Tipifarnib as a Precision Therapy for HRAS-Mutant Head and Neck Squamous Cell Carcinomas

Phase 2 trial of the farnesyltransferase inhibitor tipifarnib for relapsed/refractory peripheral T-cell lymphoma

ABSTRACT

A phase 2, international, open-label, nonrandomized, single-arm trial was conducted to evaluate the efficacy and safety of tipifarnib, a farnesyltransferase inhibitor, as monotherapy for relapsed/refractory peripheral T-cell lymphoma (PTCL) and to evaluate tumor mutation profile as a biomarker of response. Adults with relapsed/refractory PTCL received tipifarnib 300 mg orally twice daily for 21 days in a 28-day cycle. The primary end point was objective response rate (ORR); secondary end points included ORR, progression-free survival (PFS), duration of response (DOR), and adverse events (AEs) in specific subtypes. Sixty-five patients with PTCL were enrolled: n = 38 angioimmunoblastic T-cell lymphoma (AITL), n = 25 PTCL not otherwise specified, and n = 2 other T-cell lymphomas. The ORR was 39.7% (95% confidence interval [CI], 28.1-52.5) in all patients and 56.3% (95% CI, 39.3-71.8) for AITL. Median PFS was 3.5 months overall (954% CI, 2.1-4.4), and 3.6 months (95% CI, 1.9-8.3) for AITL. Median DOR was 3.7 months (95% CI, 2.0-15.3), and greatest in patients with AITL (7.8 months; 95% CI, 2.0-16.3). The median overall survival was 32.8 months (95% CI, 14.4 to not applicable). Tipifarnib-related hematologic AEs were manageable and included neutropenia (43.1%), thrombocytopenia (36.9%), and anemia (30.8%); other tipifarnib-related AEs included nausea (29.2%) and diarrhea (27.7%). One treatment-related death occurred. Mutations in RhoA, DNMT3A, and IDH2 were seen in 60%, 33%, and 27%, respectively, in the AITL tipifarnib responder group vs 36%, 9%, and 9% in the nonresponder group. Tipifarnib monotherapy demonstrated encouraging clinical activity in heavily pretreated relapsed/refractory PTCL, especially in AITL, with a manageable safety profile. This trial was registered at www.ClinicalTrials.gov as #NCT02464228.

Targeting Ras-, Rho-, and Rab-family GTPases via a conserved cryptic pocket

The family of Ras-like GTPases consists of over 150 different members, regulated by an even larger number of guanine exchange factors (GEFs) and GTPase-activating proteins (GAPs) that comprise cellular switch networks that govern cell motility, growth, polarity, protein trafficking, and gene expression. Efforts to develop selective small molecule probes and drugs for these proteins have been hampered by the high affinity of guanosine triphosphate (GTP) and lack of allosteric regulatory sites. This paradigm was recently challenged by the discovery of a cryptic allosteric pocket in the switch II region of K-Ras. Here, we ask whether similar pockets are present in GTPases beyond K-Ras. We systematically surveyed members of the Ras, Rho, and Rab family of GTPases and found that many GTPases exhibit targetable switch II pockets. Notable differences in the composition and conservation of key residues offer potential for the development of optimized inhibitors for many members of this previously undruggable family.

The biomarkers for maintenance Cancer stem cell features can be applicable in precision medicine of head and neck squamous cell carcinoma

Cancer stem cells (CSCs) play a crucial role in tumor relapse, proliferation, invasion, and drug resistance in head and neck squamous cell carcinoma (HNSCC). This narrative review aims to synthesize data from articles published between 2019 and 2023 on biomarkers for detecting CSCs in HNSCC and changes in molecular pathways, genetics, epigenetics, and non-coding RNAs (ncRNAs) in CSCs relevant to precision medicine approaches in HNSCC management. The search encompassed 41 in vitro studies and 22 clinical studies. CSCs exhibit diverse molecular profiles and unique biomarker expression patterns, offering significant potential for HNSCC diagnosis, treatment, and prognosis, thereby enhancing patient survival. Their remarkable self-renewal ability and adaptability are closely linked to tumorigenicity development and maintenance. Assessing biomarkers before and after therapy can aid in identifying various cell types associated with cancer progression and relapse. Screening for CSCs, senescent tumor cells, and cells correlated with the senescence process post-treatment has proven highly beneficial. However, the clinical application of precision medicine in HNSCC management is hindered by the lack of specific and definitive CSC biomarkers. Furthermore, our limited understanding of CSC plasticity, governed by genomic, transcriptomic, and epigenomic alterations during tumorigenesis, as well as the bidirectional interaction of CSCs with the tumor microenvironment, underscores the need for further research. Well-designed studies involving large patient cohorts are, therefore, essential to establish a standardized protocol and address these unresolved queries.

Cooperative genomic lesions in HRAS-mutant cancers predict resistance to farnesyltransferase inhibitors

In the clinical development of farnesyltransferase inhibitors (FTIs) for HRAS-mutant tumors, responses varied by cancer type. Co-occurring mutations may affect responses. We aimed to uncover cooperative genetic events specific to HRAS-mutant tumors and to study their effect on sensitivity to FTIs. Using targeted sequencing data from the MSK-IMPACT and Dana-Farber Cancer Institute Genomic Evidence Neoplasia Information Exchange databases, we identified comutations that were observed predominantly in HRAS-mutant versus KRAS-mutant or NRAS-mutant cancers. HRAS-mutant cancers had a higher frequency of coaltered mutations (48.8%) in the MAPK, PI3K, or RTK pathway genes, compared with KRAS-mutant (41.4%) and NRAS-mutant (38.4%) cancers (p < 0.05). Class 3 BRAF, NF1, PTEN, and PIK3CA mutations were more prevalent in HRAS-mutant lineages. To study the effects of comutations on sensitivity to FTIs, HrasG13R was transfected into "RASless" (Kraslox/lox/Hras-/-/Nras-/-/RERTert/ert) mouse embryonic fibroblasts (MEFs), which sensitized nontransfected MEFs to tipifarnib. Comutation in the form of Pten or Nf1 deletion and Pik3caH1047R transduction led to resistance to tipifarnib in HrasG13R-transfected MEFs in the presence or absence of KrasWT, whereas BrafG466E transduction led to resistance to tipifarnib only in the presence of KrasWT. Combined treatment with tipifarnib and MEK inhibition sensitized cells to tipifarnib in all settings, including in MEFs with PI3K pathway comutations. HRAS-mutant tumors demonstrate lineage-dependent MAPK or PI3K pathway alterations, which confer resistance to tipifarnib. The combined use of FTIs and MEK inhibition is a promising strategy for HRAS-mutant tumors.

Identification and Characterization of Novel Small-Molecule Enhancers of the CUL3LZTR1 E3 Ligase KRAS Complex

The RAS family of GTPases is among the most frequently mutated proteins in human cancer, creating a high clinical demand for therapies that counteract their signaling activity. An important layer of regulation that could be therapeutically exploited is the proteostatic regulation of the main RAS GTPases KRAS, NRAS, and HRAS, as well as the closely related members, MRAS and RIT1, by the leucine zipper-like transcriptional regulator 1 cullin 3 RING E3 ubiquitin ligase complex (CUL3LZTR1). Genetic inactivation of LZTR1, as observed in different cancer entities and Noonan syndrome leads to enhanced RAS GTPase abundance and altered MAPK pathway activation state. Novel therapeutic approaches to interfere with hyperactive RAS signaling, thereby complementing existing treatments, are highly sought after. Motivated by the growing arsenal of molecular glue degraders, we report the identification of novel chemical fragments that enhance the protein-protein interaction (PPI) of the KRAS-LZTR1 complex. We established a split-luciferase-based reporter assay that monitors the RAS GTPase-LZTR1 interaction in a scalable format, capable of capturing chemical, as well as mutational perturbations. Using this screening system, in combination with a small fragment library, we identified two fragments, C53 and Z86, that enhance the interaction of the KRAS-LZTR1 complex in a dose-dependent manner. Further orthogonal validation experiments using proximity biotinylation (BioID), thermal shift assays, and NMR spectroscopy demonstrated fragment-dependent enhanced recruitment of endogenous LZTR1 and physical engagement of KRAS. The two fragments, which potentiate the KRAS-LZTR1 interaction, serve as starting points for fragment-based drug discovery. Additionally, the assay we introduced is amenable to high-throughput screening to further explore the pharmacological modulation of the CUL3LZTR1-RAS GTPase complex.

Paraneoplastic leukocytosis induces NETosis and thrombosis in bladder cancer PDX model

Paraneoplastic leukocytosis (PNL) in genitourinary cancer, though rare, can indicate aggressive behavior and poor outcomes. It has been potentially linked to cancer expressing G-CSF and GM-CSF, along with their respective receptors, exerting an autocrine/paracrine effect. In our study, we successfully established four patient-derived xenograft (PDX) lines and related cell lines from urothelial cancer (UC), conducting next-generation sequencing (NGS) for genetic studies. UC-PDX-LN1, originating from bladder cancer, exhibited two druggable targets - HRAS and ERCC2 - responding well to chemotherapy and targeted therapy, though not to tipifarnib, an HRAS inhibitor. Transcriptome analysis post-treatment illuminated potential mechanisms, with index protein analysis confirming their anticancer pathways. Mice implanted with UC-PDX-LN1 mirrored PNL observed in the patient's original tumor. Cytokine array and RT-PCR analyses revealed high levels of G-CSF and GM-CSF in our PDX and cell lines, along with their presence in culture media and tumor cysts.Leukocytosis within small vessels in and around the tumor, associated with NETosis and thrombus formation, suggested a mechanism wherein secreted growth factors were retained, further fueling tumor growth via autocrine/paracrine signaling. Disrupting this cancer cell-NETosis-thrombosis cycle, we demonstrated that anti-neutrophil or anticoagulant interventions enhanced chemotherapy's antitumor effects or prolonged survival in mice, even though these drugs lacked direct antitumor efficacy when used independently. Clinical observations in bladder cancer patients revealed PNL in 1.61% of cases (35/2162) with associated poor prognosis. These findings propose a novel approach, advocating for the combination of anticancer/NETosis/thrombosis strategies for managing UC patients presenting with PNL in clinical settings.

Tipifarnib physiologically-based pharmacokinetic modeling to assess drug-drug interaction, organ impairment, and biopharmaceutics in healthy subjects and cancer patients

A physiologically-based pharmacokinetic (PBPK) model for tipifarnib, which included mechanistic absorption, was built and verified by integrating in vitro data and several clinical data in healthy subjects and cancer patients. The final PBPK model was able to recover the clinically observed single and multiple-dose plasma concentrations of tipifarnib in healthy subjects and cancer patients under several dosing conditions, such as co-administration with a strong CYP3A4 inhibitor and inducer, an acid-reducing agent (proton pump inhibitor and H2 receptor antagonist), and with a high-fat meal. In addition, the model was able to accurately predict the effect of mild or moderate hepatic impairment on tipifarnib exposure. The appropriately verified model was applied to prospectively simulate the liability of tipifarnib as a victim of CYP3A4 enzyme-based drug-drug interactions (DDIs) with a moderate inhibitor and inducer as well as tipifarnib as a perpetrator of DDIs with sensitive substrates of CYP3A4, CYP2B6, CYP2D6, CYP2C9, and CYP2C19 in healthy subjects and cancer patients. The effect of a high-fat meal, acid-reducing agent, and formulation change at the therapeutic dose was simulated. Finally, the model was used to predict the effect of mild, moderate, or severe hepatic, and renal impairment on tipifarnib PK. This multipronged approach of combining the available clinical data with PBPK modeling-guided dosing recommendations for tipifarnib under several conditions. This example showcases the totality of the data approach to gain a more thorough understanding of clinical pharmacology and biopharmaceutic properties of oncology drugs in development.

Neuroblastoma-A Review of Combination Immunotherapy

Neuroblastoma is the most common extracranial solid tumor found in childhood and is responsible for 15% of deaths among children with cancer. Although multimodal therapies focused on surgery, chemotherapy, radiotherapy, and stem cell transplants have favorable results in many cases, the use of conventional therapies has probably reached the limit their possibility. Almost half of the patients with neuroblastoma belong to the high-risk group. Patients in this group require a combination of several therapeutic approaches. It has been shown that various immunotherapies combined with conventional methods can work synergistically. Due to the development of such therapeutic methods, we present combinations and forms of combining immunotherapy, focusing on their mechanisms and benefits but also their limitations and potential side effects.

Genomic profiles of Japanese patients with vulvar squamous cell carcinoma

The incidence of vulvar carcinoma varies by race; however, it is a rare disease, and its genomic profiles remain largely unknown. This study examined the characteristics of vulvar squamous cell carcinoma (VSCC) in Japanese patients, focusing on genomic profiles and potential racial disparities. The study included two Japanese groups: the National Cancer Center Hospital (NCCH) group comprised 19 patients diagnosed between 2015 and 2023, and the Center for Cancer Genomics and Advanced Therapeutics group comprised 29 patients diagnosed between 2019 and 2022. Somatic mutations were identified by targeted or panel sequencing, and TP53 was identified as the most common mutation (52-81%), followed by HRAS (7-26%), CDKN2A (21-24%), and PIK3CA (5-10%). The mutation frequencies, except for TP53, were similar to those of Caucasian cohorts. In the NCCH group, 16 patients of HPV-independent tumors were identified by immunohistochemistry and genotyping. Univariate analysis revealed that TP53-mutated patients were associated with a poor prognosis (log-rank test, P = 0.089). Japanese VSCC mutations resembled those of Caucasian vulvar carcinomas, and TP53 mutations predicted prognosis regardless of ethnicity. The present findings suggest potential molecular-targeted therapies for select VSCC patients.

The Genomic, Transcriptomic, and Immunologic Landscape of HRAS Mutations in Solid Tumors

Tipifarnib is the only targeted therapy breakthrough for HRAS-mutant (HRASmt) recurrent or metastatic head and neck squamous cell carcinoma (HNSCC). The molecular profiles of HRASmt cancers are difficult to explore given the low frequency of HRASmt. This study aims to understand the molecular co-alterations, immune profiles, and clinical outcomes of 524 HRASmt solid tumors including urothelial carcinoma (UC), breast cancer (BC), non-small-cell lung cancer (NSCLC), melanoma, and HNSCC. HRASmt was most common in UC (3.0%), followed by HNSCC (2.82%), melanoma (1.05%), BC (0.45%), and NSCLC (0.44%). HRASmt was absent in Her2+ BC regardless of hormone receptor status. HRASmt was more frequently associated with squamous compared to non-squamous NSCLC (60% vs. 40% in HRASwt, p = 0.002). The tumor microenvironment (TME) of HRASmt demonstrated increased M1 macrophages in triple-negative BC (TNBC), HNSCC, squamous NSCLC, and UC; increased M2 macrophages in TNBC; and increased CD8+ T-cells in HNSCC (all p < 0.05). Finally, HRASmt was associated with shorter overall survival in HNSCC (HR: 1.564, CI: 1.16-2.11, p = 0.003) but not in the other cancer types examined. In conclusion, this study provides new insights into the unique molecular profiles of HRASmt tumors that may help to identify new targets and guide future clinical trial design.

Protein lipidation in health and disease: molecular basis, physiological function and pathological implication

Posttranslational modifications increase the complexity and functional diversity of proteins in response to complex external stimuli and internal changes. Among these, protein lipidations which refer to lipid attachment to proteins are prominent, which primarily encompassing five types including S-palmitoylation, N-myristoylation, S-prenylation, glycosylphosphatidylinositol (GPI) anchor and cholesterylation. Lipid attachment to proteins plays an essential role in the regulation of protein trafficking, localisation, stability, conformation, interactions and signal transduction by enhancing hydrophobicity. Accumulating evidence from genetic, structural, and biomedical studies has consistently shown that protein lipidation is pivotal in the regulation of broad physiological functions and is inextricably linked to a variety of diseases. Decades of dedicated research have driven the development of a wide range of drugs targeting protein lipidation, and several agents have been developed and tested in preclinical and clinical studies, some of which, such as asciminib and lonafarnib are FDA-approved for therapeutic use, indicating that targeting protein lipidations represents a promising therapeutic strategy. Here, we comprehensively review the known regulatory enzymes and catalytic mechanisms of various protein lipidation types, outline the impact of protein lipidations on physiology and disease, and highlight potential therapeutic targets and clinical research progress, aiming to provide a comprehensive reference for future protein lipidation research.

DHX33 mediates p53 to regulate mevalonate pathway gene transcription in human cancers

Tumor suppressor p53 is frequently null or mutated in human cancers. Here in this study, DHX33 protein was found to be induced in p53 null cells in vitro, and in p53 mutant lung tumorigenesis in vivo. Cholesterol metabolism through mevalonate pathway is pivotal for cell proliferation and is frequently altered in human cancers. Mice carrying mutant p53 and KrasG12D alleles showed upregulation of mevalonate pathway gene expression. However upon DHX33 loss, their upregulation was significantly debilitated. Additionally, in many human cancer cells, DHX33 knockdown caused inhibition of mavelonate pathway gene transcription. We propose DHX33 locates downstream of mutant p53 and Ras to regulate mevalonate pathway gene transcription and thereby supports cancer development in vivo.

Unlocking the therapeutic potential of drug combinations through synergy prediction using graph transformer networks

Drug combinations are frequently used to treat cancer to reduce side effects and increase efficacy. The experimental discovery of drug combination synergy is time-consuming and expensive for large datasets. Therefore, an efficient and reliable computational approach is required to investigate these drug combinations. Advancements in deep learning can handle large datasets with various biological problems. In this study, we developed a SynergyGTN model based on the Graph Transformer Network to predict the synergistic drug combinations against an untreated cancer cell line expression profile. We represent the drug via a graph, with each node and edge of the graph containing nine types of atomic feature vectors and four bonds features, respectively. The cell lines represent based on their gene expression profiles. The drug graph was passed through the GTN layers to extract a generalized feature map for each drug pairs. The drug pair extracted features and cell-line gene expression profiles were concatenated and subsequently subjected to processing through multiple densely connected layers. SynergyGTN outperformed the state-of-the-art methods, with a receiver operating characteristic area under the curve improvement of 5% on the 5-fold cross-validation. The accuracy of SynergyGTN was further verified through three types of cross-validation tests strategies namely leave-drug-out, leave-combination-out, and leave-tissue-out, resulting in improvement in accuracy of 8%, 1%, and 2%, respectively. The Astrazeneca Dream dataset was utilized as an independent dataset to validate and assess the generalizability of the proposed method, resulting in an improvement in balanced accuracy of 13%. In conclusion, SynergyGTN is a reliable and efficient computational approach for predicting drug combination synergy in cancer treatment. Finally, we developed a web server tool to facilitate the pharmaceutical industry and researchers, as available at: http://nsclbio.jbnu.ac.kr/tools/SynergyGTN/.

Evolutionary dynamics of tipifarnib in HRAS mutated head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a highly prevalent malignancy worldwide, with a significant proportion of patients developing recurrent and/or metastatic (R/M) disease. Despite recent advances in therapy, the prognosis for patients with advanced HNSCC remains poor. Here, we present the case of a patient with recurrent metastatic HNSCC harboring an HRAS G12S mutation who achieved a durable response to treatment with tipifarnib, a selective inhibitor of farnesyltransferase. The patient was a 48-year-old woman who had previously received multiple lines of therapy with no significant clinical response. However, treatment with tipifarnib resulted in a durable partial response that lasted 8 months. Serial genomic and transcriptomic analyses demonstrated upregulation of YAP1 and AXL in metastatic lesions compared with the primary tumor, the evolution of the tumor microenvironment from an immune-enriched to a fibrotic subtype with increased angiogenesis, and activation of the PI3K/AKT/mTOR pathway in tipifarnib treatment. Lastly, in HRAS-mutated PDXs and in the syngeneic HRAS model, we demonstrated that tipifarnib efficacy is limited by activation of the AKT pathway, and dual treatment with tipifarnib and the PI3K inhibitor, BYL719, resulted in enhanced anti-tumor efficacy. Our case study highlights the potential of targeting HRAS mutations with tipifarnib in R/M HNSCC and identifies potential mechanisms of acquired resistance to tipifarnib, along with immuno-, chemo-, and radiation therapy. Preclinical results provide a firm foundation for further investigation of drug combinations of HRAS-and PI3K -targeting therapeutics in R/M HRAS-driven HNSCC.

Whole exome sequencing uncovers HRAS mutations as potential mediators of resistance to metronomic chemotherapy

OBJECTIVES

The aim of this pilot study is to identify the genetic factors that contribute to the response of metronomic chemotherapy in head and neck squamous cell carcinoma (HNSCC) patients using whole-exome sequencing (WES). This study would facilitate the identification of predictive biomarkers, which would enable personalized treatment strategies and improve treatment outcomes for patients with HNSCC.

MATERIALS AND METHODS

We have selected patients with recurrent head and neck cancer who underwent metronomic chemotherapy. Sequential tumor biopsies were collected from the patients at different stages of treatment to capture the genomic alterations and tumor evolution during metronomic chemotherapy and sequenced using WES.

RESULTS

We identified several known HNSCC hallmark genes reported in COSMIC, including KMT2B, NOTCH1, FAT1, TP53, HRAS, CASP8, and CDKN2A. Copy number alteration analysis revealed amplifications and deletions in several oncogenic and tumor suppressor genes. COSMIC Mutational Signature 15 associated with defective DNA mismatch repair was enriched in 73% of HNSCC samples. Further, the comparison of genomic alterations between responders and non-responders identified HRAS gene uniquely mutated in non-responders that could potentially contribute to resistance against metronomic chemotherapy.

DISCUSSION

Our findings corroborate the molecular heterogeneity of recurrent HNSCC tumors and establish an association between HRAS mutations and resistance to metronomic chemotherapy, suggesting HRAS as a potential therapeutic target. Combining HRAS inhibitors with metronomic regimens could improve treatment sensitivity in HRAS-mutated HNSCC patients. Further studies are needed to fully elucidate the genomic mechanisms underlying the response to metronomic chemotherapy.

Unraveling the Role of Ras Homolog Enriched in Brain (Rheb1 and Rheb2): Bridging Neuronal Dynamics and Cancer Pathogenesis through Mechanistic Target of Rapamycin Signaling

Ras homolog enriched in brain (Rheb1 and Rheb2), small GTPases, play a crucial role in regulating neuronal activity and have gained attention for their implications in cancer development, particularly in breast cancer. This study delves into the intricate connection between the multifaceted functions of Rheb1 in neurons and cancer, with a specific focus on the mTOR pathway. It aims to elucidate Rheb1's involvement in pivotal cellular processes such as proliferation, apoptosis resistance, migration, invasion, metastasis, and inflammatory responses while acknowledging that Rheb2 has not been extensively studied. Despite the recognized associations, a comprehensive understanding of the intricate interplay between Rheb1 and Rheb2 and their roles in both nerve and cancer remains elusive. This review consolidates current knowledge regarding the impact of Rheb1 on cancer hallmarks and explores the potential of Rheb1 as a therapeutic target in cancer treatment. It emphasizes the necessity for a deeper comprehension of the molecular mechanisms underlying Rheb1-mediated oncogenic processes, underscoring the existing gaps in our understanding. Additionally, the review highlights the exploration of Rheb1 inhibitors as a promising avenue for cancer therapy. By shedding light on the complicated roles between Rheb1/Rheb2 and cancer, this study provides valuable insights to the scientific community. These insights are instrumental in guiding the identification of novel targets and advancing the development of effective therapeutic strategies for treating cancer.

An innovative gene expression modulating strategy by converting nucleic acids into HNC therapeutics using carrier-free nanoparticles

Background

Cell fate and microenvironmental changes resulting from aberrant expression of specific proteins in tumors are one of the major causes of inadequate anti-tumor immune response and poor prognosis in head and neck cancer (HNC). Eukaryotic initiation factor 3C (eIF3c) has emerged as a promising therapeutic target for HNC due to its ability to regulate protein expression levels in tumor cells, but its drug development is difficult to achieve by targeting traditional protein-protein interactions. siRNA has emerged as a highly promising modality for drug development targeting eIF3c, while its application is hindered by challenges pertaining to inadequate stability and insufficient concentration specifically within tumor sites.

Method

We employed a method to convert flexible siRNAs into stable and biologically active infinite Auric-sulfhydryl coordination supramolecular siRNAs (IacsRNAs). Through coordinated self-assembly, we successfully transformed eIF3C siRNAs into the carrier-free HNC nanotherapeutic agent Iacs-eif3c-RNA. The efficacy of this agent was evaluated in vivo using HNC xenograft models, demonstrating promising antitumor effects.

Results

Iacs-eif3c-RNA demonstrated the ability to overcome the pharmacological obstacle associated with targeting eIF3C, resulting in a significant reduction in eIF3C expression within tumor tissues, as well as effective tumor cell proliferating suppression and apoptosis promotion. In comparison to monotherapy utilizing the chemotherapeutic agent cisplatin, Iacs-eif3c-RNA exhibited superior anti-tumor efficacy and favorable biosafety.

Conclusion

The utilization of Iacs-eif3c-RNA as a carrier-free nanotherapeutic agent presents a promising and innovative approach for addressing HNC treating challenges. Moreover, this strategy demonstrates potential for the translation of therapeutic siRNAs into clinical drugs, extending its applicability to the treatment of other cancers and various diseases.

The repertoire of mutational signatures in tobacco- and non-tobacco-induced oral cancer

The use of tobacco products is one of the established contributors toward the development and spread of oral cancer. Additionally, recent research has indicated oral microbiome, infections with Human papilloma virus (HPV), Epstein-Barr virus (EBV), Candida as significant contributing factors to this disease along with lifestyle habits. Deregulation of cellular pathways envisaging metabolism, transcription, translation, and epigenetics caused by these risk factors either individually or in unison is manifold, resulting in the increased risk of oral cancer. Globally, this cancer continues to exist as one of the major causes of cancer-related mortalities; the numbers in the developing South Asian countries clearly indicate yearly escalation. This review encompasses the variety of genetic modifications, including adduct formation, mutation (duplication, deletion, and translocation), and epigenetic changes evident in oral squamous cell carcinoma (OSCC). In addition, it highlights the interference caused by tobacco products in Wnt signaling, PI3K/Akt/mTOR, JAK-STAT, and other important pathways. The information provided also ensures a comprehensive and critical revisit to non-tobacco-induced OSCC. Extensive literature survey and analysis has been conducted to generate the chromosome maps specifically highlighting OSCC-related mutations with the potential to act as spectacles for the early diagnosis and targeted treatment of this disease cancer.

New insights into RAS in head and neck cancer

RAS genes are known to be dysregulated in cancer for several decades, and substantial effort has been dedicated to develop agents that reduce RAS expression or block RAS activation. The recent introduction of RAS inhibitors for cancer patients highlights the importance of comprehending RAS alterations in head and neck cancer (HNC). In this regard, we examine the published findings on RAS alterations and pathway activations in HNC, and summarize their role in HNC initiation, progression, and metastasis. Specifically, we focus on the intrinsic role of mutated-RAS on tumor cell signaling and its extrinsic role in determining tumor-microenvironment (TME) heterogeneity, including promoting angiogenesis and enhancing immune escape. Lastly, we summarize the intrinsic and extrinsic role of RAS alterations on therapy resistance to outline the potential of targeting RAS using a single agent or in combination with other therapeutic agents for HNC patients with RAS-activated tumors.

Molecular classification of human papilloma virus-negative head and neck squamous cell carcinomas: Cell cycle-based classifier and prognostic signature

The molecular classification of human papillomavirus (HPV)-negative head and neck squamous cell carcinomas (HNSCCs) remains questionable. Differentially expressed genes were detected between tumor and normal tissues and GSEA showed they are associated with cell cycle pathways. This study aimed to classify HPV-negative HNSCCs based on cell cycle-related genes. The established gene pattern was correlated with tumor progression, clinical prognosis, and drug treatment efficacy. Biological analysis was performed using HNSCC patient sample data obtained from the Cancer Genome Atlas (TCGA), Clinical Proteomic Tumor Analysis Consortium (CPTAC), and Gene Expression Omnibus (GEO) databases. All samples included in this study contained survival information. RNA sequencing data from 740 samples were used for the analysis. Previously characterized cell cycle-related genes were included for unsupervised consensus clustering. Two subtypes of HPV-negative HNSCCs (C1, C2) were identified. Subtype C1 displayed low cell cycle activity, 'hot' tumor microenvironment (TME), earlier N stage, lower pathological grade, better prognosis, and higher response rate to the immunotherapy and targeted therapy. Subtype C2 was associated with higher cell cycle activity, 'cold' TME, later N stage, higher pathological grade, worse prognosis, and lower response rate to the treatment. According to the nearest template prediction method, classification rules were established and verified. Our work explored the molecular mechanism of HPV-negative HNSCCs in the view of cell cycle and might provide new sights for personalized anti-cancer treatment.

Tipifarnib Potentiates the Antitumor Effects of PI3Kα Inhibition in PIK3CA- and HRAS-Dysregulated HNSCC via Convergent Inhibition of mTOR Activity

Outcomes for patients with recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) are poor, with median overall survival (OS) ranging from 6 to 18 months. For those who progress on standard-of-care (chemo)immunotherapy, treatment options are limited, necessitating the development of rational therapeutic strategies. Toward this end, we targeted the key HNSCC drivers PI3K-mTOR and HRAS via the combination of tipifarnib, a farnesyltransferase (FTase) inhibitor, and alpelisib, a PI3Kα inhibitor, in multiple molecularly defined subsets of HNSCC. Tipifarnib synergized with alpelisib at the level of mTOR in PI3Kα- or HRAS-dependent HNSCCs, leading to marked cytotoxicity in vitro and tumor regression in vivo. On the basis of these findings, the KURRENT-HN trial was launched to evaluate the effectiveness of this combination in PIK3CA-mutant/amplified and/or HRAS-overexpressing R/M HNSCC. Preliminary evidence supports the clinical activity of this molecular biomarker-driven combination therapy. Combined alpelisib and tipifarnib has potential to benefit >45% of patients with R/M HNSCC. By blocking feedback reactivation of mTORC1, tipifarnib may prevent adaptive resistance to additional targeted therapies, enhancing their clinical utility.

SIGNIFICANCE

The mechanistically designed, biomarker-matched strategy of combining alpelisib and tipifarnib is efficacious in PIK3CA- and HRAS-dysregulated head and neck squamous carcinoma and could improve outcomes for many patients with recurrent, metastatic disease. See related commentary by Lee et al., p. 3162.

The Mutational, Prognostic, and Therapeutic Landscape of Neuroendocrine Neoplasms

BACKGROUND

Neuroendocrine neoplasms (NENs) represent clinically and genetically heterogeneous malignancies, thus a comprehensive understanding of underlying molecular characteristics, prognostic signatures, and potential therapeutic targets is urgently needed.

METHODS

Next-generation sequencing (NGS) and immunohistochemistry were applied to acquire genomic and immune profiles of NENs from 47 patients.

RESULTS

Difference was distinguished based on differentiation grade and primary localization. Poorly differentiated neuroendocrine carcinomas (NECs) and well-differentiated neuroendocrine tumors (NETs) harbored distinct molecular features; we observed that tumor mutational burden (TMB) and tumor neoantigen burden (TNB) were significantly higher in NECs versus NETs. Notably, we identified a 7-gene panel (MLH3, NACA, NOTCH1, NPAP1, RANBP17, TSC2, and ZFHX4) as a novel prognostic signature in NENs; patients who carried mutations in any of the 7 genes exhibited significantly poorer survival. Furthermore, loss of heterozygosity (LOH) and germline homogeneity in human leukocyte antigen (HLA) are common in NENs, accounting for 39% and 36%, respectively. Notably, HLA LOH was an important prognostic biomarker for a subgroup of NEN patients. Finally, we analyzed clinically actionable targets in NENs, revealing that TMB high (TMB-H) or gene mutations in TP53, KRAS, and HRAS were the most frequently observed therapeutic indicators, which granted eligibility to immune checkpoint blockade (ICB) and targeted therapy.

CONCLUSION

Our study revealed heterogeneity of NENs, and identified novel prognostic signatures and potential therapeutic targets, which directing improvements of clinical management for NEN patients in the foreseeable future.

Mutant HRas Signaling and Rationale for Use of Farnesyltransferase Inhibitors in Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinomas (HNSCCs) are often associated with poor outcomes, due at least in part to the limited number of treatment options available for those patients who develop recurrent and/or metastatic disease (R/M HNSCC). Even with the recent validation and approval of immunotherapies in the first-line setting for these patients, the need for the development of new and alternative precision medicine strategies with survival benefit is clear. Oncogenic alterations in the HRAS (Harvey rat sarcoma virus) proto-oncogene are seen in approximately 4-8% of R/M HNSCC tumors. Recently, several preclinical and clinical advancements have been made in the implementation of small-molecule inhibitors that block post-translational farnesylation of HRas, thereby abrogating its downstream oncogenic activity. In this review, we focus on the biology of wild-type and mutant HRas signaling in HNSCC, and rationale for use and outcomes of farnesyltransferase inhibitors in patients with HRAS-mutant tumors.

Oncogenic Ras and ΔNp63α cooperate to recruit immunosuppressive polymorphonuclear myeloid-derived suppressor cells in a mouse model of squamous cancer pathogenesis

Introduction

Amplification of human chromosome 3q26-29, which encodes oncoprotein ΔNp63 among other isoforms of the p63 family, is a feature common to squamous cell carcinomas (SCCs) of multiple tissue origins. Along with overexpression of ΔNp63, activation of the protooncogene, RAS, whether by overexpression or oncogenic mutation, is frequently observed in many cancers. In this study, analysis of transcriptome data from The Cancer Genome Atlas (TCGA) demonstrated that expression of TP63 mRNA, particularly ΔNp63 isoforms, and HRAS are significantly elevated in advanced squamous cell carcinomas of the head and neck (HNSCCs), suggesting pathological significance. However, how co-overexpressed ΔNp63 and HRAS affect the immunosuppressive tumor microenvironment (TME) is incompletely understood.

Methods

Here, we established and characterized an immune competent mouse model using primary keratinocytes with retroviral-mediated overexpression of ΔNp63α and constitutively activated HRAS (v-rasHa G12R) to evaluate the role of these oncogenes in the immune TME.

Results

In this model, orthotopic grafting of wildtype syngeneic keratinocytes expressing both v-rasHa and elevated levels of ΔNp63α consistently yield carcinomas in syngeneic hosts, while cells expressing v-rasHa alone yield predominantly papillomas. We found that polymorphonuclear (PMN) myeloid cells, experimentally validated to be immunosuppressive and thus representing myeloid-derived suppressor cells (PMN-MDSCs), were significantly recruited into the TME of carcinomas arising early following orthotopic grafting of ΔNp63α/v-rasHa-expressing keratinocytes. ΔNp63α/v-rasHa-driven carcinomas expressed higher levels of chemokines implicated in recruitment of MDSCs compared to v-rasHa-initiated tumors, providing a heretofore undescribed link between ΔNp63α/HRAS-driven carcinomas and the development of an immunosuppressive TME.

Conclusion

These results support the utilization of a genetic carcinogenesis model harboring specific genomic drivers of malignancy to study mechanisms underlying the development of local immunosuppression.

Suppression of NASH-Related HCC by Farnesyltransferase Inhibitor through Inhibition of Inflammation and Hypoxia-Inducible Factor-1α Expression

Inflammatory processes play major roles in carcinogenesis and the progression of hepatocellular carcinoma (HCC) derived from non-alcoholic steatohepatitis (NASH). But, there are no therapies for NASH-related HCC, especially focusing on these critical steps. Previous studies have reported that farnesyltransferase inhibitors (FTIs) have anti-inflammatory and anti-tumor effects. However, the influence of FTIs on NASH-related HCC has not been elucidated. In hepatoblastoma and HCC cell lines, HepG2, Hep3B, and Huh-7, we confirmed the expression of hypoxia-inducible factor (HIF)-1α, an accelerator of tumor aggressiveness and the inflammatory response. We established NASH-related HCC models under inflammation and free fatty acid burden and confirmed that HIF-1α expression was increased under both conditions. Tipifarnib, which is an FTI, strongly suppressed increased HIF-1α, inhibited cell proliferation, and induced apoptosis. Simultaneously, intracellular interleukin-6 as an inflammation marker was increased under both conditions and significantly suppressed by tipifarnib. Additionally, tipifarnib suppressed the expression of phosphorylated nuclear factor-κB and transforming growth factor-β. Finally, in a NASH-related HCC mouse model burdened with diethylnitrosamine and a high-fat diet, tipifarnib significantly reduced tumor nodule formation in association with decreased serum interleukin-6. In conclusion, tipifarnib has anti-tumor and anti-inflammatory effects in a NASH-related HCC model and may be a promising new agent to treat this disease.

Cooperative Genomic Lesions in HRAS-Mutant Cancers Predict Resistance to Farnesyltransferase Inhibitors

The clinical development of farnesyltransferase inhibitors (FTI) for HRAS-mutant tumors showed mixed responses dependent on cancer type. Co-occurring mutations may affect response. We aimed to uncover cooperative genetic events specific to HRAS-mutant tumors and study their effect on FTI sensitivity. Using targeted sequencing data from MSK-IMPACT and DFCI-GENIE databases we identified co-mutations in HRAS- vs KRAS- and NRAS-mutant cancers. HRAS-mutant cancers had a higher frequency of co-altered mutations (48.8%) in MAPK, PI3K, or RTK pathways genes compared to KRAS- and NRAS-mutant cancers (41.4% and 38.4%, respectively; p < 0.05). Class 3 BRAF, NF1, PTEN, and PIK3CA mutations were more prevalent in HRAS-mutant lineages. To study the effect of comutations on FTI sensitivity, HrasG13R was transfected into 'RASless' (Kraslox/lox;Hras-/-;Nras-/-) mouse embryonic fibroblasts (MEFs) which sensitized non-transfected MEFs to tipifarnib. Comutation in the form of Pten or Nf1 deletion or Pik3caH1047R or BrafG466E transduction led to relative resistance to tipifarnib in HrasG13R MEFs in the presence or absence of KrasWT. Combined treatment of tipifarnib with MEK inhibition sensitized cells to tipifarnib, including in MEFs with PI3K pathway comutations. HRAS-mutant tumors demonstrate lineage demonstrate lineage-dependent MAPK/PI3K pathway alterations that confer relative resistance to tipifarnib. Combined FTI and MEK inhibition is a promising combination for HRAS-mutant tumors.

The applications and techniques of organoids in head and neck cancer therapy

Head and neck cancer (HNC) is one of the most common cancers on the planet, with approximately 600,000 new cases diagnosed and 300,000 deaths every year. Research into the biological basis of HNC has advanced slowly over the past decades, which has made it difficult to develop new, more effective treatments. The patient-derived organoids (PDOs) are made from patient tumor cells, resembling the features of their tumors, which are high-fidelity models for studying cancer biology and designing new precision medicine therapies. In recent years, considerable effort has been focused on improving "organoids" technologies and identifying tumor-specific medicine using head and neck samples and a variety of organoids. A review of improved techniques and conclusions reported in publications describing the application of these techniques to HNC organoids is presented here. Additionally, we discuss the potential application of organoids in head and neck cancer research as well as the limitations associated with these models. As a result of the integration of organoid models into future precision medicine research and therapeutic profiling programs, the use of organoids will be extremely significant in the future.

Direct Amination of α-Triaryl Alcohols via Vanadium Catalysis

α-Triaryl amines have been used as pharmaceuticals and pharmaceutical intermediates for antifungal and anticancer applications. Current methods to synthesize such compounds require at least two steps, and no direct amination of tertiary alcohols has been reported. Herein, we disclose efficient catalytic conditions for the direct amination of α-triaryl alcohols to access α-triaryl amines. VO(OⁱPr)₃, a commercially available reagent, has been identified as an effective catalyst for the direct amination of several α-triaryl alcohols. This process is scalable, as demonstrated by a gram-scale synthesis, and the reaction still works at as low as a 0.01 mol % catalyst loading with the turnover number reaching 3900. Moreover, commercial pharmaceuticals including clotrimazole and flutrimazole have been successfully prepared rapidly and efficiently using this newly developed method.

Targeting Harvey rat sarcoma viral oncogene homolog in head and neck cancer: how to move forward?

PURPOSE OF REVIEW

Despite recent advances, treatment personalization remains an issue for recurrent metastatic head and neck squamous cell carcinoma (RM HNSCC) patients. After human papilloma virus (HPV) and programmed death ligand 1 (PDL1) expression, Harvey rat sarcoma viral oncogene homolog (HRAS) appears as an emerging target in this field. In this review, we summarize the features of HRAS -mutated HNSCC and its targeting by farnesyl transferase inhibitors.

RECENT FINDINGS

HRAS mutations define a small subgroup of RM HNSCC patients with a poor prognosis and often refractory to the standard treatments. Posttranslational processing of HRAS being dependent on farnesylation, farnesyl transferase inhibitors have been evaluated in HRAS -mutated tumors. Tipifarnib, a first in class farnesyl transferase inhibitor, has shown efficacy in phase 2 trials with HRAS -mutated tumors. Despite reported high response rates in selected population, the efficacy of Tipifarnib is inconsistent and always transient, probably because of limiting hematological toxicities leading to dose reduction and occurrence of secondary resistance mutations.

SUMMARY

Tipifarnib is the first in the class of farnesyl transferase inhibitors to show efficacy in HRAS -mutated RM HNSCC. The understanding of mechanisms of resistance will pave the way for the design of second-generation farnesyl transferases inhibitors.

Mutated HRAS Activates YAP1-AXL Signaling to Drive Metastasis of Head and Neck Cancer

The survival rate for patients with head and neck cancer (HNC) diagnosed with cervical lymph node (cLN) or distant metastasis is low. Genomic alterations in the HRAS oncogene are associated with advanced tumor stage and metastasis in HNC. Elucidation of the molecular mechanisms by which mutated HRAS (HRASmut) facilitates HNC metastasis could lead to improved treatment options for patients. Here, we examined metastasis driven by mutant HRAS in vitro and in vivo using HRASmut human HNC cell lines, patient-derived xenografts, and a novel HRASmut syngeneic model. Genetic and pharmacological manipulations indicated that HRASmut was sufficient to drive invasion in vitro and metastasis in vivo. Targeted proteomic analysis showed that HRASmut promoted AXL expression via suppressing the Hippo pathway and stabilizing YAP1 activity. Pharmacological blockade of HRAS signaling with the farnesyltransferase inhibitor tipifarnib activated the Hippo pathway and reduced the nuclear export of YAP1, thus suppressing YAP1-mediated AXL expression and metastasis. AXL was required for HRASmut cells to migrate and invade in vitro and to form regional cLN and lung metastases in vivo. In addition, AXL-depleted HRASmut tumors displayed reduced lymphatic and vascular angiogenesis in the primary tumor. Tipifarnib treatment also regulated AXL expression and attenuated VEGFA and VEGFC expression, thus regulating tumor-induced vascular formation and metastasis. Our results indicate that YAP1 and AXL are crucial factors for HRASmut-induced metastasis and that tipifarnib treatment can limit the metastasis of HNC tumors with HRAS mutations by enhancing YAP1 cytoplasmic sequestration and downregulating AXL expression.

SIGNIFICANCE

Mutant HRAS drives metastasis of head and neck cancer by switching off the Hippo pathway to activate the YAP1-AXL axis and to stimulate lymphovascular angiogenesis.

Circulating Tumor DNA in Head and Neck Squamous Cell Carcinoma

Tumors shed cell-free DNA (cfDNA) into the plasma. "Liquid biopsies" are a diagnostic test to analyze cfDNA in order to detect minimal residual cancer, profile the genomic tumor landscape, and monitor cancers non-invasively over time. This technique may be useful in patients with head and neck squamous cell carcinoma (HNSCC) due to genetic tumor heterogeneity and limitations in imaging sensitivity. However, there are technical challenges that need to be overcome for the widespread use of liquid biopsy in the clinical management of these patients. In this review, we discuss our current understanding of HNSCC genetics and the role of cfDNA genomic analyses as an emerging precision diagnostic tool.

Molecular profiling and target actionability for precision medicine in neuroendocrine neoplasms: real-world data

BACKGROUND

Key molecular alterations (MA) of neuroendocrine neoplasm (NEN) of various grade/primaries have been described but the applicability of molecular profiling (MP) for precision medicine in NEN remains to be demonstrated.

METHODS

We conducted a retrospective study of all patients with metastatic NEN who had MP on tumour tissue at Gustave Roussy. The primary objective was to assess the clinical applicability of MP by evaluating the growth modulator index (GMI) as the primary end-point.

RESULTS

MPs were obtained in 114 out of 156 eligible patients, including 12% NET-G1, 42% NET-G2, 13% NET-G3 and 35% neuroendocrine carcinoma (NEC). Primary sites were lung/thymus (40%), pancreas (19%), gastro-intestinal (16%), head&neck (10%), unknown (10%) and others (10%) with synchronous metastases in 61% of the patients. Most frequent MA were: MEN1 (25%), PTEN (13%), TP53 (11%) and TSC2 (9%), in neuroendocrine tumour (NET), and TP53 (50%) and RB1 (18%) in NEC. ESMO Scale for Clinical Actionability of Molecular Targets (ESCAT) classification of these MA were: I(5%), III(20%), IV(23%), X(27%); a putative actionable MA was identified in 48% patients. Median TMB was 5.7 Mut/Mb, with 3 TMB > 10 and 1 MSI NET. No MA was found in 26% patients. Molecularly matched treatment was administered to 19 patients (4 NEC, 15 NET): immunotherapy (n = 3), tipifarnib (n = 1), NOTCHi (n = 1), EGFRi (n = 2), HER2i (n = 1) and everolimus (n = 11). Overall, 67% of patients had a clinical benefit defined as a GMI over 1.3 with a 78% disease control rate.

CONCLUSION

We report 48% of NEN with a putative actionable MA of which 35% received molecularly matched treatment, with a clinical benefit in 67% of the cases.

The lncRNA XIST/miR-29b-3p/COL3A1 axis regulates central carbon metabolism in head and neck squamous cell carcinoma and is associated with poor tumor prognosis

Background

Recent evidence shows that COL3A1 promotes the progression of many types of cancer. The purpose of our study is to explore the correlation between COL3A1 and the prognosis of patients with head and neck squamous cell carcinoma (HNSCC) and its potential mechanism.

Methods

We initially screened the differentially expressed gene COL3A1 in The Cancer Genome Atlas (TCGA) database, and the association between the expression level of COL3A1, prognosis, and the clinical parameters of HNSCC patients was verified. A nomogram was constructed according to the multivariate analysis results. Next, a heatmap of COL3A1 co-expressed genes was constructed in TCGA database. The TargetScan database is used to explore the microRNAs (miRNA) related to COL3A1. The starBase database was used to explore and predict the long non-coding RNAs (lncRNAs) that the candidate miRNAs might bind to. Finally, the potential mechanism of action was investigated using Gene Set Enrichment Analysis (GSEA).

Results

COL3A1 expression is elevated in HNSCC tumor tissues, and HNSCC patients with high COL3A1 expression have worse prognostic factors. COL3A1 was positively correlated with the central carbon metabolism-related proteins: epidermal growth factor receptor (EGFR), phosphoglycerate mutase 1 (PGAM1), hexokinase 3 (HK3), and phosphofructokinase, platelet (PFKP). The TargetScan database showed that the best candidate miRNA for binding to the three prime untranslated region (3'UTR) end of COL3A1 mRNA was hsa-miR-29b-3p, which was negatively correlated with COL3A1. The starBase database showed that the lncRNA X Inactive Specific Transcript (lncRNA XIST) was the best candidate upstream non-coding RNA for regulating hsa-miR-29b-3p. GSEA showed that COL3A1 may be involved in the poor prognosis of HNSCC by participating in carbon metabolism, glucose metabolism, oxidative stress, and the Wingless-Type MMTV Integration Site Family (Wnt) and vascular endothelial growth factor A-vascular endothelial growth factor receptor 2 (VEGFA-VEGFR2) pathways.

Conclusions

Low COL3A1 expression can be employed as a new HNSCC predictive biomarker, and the prognosis of HNSCC patients with lower COL3A1 expression can be greatly improved. At the same time, we found that the lncRNA XIST/miR-29b-3p/COL3A1 axis may regulate the central carbon metabolism of HNSCC and is associated with poor prognosis. These findings point to a potential target for developing HNSCC anticancer therapies.

Treating Head and Neck Cancer in the Age of Immunotherapy: A 2023 Update

Most patients diagnosed with head and neck squamous cell carcinoma (HNSCC) will present with locally advanced disease, requiring multimodality therapy. While this approach has a curative intent, a significant subset of these patients will develop locoregional failure and/or distant metastases. The prognosis of these patients is poor, and therapeutic options other than palliative chemotherapy are urgently needed. Epidermal growth factor receptor (EGFR) overexpression is an important factor in the pathogenesis of HNSCC, and a decade ago, the EGFR targeting monoclonal antibody cetuximab was approved for the treatment of late-stage HNSCC in different settings. In 2016, the anti-programmed death-1 (PD-1) immune checkpoint inhibitors nivolumab and pembrolizumab were both approved for the treatment of patients with recurrent or metastatic HNSCC with disease progression on or after platinum-containing chemotherapy, and in 2019, pembrolizumab was approved for first-line treatment (either as monotherapy in PD-L1 expressing tumors, or in combination with chemotherapy). Currently, trials are ongoing to include immune checkpoint inhibition in the (neo)adjuvant treatment of HNSCC as well as in novel combinations with other drugs in the recurrent/metastatic setting to improve response rates and survival and help overcome resistance mechanisms to immune checkpoint blockade. This article provides a comprehensive review of the management of head and neck cancers in the current era of immunotherapy.

Recommendations for the use of biomarkers for head and neck cancer, including salivary gland tumours: A Consensus of the Spanish Society of Medical Oncology and the Spanish Society of Pathology

The treatment of head and neck and salivary gland tumours is complicated and is constantly evolving. Prognostic and predictive indicators of response to treatment are enormously valuable for designing individualized therapies, which justifies their research and validation. Some biomarkers, such as p16, Epstein-Barr virus, PD-L1, androgen receptors and HER-2, are already used routinely in clinical practice. These biomarkers, along with other markers that are currently under development, and the massively parallel sequencing of genes, ensure future advances in the treatment of these neoplasms. In this consensus, a group of experts in the diagnosis and treatment of tumours of the head and neck and salivary glands were selected by the Spanish Society of Pathology (Sociedad Española de Anatomía Patológica - SEAP) and the Spanish Society of Medical Oncology (Sociedad Española de Oncología Médica - SEOM) to evaluate the currently available information and propose a series of recommendations to optimize the determination and daily clinical use of biomarkers.

Tumor heterogeneity: preclinical models, emerging technologies, and future applications

Heterogeneity describes the differences among cancer cells within and between tumors. It refers to cancer cells describing variations in morphology, transcriptional profiles, metabolism, and metastatic potential. More recently, the field has included the characterization of the tumor immune microenvironment and the depiction of the dynamics underlying the cellular interactions promoting the tumor ecosystem evolution. Heterogeneity has been found in most tumors representing one of the most challenging behaviors in cancer ecosystems. As one of the critical factors impairing the long-term efficacy of solid tumor therapy, heterogeneity leads to tumor resistance, more aggressive metastasizing, and recurrence. We review the role of the main models and the emerging single-cell and spatial genomic technologies in our understanding of tumor heterogeneity, its contribution to lethal cancer outcomes, and the physiological challenges to consider in designing cancer therapies. We highlight how tumor cells dynamically evolve because of the interactions within the tumor immune microenvironment and how to leverage this to unleash immune recognition through immunotherapy. A multidisciplinary approach grounded in novel bioinformatic and computational tools will allow reaching the integrated, multilayered knowledge of tumor heterogeneity required to implement personalized, more efficient therapies urgently required for cancer patients.

Predicting the effects of rare genetic variants on oncogenic signaling pathways: A computational analysis of HRAS protein function

The HRAS gene plays a crucial role in regulating essential cellular processes for life, and this gene's misregulation is linked to the development of various types of cancers. Nonsynonymous single nucleotide polymorphisms (nsSNPs) within the coding region of HRAS can cause detrimental mutations that disrupt wild-type protein function. In the current investigation, we have employed in-silico methodologies to anticipate the consequences of infrequent genetic variations on the functional properties of the HRAS protein. We have discovered a total of 50 nsSNPs, of which 23 were located in the exon region of the HRAS gene and denoting that they were expected to cause harm or be deleterious. Out of these 23, 10 nsSNPs ([G60V], [G60D], [R123P], [D38H], [I46T], [G115R], [R123G], [P11OL], [A59L], and [G13R]) were identified as having the most delterious effect based on results of SIFT analysis and PolyPhen2 scores ranging from 0.53 to 69. The DDG values -3.21 kcal/mol to 0.87 kcal/mol represent the free energy change associated with protein stability upon mutation. Interestingly, we identified that the three mutations (Y4C, T58I, and Y12E) were found to improve the structural stability of the protein. We performed molecular dynamics (MD) simulations to investigate the structural and dynamic effects of HRAS mutations. Our results showed that the stable model of HRAS had a significantly lower energy value of -18756 kj/mol compared to the initial model of -108915 kj/mol. The RMSD value for the wild-type complex was 4.40 Å, and the binding energies for the G60V, G60D, and D38H mutants were -107.09 kcal/mol, -109.42 kcal/mol, and -107.18 kcal/mol, respectively as compared to wild-type HRAS protein had -105.85 kcal/mol. The result of our investigation presents convincing corroboration for the potential functional significance of nsSNPs in augmenting HRAS expression and adding to the activation of malignant oncogenic signalling pathways.

Recommendations for the use of biomarkers for head and neck cancer, including salivary gland tumours: a consensus of the Spanish Society of Medical Oncology and the Spanish Society of Pathology

The treatment of head and neck and salivary gland tumours is complicated and evolves constantly. Prognostic and predictive indicators of response to treatment are enormously valuable for designing individualized therapies, which justifies their research and validation. Some biomarkers, such as p16, Epstein-Barr virus, PD-L1, androgen receptors and HER-2, are already used routinely in clinical practice. These biomarkers, along with other markers that are currently under development, and the massively parallel sequencing of genes, ensure future advances in the treatment of these neoplasms. In this consensus, a group of experts in the diagnosis and treatment of tumours of the head and neck and salivary glands were selected by the Spanish Society of Pathology (Sociedad Española de Anatomía Patológica-SEAP) and the Spanish Society of Medical Oncology (Sociedad Española de Oncología Médica-SEOM) to evaluate the currently available information and propose a series of recommendations to optimize the determination and daily clinical use of biomarkers.

MAPK Signaling Pathway in Oral Squamous Cell Carcinoma: Biological Function and Targeted Therapy

Oral squamous cell carcinoma accounts for 95% of human head and neck squamous cell carcinoma cases. It is highly malignant and aggressive, with a poor prognosis and a 5-year survival rate of <50%. In recent years, basic and clinical studies have been performed on the role of the mitogen-activated protein kinase (MAPK) signaling pathway in oral cancer. The MAPK signaling pathway is activated in over 50% of human oral cancer cases. Herein, we review research progress on the MAPK signaling pathway and its potential therapeutic mechanisms and discuss its molecular targeting to explore its potential as a therapeutic strategy for oral squamous cell carcinoma.

Targeting HRAS in Head and Neck Cancer: Lessons From the Past and Future Promise

ABSTRACT

HRAS mutations define a unique biologic subset of head and neck squamous cell carcinoma. Oncogenic HRAS is uniquely dependent on posttranslational farnesylation for membrane localization and activation of downstream signaling. Tipifarnib, a farnesyltransferase inhibitor, demonstrated encouraging antitumor activity for HRAS mutant head and neck squamous cell carcinoma and modest activity for HRAS mutant salivary gland cancer. New combination strategies to circumvent intrinsic and acquired resistance to TFIs are being investigated.

Targeting KRAS: Crossroads of Signaling and Immune Inhibition

Mutations of RAS are commonly seen in human cancers, especially in lung, colorectal, and pancreatic adenocarcinoma. Despite huge effort for decades, targeting RAS mutations has been “undruggable” because of the molecular instability of RAS protein inhibition. However, the recent discovery of the KRAS G12C inhibitor paved the way to expand therapeutic options for patients with cancer harboring the KRAS G12C mutation. At the same time, the successful development of immune checkpoint inhibitors (ICIs) drastically changed the paradigm of cancer treatment and resulted in a better understanding of the tumor immune microenvironment in patients with KRAS-mutant cancer. This review describes the following: the clinical characteristics of cancer with KRAS mutation; successful development of the KRAS G12C inhibitor and its impact on the tumor immune microenvironment; and potential new avenues such as the combination strategy using KRAS inhibitor and ICI, with preclinical and clinical rationales for overcoming resistance to inhibition of KRAS to improve therapeutic efficacy for patients with cancer harboring KRAS mutations.

Effects of silencing farnesyltransferase on the migration, invasion, and epithelial-mesenchymal transition of salivary adenoid cystic carcinoma cells

OBJECTIVES

This study aimed to investigate the effects of farnesyltransferase (FTase) on the migration, invasion, and epithelial-mesenchymal transition (EMT) of SACC-LM and SACC-83 cells in salivary adenoid cystic carcinoma and determine the relative mechanism.

METHODS

Three small interfering RNA (siRNA) sequences were designed and constructed based on the human FTase gene sequence. The SACC-LM and SACC-83 cells in the logarithmic growth period were used, and the expression of FTase was suppressed by liposomal transient transfection. The tested cells were categorized as the FTase-siRNA-1, FTase-siRNA-2, and FTase-siRNA-3 groups. Both negative control group (NC-siRNA) and blank control group (only transfection reagent was added) were set. The mRNA expression of FTase and HRAS was detected by quantitive real-time polymerase chain reaction, and the silencing efficiency was determined. The expression levels of FTase, HRAS, protein kinase B (AKT), phospho-AKT, p65, phospho-p65 (Ser563), E-cadherin, vimentin, matrix metalloproteinase (MMP)-9 protein, and HRAS membrane protein were detected by Western blot. Transwell assay and wound healing assay were used to detect the invasion and migration abilities of cells.

RESULTS

The relative expression of FTase mRNA and protein in the FTase-siRNA-1 group decreased compared with those in the control group (P<0.05). HRAS mRNA and total protein expression had no significant difference (P>0.05), and the relative expression of HRAS membrane protein decreased (P<0.05). The relative expression of E-cadherin increased (P<0.05), vimentin decreased (P<0.05), and MMP-9 decreased (P<0.05). There was no significant difference in the relative expression levels of the RAS/PI3K/AKT/nuclear factor-κB signaling pathway-related proteins AKT and p65 (P>0.05), but the relative expression levels of phospho-AKT and phospho-p65 decreased. The invasion and migration ability of the FTase-siRNA-1 group significantly decreased compared with that in the control group (P<0.05).

CONCLUSIONS

Silencing FTase in vitro could effectively inhibit the invasion and migration of SACC-LM and SACC-83 cells by interfering with the localization of the HRAS membrane protein and regulating the RAS/PI3K/AKT/nuclear factor-κB signaling pathway to mediate EMT.

Protein Farnesylation on Nasopharyngeal Carcinoma, Molecular Background and Its Potential as a Therapeutic Target

Simple Summary

Nasopharyngeal carcinoma is distinguished from other head and neck carcinomas by the association of its carcinogenesis with the Epstein–Barr virus. It is highly metastatic, and a novel therapeutic modality for metastatic nasopharyngeal carcinoma is keenly awaited. Protein farnesylation is a C-terminal lipid modification of proteins and was initially investigated as a key process in activating the RAS oncoprotein through its association with the cellular membrane structure. Since then, more and more evidence has accumulated to indicate that proteins other than RAS are also farnesylated and have significant roles in carcinogenesis. This review delineates molecular pathogenesis through protein farnesylation in the context of nasopharyngeal carcinoma and discusses the potential of farnesylation as a therapeutic target.

Abstract

Nasopharyngeal carcinoma (NPC) is one of the Epstein–Barr virus (EBV)-associated malignancies. NPC is highly metastatic compared to other head and neck carcinomas, and evidence has shown that the metastatic features of NPC are involved in EBV infection. The prognosis of advanced cases, especially those with distant metastasis, is still poor despite advancements in molecular research and its application to clinical settings. Thus, further advancement in basic and clinical research that may lead to novel therapeutic modalities is needed. Farnesylation is a lipid modification in the C-terminus of proteins. It enables proteins to attach to the lipid bilayer structure of cellular membranes. Farnesylation was initially identified as a key process of membrane association and activation of the RAS oncoprotein. Farnesylation is thus expected to be an ideal therapeutic target in anti-RAS therapy. Additionally, more and more molecular evidence has been reported, showing that proteins other than RAS are also farnesylated and have significant roles in cancer progression. However, although several clinical trials have been conducted in cancers with high rates of ras gene mutation, such as pancreatic carcinomas, the results were less favorable than anticipated. In contrast, favorable outcomes were reported in the results of a phase II trial on head and neck carcinoma. In this review, we provide an overview of the molecular pathogenesis of NPC in terms of the process of farnesylation and discuss the potential of anti-farnesylation therapy in the treatment of NPC.

HRAS Q61L Mutation as a Possible Target for Non-Small Cell Lung Cancer: Case Series and Review of Literature

Introduction: Assessment of actionable gene mutations and oncogene fusions have made a paradigm shift in treatment strategies of non-small cell lung cancer (NSCLC). HRAS mutations involved around 0.2–0.8% of NSCLC patients, mostly on codon 61. For these patients, few data are available regarding clinical characteristics and response to therapies. Methods: Next-Generation Sequencing (NGS) done routinely at Nantes University Hospital was used to identify HRAS molecular alterations in NSCLC patients. We identified and described four HRAS p.GlnQ61Leu mutated patients. Literature of previously HRAS-mutant NSCLC cases was reviewed, and available data in solid tumour with the most advanced H-Ras specific inhibitor, tipifarnib, were presented. Results: Of 1614 patients diagnosed with advanced NSCLC from January 2018 to December 2020, four (0.25%) had HRAS p.Gln61Leu mutation. Three of them died during the first-line systemic therapy. Furthermore, three additional cases were identified in literature. All cases were current or former smokers, most of them had pleural or pericardial effusion at diagnosis. Conclusions: The clinical course of patients with HRAS-mutant NSCLC remains unclear. Furthers cases should be identified in order to clarify prognosis and response to therapies. Tipifarnib, a farnesyl transferase inhibitor, is a promising candidate to target HRAS-mutant tumours and should be explored in NSCLC patients.

Emerging RAS-directed therapies for cancer

RAS oncogenes are the most commonly mutated oncogenes in human cancer, and RAS-mutant cancers represent a major burden of human disease. Though these oncogenes were discovered decades ago, recent years have seen major advances in understanding of their structure and function, including the therapeutic and prognostic significance of diverse isoforms. Targeting of these mutations has proven difficult, despite some successes with inhibition of RAS effector signalling. More recently, direct RAS inhibition has been achieved in a trial setting. While this has yet to be translated to everyday clinical practice, this development carries much promise. This review summarizes the diverse approaches that have been taken to RAS inhibition and then focuses on the most recent developments in direct inhibition of KRAS(G12C).

Concurrent Inhibition of ERK and Farnesyltransferase Suppresses the Growth of HRAS Mutant Head and Neck Squamous Cell Carcinoma

Human papilloma virus (HPV)-negative head and neck squamous cell carcinoma (HNSCC) is a common cancer worldwide with an unmet need for more effective, less toxic treatments. Currently, both the disease and the treatment of HNSCC cause significant mortality and morbidity. Targeted therapies hold new promise for patients with HPV-negative status whose tumors harbor oncogenic HRAS mutations. Recent promising clinical results have renewed interest in the development of farnesyltransferase inhibitors (FTIs) as a therapeutic strategy for HRAS-mutant cancers. With the advent of clinical evaluation of the FTI tipifarnib for the treatment of HRAS-mutant HNSCC, we investigated the activity of tipifarnib and inhibitors of HRAS effector signaling in HRAS-mutant HNSCC cell lines. First, we validated that HRAS is a cancer driver in HRAS-mutant HNSCC lines. Second, we showed that treatment with the FTI tipifarnib largely phenocopied HRAS silencing, supporting HRAS as a key target of FTI antitumor activity. Third, we performed reverse-phase protein array analyses to profile FTI treatment-induced changes in global signaling, and conducted CRISPR/Cas9 genetic loss-of-function screens to identify previously unreported genes and pathways that modulate sensitivity to tipifarnib. Fourth, we determined that concurrent inhibition of HRAS effector signaling (ERK, PI3K, mTORC1) increased sensitivity to tipifarnib treatment, in part by overcoming tipifarnib-induced compensatory signaling. We also determined that ERK inhibition could block tipifarnib-induced epithelial-to-mesenchymal transition, providing a potential basis for the effectiveness of this combination. Our results support future investigations of these and other combination treatments for HRAS mutant HNSCC.

Targeting farnesylation as a novel therapeutic approach in HRAS-mutant rhabdomyosarcoma

Activating RAS mutations are found in a subset of fusion-negative rhabdomyosarcoma (RMS), and therapeutic strategies to directly target RAS in these tumors have been investigated, without clinical success to date. A potential strategy to inhibit oncogenic RAS activity is the disruption of RAS prenylation, an obligate step for RAS membrane localization and effector pathway signaling, through inhibition of farnesyltransferase (FTase). Of the major RAS family members, HRAS is uniquely dependent on FTase for prenylation, whereas NRAS and KRAS can utilize geranylgeranyl transferase as a bypass prenylation mechanism. Tumors driven by oncogenic HRAS may therefore be uniquely sensitive to FTase inhibition. To investigate the mutation-specific effects of FTase inhibition in RMS we utilized tipifarnib, a potent and selective FTase inhibitor, in in vitro and in vivo models of RMS genomically characterized for RAS mutation status. Tipifarnib reduced HRAS processing, and plasma membrane localization leading to decreased GTP-bound HRAS and decreased signaling through RAS effector pathways. In HRAS-mutant cell lines, tipifarnib reduced two-dimensional and three-dimensional cell growth, and in vivo treatment with tipifarnib resulted in tumor growth inhibition exclusively in HRAS-mutant RMS xenografts. Our data suggest that small molecule inhibition of FTase is active in HRAS-driven RMS and may represent an effective therapeutic strategy for a genomically-defined subset of patients with RMS.

Small extracellular vesicles induce resistance to anti-GD2 immunotherapy unveiling tipifarnib as an adjunct to neuroblastoma immunotherapy

Background

Anti-GD2 monoclonal antibody immunotherapy has significantly improved the overall survival rate for high-risk neuroblastoma patients. However, 40% of patients fail to respond or develop resistance to treatment, and the molecular mechanisms by which this occurs remain poorly understood. Tumor-derived small extracellular vesicles (sEVs) have emerged as critical regulators in modulating the response to immunotherapy. In this study, we investigated the role of neuroblastoma-derived sEVs in promoting resistance to the anti-GD2 monoclonal antibody dinutuximab. Moreover, to determine whether pharmacologic inhibition of sEV secretion sensitizes tumors to dinutuximab treatment, we combined dinutuximab with tipifarnib, a farnesyltransferase inhibitor that inhibits sEV secretion.

Methods

We investigated the role of neuroblastoma-derived sEVs in modulating the response to dinutuximab by utilizing the syngeneic 9464D-GD2 mouse model. The effect of neuroblastoma-derived sEVs in modulating the tumor microenvironment (TME) and host immune system were evaluated by RNA-sequencing and flow cytometry. Importantly, we used this mouse model to investigate the efficacy of tipifarnib in sensitizing neuroblastoma tumors to dinutuximab. The effect of tipifarnib on both the TME and host immune system were assessed by flow cytometry.

Results

We demonstrated that neuroblastoma-derived sEVs significantly attenuated the efficacy of dinutuximab in vivo and modulated tumor immune cell infiltration upon dinutuximab treatment to create an immunosuppressive TME that contains more tumor-associated macrophages and fewer tumor-infiltrating NK cells. In addition, we demonstrated that neuroblastoma-derived sEVs suppress splenic NK cell maturation in vivo and dinutuximab-induced NK cell-mediated antibody-dependent cellular cytotoxicity in vitro. Importantly, tipifarnib drastically enhanced the efficacy of dinutuximab-mediated inhibition of tumor growth and prevented the immunosuppressive effects of neuroblastoma-derived sEVs in vivo.

Conclusions

These preclinical findings uncover a novel mechanism by which neuroblastoma-derived sEVs modulate the immune system to promote resistance to dinutuximab and suggest that tipifarnib-mediated inhibition of sEV secretion may serve as a viable treatment strategy to enhance the antitumor efficacy of anti-GD2 immunotherapy in high-risk neuroblastoma patients.

Microneedle-mediated Intratumoral Delivery of Anti-CTLA-4 Promotes cDC1-dependent Eradication of Oral Squamous Cell Carcinoma with Limited irAEs

Head and neck squamous cell carcinoma (HNSCC) ranks sixth in cancer incidence worldwide and has a 5-year survival rate of only 63%. Immunotherapies-principally immune checkpoint inhibitors (ICI), such as anti-PD-1 and anti-CTLA-4 antibodies that restore endogenous antitumor T-cell immunity-offer the greatest promise for HNSCC treatment. Anti-PD-1 has been recently approved for first-line treatment of recurrent and metastatic HNSCC; however, less than 20% of patients show clinical benefit and durable responses. In addition, the clinical application of ICI has been limited by immune-related adverse events (irAE) consequent to compromised peripheral immune tolerance. Although irAEs are often reversible, they can become severe, prompting premature therapy termination or becoming life threatening. To address the irAEs inherent to systemic ICI therapy, we developed a novel, local delivery strategy based upon an array of soluble microneedles (MN). Using our recently reported syngeneic, tobacco-signature murine HNSCC model, we found that both systemic and local-MN anti-CTLA-4 therapy lead to >90% tumor response, which is dependent on CD8 T cells and conventional dendritic cell type 1 (cDC1). However, local-MN delivery limited the distribution of anti-CTLA-4 antibody from areas distal to draining lymphatic basins. Employing Foxp3-GFPDTR transgenic mice to interrogate irAEs in vivo, we found that local-MN delivery of anti-CTLA-4 protects animals from irAEs observed with systemic therapy. Taken together, our findings support the exploration of MN-intratumoral ICI delivery as a viable strategy for HNSCC treatment with reduced irAEs, and the opportunity to target cDC1s as part of multimodal treatment options to boost ICI therapy.

Sporadic Medullary Thyroid Carcinoma: Towards a Precision Medicine

Medullary thyroid carcinoma (MTC) is a neuroendocrine malignant tumor originating from parafollicular C-cells producing calcitonin. Most of cases (75%) are sporadic while the remaining (25%) are hereditary. In these latter cases medullary thyroid carcinoma can be associated (multiple endocrine neoplasia type IIA and IIB) or not (familial medullary thyroid carcinoma), with other endocrine diseases such as pheochromocytoma and/or hyperparathyroidism. RET gene point mutation is the main molecular alteration involved in MTC tumorigenesis, both in sporadic and in hereditary cases. Total thyroidectomy with prophylactic/therapeutic central compartment lymph nodes dissection is the initial treatment of choice. Further treatments are needed according to tumor burden and rate of progression. Surgical treatments and local therapies are advocated in the case of single or few local or distant metastasis and slow rate of progression. Conversely, systemic treatments should be initiated in cases with large metastatic and rapidly progressive disease. In this review, we discuss the details of systemic treatments in advanced and metastatic sporadic MTC, focusing on multikinase inhibitors, both those already used in clinical practice and under investigation, and on emerging treatments such as highly selective RET inhibitors and radionuclide therapy.