Inhibition of the hedgehog pathway in advanced basal-cell carcinoma

Primary cilia and cancer: a tale of many faces

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

Double-sided niche regulation in skin stem cell and cancer: mechanisms and clinical applications

The niche microenvironment plays a crucial role in regulating the fate of normal skin stem cells (SSCs) and cancer stem cells (CSCs). Therapeutically targeting the CSC niche holds promise as an effective strategy; however, the dual effects of shared SSC niche signaling in CSCs have contributed to the aggressive characteristics of tumors and poor survival rates in skin cancer patients. The lack of a clear underlying mechanism has significantly hindered drug development for effective treatment. This article explores recent advances in understanding how niche factors regulate cell fate determination between skin stem cells and skin CSCs, along with their clinical implications. The dual roles of key components of the adhesive niche, including the dermo-epidermal junction and adherens junction, various cell types-especially immune cells and fibroblasts-as well as major signaling pathways such as Sonic hedgehog (Shh), Wingless-related integration site (Wnt)/β-catenin, YAP (Yes-associated protein)/TAZ (transcriptional coactivator with PDZ-binding motif), and Notch, are highlighted. Additionally, recent advances in clinical trials and drug development targeting these pathways are discussed. Overall, this review provides valuable insights into the complex interactions between skin cancer stem cells and their microenvironment, laying the groundwork for future research and clinical strategies.

Recurrent vismodegib drug-induced liver injury with corticosteroid response

SummaryA man in his 60s with a history of multiple basal cell carcinomas was started on vismodegib, a Hedgehog signalling pathway inhibitor. Despite initial clinical response, he developed asymptomatic drug-induced liver injury (DILI) with elevated alanine transaminase (ALT) after 7 weeks of treatment. Vismodegib was stopped, and liver chemistry normalised. On rechallenge, ALT levels rose significantly higher, requiring discontinuation of vismodegib. However, despite discontinuation, ALT levels continued to rise, as did bilirubin levels. Liver biopsy confirmed inflammatory infiltrate primarily affecting the lobule with hepatocyte cell loss, consistent with DILI, and prednisolone was started. Liver function rapidly improved on prednisolone, and liver chemistry has remained normal since cessation of both vismodegib and prednisolone. This case highlights the need for careful liver monitoring in patients on vismodegib, emphasising the potential for significant DILI on re-exposure.

Surgical Management of Giant Basal Cell Carcinoma in the Maxillofacial Region: Ablative and Reconstructive Strategies

INTRODUCTION

Giant basal cell carcinoma (GBCC) is a rare and aggressive subtype of basal cell carcinoma (BCC), characterized by a diameter of ≥5 cm and a potential for deep tissue invasion. This study aimed to present our experience with the surgical management of GBCC in the maxillofacial region, focusing on resection and immediate reconstruction strategies.

METHODS

We conducted a retrospective analysis of 5926 patients with BCC in the maxillofacial region from 2010 to 2020, with a specific emphasis on 32 patients diagnosed with GBCC. Associations between patient and tumor characteristics were analyzed, treatment approaches evaluated, and clinical outcomes assessed.

RESULTS

The cohort comprised 20 males (62.5%) and 12 females (37.5%) ( P > 0.05), with a median age of 71 years (range: 40-86 years). The median time from tumor onset to presentation was 4 years (range: 2-7 years). A total of 24 GBCCs (75%) developed de novo, whereas 8 (25%) were recurrent BCCs ( P < 0.05). The median tumor diameter was 8 cm (range: 5-15 cm), with local invasiveness extending to cartilage in 31.25% of cases, facial muscles in 29.41%, neural tissues in 21.87%, and bone in 18.75%. Surgical resections included orbital exenteration (3 cases, 9.38%), total parotidectomy (2 cases, 6.25%), partial maxillectomy (2 cases, 6.25%), frontal craniofacial resection (2 cases, 6.25%), partial petrosectomy with mastoidectomy (1 case, 3.13%), and near-total rhinectomy (1 case, 3.13%). For reconstruction, a skin graft was used in 3 patients (9.38%), local skin flaps in 15 (46.88%), locoregional flaps in 10 (31.25%), and free flaps in 4 (12.5%). The 5-year overall survival, disease-free survival, and disease-specific survival for the cohort were 87.5%, 93.75%, and 96.88%, respectively.

CONCLUSIONS

Our findings suggest that a single-stage procedure featuring aggressive surgical resection and reconstruction achieves low complication rates, excellent oncologic control, and acceptable cosmetic outcomes.

Identification of RCC2 as a Risk Gene Associated With Basal Cell Carcinoma and Experimental Validation

Basal cell carcinoma (BCC) is a common type of skin cancer that is increasing in prevalence worldwide. Previous genome-wide association studies (GWAS) have identified certain genetic loci associated with BCC. However, many potential disease-causing genes of BCC remain to be discovered. While the sonic hedgehog (SHH) signalling pathway and mutations in PTCH1/2 and SMO are well-established drivers of BCC pathogenesis, novel genetic factors may complement existing therapeutic targets such as vismodegib and sonidegib. The Mendelian Randomization (MR) study used multiple omics datasets including expression quantitative trait loci (eQTL), methylation quantitative trait loci (mQTL), and protein quantitative trait loci (pQTL) to identify genetic factors associated with an increased risk of developing BCC. Transcriptome analysis of the GEO database then verified the specific expression of key genes. In addition, in vitro experiments were used to silence the key gene to observe the effect of this gene on the proliferation ability of A431 cells. Combined with the multi-omics MR Analysis results, six CpG sites were identified with the RCC2 gene associated with BCC risk. Additionally, single-cell transcriptome analysis confirmed the specific expression of RCC2 in the BCC cohort. In the in vitro validation experiment, siRCC2-1/2 was transfected into the A431 cells, significantly decreasing the expression of RCC2 in the cells. Moreover, the proliferation of A431 cells was significantly inhibited after RCC2 was knocked down. We identified a risk gene RCC2 associated with BCC by MR-based bioinformatics analysis and demonstrated that inhibition of RCC2 inhibited the proliferation of A431 in vitro. These findings provide new strategies for targeted therapy of BCC.

The Role of Radiation, Immunotherapy, and Chemotherapy in the Management of Locally Advanced or Metastatic Cutaneous Malignancies

INTRODUCTION

Skin cancer impacts a significant proportion of the population. While surgical management is often the mainstay of treatment, advanced or metastatic cutaneous malignancies require additional local and/or systemic therapies.

METHODS

A review of the literature was performed studying the use of radiation therapy, chemotherapy, and immunotherapy for locally advanced or metastatic cutaneous malignancies.

RESULTS

A summary of the present literature on the management of locally advanced or metastatic cutaneous malignancies is presented across cutaneous head and neck basal cell carcinoma, squamous cell carcinoma, melanoma, and Merkel cell carcinoma. The addition of multidisciplinary therapies to resection is often associated with improved outcomes.

CONCLUSION

The management of cutaneous head and neck malignancies requires an approach integrating multiple specialties, to optimize outcomes and minimize toxicities.

Computer-Aided Identification and Design of Ligands for Multi-Targeting Inhibition of a Molecular Acute Myeloid Leukemia Network

BACKGROUND/OBJECTIVES

Acute myeloid leukemia (AML) is characterized by therapeutic failure and long-term risk for disease relapses. As several therapeutic targets participate in networks, they can rewire to eventually evade single-target drugs. Hence, multi-targeting approaches are considered on the expectation that interference with many different components could synergistically hinder activation of alternative pathways and demolish the network one-off, leading to complete disease remission.

METHODS

Herein, we established a network-based, computer-aided approach for the rational design of drug combinations and de novo agents that interact with many AML network components simultaneously.

RESULTS

A reconstructed AML network guided the selection of suitable protein hubs and corresponding multi-targeting strategies. For proteins responsive to existing drugs, a greedy algorithm identified the minimum amount of compounds targeting the maximum number of hubs. We predicted permissible combinations of amiodarone, artenimol, fostamatinib, ponatinib, procaine, and vismodegib that interfere with 3-8 hubs, and we elucidated the pharmacological mode of action of procaine on DNMT3A. For proteins that do not respond to any approved drugs, namely cyclins A1, D2, and E1, we used structure-based de novo drug design to generate a novel triple-targeting compound of the chemical formula C15H15NO5, with favorable pharmacological and drug-like properties.

CONCLUSIONS

Overall, by integrating network and structural pharmacology with molecular modeling, we determined two complementary strategies with the potential to annihilate the AML network, one in the form of repurposable drug combinations and the other as a de novo synthesized triple-targeting agent. These target-drug interactions could be prioritized for preclinical and clinical testing toward precision medicine for AML.

Evaluation of the Tolerability of Hedgehog Pathway Inhibitors in the Treatment of Advanced Basal Cell Carcinoma: A Narrative Review of Treatment Strategies

Hedgehog pathway inhibitors (HHIs) have broadened the treatment options available for patients with advanced basal cell carcinoma (BCC) for whom traditional therapeutic approaches are not feasible or effective. Sonidegib and vismodegib are oral HHIs that were approved for treatment of patients with advanced BCC after demonstrating promising efficacy in the pivotal Phase II BOLT (NCT01327053) and ERIVANCE (NCT00833417) trials, respectively. However, the incidence and types of treatment-emergent adverse events (AEs) observed with these agents may limit continuous use of HHIs and ultimately impact clinical outcomes. In this review, we summarize the safety and tolerability profiles of sonidegib and vismodegib and discuss potential management strategies for HHI class-effect AEs, including muscle spasms, creatine phosphokinase increase, alopecia, and dysgeusia. These AEs primarily occur early in treatment and can lead to treatment discontinuation. Differences in the pharmacokinetic profiles of sonidegib and vismodegib may contribute to the variability noted in times to onset and resolution of these and other AEs. Evidence suggests that protocol modifications, such as treatment interruptions and dose reductions, are effective ways to manage AEs while maintaining disease control. Nonpharmacologic and pharmacologic interventions may also be considered as part of an AE management strategy. Overall, healthcare providers and patients with advanced BCC should be aware of the HHI class-effect AEs and plan effective management strategies to avoid treatment discontinuation and optimize therapeutic response.

Extensive head and neck skin cancers: Carcinologic surgery as a cornerstone of treatment

BACKGROUND AND OBJECTIVE

The prevalence of extensive skin cancers increases with the aging of the population. Surgical management is the gold standard of curative treatment while morbidity is not negligible. There are few data in the literature concerning extensive head and neck cutaneous cancers. The aim of this article is to report our experience of curative management of head and neck extensive skin cancers.

METHOD

In this single-center retrospective observational study, we report a series of 17 patients with extensive skin facial cancers treated by surgery between 2013 and 2022 in the maxillofacial surgery department of the Pitié-Salpêtrière Hospital. We collected clinical, therapeutic, histological, and carcinologic data.

RESULTS

The median age of the patients was 66 years [35-94]. There were 9 male and 8 women. Scalp (39 %) and cheek (22 %) locations were the most frequent ones. The most frequent histological types were squamous cell carcinoma (61 %) and basal cell carcinoma (17 %). Three patients received neoadjuvant treatment. The surgical treatment consisted mainly of carcinological resection followed by one-stage reconstruction by free flap for 5 (30 %) patients and without reconstruction for primary for 12 (70 %) patients, of whom 8 benefited from secondary reconstruction. Five patients received adjuvant radiotherapy or radio-chemotherapy. With a median follow-up of 40 months (2-72), the median overall survival was 40 months (12-72).

CONCLUSION

We know that extensive skin cancers of the face have a good prognosis on condition that the carcinological and reconstructive requirements are respected. Surgery remains the cornerstone of treatment while the improvement of adjuvant therapies, in particular the rise of immunotherapies or other targeted therapies, may allow to limit recurrences.

Systemic Therapy for Non-Melanoma Skin Cancers: Latest Advances

PURPOSE OF REVIEW

This review provides an update on approved and emerging systemic therapies in the treatment of locally advanced or metastatic non-melanoma skin cancers (squamous cell carcinoma, basal cell carcinoma, Merkel cell carcinoma).

RECENT FINDINGS

Many studies demonstrate the effectiveness of immunotherapy for all types of non-melanoma skin cancer. For basal cell carcinoma (BCC), hedgehog inhibitors (HHI) remain first-line but with poor tolerability. Numerous clinical trials studying both neoadjuvant and adjuvant use of anti-PD-1 and anti-PD-L1 therapies in advanced NMSC are under investigation. There is a growing number of systemic therapies available to treat non-melanoma skin cancers. The advent of immunotherapy has revolutionized the field and greatly improved survival compared to historical survival rates with cytotoxic chemotherapy.

Focal adhesion kinase as a new player in the biology of onco-hematological diseases: the starting evidence

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase mainly found in the focal adhesion regions of the plasma membrane and it has a crucial role in migration and the remodeling of cellular morphology. FAK is also linked to several aspects of cancer biology, from cytokine production to angiogenesis, drug resistance, invasion, and metastasis, as well as epithelial-to-mesenchymal transition. The gene locus of FAK is frequently amplified in several human tumors, thus causing FAK overexpression in several cancers. Furthermore, FAK can influence extracellular matrix production and exosome secretion through cancer-associated fibroblasts, thus it has an important role in tumor microenvironment regulation. Although the role of FAK in solid tumors is well known, its importance in onco-hematological diseases remains poorly explored. This review collects studies related to FAK significance in onco-hematological diseases and their microenvironments. Overall, the importance of FAK in blood tumors is increasingly evident, but further research is required to confirm it as a new therapeutic target in hematological contexts.

Hedgehog pathway inhibitors for locally advanced and metastatic basal cell carcinoma: A real-world single-center retrospective review

Basal cell carcinoma (BCC) is highly curable by surgical excision or radiation. In rare cases, BCC can be locally destructive or difficult to surgically remove. Hedgehog inhibition (HHI) with vismodegib or sonidegib induces a 50-60% response rate. Long-term toxicity includes muscle spasms and weight loss leading to dose decreases. This retrospective chart review also investigates the impact of CoQ10 and calcium supplementation in patients treated with HHI drugs at a single academic medical center from 2012 to 2022. We reviewed the charts of adult patients diagnosed with locally advanced or metastatic BCC treated with vismodegib or sonidegib primarily for progression-free survival (PFS). Secondary objectives included overall survival, BCC-specific survival, time to and reasons for discontinuation, overall response rate, safety and tolerability, use of CoQ10 and calcium supplements, and insurance coverage. Of 55 patients assessable for outcome, 34 (61.8%) had an overall clinical benefit, with 25 (45.4%) having a complete response and 9 (16.3%) a partial response. Stable disease was seen in 14 (25.4%) and 7 (12.7%) progressed. Of the 34 patients who responded to treatment, 9 recurred. Patients who were rechallenged with HHI could respond again. The median overall BCC-specific survival rate at 5 years is 89%. Dose reductions or discontinuations for vismodegib and sonidegib occurred in 59% versus 24% of cases, or 30% versus 9% of cases, respectively. With CoQ10 and calcium supplementation, only 17% required a dose reduction versus 42% without. HHI is highly effective for treating advanced BCC but may require dosing decreases. Sonidegib was better tolerated than vismodegib. CoQ10 and calcium supplementation can effectively prevent muscle spasms.

Informed by Cancer Stem Cells of Solid Tumors: Advances in Treatments Targeting Tumor-Promoting Factors and Pathways

Cancer stem cells (CSCs) represent a subpopulation within tumors that promote cancer progression, metastasis, and recurrence due to their self-renewal capacity and resistance to conventional therapies. CSC-specific markers and signaling pathways highly active in CSCs have emerged as a promising strategy for improving patient outcomes. This review provides a comprehensive overview of the therapeutic targets associated with CSCs of solid tumors across various cancer types, including key molecular markers aldehyde dehydrogenases, CD44, epithelial cellular adhesion molecule, and CD133 and signaling pathways such as Wnt/β-catenin, Notch, and Sonic Hedgehog. We discuss a wide array of therapeutic modalities ranging from targeted antibodies, small molecule inhibitors, and near-infrared photoimmunotherapy to advanced genetic approaches like RNA interference, CRISPR/Cas9 technology, aptamers, antisense oligonucleotides, chimeric antigen receptor (CAR) T cells, CAR natural killer cells, bispecific T cell engagers, immunotoxins, drug-antibody conjugates, therapeutic peptides, and dendritic cell vaccines. This review spans developments from preclinical investigations to ongoing clinical trials, highlighting the innovative targeting strategies that have been informed by CSC-associated pathways and molecules to overcome therapeutic resistance. We aim to provide insights into the potential of these therapies to revolutionize cancer treatment, underscoring the critical need for a multi-faceted approach in the battle against cancer. This comprehensive analysis demonstrates how advances made in the CSC field have informed significant developments in novel targeted therapeutic approaches, with the ultimate goal of achieving more effective and durable responses in cancer patients.

Japanese Dermatological Association guidelines: Outlines of Japanese clinical guidelines for basal cell carcinoma 2021

To summarize the current therapies for skin cancers, the Japanese Skin Cancer Society issued the first guidelines for skin cancers, including melanoma, squamous cell carcinoma, basal cell carcinoma (BCC), and extramammary Paget's disease, in 2007. These guidelines were revised in 2015. Herein, we present the English version of the 2021 edition of the Japanese clinical guidelines for BCC. In the latest edition, all procedures were performed according to the Grading of Recommendations, Assessment, Development and Evaluation systems. The clinical questions that could not be answered were selected for further analysis. A comprehensive literature search, systematic review, and recommendations for each clinical question were determined by a multidisciplinary expert panel comprising dermatologists, a plastic and reconstructive surgeon, and a pathologist. Surgical resection is the gold-standard therapy of BCC. Radiotherapy or topical treatments, other than surgical resection, have been used in some cases. Patients with unresectable or metastatic BCC require systemic therapy. Novel agents, such as immune response modifiers or hedgehog pathway inhibitors, are emerging worldwide for the treatment of BCC. Based on these viewpoints, four relevant clinical questions regarding, surgical resection, radiotherapy, topical treatment, and systemic therapy, were raised in this report that aims to help clinicians select suitable therapies for their patients.

Design, Synthesis, and Evaluation of Inhibitors of Hedgehog Acyltransferase

Hedgehog signaling is involved in embryonic development and cancer growth. Functional activity of secreted Hedgehog signaling proteins is dependent on N-terminal palmitoylation, making the palmitoyl transferase Hedgehog acyltransferase (HHAT), a potential drug target and a series of 4,5,6,7-tetrahydrothieno[3,2-c]pyridines have been identified as HHAT inhibitors. Based on structural data, we designed and synthesized 37 new analogues which we profiled alongside 13 previously reported analogues in enzymatic and cellular assays. Our results show that a central amide linkage, a secondary amine, and (R)-configuration at the 4-position of the core are three key factors for inhibitory potency. Several potent analogues with low- or sub-μM IC50 against purified HHAT also inhibit Sonic Hedgehog (SHH) palmitoylation in cells and suppress the SHH signaling pathway. This work identifies IMP-1575 as the most potent cell-active chemical probe for HHAT function, alongside an inactive control enantiomer, providing tool compounds for validation of HHAT as a target in cellular assays.

Cyclophosphamide induces the loss of taste bud innervation in mice

Many common chemotherapeutics produce disruptions in the sense of taste which can lead to loss of appetite, nutritional imbalance, and reduced quality of life, especially if taste loss persists after treatment ends. Cyclophosphamide (CYP), an alkylating chemotherapeutic agent, affects taste sensitivity through its cytotoxic effects on mature taste receptor cells (TRCs) and on taste progenitor cell populations, retarding the capacity to replace TRCs. Mechanistic studies have focused primarily on taste cells, however, taste signaling requires communication between TRCs and the gustatory nerve fibers that innervate them. Here, we evaluate cyclophosphamide's effects on the peripheral gustatory nerve fibers that innervate the taste buds. Following histological analysis of tongue tissues, we find that CYP reduces innervation within the fungiform and circumvallates taste buds within 4 days after administration. To better understand the dynamics of the denervation process, we used 2-photon intravital imaging to visualize the peripheral gustatory nerve fibers within individual fungiform taste buds up to 20 days after CYP treatment. We find that gustatory fibers retract from the taste bud properly but are maintained within the central papilla core. These data indicate that in addition to TRCs, gustatory nerve fibers are also affected by CYP treatment. Because the connectivity between TRCs and gustatory neurons must be re-established for proper function, gustatory fibers should continue to be included in future studies to understand the mechanisms leading to chemotherapy-induced persistent taste loss.

Targeting cancer hallmark vulnerabilities in hematologic malignancies by interfering with Hedgehog/GLI signaling

Understanding the genetic alterations, disrupted signaling pathways, and hijacked mechanisms in oncogene-transformed hematologic cells is critical for the development of effective and durable treatment strategies against liquid tumors. In this review, we focus on the specific involvement of the Hedgehog (HH)/GLI pathway in the manifestation and initiation of various cancer features in hematologic malignancies, including multiple myeloma, T- and B-cell lymphomas, and lymphoid and myeloid leukemias. By reviewing canonical and noncanonical, Smoothened-independent HH/GLI signaling and summarizing preclinical in vitro and in vivo studies in hematologic malignancies, we elucidate common molecular mechanisms by which HH/GLI signaling controls key oncogenic processes and cancer hallmarks such as cell proliferation, cancer stem cell fate, genomic instability, microenvironment remodeling, and cell survival. We also summarize current clinical trials with HH inhibitors and discuss successes and challenges, as well as opportunities for future combined therapeutic approaches. By providing a bird's eye view of the role of HH/GLI signaling in liquid tumors, we suggest that a comprehensive understanding of the general oncogenic effects of HH/GLI signaling on the formation of cancer hallmarks is essential to identify critical vulnerabilities within tumor cells and their supporting remodeled microenvironment, paving the way for the development of novel and efficient personalized combination therapies for hematologic malignancies.

Guidelines for the diagnosis and treatment of basal cell carcinoma: a GRADE approach for evidence evaluation and recommendations by the Italian Association of Medical Oncology

Basal cell carcinoma (BCC) is the most common form of cancer, with a high impact on the public health burden and social costs. Despite the overall prognosis for patients with BCC being excellent, if lesions are allowed to progress, or in a small subset of cases harboring an intrinsically aggressive biological behavior, it can result in local spread and significant morbidity, and conventional treatments (surgery and radiotherapy) may be challenging. When a BCC is not amenable to either surgery or radiotherapy with a reasonable curative intent, or when metastatic spread occurs, systemic treatments with Hedgehog inhibitors are available. These guidelines were developed, applying the GRADE approach, on behalf of the Italian Association of Medical Oncologists (AIOM) to assist clinicians in treating patients with BCC. They contain recommendations with regard to the diagnosis, treatment and follow-up, from primitive tumors to those locally advanced or metastatic, addressing the aspects of BCC management considered as priorities by a panel of experts selected by AIOM and other national scientific societies. The use of these guidelines in everyday clinical practice should improve patient care.

Exploring multisite heterogeneity of human basal cell carcinoma proteome and transcriptome

Basal cell carcinoma (BCC) is the most common type of skin cancer. Due to multiple, potential underlying molecular tumor aberrations, clinical treatment protocols are not well-defined. This study presents multisite molecular heterogeneity profiles of human BCC based on RNA and proteome profiling. Three areas from lesions excised from 9 patients were analyzed. The focus was gene expression profiles based on proteome and RNA measurements of intra-tumor heterogeneity from the same patient and inter-tumor heterogeneity in nodular, infiltrative, and superficial BCC tumor subtypes from different patients. We observed significant overlap in intra- and inter-tumor variability of proteome and RNA expression profiles, showing significant multisite heterogeneity of protein expression in the BCC tumors. Inter-subtype analysis has also identified unique proteins for each BCC subtype. This profiling leads to a deeper understanding of BCC molecular heterogeneity and potentially contributes to developing new sampling tools for personalized diagnostics therapeutic approaches to BCC.

Unraveling the structural aspects of the G-quadruplex in SMO promoter and elucidating its contribution in transcriptional regulation

We located a 25 nt G-rich sequence in the promoter region of SMO oncogene. We performed an array of biophysical and biochemical assays and confirmed the formation of a parallel G quadruplex (SMO1-GQ) by the identified sequence. SMO1-GQ is highly conserved in primates. For a comprehensive characterization of the SMO quadruplex structure, we have performed spectroscopic and in silico analysis with established GQ binder small molecules TMPyP4 and BRACO-19. We observed comparatively higher stable interaction of BRACO-19 with SMO1-GQ. Structure-based, rational drug design against SMO1-GQ to target SMO oncogene requires a detailed molecular anatomy of the G-quadruplex. We structurally characterised the SMO1-GQ using DMS footprinting assay and molecular modelling, docking, and MD simulation to identify the probable atomic regions that interact with either of the small molecules. We further investigated SMO1-GQ in vivo by performing chromatin immunoprecipitation (ChIP) assay. ChIP data revealed that this gene element functions as a scaffold for a number of transcription factors: specificity protein (Sp1), nucleolin (NCL), non-metastatic cell 2 (NM23-H2), cellular nucleic acid binding protein (CNBP), and heterogeneous nuclear ribonucleoprotein K (hnRNPK) which reflects the SMO1-P1 G-quadruplex to be the master regulator of SMO1 transcriptional activity. The strong binding interaction detected between SMO1-GQ and BRACO-19 contemplates the potential of the G quadruplex as a promising anti-cancer druggable target to downregulate SMO1 oncogene driven cancers.Communicated by Ramaswamy H. Sarma.

The strategies to cure cancer patients by eradicating cancer stem-like cells

Cancer stem-like cells (CSCs), a subpopulation of cancer cells, possess remarkable capability in proliferation, self-renewal, and differentiation. Their presence is recognized as a crucial factor contributing to tumor progression and metastasis. CSCs have garnered significant attention as a therapeutic focus and an etiologic root of treatment-resistant cells. Increasing evidence indicated that specific biomarkers, aberrant activated pathways, immunosuppressive tumor microenvironment (TME), and immunoevasion are considered the culprits in the occurrence of CSCs and the maintenance of CSCs properties including multi-directional differentiation. Targeting CSC biomarkers, stemness-associated pathways, TME, immunoevasion and inducing CSCs differentiation improve CSCs eradication and, therefore, cancer treatment. This review comprehensively summarized these targeted therapies, along with their current status in clinical trials. By exploring and implementing strategies aimed at eradicating CSCs, researchers aim to improve cancer treatment outcomes and overcome the challenges posed by CSC-mediated therapy resistance.

An update on the current and emerging pharmacotherapies for basal cell carcinomas

INTRODUCTION

Despite surgical approach is still the mainstay for basal cell carcinoma (BCC) management, several issues may limit the use of this technique, leading to the need for new treatments to offer patients a personalized approach.

AREAS COVERED

A comprehensive review of the available and emerging pharmacologic strategies for BCC management, including mechanisms of action, and potential adverse effects, has been performed to provide with an up-to-date manuscript on the current treatment scenario of BCC. Globally, targeting the Sonic-Hedgehog pathway is one of the main mechanisms of action of currently investigated drugs. Other alternatives are based on the concept of an enhancement of the immune response such as immune checkpoint inhibitors, or intra-tumor treatments.

EXPERT OPINION

Although low-risk BCCs are often treated with destructive methods or topical treatments, surgery is the mainstay of treatment for the majority of BCCs. However, several factors may limit the use of surgery in BCC management. Recently, major knowledge on BCCs pathogenesis has led to the development of effective and selective drugs. In our opinion, soon many drugs will be licensed, allowing clinicians to offer patients with BCC the right treatment at the right moment. Certainly, further studies are needed.

Pharmacogenomics: Driving Personalized Medicine

Personalized medicine tailors therapies, disease prevention, and health maintenance to the individual, with pharmacogenomics serving as a key tool to improve outcomes and prevent adverse effects. Advances in genomics have transformed pharmacogenetics, traditionally focused on single gene-drug pairs, into pharmacogenomics, encompassing all "-omics" fields (e.g., proteomics, transcriptomics, metabolomics, and metagenomics). This review summarizes basic genomics principles relevant to translation into therapies, assessing pharmacogenomics' central role in converging diverse elements of personalized medicine. We discuss genetic variations in pharmacogenes (drug-metabolizing enzymes, drug transporters, and receptors), their clinical relevance as biomarkers, and the legacy of decades of research in pharmacogenetics. All types of therapies, including proteins, nucleic acids, viruses, cells, genes, and irradiation, can benefit from genomics, expanding the role of pharmacogenomics across medicine. Food and Drug Administration approvals of personalized therapeutics involving biomarkers increase rapidly, demonstrating the growing impact of pharmacogenomics. A beacon for all therapeutic approaches, molecularly targeted cancer therapies highlight trends in drug discovery and clinical applications. To account for human complexity, multicomponent biomarker panels encompassing genetic, personal, and environmental factors can guide diagnosis and therapies, increasingly involving artificial intelligence to cope with extreme data complexities. However, clinical application encounters substantial hurdles, such as unknown validity across ethnic groups, underlying bias in health care, and real-world validation. This review address the underlying science and technologies germane to pharmacogenomics and personalized medicine, integrated with economic, ethical, and regulatory issues, providing insights into the current status and future direction of health care. SIGNIFICANCE STATEMENT: Personalized medicine aims to optimize health care for the individual patients with use of predictive biomarkers to improve outcomes and prevent adverse effects. Pharmacogenomics drives biomarker discovery and guides the development of targeted therapeutics. This review addresses basic principles and current trends in pharmacogenomics, with large-scale data repositories accelerating medical advances. The impact of pharmacogenomics is discussed, along with hurdles impeding broad clinical implementation, in the context of clinical care, ethics, economics, and regulatory affairs.

The tumor immune microenvironment in pancreatic cancer and its potential in the identification of immunotherapy biomarkers

INTRODUCTION

Pancreatic cancer (PC) has an extremely poor prognosis, even with surgical resection and triplet chemotherapy treatment. Cancer immunotherapy has been recently approved for tumor-agnostic treatment with genome analysis, including in PC. However, it has limited efficacy.

AREAS COVERED

In addition to the low tumor mutation burden, one of the difficulties of immunotherapy in PC is the presence of abundant stromal cells in its microenvironment. Among stromal cells, cancer-associated fibroblasts (CAFs) play a major role in immunotherapy resistance, and CAF-targeted therapies are currently under development, including those in combination with immunotherapies. Meanwhile, microbiomes and tumor-derived exosomes (TDEs) have been shown to alter the behavior of distant receptor cells in PC. This review discusses the role of CAFs, microbiomes, and TDEs in PC tumor immunity.

EXPERT OPINION

Elucidating the mechanisms by which CAFs, microbiomes, and TDEs are involved in the tumorigenesis of PC will be helpful for developing novel immunotherapeutic strategies and identifying companion biomarkers for immunotherapy. Spatial single-cell analysis of the tumor microenvironment will be useful for identifying biomarkers of PC immunity. Furthermore, given the complexity of immune mechanisms, artificial intelligence models will be beneficial for predicting the efficacy of immunotherapy.

Therapeutic Targeting of DNA Replication Stress in Cancer

This article reviews the currently used therapeutic strategies to target DNA replication stress for cancer treatment in the clinic, highlighting their effectiveness and limitations due to toxicity and drug resistance. Cancer cells experience enhanced spontaneous DNA damage due to compromised DNA replication machinery, elevated levels of reactive oxygen species, loss of tumor suppressor genes, and/or constitutive activation of oncogenes. Consequently, these cells are addicted to DNA damage response signaling pathways and repair machinery to maintain genome stability and support survival and proliferation. Chemotherapeutic drugs exploit this genetic instability by inducing additional DNA damage to overwhelm the repair system in cancer cells. However, the clinical use of DNA-damaging agents is limited by their toxicity and drug resistance often arises. To address these issues, the article discusses a potential strategy to target the cancer-associated isoform of proliferating cell nuclear antigen (caPCNA), which plays a central role in the DNA replication and damage response network. Small molecule and peptide agents that specifically target caPCNA can selectively target cancer cells without significant toxicity to normal cells or experimental animals.

Establishment of induced pluripotent stem cells derived from patients and healthy siblings of a nevoid basal cell carcinoma syndrome family

It is known that a nevoid basal cell carcinoma syndrome (NBCCS) is characterized by a combination of developmental abnormalities and a predisposition to form various tumors. Although it is possible to create disease models via gene editing, there are significant potential problems with this approach such as off-target mutations and differences in SNPs. On the other hand, since disease families share common SNPs, research using iPSCs derived from both patients and healthy siblings of the same disease family is very important. Thus, establishment of induced pluripotent stem cells derived from patients and healthy siblings of the same NBCCS family will be of great importance to study the etiology of this disease and to develop therapeutics. In this study, we generated hiPSCs using peripheral blood mononuclear cells derived from the patients and healthy siblings of familial NBCCS with the novel mutation in PTCH1_c.3298_3299insAAG in the feeder- and serum-free culture conditions using SeVdp. In addition, disease-specific hiPSCs such as those expressing the PTCH1_c.3298_3299insAAG mutation could be powerful tools for revealing the genotype-phenotype relationship and pathogenicity of NBCCS.

Recommendations of the International Society of Geriatric Oncology on skin cancer management in older patients

INTRODUCTION

Non-melanoma skin cancer (NMSC) is becoming ever more prevalent among older adults. However, older adults with NMSC are often underrepresented in clinical trials and guidelines on effective management is still unclear. The International Society of Geriatric Oncology (SIOG) created a multi-disciplinary task force to explore the potential in developing practical guidelines for the treatment of older patients with basal cell carcinoma (BCC) and skin (cutaneous) squamous cell carcinoma (cSCC).

MATERIALS AND METHODS

A systematic literature search to identify relevant and up-to-date literature on treatment of NMSC in older adults was conducted on various databases including MEDLINE, Embase, CINAHL, Cochrane, and PubMed. The resulting papers were discussed by an expert panel, leading to a consensus recommendation.

RESULTS

A total of 154 articles were identified for the expert panel to utilise in generating consensus recommendations. A major focus on geriatric assessment and management options including surgery, radiotherapy, systemic therapy, clinical monitoring, and medical/medicophysical therapy were reviewed for recommendations.

DISCUSSION

Patient age should not be the sole deciding factor in the management of patients with NMSC. Assessment from a multidisciplinary team (MDT) is crucial, and the decision-making process should consider the patient's lifestyle, needs, and expectations. A comprehensive geriatric assessment should also be considered. Patients should feel empowered to advocate for themselves and have their views considered a part of the MDT discussion.

Association of the Depth of Invasion With Recurrence Rates of Basal Cell Carcinoma in a Tertiary Health Care Facility: A Retrospective Study Over a Period of Six Years

Background Basal cell carcinoma (BCC) is one of the most common types of cutaneous malignancies and the most frequently occurring form of cancer worldwide. The incidence of basal cell carcinoma is difficult to determine due to its wide geographic variations; however, it has been increasing worldwide with an annual increase of 7% in the number of reported cases. Although BCC is more prevalent in the aging population, diagnosis in younger individuals is steadily increasing. BCC has overall low mortality, however, it leads to significant economic and physical impact on patients and their families along with adding burden to the healthcare system. The primary risk factor for the development of BCC is increased cumulative sun exposure, particularly to UV radiation. The UV index of Karachi averages around 12 (extremely high) during summer months, putting the population at a significantly higher risk of developing BCC in the long term. Objectives This audit was undertaken with the following primary objectives: to use the data collected to determine possible prognostic factors for BCC, to measure the rate of recurrence and the number of new primary tumors detected, to study the completeness of follow-up by patients, and to co-relate histopathological findings with the recurrence rate of basal cell carcinoma. Methods A retrospective analysis was performed for all patients with BCC who had undergone surgical resection over a six-year time period. Patient charts were reviewed for demographic information, tumor size, onset-to-diagnosis, anatomic location, clinical subtype, histologic differentiation, method of surgical treatment, and recurrence. Data were entered and analyzed in SPSS version 23 (IBM Corp., Armonk, NY). Results The review identified cases of BCC in 99 patients. Of the 99 patients, 60.39% were men and 38.38% were women. The most frequent age group was 65-85-year-olds (42 patients, 42.85%) for BCC. Based on the aesthetic units of the face, the most common location was the nasal unit (30 cases, 30.30%) for BCC. Most of the lesions were closed primarily; however; local flaps were used in the case of surgical defects. The recurrence rate was 19.19% for BCC in this study. Our study included 1.0% of patients who were classified as Clark classification level 2 of BCC, 6.1% as Clark level 3, 23.4% as Clark level 4, and 0.16% as Clark level 5. Recurrence rates were seen to increase with increasing Clark classification level in this study. Conclusion In our study, many characteristics of BCC were compared to previously published reports and the results were seen to be generally similar. This study correlates the recurrence of BCC with Clark's classification, showing that depth of invasion is a significant factor in predicting recurrence. There is a paucity of literature regarding the depth of invasion of BCC along with its' Clarks classification and recurrence. Further studies can help explore and establish the characteristics of BCC.

Involvement of redox signalling in tumour cell dormancy and metastasis

Decades of research on oncogene-driven carcinogenesis and gene-expression regulatory networks only started to unveil the complexity of tumour cellular and molecular biology. This knowledge has been successfully implemented in the clinical practice to treat primary tumours. In contrast, much less progress has been made in the development of new therapies against metastasis, which are the main cause of cancer-related deaths. More recently, the role of epigenetic and microenviromental factors has been shown to play a key role in tumour progression. Free radicals are known to communicate the intracellular and extracellular compartments, acting as second messengers and exerting a decisive modulatory effect on tumour cell signalling. Depending on the cellular and molecular context, as well as the intracellular concentration of free radicals and the activation status of the antioxidant system of the cell, the signalling equilibrium can be tilted either towards tumour cell survival and progression or cell death. In this regard, recent advances in tumour cell biology and metastasis indicate that redox signalling is at the base of many cell-intrinsic and microenvironmental mechanisms that control disseminated tumour cell fate and metastasis. In this manuscript, we will review the current knowledge about redox signalling along the different phases of the metastatic cascade, including tumour cell dormancy, making emphasis on metabolism and the establishment of supportive microenvironmental connections, from a redox perspective.

Efficacy and Safety of Sonic Hedgehog Inhibitors in Basal Cell Carcinomas: An Updated Systematic Review and Meta-analysis (2009-2022)

BACKGROUND

Basal cell carcinoma (BCC) of the skin is the most common form of skin cancer in the United States. In life-threatening, advanced BCC, sonic hedgehog inhibitors (SSHis) remain a pre-eminent treatment option for locally advanced BCC and metastatic BCC.

OBJECTIVE

In this updated systematic review and meta-analysis, we aimed to better characterize the efficacy and safety of SSHis by including final updates from pivotal clinical trials and additional new recent studies.

METHODS

An electronic database search was performed for articles including clinical trials, prospective case series, and retrospective medical record reviews on human subjects. Overall response rates (ORRs) and complete response rates (CRRs) were the primary outcomes. For safety assessment, the prevalence of the following adverse effects was analyzed: muscle spasms, dysgeusia, alopecia, weight loss, fatigue, nausea, myalgias, vomiting, skin squamous cell carcinoma, increased creatine kinase, diarrhea, decreased appetite, and amenorrhea. Analyses were performed using R statistical software. Data were pooled using linear models with fixed effects meta-analysis for primary analyses, along with 95% confidence intervals (CIs) and p-values. Intermolecular differences were calculated using Fisher's exact test.

RESULTS

A total of 22 studies (N = 2384 patients) were included in the meta-analysis: 19 studies assessing both efficacy and safety, 2 studies assessing safety only, and 1 study assessing efficacy only. Overall, the pooled ORR for all patients was 64.9% (95% CI 48.2-81.6%), implicating there is at least a partial response (z = 7.60, p < 0.0001) in most patients receiving SSHis. The ORR for vismodegib was 68.5% and 50.1% for sonidegib. The most common adverse effects for vismodegib and sonidegib were muscle spasms (70.5% and 61.0%, respectively), dysgeusia (58.4% and 48.6%, respectively), and alopecia (59.9% and 51.1%, respectively). Patients were likely to experience weight loss (35.1%, p < 0.0001) from vismodegib. Alternatively, patients taking sonidegib experienced more nausea, diarrhea, increased creatine kinase levels, and decreased appetite compared with those receiving vismodegib.

CONCLUSION

SSHis are an effective treatment for advanced BCC disease. Given the high discontinuation rates, management of patient expectations is warranted for compliance and achieving long-term efficacy. It is essential to stay updated with the latest discoveries on the efficacy and safety of SSHis.

Understanding the Roles of the Hedgehog Signaling Pathway during T-Cell Lymphopoiesis and in T-Cell Acute Lymphoblastic Leukemia (T-ALL)

The Hedgehog (HH) signaling network is one of the main regulators of invertebrate and vertebrate embryonic development. Along with other networks, such as NOTCH and WNT, HH signaling specifies both the early patterning and the polarity events as well as the subsequent organ formation via the temporal and spatial regulation of cell proliferation and differentiation. However, aberrant activation of HH signaling has been identified in a broad range of malignant disorders, where it positively influences proliferation, survival, and therapeutic resistance of neoplastic cells. Inhibitors targeting the HH pathway have been tested in preclinical cancer models. The HH pathway is also overactive in other blood malignancies, including T-cell acute lymphoblastic leukemia (T-ALL). This review is intended to summarize our knowledge of the biological roles and pathophysiology of the HH pathway during normal T-cell lymphopoiesis and in T-ALL. In addition, we will discuss potential therapeutic strategies that might expand the clinical usefulness of drugs targeting the HH pathway in T-ALL.

Superenhancer activation of KLHDC8A drives glioma ciliation and hedgehog signaling

Glioblastoma ranks among the most aggressive and lethal of all human cancers. Self-renewing, highly tumorigenic glioblastoma stem cells (GSCs) contribute to therapeutic resistance and maintain cellular heterogeneity. Here, we interrogated superenhancer landscapes of primary glioblastoma specimens and patient-derived GSCs, revealing a kelch domain-containing gene, specifically Kelch domain containing 8A (KLHDC8A) with a previously unknown function as an epigenetically driven oncogene. Targeting KLHDC8A decreased GSC proliferation and self-renewal, induced apoptosis, and impaired in vivo tumor growth. Transcription factor control circuitry analyses revealed that the master transcriptional regulator SOX2 stimulated KLHDC8A expression. Mechanistically, KLHDC8A bound chaperonin-containing TCP1 (CCT) to promote the assembly of primary cilia to activate hedgehog signaling. KLHDC8A expression correlated with Aurora B/C Kinase inhibitor activity, which induced primary cilia and hedgehog signaling. Combinatorial targeting of Aurora B/C kinase and hedgehog displayed augmented benefit against GSC proliferation. Collectively, superenhancer-based discovery revealed KLHDC8A as what we believe to be a novel molecular target of cancer stem cells that promotes ciliogenesis to activate the hedgehog pathway, offering insights into therapeutic vulnerabilities for glioblastoma treatment.

Emerging Roles of Hedgehog Signaling in Cancer Immunity

Hedgehog-GLI (HH) signaling plays an essential role in embryogenesis and tissue homeostasis. Aberrant activation of the pathway through mutations or other mechanisms is involved in the development and progression of numerous types of cancer, including basal cell carcinoma, medulloblastoma, melanoma, breast, prostate, hepatocellular and pancreatic carcinomas. Activation of HH signaling sustains proliferation, suppresses cell death signals, enhances invasion and metastasis, deregulates cellular metabolism and promotes angiogenesis and tumor inflammation. Targeted inhibition of the HH pathway has therefore emerged as an attractive therapeutic strategy for the treatment of a wide range of cancers. Currently, the Smoothened (SMO) receptor and the downstream GLI transcriptional factors have been investigated for the development of targeted drugs. Recent studies have revealed that the HH signaling is also involved in tumor immune evasion and poor responses to cancer immunotherapy. Here we focus on the effects of HH signaling on the major cellular components of the adaptive and innate immune systems, and we present recent discoveries elucidating how the immunosuppressive function of the HH pathway is engaged by cancer cells to prevent immune surveillance. In addition, we discuss the future prospect of therapeutic options combining the HH pathway and immune checkpoint inhibitors.

ABTC-0904: targeting glioma stem cells in GBM: a phase 0/II study of hedgehog pathway inhibitor GDC-0449

PURPOSE

Gliomagenesis and resistance of glioblastoma (GBM) are believed to be mediated by glioma stem cells (GSC). Evidence suggests that SHH signaling promotes GSC proliferation and self-renewal.

METHODS

ABTC-0904 was a two-arm, multicenter phase 0/II study of GDC-0449, an oral inhibitor of Smoothened (SMO) in patients undergoing resection for recurrent GBM. All patients (Arms I and II) had surgery and received drug post-operatively. Only patients in Arm I received drug prior to surgery. The primary objective was to determine 6-month progression free survival (PFS-6). Secondary endpoints include median PFS (mPFS) and overall survival (mOS), response rate, and toxicity. Correlative studies included bioanalysis of GDC-0449, and inhibition of SHH signaling, GSC proliferation and self-renewal.

RESULTS

Forty-one patients were enrolled. Pharmacokinetics of GDC-0449 in plasma demonstrated levels within expected therapeutic range in 75% of patients. The proportion of tumorcells producing CD133+ neurospheres, neurosphere proliferation, self-renewal, and expression of the SHh downstream signaling was significantly decreased in Arm I following GDC-0449 treatment (p < 0.005; p < 0.001 respectively) compared to Arm II (no drug pre-op). Treatment was well tolerated. There were no objective responders in either arm. Overall PFS-6 was 2.4% (95% CI 0.9-11.1%). Median PFS was 2.3 months (95% CI 1.9-2.6) and mOS was 7.8 months (95% CI 5.4-10.1).

CONCLUSIONS

GDC-0449 was well tolerated, reached tumor, and inhibited CD133+ neurosphere formation, but had little clinical efficacy as a single agent in rGBM. This suggests growth and maintenance of rGBM is not solely dependent on the SHH pathway thus targeting SMO may require combined approaches.

Molecular Mechanisms of Sanguinarine in Cancer Prevention and Treatment

Historically, natural plant-derived drugs received a great impact of consideration in the treatment of several human-associated disorders. Cancer is a devastating disease and the second most cause of mortality. Sanguinarine (SANG), a naturally isolated plant alkaloidal agent, possesses chemo-preventive effects. Several studies have revealed that SANG impedes tumor metastasis and development by disrupting a wide range of cell signaling pathways and its molecular targets, such as BCL-2, MAPKs, Akt, NF-κB, ROS, and microRNAs (miRNAs). However, its low chemical stability and poor oral bioavailability remain key issues in its use as a medicinal molecule. A novel method (e.g., liposomes, nanoparticles, and micelles) and alternative analogs provide an exciting approach to alleviate these problems and broaden its pharmacokinetic profile. Cancer-specific miRNA expression is synchronized by SANG, which has also been uncertain. In this critical study, we review the utilization of SANG mimics and nano-technologies to improve its support in cancer. We focus on recently disclosed studies on SANG anti-cancer properties.

Interactions of melatonin with various signaling pathways: implications for cancer therapy

Melatonin is a neuro-hormone with conserved roles in evolution. Initially synthetized as an antioxidant molecule, it has gained prominence as a key molecule in the regulation of the circadian rhythm. Melatonin exerts its effect by binding to cytoplasmic and intra-nuclear receptors, and is able to regulate the expression of key mediators of different signaling pathways. This ability has led scholars to investigate the role of melatonin in reversing the process of carcinogenesis, a process in which many signaling pathways are involved, and regulating these pathways may be of clinical significance. In this review, the role of melatonin in regulating multiple signaling pathways with important roles in cancer progression is discussed, and evidence regarding the beneficence of targeting malignancies with this approach is presented.

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.

Safety and efficacy of nivolumab, an anti-PD1 immunotherapy, in patients with advanced basal cell carcinoma, after failure or intolerance to sonic Hedgehog inhibitors: UNICANCER AcSé NIVOLUMAB trial

BACKGROUND

Basal cell carcinoma (BCC) is the most common human malignancy. In most cases, BCC has slow progression and can be definitively cured by surgery or radiotherapy. However, in rare cases, it can become locally advanced or, even more rarely, metastatic. The alternative recommended treatments are Sonic Hedgehog pathway inhibitors; however, the response is often short-lived.

METHODS

This was a phase 2 basket study (NCT03012581) evaluating the efficacy and safety of nivolumab in a cohort of 32 advanced BCC patients, enrolled after failure of Sonic Hedgehog inhibitors, including 29 laBCC (91%) and 3 mBCC (9%).

RESULTS

Compared to previously published studies, our population consisted of severe patients with a poor prognosis because they had already received multiple lines of treatment: all patients received previous Sonic Hedgehog inhibitors, 53% of patients already had chemotherapy and 75% radiotherapy. At 12 weeks, we reported 3.1% of complete responses, 18.8% of partial responses, and 43.8% of stable diseases. The best response rate to nivolumab reached 12.5% of complete responses (four patients), 18.8% of partial responses (three patients), and 43.8% of stable diseases (14 patients). Adverse events (AE) were mostly grade 2 or 3, slightly different to the adverse events observed in the treatment of metastatic melanoma (higher rate of diabetes, no thyroid dysfunction).

CONCLUSION

Nivolumab is a relevant therapeutic option for patients with advanced relapsing/refractory BCC.

Analysis of residual disease in periocular basal cell carcinoma following hedgehog pathway inhibition: Follow up to the VISORB trial

Basal cell carcinoma (BCC) is a common skin cancer caused by deregulated hedgehog signaling. BCC is often curable surgically; however, for orbital and periocular BCCs (opBCC), surgical excision may put visual function at risk. Our recent clinical trial highlighted the utility of vismodegib for preserving visual organs in opBCC patients: 67% of patients displayed a complete response histologically. However, further analysis of excision samples uncovered keratin positive, hedgehog active (Gli1 positive), proliferative micro-tumors. Sequencing of pre-treatment tumors revealed resistance conferring mutations present at low frequency. In addition, one patient with a low-frequency SMO W535L mutation recurred two years post study despite no clinical evidence of residual disease. Sequencing of this recurrent tumor revealed an enrichment for the SMO W535L mutation, revealing that vismodegib treatment enriched for resistant cells undetectable by traditional histology. In the age of targeted therapies, linking molecular genetic analysis to prospective clinical trials may be necessary to provide mechanistic understanding of clinical outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT02436408.

Hedgehog signaling mechanism and role in cancer

Cell-cell communication through evolutionarily conserved signaling pathways governs embryonic development and adult tissue homeostasis. Deregulation of these signaling pathways has been implicated in a wide range of human diseases including cancer. One such pathway is the Hedgehog (Hh) pathway, which was originally discovered in Drosophila and later found to play a fundamental role in human development and diseases. Abnormal Hh pathway activation is a major driver of basal cell carcinomas (BCC) and medulloblastoma. Hh exerts it biological influence through a largely conserved signal transduction pathway from the activation of the GPCR family transmembrane protein Smoothened (Smo) to the conversion of latent Zn-finger transcription factors Gli/Ci proteins from their repressor (GliR/CiR) to activator (GliA/CiA) forms. Studies from model organisms and human patients have provided deep insight into the Hh signal transduction mechanisms, revealed roles of Hh signaling in a wide range of human cancers, and suggested multiple strategies for targeting this pathway in cancer treatment.

Advances in Management and Therapeutics of Cutaneous Basal Cell Carcinoma

Simple Summary

Basal cell carcinoma (BCC) is the most common malignancy in humans with a range of treatment options available. Tumor and patient characteristics aid in risk-stratification, which influences treatment considerations. Here, we review the advancements in surgical, topical, field, immunotherapeutic, molecular-targeted, and experimental treatment modalities that can be employed in the correct clinical setting for the treatment of BCC.

Abstract

Basal cell carcinoma (BCC), the most common cancer in humans, is a malignant neoplasm of cells derived from the basal layer of the epidermis. Tumor characteristics such as histologic subtype, primary versus recurrent tumor, anatomic location, size, and patient attributes determine the risk level and acceptable treatment options. Surgical options offer histologic confirmation of tumor clearance. Standard excision provides post-treatment histologic assessment, while Mohs micrographic surgery (MMS) provides complete margin assessment intraoperatively. Additional treatment options may be employed in the correct clinical context. Small and low-risk BCCs, broad field cancerization, locally-advanced disease, metastatic disease, cosmetic concerns, or morbidity with surgical approaches raise consideration of other treatment modalities. We review herein a range of treatment approaches and advances in treatments for BCC, including standard excision, MMS, electrodesiccation and curettage, ablative laser treatment, radiation therapy, targeted molecular therapies, topical therapies, field therapies, immunotherapy, and experimental therapies.

Basal cell carcinoma of the prostate: a case report responding to the FGFR inhibitor pemigatinib and literature review

PURPOSE OF REVIEW

Due to the limited number of cases, there are no guidelines for basal cell carcinoma (BCC) of the prostate. This review combines an unpublished case report of a 55-year-old patient with BCC with an assessment of the latest literature.

RECENT FINDINGS

BCC of the prostate has previously been described in only approximately 140 cases. We describe the diagnostic process, including the uropathological and DNA-sequencing results, which allowed us to start an experimental treatment with pemigatinib. BCC of the prostate is associated with an aggressive biological and clinical behavior, such as recurrence and metastasis. Several immunohistochemical stainings are available to differentiate BCC from adenocarcinoma of the prostate. Based on pathology and results from next-generation sequencing (NGS), patients can be offered targeted therapies.

SUMMARY

With the aid of histological work-up and immunostaining, prostatic BCC can be accurately diagnosed. Our patient underwent radical prostatectomy and staged extended lymphadenectomy due to lymph node recurrence. The patient subsequently developed progressive disease and was treated with the FGFR-inhibitor pemigatinib. The patient's liver metastasis significantly responded. The present case confirms the possibility of aggressive behavior of prostatic BCC and highlights the importance of a thorough uropathological and molecular biological analysis with a precision medicine strategy.

Pilot study of bempegaldesleukin in combination with nivolumab in patients with metastatic sarcoma

PD-1 blockade (nivolumab) efficacy remains modest for metastatic sarcoma. In this paper, we present an open-label, non-randomized, non-comparative pilot study of bempegaldesleukin, a CD122-preferential interleukin-2 pathway agonist, with nivolumab in refractory sarcoma at Memorial Sloan Kettering/MD Anderson Cancer Centers (NCT03282344). We report on the primary outcome of objective response rate (ORR) and secondary endpoints of toxicity, clinical benefit, progression-free survival, overall survival, and durations of response/treatment. In 84 patients in 9 histotype cohorts, all patients experienced ≥1 adverse event and treatment-related adverse event; 1 death was possibly treatment-related. ORR was highest in angiosarcoma (3/8) and undifferentiated pleomorphic sarcoma (2/10), meeting predefined endpoints. Results of our exploratory investigation of predictive biomarkers show: CD8 + T cell infiltrates and PD-1 expression correlate with improved ORR; upregulation of immune-related pathways correlate with improved efficacy; Hedgehog pathway expression correlate with resistance. Exploration of this combination in selected sarcomas, and of Hedgehog signaling as a predictive biomarker, warrants further study in larger cohorts.

PTCH1-null induced pluripotent stem cells exclusively differentiate into immature ectodermal cells with large areas of medulloblastoma-like tissue

Nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant disorder with an increased incidence of tumors, such as basal cell carcinomas and medulloblastomas. The PTCH1 gene, responsible for NBCCS, suppresses the hedgehog signaling pathway, which is recognized as one of the important pathways in tumorigenesis and, thus, is a therapeutic target in cancer. In the present study, we generated PTCH1^-/- induced pluripotent stem cells (iPSCs) from NBCCS patient-derived iPSCs (PTCH1^+/-) by gene editing. The proliferation of PTCH1^-/- iPSCs was accelerated due to the activation of the hedgehog signaling pathway. When PTCH1^-/- iPSCs were subcutaneously injected into immunodeficient mice, the resulting teratomas almost exclusively contained immature ectodermal lineage cells expressing medulloblastoma markers, and the percentages of the area occupied by medulloblastoma-like tissue were larger in PTCH1^-/- teratomas than in PTCH1^+/- teratomas. In contrast, in PTCH1^+/+ teratomas, medulloblastoma-like tissue positive for all of these medulloblastoma markers was not observed. The present results indicate the importance of PTCH1 in medulloblastoma formation and the suitability of these gene-edited iPSCs and PTCH1^-/- teratomas as models for the formation of tumors, such as medulloblastomas and Hh-related tumors.

Basal cell carcinomas acquire secondary mutations to overcome dormancy and progress from microscopic to macroscopic disease

Basal cell carcinomas (BCCs) frequently possess immense mutational burdens; however, the functional significance of most of these mutations remains unclear. Here, we report that loss of Ptch1, the most common mutation that activates upstream Hedgehog (Hh) signaling, initiates the formation of nascent BCC-like tumors that eventually enter into a dormant state. However, rare tumors that overcome dormancy acquire the ability to hyperactivate downstream Hh signaling through a variety of mechanisms, including amplification of Gli1/2 and upregulation of Mycn. Furthermore, we demonstrate that MYCN overexpression promotes the progression of tumors induced by loss of Ptch1. These findings suggest that canonical mutations that activate upstream Hh signaling are necessary, but not sufficient, for BCC to fully progress. Rather, tumors likely acquire secondary mutations that further hyperactivate downstream Hh signaling in order to escape dormancy and enter a trajectory of uncontrolled expansion.

Trieu et al. generate BCC mouse models in which rare macroscopic tumors form alongside numerous failed microscopic lesions. Successful macroscopic tumors acquire secondary changes that elevate Gli1, Gli2, and/or Mycn levels, causing hyperactivation of downstream Hedgehog (Hh) signaling. Loss of p53 and Notch1 also contributes to tumor progression.

Hedgehog signaling plays a crucial role in hyperalgesia associated with neuropathic pain in mice

Neuropathic pain is a debilitating chronic syndrome of the nervous system caused by nerve injury. In Drosophila, the Hedgehog (Hh) signaling pathway is related to increased pain sensitivity (hyperalgesia) but does not affect the baseline nociceptive threshold. In general, the contribution of the Hh signaling pathway to neuropathic pain in vertebrates is a highly debated issue. Alternatively, we investigated the potential role of Hh signaling in mechanical allodynia using a mouse model of neuropathic pain. Seven days after spinal nerve-transection (SNT) surgery, microglial activation increased in the ipsilateral spinal dorsal horn compared with that in the sham group; however, 21 days after surgery, microglial activation decreased. Contrastingly, astrocyte activation in the spinal cord did not differ between the groups. On day 21 of postsurgery, the SNT group showed marked upregulation of sonic hedgehog expression in peripheral glial cells but not in dorsal root ganglion (DRG) neurons. Intrathecal administration of the Hh signaling inhibitor vismodegib attenuated the mechanical allodynia observed on day 21 postsurgery. Conversely, intrathecal treatment with the Hh signaling activator smoothened agonist in naive mice induced mechanical allodynia, which was abolished by the ATP transporter inhibitor clodronate. Moreover, inhibition of Hh signaling by pretreatment with vismodegib significantly reduced ATP secretion and the frequency/number of spontaneous elevations of intracellular calcium ion levels in cultured DRG cells. Thus, the Hh signaling pathway appears to modulate the neural activity of DRG neurons via ATP release, and it plays an important role in sustaining mechanical allodynia and hypersensitivity in a mouse model of neuropathic pain.