow processes and controlling the order of addition to minimize undesired reactivity. Overall, the work demonstrates how automation, machine learning, and robotics enhance manual experimentation through assistance with idea generation, experimental design, execution, and optimization.

Role of collagen regulators in cancer treatment: A comprehensive review

Abstract:

Collagen is the most important structural protein and also a main component of extra-cellular matrix (ECM). It plays a role in tumor progression. Collagen can be regulated by altering it’s biosynthesis pathway through various signaling pathways, receptors and genes. Activity of cancer cells can also be regulated by other ECM components like metalloproteinases, hyaluronic acid, fibronectin and so on. Hypoxia is also one of the condition which leads to cancer progression by stimulating the expression of procollagen lysine as a collagen crosslinker, which increases the size of collagen fibres promoting cancer spread. The collagen content in cancerous cells leads to resistance in chemotherapy. So, to reduce this resistance, some of the collagen regulating therapies are introduced, which include inhibiting its biosynthesis, disturbing cancer cell signaling pathway, mediating ECM components and directly utilizing collagenase. This study is an effort to compile the strategies reported to control the collagen level and different collagen inhibitors reported so far. More research is needed in this area, growing understandings of collagen’s structural features and its role in cancer progression will aid in the advancement of newer chemotherapies.

Nuclear receptor coactivator SRC-1 promotes colorectal cancer progression through enhancing GLI2-mediated Hedgehog signaling

Overexpression of nuclear coactivator steroid receptor coactivator 1 (SRC-1) and aberrant activation of the Hedgehog (Hh) signaling pathway are associated with various tumorigenesis; however, the significance of SRC-1 in colorectal cancer (CRC) and its contribution to the activation of Hh signaling are unclear. Here, we identified a conserved Hh signaling signature positively correlated with SRC-1 expression in CRC based on TCGA database; SRC-1 deficiency significantly inhibited the proliferation, survival, migration, invasion, and tumorigenesis of both human and mouse CRC cells, and SRC-1 knockout significantly suppressed azoxymethane/dextran sodium sulfate (AOM/DSS)-induced CRC in mice. Mechanistically, SRC-1 promoted the expression of GLI family zinc finger 2 (GLI2), a major downstream transcription factor of Hh pathway, and cooperated with GLI2 to enhance multiple Hh-regulated oncogene expression, including Cyclin D1, Bcl-2, and Slug. Pharmacological blockages of SRC-1 and Hh signaling retarded CRC progression in human CRC cell xenograft mouse model. Together, our studies uncover an SRC-1/GLI2-regulated Hh signaling looping axis that promotes CRC tumorigenesis, offering an attractive strategy for CRC treatment.

FDA-Approved Small Molecule Compounds as Drugs for Solid Cancers from Early 2011 to the End of 2021

Solid cancers are the most common types of cancers diagnosed globally and comprise a large number of deaths each year. The main challenge currently in drug development for tumors raised from solid organs is to find more selective compounds, which exploit specific molecular targets. In this work, the small molecule drugs registered by the Food and Drug Administration (FDA) for solid cancers treatment between 2011 and 2022 were identified and analyzed by investigating a type of therapy they are used for, as well as their structures and mechanisms of action. On average, 4 new small molecule agents were introduced each year, with a few exceptions, for a total of 62 new drug approvals. A total of 50 of all FDA-approved drugs have also been authorized for use in the European Union by the European Medicines Agency (EMA). Our analysis indicates that many more anticancer molecules show a selective mode of action, i.e., 49 targeted agents, 5 hormone therapies and 3 radiopharmaceuticals, compared to less specific cytostatic action, i.e., 5 chemotherapeutic agents. It should be emphasized that new medications are indicated for use mainly for monotherapy and less for a combination or adjuvant therapies. The comprehensive data presented in this review can serve for further design and development of more specific targeted agents in clinical usage for solid tumors.

Molecular Targeted Therapies: Time for a Paradigm Shift in Medulloblastoma Treatment?

Medulloblastoma is a rare malignancy of the posterior cranial fossa. Although until now considered a single disease, according to the current WHO classification, it is a heterogeneous tumor that comprises multiple molecularly defined subgroups, with distinct gene expression profiles, pathogenetic driver alterations, clinical behaviors and age at onset. Adult medulloblastoma, in particular, is considered a rarer "orphan" entity in neuro-oncology practice because while treatments have progressively evolved for the pediatric population, no practice-changing prospective, randomized clinical trials have been performed in adults. In this scenario, the toughest challenge is to transfer the advances in cancer genomics into new molecularly targeted therapeutics, to improve the prognosis of this neoplasm and the treatment-related toxicities. Herein, we focus on the recent advances in targeted therapy of medulloblastoma based on the new and deeper knowledge of disease biology.

Role of aberrant Sonic hedgehog signaling pathway in cancers and developmental anomalies

Development is a sophisticated process maintained by various signal transduction pathways, including the Hedgehog (Hh) pathway. Several important functions are executed by the Hh signaling cascade such as organogenesis, tissue regeneration, and tissue homeostasis, among various others. Considering the multiple functions carried out by this pathway, any mutation causing aberrant Hh signaling may lead to myriad developmental abnormalities besides cancers. In the present review article, we explored a wide range of diseases caused by aberrant Hh signaling, including developmental defects and cancers. Finally, we concluded this mini-review with various treatment strategies for Hh-induced diseases.

Evaluation of Hedgehog Pathway Inhibition on Nevoid Basal Cell Carcinoma Syndrome Fibroblasts and Basal Cell Carcinoma-Associated Fibroblasts: Are Vismodegib and Sonidegib Useful to Target Cancer-Prone Fibroblasts?

Activating mutations in the Hh pathway underlies the development of sporadic and familial skin BCC. For these oncogenic proliferations displaying ligand-independent activation of the intracellular pathway, two molecules have been approved for therapeutic purposes: vismodegib and sonidegib. Improper Hh signalling occurs in many human tumours also via a paracrine mechanism (ligand-dependent) in which the secretion of Hh ligands by stromal cells support tumour growth. On the other hand, the mobilization of neoplastic stroma by cancer cells is sustained by the activation of Hh signalling in surrounding fibroblasts suggesting a central role of this bidirectional crosstalk in carcinogenesis. Additionally, loss-of-function mutations in the PTCH1 gene in the context of NBCCS, an autosomal dominant disorder predisposing to multiple BCCs, determine tumour permissive phenotypes in dermal fibroblasts. Here, profiling syndromic and BCC-associated fibroblasts unveiled an extraordinary similarity characterized by overexpression of several Hh target genes and a marked pro-inflammatory outline. Both cell types exposed to Hh inhibitors displayed reversion of the tumour-prone phenotype. Under vismodegib and sonidegib treatment, the Wnt/β-catenin pathway, frequently over-active in tumour stroma, resulted down-regulated by pAKT-GSK3β axis and consequent increase of β-catenin turnover. Overall, this study demonstrated that vismodegib and sonidegib impacting on fibroblast tumour supportive functions might be considered in therapy for BCC independently to the mutation status of Hh components in neoplastic cells.

Hedgehog Pathway Inhibitors against Tumor Microenvironment

Targeting the hedgehog (HH) pathway to treat aggressive cancers of the brain, breast, pancreas, and prostate has been ongoing for decades. Gli gene amplifications have been long discovered within malignant glioma patients, and since then, inhibitors against HH pathway-associated molecules have successfully reached the clinical stage where several of them have been approved by the FDA. Albeit this success rate implies suitable progress, clinically used HH pathway inhibitors fail to treat patients with metastatic or recurrent disease. This is mainly due to heterogeneous tumor cells that have acquired resistance to the inhibitors along with the obstacle of effectively targeting the tumor microenvironment (TME). Severe side effects such as hyponatremia, diarrhea, fatigue, amenorrhea, nausea, hair loss, abnormal taste, and weight loss have also been reported. Furthermore, HH signaling is known to be involved in the regulation of immune cell maturation, angiogenesis, inflammation, and polarization of macrophages and myeloid-derived suppressor cells. It is critical to determine key mechanisms that can be targeted at different levels of tumor development and progression to address various clinical issues. Hence current research focus encompasses understanding how HH controls TME to develop TME altering and combinatorial targeting strategies. In this review, we aim to discuss the pros and cons of targeting HH signaling molecules, understand the mechanism involved in treatment resistance, reveal the role of the HH pathway in anti-tumor immune response, and explore the development of potential combination treatment of immune checkpoint inhibitors with HH pathway inhibitors to target HH-driven cancers.

Smoothened is a therapeutic target for reducing glutamate toxicity in ischemic stroke

[Figure: see text].

Identification of Key Genes and Pathways in Persistent Hyperplastic Primary Vitreous of the Eye Using Bioinformatic Analysis

Background: The failure of the embryonic hyaloid vascular system to regress naturally causes persistent hyperplastic primary vitreous (PHPV), a congenital eye disease. PHPVs molecular pathway, candidate genes, and drug targets are unknown. The current paper describes a comprehensive analysis using bioinformatics to identify the key genes and molecular pathways associated with PHPV, and to evaluate potential therapeutic agents for disease management. Methods: The genes associated with PHPV were identified using the pubmed2ensembl text mining platform. GeneCodis was employed to evaluate the Gene Ontology (GO) biological process terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Search Tool for the Retrieval of Interacting Genes (STRING) constructed a protein-protein interaction (PPI) network from the text mining genes (TMGs) in Cytoscape. The significant modules were clustered using Molecular Complex Detection (MCODE), and the GO and KEGG analysis for the hub genes were analyzed with the Database of Annotation, Visualization and Integrated Discovery (DAVID) tool. ClueGO, CluePedia, and ShinyGo were used to illustrate the functions and pathways of the clustered hub genes in a significant module. The Drug-Gene Interaction database (DGIdb) was used to evaluate drug-gene interactions of the hub genes to identify potential PHPV drug candidates. Results: A total of 50 genes associated with PHPV were identified. Overall, 35 enriched GO terms and 15 KEGG pathways were discovered by the gene functional enrichment analysis. Two gene modules were obtained from the PPI network constructed with 31 nodes with 42 edges using MCODE. We selected 14 hub genes as core candidate genes: TP53, VEGFA, SMAD2, CDKN2A, FOXC, FZD4, LRP5, KDR, FZD5, PAX6, MYCN, NDP, PITX2, and PAX2, primarily associated with camera-type eye morphogenesis, pancreatic cancer, the apoptotic process involved in morphogenesis, and the VEGF receptor signaling pathway. We discovered that 26 Food and Drug Administration (FDA)-approved drugs could target 7 of the 14 hub genes. Conclusions: In conclusion, the results revealed a total of 14 potential genes, 4 major pathways, 7 drug gene targets, and 26 candidate drugs that could provide the basis of novel targeted therapies for targeted treatment and management of PHPV.

Development of Randomized Trials in Adults with Medulloblastoma-The Example of EORTC 1634-BTG/NOA-23

Simple Summary

Medulloblastoma is rare after puberty. Among several molecular subgroups that have been described, the sonic hedgehog (SHH) subgroup is highly overrepresented in the post-pubertal population and can be targeted with smoothened (SMO) inhibitors. However, no practice-changing prospective clinical trials have been published in adults to date. Tumors often recur, and treatment toxicity is relevant. Thus, the EORTC 1634-BTG/NOA-23 trial for post-pubertal patients with standard risk medulloblastoma will aim to increase treatment efficacy and to decrease treatment toxicity. Patients will be randomized between standard-dose vs. reduced-dosed radiotherapy, and SHH-subgroup patients will also be randomized between the SMO inhibitor sonidegib (Odomzo^TM,, Sun Pharmaceuticals Industries, Inc., New York, USA) in addition to standard radio-chemotherapy vs. standard radio-chemotherapy alone. In ancillary studies, we will investigate tumor tissue, blood and cerebrospinal fluid samples, magnetic resonance images, and radiotherapy plans to gain information that may improve future treatment. Patients will also be monitored long-term for late side effects of therapy, health-related quality of life, cognitive function, social and professional live outcomes, and reproduction and fertility. In summary, EORTC 1634-BTG/NOA-23 is a unique multi-national effort that will help to council patients and clinical scientists for the appropriate design of treatments and future clinical trials for post-pubertal patients with medulloblastoma.

Abstract

Medulloblastoma is a rare brain malignancy. Patients after puberty are rare and bear an intermediate prognosis. Standard treatment consists of maximal resection plus radio-chemotherapy. Treatment toxicity is high and produces disabling long-term side effects. The sonic hedgehog (SHH) subgroup is highly overrepresented in the post-pubertal and adult population and can be targeted by smoothened (SMO) inhibitors. No practice-changing prospective randomized data have been generated in adults. The EORTC 1634-BTG/NOA-23 trial will randomize patients between standard-dose vs. reduced-dosed craniospinal radiotherapy and SHH-subgroup patients between the SMO inhibitor sonidegib (Odomzo^TM, Sun Pharmaceuticals Industries, Inc., New York, USA) in addition to standard radio-chemotherapy vs. standard radio-chemotherapy alone to improve outcomes in view of decreased radiotherapy-related toxicity and increased efficacy. We will further investigate tumor tissue, blood, and cerebrospinal fluid as well as magnetic resonance imaging and radiotherapy plans to generate information that helps to further improve treatment outcomes. Given that treatment side effects typically occur late, long-term follow-up will monitor classic side effects of therapy, but also health-related quality of life, cognition, social and professional outcome, and reproduction and fertility. In summary, we will generate unprecedented data that will be translated into treatment changes in post-pubertal patients with medulloblastoma and will help to design future clinical trials.

Premature Growth Plate Closure Caused by a Hedgehog Cancer Drug Is Preventable by Co-Administration of a Retinoid Antagonist in Mice

The growth plates are key engines of skeletal development and growth and contain a top reserve zone followed by maturation zones of proliferating, prehypertrophic, and hypertrophic/mineralizing chondrocytes. Trauma or drug treatment of certain disorders can derange the growth plates and cause accelerated maturation and premature closure, one example being anti-hedgehog drugs such as LDE225 (Sonidegib) used against pediatric brain malignancies. Here we tested whether such acceleration and closure in LDE225-treated mice could be prevented by co-administration of a selective retinoid antagonist, based on previous studies showing that retinoid antagonists can slow down chondrocyte maturation rates. Treatment of juvenile mice with an experimental dose of LDE225 for 2 days (100 mg/kg by gavage) initially caused a significant shortening of long bone growth plates, with concomitant decreases in chondrocyte proliferation; expression of Indian hedgehog, Sox9, and other key genes; and surprisingly, the number of reserve progenitors. Growth plate involution followed with time, leading to impaired long bone lengthening. Mechanistically, LDE225 treatment markedly decreased the expression of retinoid catabolic enzyme Cyp26b1 within growth plate, whereas it increased and broadened the expression of retinoid synthesizing enzyme Raldh3, thus subverting normal homeostatic retinoid circuitries and in turn accelerating maturation and closure. All such severe skeletal and molecular changes were prevented when LDE-treated mice were co-administered the selective retinoid antagonist CD2665 (1.5 mg/kg/d), a drug targeting retinoid acid receptor γ, which is most abundantly expressed in growth plate. When given alone, CD2665 elicited the expected maturation delay and growth plate expansion. In vitro data showed that LDE225 acted directly to dampen chondrogenic phenotypic expression, a response fully reversed by CD2665 co-treatment. In sum, our proof-of-principle data indicate that drug-induced premature growth plate closures can be prevented or delayed by targeting a separate phenotypic regulatory mechanism in chondrocytes. The translation applicability of the findings remains to be studied. © 2021 American Society for Bone and Mineral Research (ASBMR).

A review of emerging and non-US FDA-approved topical agents for the treatment of basal cell carcinoma

Although surgical therapy continues to be the gold standard for the treatment of basal cell carcinoma given high cure rates and the ability to histologically confirm tumor clearance, there are a number of nonsurgical treatment options that may be considered based on individual tumor characteristics, functional and cosmetic considerations, patient comorbidities and patient preference. Topical 5-fluorouracil 5% cream and imiquimod 5% cream have been US FDA-approved for the treatment of superficial basal cell carcinoma. Additionally, a number of new and emerging topical agents and techniques have been described for the treatment of basal cell carcinoma and will be reviewed herein.

Small molecules in targeted cancer therapy: advances, challenges, and future perspectives

Due to the advantages in efficacy and safety compared with traditional chemotherapy drugs, targeted therapeutic drugs have become mainstream cancer treatments. Since the first tyrosine kinase inhibitor imatinib was approved to enter the market by the US Food and Drug Administration (FDA) in 2001, an increasing number of small-molecule targeted drugs have been developed for the treatment of malignancies. By December 2020, 89 small-molecule targeted antitumor drugs have been approved by the US FDA and the National Medical Products Administration (NMPA) of China. Despite great progress, small-molecule targeted anti-cancer drugs still face many challenges, such as a low response rate and drug resistance. To better promote the development of targeted anti-cancer drugs, we conducted a comprehensive review of small-molecule targeted anti-cancer drugs according to the target classification. We present all the approved drugs as well as important drug candidates in clinical trials for each target, discuss the current challenges, and provide insights and perspectives for the research and development of anti-cancer drugs.

First reported case of concurrent sonidegib and radiotherapy for recurrent, advanced basal cell carcinoma

Basal cell carcinoma (BCC ) is the most common human malignancy. Systemic therapy with a sonic hedgehog (SHH) pathway inhibitor plays an important role in the treatment of advanced BCC . Literature on concurrent use of radiation therapy (RT ) with SHH inhibitors has been minimal and has solely been focused on vismodegib. We present a case report of a patient with recurrent basal cell carcinoma involving the high-risk area of the face, who was denied surgery due to comorbidities and difficulty in obtaining complete tumor removal without cosmetic or functional impairment. The patient received combined treatment of fractionated radiation with concurrent sonidegib and had complete clinical response with no significant toxicities. This is the first reported case on the use of concurrent RT with sonidegib for management of recurrent basal cell carcinoma of the head and neck.

Regulation of Hedgehog Signaling by miRNAs and Nanoformulations: A Possible Therapeutic Solution for Colorectal Cancer

Hedgehog (Hh) signaling aberrations trigger differentiation and proliferation in colorectal cancer (CRC). However, the current approaches which inhibit this vital cellular pathway provoke some side effects. Therefore, it is necessary to look for new therapeutic options. MicroRNAs are small molecules that modulate expression of the target genes and can be utilized as a potential therapeutic option for CRC. On the other hand, nanoformulations have been implemented in the treatment of plethora of diseases. Owing to their excessive bioavailability, limited cytotoxicity and high specificity, nanoparticles may be considered as an alternative drug delivery platform for the Hh signaling mediated CRC. This article reviews the Hh signaling and its involvement in CRC with focus on miRNAs, nanoformulations as potential diagnostic/prognostic and therapeutics for CRC.

Palladium catalyzed C–C and C–N bond forming reactions: an update on the synthesis of pharmaceuticals from 2015–2020

Some of the most prominent and promising catalysts in organic synthesis for the requisite construction of C–C and C–N bonds are palladium (Pd) catalysts, which play a pivotal role in pharmaceutical and medicinal chemistry.

Synthesis of 2-methoxybenzamide derivatives and evaluation of their hedgehog signaling pathway inhibition

Aberrant hedgehog (Hh) signaling is implicated in the development of a variety of cancers. Smoothened (Smo) protein is a bottleneck in the Hh signal transduction. The regulation of the Hh signaling pathway to target the Smo receptor is a practical approach for development of anticancer agents. We report herein the design and synthesis of a series of 2-methoxybenzamide derivatives as Hh signaling pathway inhibitors. The pharmacological data demonstrated that compound 21 possessed potent Hh pathway inhibition with a nanomolar IC₅₀ value, and it prevented Shh-induced Smo from entering the primary cilium. Furthermore, mutant Smo was effectively suppressed via compound 21. The in vitro antiproliferative activity of compound 21 against a drug-resistant cell line gave encouraging results.

Benzamide analog (21) was identified as a potent hedgehog signaling pathway inhibitor that targeted the Smo receptor and blocked Daoy cell proliferation.

Downregulation of miR-506-3p Facilitates EGFR-TKI Resistance through Induction of Sonic Hedgehog Signaling in Non-Small-Cell Lung Cancer Cell Lines

Non-small-cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutation eventually develop resistance to EGFR-targeted tyrosine kinase inhibitors (TKIs). Treatment resistance remains the primary obstacle to the successful treatment of NSCLC. Although drug resistance mechanisms have been studied extensively in NSCLC, the regulation of these mechanisms has not been completely understood. Recently, increasing numbers of microRNAs (miRNAs) are implicated in EGFR-TKI resistance, indicating that miRNAs may serve as novel targets and may hold promise as predictive biomarkers for anti-EGFR therapy. MicroRNA-506 (miR-506) has been identified as a tumor suppressor in many cancers, including lung cancer; however, the role of miR-506 in lung cancer chemoresistance has not yet been addressed. Here we report that miR-506-3p expression was markedly reduced in erlotinib-resistant (ER) cells. We identified Sonic Hedgehog (SHH) as a novel target of miR-506-3p, aberrantly activated in ER cells. The ectopic overexpression of miR-506-3p in ER cells downregulates SHH signaling, increases E-cadherin expression, and inhibits the expression of vimentin, thus counteracting the epithelial-mesenchymal transition (EMT)-mediated chemoresistance. Our results advanced our understanding of the molecular mechanisms underlying EGFR-TKI resistance and indicated that the miR-506/SHH axis might represent a novel therapeutic target for future EGFR mutated lung cancer treatment.

Cancer Predisposition Syndromes and Medulloblastoma in the Molecular Era

Medulloblastoma is the most common malignant brain tumor in children. In addition to sporadic cases, medulloblastoma may occur in association with cancer predisposition syndromes. This review aims to provide a complete description of inherited cancer syndromes associated with medulloblastoma. We examine their epidemiological, clinical, genetic, and diagnostic features and therapeutic approaches, including their correlation with medulloblastoma. Furthermore, according to the most recent molecular advances, we describe the association between the various molecular subgroups of medulloblastoma and each cancer predisposition syndrome. Knowledge of the aforementioned conditions can guide pediatric oncologists in performing adequate cancer surveillance. This will allow clinicians to promptly diagnose and treat medulloblastoma in syndromic children, forming a team with all specialists necessary for the correct management of the other various manifestations/symptoms related to the inherited cancer syndromes.

Combined inhibition of JAK2-STAT3 and SMO-GLI1/tGLI1 pathways suppresses breast cancer stem cells, tumor growth, and metastasis

Triple-negative breast cancer (TNBC) and HER2-positive breast cancer are particularly aggressive and associated with unfavorable prognosis. TNBC lacks effective treatments. HER2-positive tumors have treatment options but often acquire resistance to HER2-targeted therapy after initial response. To address these challenges, we determined whether novel combinations of JAK2-STAT3 and SMO-GLI1/tGLI1 inhibitors synergistically target TNBC and HER2 breast cancer since these two pathways are concurrently activated in both tumor types and enriched in metastatic tumors. Herein, we show that novel combinations of JAK2 inhibitors (ruxolitinib and pacritinib) with SMO inhibitors (vismodegib and sonidegib) synergistically inhibited in vitro growth of TNBC and HER2-positive trastuzumab-resistant BT474-TtzmR cells. Synergy was also observed against breast cancer stem cells. To determine if the combination is efficacious in inhibiting metastasis, we treated mice with intracardially inoculated TNBC cells and found the combination to inhibit lung and liver metastases, and prolong host survival without toxicity. The combination inhibited orthotopic growth, VEGF-A expression, and tumor vasculature of both TNBC and HER2-positive trastuzumab-refractory breast cancer. Lung metastasis of orthotopic BT474-TtzmR xenografts was suppressed by the combination. Together, our results indicated that dual targeting of JAK2 and SMO resulted in synergistic suppression of breast cancer growth and metastasis, thereby supporting future clinical testing.

Baicalin Attenuates YAP Activity to Suppress Ovarian Cancer Stemness

Purpose

This study aims to reveal the mechanism underlying baicalin-suppressing ovarian cancer stemness.

Methods

OVCAR-3 and the primary ovarian cancer cells were used for cell model. The ovarian cancer stem cells were isolated by suspension culture. Cell viability and clonogenicity were examined by CCK-8 assay and colony formation assay. The self-renewal of the cells was evaluated by the determination of sphere-forming capacity and the frequency of in vitro sphere-forming and in vivo tumor-initiating cells. The mRNA and protein levels were relatively quantified by qRT-PCR and Western blot. The transcription regulation of target genes was tested by luciferase reporter assay and a modified nuclear rn-on qRT-PCR assay.

Results

Treatment with a non-toxic dose of baicalin significantly inhibited the spherogenicity of ovarian cancer cells. Moreover, a non-toxic dose of baicalin treatment suppressed the frequency of sphere-forming and tumor-initiating ovarian cancer cells. Furthermore, the expression of ovarian cancer stem cell markers (CD133 and ALDH1A1) was inhibited by a non-toxic dose of baicalin treatment. Baicalin inhibits YAP activity and suppresses RASSF6, a positive regulator of YAP, at the transcriptional level. Overexpression of both YAP and RASSF6 abolished the inhibitory effect of baicalin on the proliferation and stemness of ovarian cancer cells.

Conclusion

The results in this study demonstrated that baicalin suppresses the stemness of ovarian cancer cells by attenuating YAP activity via inhibiting RASSF6 at the transcriptional level. This finding revealed baicalin as a novel YAP inhibitor that could serve as an anti-cancer drug for eradicating ovarian cancer stem cells.

Sonidegib: Safety and Efficacy in Treatment of Advanced Basal Cell Carcinoma

Hedgehog inhibitors are promising alternative treatments for patients with advanced basal cell carcinomas. Sonidegib (Odomzo®), an oral smoothened (SMO) antagonist, is indicated for the treatment of adult patients with locally advanced basal cell carcinoma (laBCC) who present recurrence following surgery or radiation therapy, or those who are not candidates for surgery or radiotherapy. Several studies and randomized controlled trials have been conducted to evaluate the efficacy, safety, and tolerability of this new molecule that has demonstrated a good response rate (44%). Grade 1-2 adverse events have also been reported. Further studies of real-world experiences are needed to better understand the correct management of the drug, alternative dosing regimens, and differences with other hedgehog inhibitors. This article provides a complete overview of the pharmacology and pharmacokinetics of sonidegib and a report of the trials and studies conducted. The most frequent adverse events and their correct management are also discussed.

Potential Drugs Targeting Early Innate Immune Evasion of SARS-Coronavirus 2 via 2'-O-Methylation of Viral RNA

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causing the COVID-19 respiratory disease pandemic utilizes unique 2'-O-methyltransferase (2'-O-MTase) capping machinery to camouflage its RNA from innate immune recognition. The nsp16 catalytic subunit of the 2'-O-MTase is unusual in its requirement for a stimulatory subunit (nsp10) to catalyze the ribose 2'-O-methylation of the viral RNA cap. Here we provide a computational basis for drug repositioning or de novo drug development based on three differential traits of the intermolecular interactions of the SARS-CoV-2-specific nsp16/nsp10 heterodimer, namely: (1) the S-adenosyl-l-methionine-binding pocket of nsp16, (2) the unique "activating surface" between nsp16 and nsp10, and (3) the RNA-binding groove of nsp16. We employed ≈9000 U.S. Food and Drug Administration (FDA)-approved investigational and experimental drugs from the DrugBank repository for docking virtual screening. After molecular dynamics calculations of the stability of the binding modes of high-scoring nsp16/nsp10-drug complexes, we considered their pharmacological overlapping with functional modules of the virus-host interactome that is relevant to the viral lifecycle, and to the clinical features of COVID-19. Some of the predicted drugs (e.g., tegobuvir, sonidegib, siramesine, antrafenine, bemcentinib, itacitinib, or phthalocyanine) might be suitable for repurposing to pharmacologically reactivate innate immune restriction and antagonism of SARS-CoV-2 RNAs lacking 2'-O-methylation.

Sonidegib: Safety and Efficacy in Treatment of Advanced Basal Cell Carcinoma

Hedgehog inhibitors are promising alternative treatments for patients with advanced basal cell carcinomas. Sonidegib (Odomzo^®), an oral smoothened (SMO) antagonist, is indicated for the treatment of adult patients with locally advanced basal cell carcinoma (laBCC) who present recurrence following surgery or radiation therapy, or those who are not candidates for surgery or radiotherapy. Several studies and randomized controlled trials have been conducted to evaluate the efficacy, safety, and tolerability of this new molecule that has demonstrated a good response rate (44%). Grade 1-2 adverse events have also been reported. Further studies of real-world experiences are needed to better understand the correct management of the drug, alternative dosing regimens, and differences with other hedgehog inhibitors. This article provides a complete overview of the pharmacology and pharmacokinetics of sonidegib and a report of the trials and studies conducted. The most frequent adverse events and their correct management are also discussed.

Clinical trials using molecular stratification of pediatric brain tumors

Brain cancer is now the leading cause of cancer death in children and adolescents, surpassing leukemia. The heterogeneity and invasiveness of pediatric brain tumors have historically made them difficult to treat. Although surgical intervention and standard of care therapies such as radiation and chemotherapy have improved the outlook for those affected, results are often transient and lend themselves to tumor recurrence or resistance. There also still exists a subset of brain tumors which remain unresponsive to treatment altogether. Therefore, there is great need for new therapeutic approaches. With the recent advent of molecularly-driven technologies, many of these complex tumors can now be classified by integrating molecular profiling data with clinical information such as demographics and outcomes. This new knowledge has allowed for the molecular stratification of pediatric brain tumors into distinct subgroups and the identification of molecular targets, which is changing how these children are treated, namely in the setting of clinical trials. Notable examples include reduced doses of radiation and chemotherapy in the wingless-activated subgroup of medulloblastoma, which has a favorable prognosis, and novel experimental drugs targeting BRAF alterations in low-grade gliomas and dopamine receptors in high-grade gliomas. In this review, we highlight several key previous and ongoing clinical trials that utilize molecular stratifications and targets for the treatment of pediatric brain tumors.

Deciphering novel chemotherapy and its impact on dentistry

In the last few decades, the number of targeted chemotherapies approved for cancer treatment and undergoing clinical trials has risen. In comparison to conventional chemotherapy, targeted therapies (TTs) act on specific molecular targets involved in cancer development and progression, with reduced detrimental effects to normal tissues. TTs have now been recognised as key treatments in a number of common cancers, including solid tumours and haematological malignancies. The number of patients undergoing novel cancer treatment will continue to increase, and a significant population will likely present to the dental environment. This paper aims to provide an insight into TTs currently available, including monoclonal antibodies, fusion proteins, tyrosine kinase inhibitors, histone deacetylase inhibitors, mammalian target of rapamycin inhibitors, phosphoinositide 3-kinase inhibitors, proteasome inhibitors and hedgehog pathway inhibitors. The mechanisms of action, indications for use and how to identify the medications will be summarised. Dental implications of these novel therapies include medication-related osteonecrosis of the jaw, delayed healing, immunosuppression and thrombocytopenia. These will be discussed to ensure oral healthcare providers are aware of their impact in a dental setting.

Complications and Toxicities Associated with Cancer Therapies in the Intensive Care Unit

Advances in the management of hematologic malignancies and solid tumors have given rise to diverse modalities to treat cancer other than cytotoxic chemotherapy, including targeted therapies, immunotherapies, and cellular therapies. Currently, there are over 175 FDA-approved antineoplastic agents in the United States, many with a diverse and profound toxicity profile. Complications of antineoplastic therapy may result in the need for intensive care unit (ICU) admission to provide acute symptom management. Accordingly, ICU providers caring for cancer patients should have a working knowledge of the toxicities and complications associated with antineoplastic therapy.

The great escape: tumour cell plasticity in resistance to targeted therapy

The success of targeted therapies in cancer treatment has been impeded by various mechanisms of resistance. Besides the acquisition of resistance-conferring genetic mutations, reversible mechanisms that lead to drug tolerance have emerged. Plasticity in tumour cells drives their transformation towards a phenotypic state that no longer depends on the drug-targeted pathway. These drug-refractory cells constitute a pool of slow-cycling cells that can either regain drug sensitivity upon treatment discontinuation or acquire permanent resistance to therapy and drive relapse. In the past few years, cell plasticity has emerged as a mode of targeted therapy evasion in various cancers, ranging from prostate and lung adenocarcinoma to melanoma and basal cell carcinoma. Our understanding of the mechanisms that control this phenotypic switch has also expanded, revealing the crucial role of reprogramming factors and chromatin remodelling. Further deciphering the molecular basis of tumour cell plasticity has the potential to contribute to new therapeutic strategies which, combined with existing anticancer treatments, could lead to deeper and longer-lasting clinical responses.

Luminescent and fluorescent triple reporter plasmid constructs for Wnt, Hedgehog and Notch pathway

Tracking the activity of signalling pathways is a fundamental method for basic science, as well as in cancer- and pharmaceutical research. The developmental pathways Wnt, Hedgehog and Notch are frequently deregulated in cancers and represent a valuable target for the discovery of novel anticancer compounds. Here we present reporter systems for tracking activity of these pathways by using specific promoter elements driving the expression of either sensitive luciferases or fluorescent proteins. A high level of sensitivity was obtained using the luciferase reporter genes for firefly (FLuc), secreted Gaussia (GLuc) and synthetic NanoLuc (NLuc). As fluorescent reporter proteins, mTurqouise2, tdTomato and iRFP720 were chosen. Specificity of pathway activity was validated by co-transfection with pathway activating genes, showing significant response to induction. In addition, multi-gene plasmids were cloned, allowing the detection of all three pathways by one vector. By using the multi-gene vector 3P-Luc (wnt-NLuc, hedgehog-FLuc, Notch-GLuc), we could unambiguously demonstrate the crosstalk between pathways, while excluding cross reactivity of luciferase substrates. First studies with synthetic compounds confirmed the applicability of the system for future drug screening approaches.

Heteroarylamide smoothened inhibitors: Discovery of N-[2,4-dimethyl-5-(1-methylimidazol-4-yl)phenyl]-4-(2-pyridylmethoxy)benzamide (AZD8542) and N-[5-(1H-imidazol-2-yl)-2,4-dimethyl-phenyl]-4-(2- pyridylmethoxy)benzamide (AZD7254)

Aberrant hedgehog (Hh) pathway signaling is implicated in multiple cancer types and targeting the Smoothened (SMO) receptor, a key protein of the Hh pathway, has proven effective in treating metastasized basal cell carcinoma. Our lead optimization effort focused on a series of heteroarylamides. We observed that a methyl substitution ortho to the heteroaryl groups on an aniline core significantly improved the potency of this series of compounds. These findings predated the availability of SMO crystal structure in 2013. Here we retrospectively applied quantum mechanics calculations to demonstrate the o-Me substitution favors the bioactive conformation by inducing a dihedral twist between the heteroaryl rings and the core aniline. The o-Me also makes favorable hydrophobic interactions with key residue side chains in the binding pocket. From this effort, two compounds (AZD8542 and AZD7254) showed excellent pharmacokinetics across multiple preclinical species and demonstrated in vivo activity in abrogating the Hh paracrine pathway as well as anti- tumor effects.

Fractionated head and neck irradiation impacts taste progenitors, differentiated taste cells, and Wnt/β-catenin signaling in adult mice

Head and neck cancer patients receiving conventional repeated, low dose radiotherapy (fractionated IR) suffer from taste dysfunction that can persist for months and often years after treatment. To understand the mechanisms underlying functional taste loss, we established a fractionated IR mouse model to characterize how taste buds are affected. Following fractionated IR, we found as in our previous study using single dose IR, taste progenitor proliferation was reduced and progenitor cell number declined, leading to interruption in the supply of new taste receptor cells to taste buds. However, in contrast to a single dose of IR, we did not encounter increased progenitor cell death in response to fractionated IR. Instead, fractionated IR induced death of cells within taste buds. Overall, taste buds were smaller and fewer following fractionated IR, and contained fewer differentiated cells. In response to fractionated IR, expression of Wnt pathway genes, Ctnnb1, Tcf7, Lef1 and Lgr5 were reduced concomitantly with reduced progenitor proliferation. However, recovery of Wnt signaling post-IR lagged behind proliferative recovery. Overall, our data suggest carefully timed, local activation of Wnt/β-catenin signaling may mitigate radiation injury and/or speed recovery of taste cell renewal following fractionated IR.

Hereditary Tumor Syndromes with Skin Involvement

Cutaneous findings that appear in childhood may be the first sign of a hereditary tumor syndrome. Early detection of genodermatoses allows the patient and at-risk family members to be screened for associated malignancies. This article provides a brief description of the pathogenesis and clinical manifestations of various inherited disorders with skin involvement, along with treatment updates. Advances in molecular-based therapy have spurred development of novel treatment methods for various genodermatoses such as xeroderma pigmentosum (XP) and Gorlin-Goltz syndrome. Further studies are needed to better assess the efficacy of many of these new treatment options.

Phase I and phase II sonidegib and vismodegib clinical trials for the treatment of paediatric and adult MB patients: a systemic review and meta-analysis

Background

Medulloblastoma (MB) is the most common malignant brain tumour in children but also rarely occur in adults. Sonic Hedgehog (SHH) driven MB is associated with aberrant activation of the SHH signalling pathway. SMO inhibitors, sonidegib and vismodegib, have been used as selective antagonist of the hedgehog pathway that acts by binding to SMO, and inhibits activation of the downstream hedgehog target genes. Several clinical trials investigating SMO inhibitors for the treatment of relapsed MB patients have been published.

Methods

We conducted a systemic review and meta-analysis among these Phase I and II clinical trials. The pooled effect of SMO inhibitors in relapsed MB were analysed using Reviewer Manager 5.3 software. The clinical efficacy of SMO inhibitors on SHH subtype of MB were measured by the objective response rate. The risk difference was obtained by comparing the ORR between SHH and non-SHH subtypes of MB.

Results

The five studies all had clear criteria for patient recruitment, adequate follow-up time for endpoint assessment and clear definition of tumour responses. MB patients had good compliance in the trials. The pooled objective response rate (ORR) of SMO inhibitor was 37% and 0 against SHH-driven and other MBs. The pooled ORR of sonidegib was 55% among MB^SHH and 0 among MB^non-SHH subgroup. Vismodegib also had no efficacy on non-SHH subtype of MB. The sonidegib against SHH-driven MB produced the ORR 1.87-fold higher than that of vismodegib (95%CI 1.23, 6.69). Among paediatric patients, the efficacy of sonidegib was 3.67-fold higher than vismodegib (p < 0.05). A total of 320 cases received SMO inhibitor therapy and 36 cases reported grade 3/4 dose-limiting toxicity (DLT). The rate of grade 3/4 DLT was similar between patients receiving vismodegib and sonidegib (11.6% vs. 11.2%).

Conclusion

Sonidegib and vismodegib were well tolerated and demonstrated anti-tumour activity in SHH-driven paediatric and adult MB by effectively inhibiting Hh signalling. These results support the ongoing clinical trials using SMO inhibitors in combination with conventional chemotherapies for the treatment of relapsed MB^SHH.

Nonsurgical Treatments for Nonmelanoma Skin Cancer

Although surgical intervention remains the standard of care for nonmelanoma skin cancer, other treatment modalities have been studied and used. Nonsurgical treatment methods include cryotherapy, topical medications, photodynamic therapy, radiation therapy, Hedgehog pathway inhibitors, programmed cell death protein 1 inhibitors, and active nonintervention. Despite the favorable efficacy of surgical treatment methods, many factors, including but not limited to patient age, preference, and severity of disease, must be taken into consideration when choosing the most appropriate, patient-centered treatment approach.