Frequent mutation of the PI3K pathway in head and neck cancer defines predictive biomarkers

A genome-wide CRISPR screen reveals that antagonism of glutamine metabolism sensitizes head and neck squamous cell carcinoma to ferroptotic cell death

Glutamine is a conditionally essential amino acid for the growth and survival of rapidly proliferating cancer cells. Many cancers are addicted to glutamine, and as a result, targeting glutamine metabolism has been explored clinically as a therapeutic approach. Glutamine-catalyzing enzymes are highly expressed in primary and metastatic head and neck squamous cell carcinoma (HNSCC). However, the nature of the glutamine-associated pathways in this aggressive cancer type has not been elucidated. Here, we explored the therapeutic potential of a broad glutamine antagonist, DRP-104 (sirpiglenastat), in HNSCC tumors and aimed at shedding light on glutamine-dependent pathways in this disease. We observed a potent antitumoral effect of sirpiglenastat in HPV- and HPV + HNSCC xenografts. We conducted a whole-genome CRISPR screen and metabolomics analyses to identify mechanisms of sensitivity and resistance to glutamine metabolism blockade. These approaches revealed that glutamine metabolism blockade results in the rapid buildup of polyunsaturated fatty acids (PUFAs) via autophagy nutrient-sensing pathways. Finally, our analysis demonstrated that GPX4 mediates the protection of HNSCC cells from accumulating toxic lipid peroxides; hence, glutamine blockade sensitizes HNSCC cells to ferroptosis cell death upon GPX4 inhibition. These findings demonstrate the therapeutic potential of sirpiglenastat in HNSCC and establish a novel link between glutamine metabolism and ferroptosis, which may be uniquely translated into targeted glutamine-ferroptosis combination therapies.

Analysis of Expression and Regulation of AKR1C2 in HPV-Positive and -Negative Oropharyngeal Squamous Cell Carcinoma

Head and Neck Squamous Cell Carcinoma (HNSCC), particularly Oropharyngeal Squamous Cell Carcinoma (OPSCC), is a major global health challenge due to its increasing incidence and high mortality rate. This study investigates the role of aldo-keto reductase 1C2 (AKR1C2) in OPSCC, focusing on its expression, correlation with Human Papillomavirus (HPV) status, oxidative stress status, and clinical outcomes, with an emphasis on sex-specific differences. We analyzed AKR1C2 expression using immunohistochemistry in formalin-fixed, paraffin-embedded tissue samples from 51 OPSCC patients. Additionally, we performed RT-qPCR in cultured HPV16-E6*I and HPV16-E6 overexpressing HEK293 cell lines (p53WT). Statistical analyses were performed to assess the correlation between AKR1C2 expression and patient data. Our results indicate a significant association between increased AKR1C2 expression and higher AJCC classification (p = 0.009) as well as positive HPV status (p = 0.008). Prognostic implications of AKR1C2 varied by sex, whereby female patients with high AKR1C2 expression had better overall survival, whereas male patients exhibited poorer outcomes. Additionally, AKR1C2 expression was linked to HPV status, suggesting a potential HPV-specific regulatory mechanism. These findings underscore the complex interplay among AKR1C2, HPV, and patient sex, highlighting the need for personalized treatment strategies for OPSCC. Targeted inhibition of AKR1C2, considering sex-specific differences, may enhance therapeutic outcomes. Future research should investigate these mechanisms to enhance treatment efficacy.

A first-in-class selective inhibitor of EGFR and PI3K offers a single-molecule approach to targeting adaptive resistance

Despite tremendous progress in precision oncology, adaptive resistance mechanisms limit the long-term effectiveness of molecularly targeted agents. Here we evaluated the pharmacological profile of MTX-531 that was computationally designed to selectively target two key resistance drivers, epidermal growth factor receptor and phosphatidylinositol 3-OH kinase (PI3K). MTX-531 exhibits low-nanomolar potency against both targets with a high degree of specificity predicted by cocrystal structural analyses. MTX-531 monotherapy uniformly resulted in tumor regressions of squamous head and neck patient-derived xenograft (PDX) models. The combination of MTX-531 with mitogen-activated protein kinase kinase or KRAS-G12C inhibitors led to durable regressions of BRAF-mutant or KRAS-mutant colorectal cancer PDX models, resulting in striking increases in median survival. MTX-531 is exceptionally well tolerated in mice and uniquely does not lead to the hyperglycemia commonly seen with PI3K inhibitors. Here, we show that MTX-531 acts as a weak agonist of peroxisome proliferator-activated receptor-γ, an attribute that likely mitigates hyperglycemia induced by PI3K inhibition. This unique feature of MTX-531 confers a favorable therapeutic index not typically seen with PI3K inhibitors.

Prevalence and effect of PIK3CA H1047R somatic mutation among Indian head and neck cancer patients

PIK3CA is one among the several mutated genes in cancer, including head and neck squamous cell carcinoma (HNSCC). H1047R is a hotspot somatic mutation in PIK3CA that occurs most frequently in several forms of cancers. Distribution of PIK3CA H1047R mutation in Indian HNSCC patients was screened and its effect on disease progression and response to treatment was analysed in this study. Genomic DNA was extracted from tumour biopsies of HNSCC patients (n = 48) and polymerase chain reaction coupled restriction fragment length polymorphism (PCR-RFLP) technique was used to screen for the mutation. Overall survival (OS) and Progression-free survival (PFS) of the patients were calculated in order to study effect of this mutation on survival and response to treatment respectively. Results showed that irrespective of patients' criteria, twenty-five patients (52 %) carried a heterozygous form of mutation (His/Arg) and the rest (48 %) were wild type (His/His). The mean OS of the cohort with the mutation was 20.451 months (SE ± 1.710 months) while 26.31 months (SE ± 2.431) was in wild type population. PFS of the patients with the mutation was 18.612 months (SE ± 2.072), and for the wild type population, it was 26.31 months (SE ± 2.431). These observations suggest that Indian HNSCC patients with PIK3CA H1047R mutation have poor prognosis.

Network pharmacology: an efficient but underutilized approach in oral, head and neck cancer therapy-a review

The application of network pharmacology (NP) has advanced our understanding of the complex molecular mechanisms underlying diseases, including neck, head, and oral cancers, as well as thyroid carcinoma. This review aimed to explore the therapeutic potential of natural network pharmacology using compounds and traditional Chinese medicines for combating these malignancies. NP serves as a pivotal tool that provides a comprehensive view of the interactions among compounds, genes, and diseases, thereby contributing to the advancement of disease treatment and management. In parallel, this review discusses the significance of publicly accessible databases in the identification of oral, head, and neck cancer-specific genes. These databases, including those for head and neck oral cancer, head and neck cancer, oral cancer, and genomic variants of oral cancer, offer valuable insights into the genes, miRNAs, drugs, and genetic variations associated with these cancers. They serve as indispensable resources for researchers, clinicians, and drug developers, contributing to the pursuit of precision medicine and improved treatment of these challenging malignancies. In summary, advancements in NP could improve the globalization and modernization of traditional medicines and prognostic targets as well as aid in the development of innovative drugs. Furthermore, this review will be an eye-opener for researchers working on drug development from traditional medicines by applying NP approaches.

A Kinome-Wide Synthetic Lethal CRISPR/Cas9 Screen Reveals That mTOR Inhibition Prevents Adaptive Resistance to CDK4/CDK6 Blockade in HNSCC

The comprehensive genomic analysis of the head and neck squamous cell carcinoma (HNSCC) oncogenome revealed the frequent loss of p16INK4A (CDKN2A) and amplification of cyclin D1 genes in most human papillomavirus-negative HNSCC lesions. However, cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors have shown modest effects in the clinic. The aberrant activation of the PI3K/mTOR pathway is highly prevalent in HNSCC, and recent clinical trials have shown promising clinical efficacy of mTOR inhibitors (mTORi) in the neoadjuvant and adjuvant settings but not in patients with advanced HNSCC. By implementing a kinome-wide CRISPR/Cas9 screen, we identified cell-cycle inhibition as a synthetic lethal target for mTORis. A combination of mTORi and palbociclib, a CDK4/6-specific inhibitor, showed strong synergism in HNSCC-derived cells in vitro and in vivo. Remarkably, we found that an adaptive increase in cyclin E1 (CCNE1) expression upon palbociclib treatment underlies the rapid acquired resistance to this CDK4/6 inhibitor. Mechanistically, mTORi inhibits the formation of eIF4G-CCNE1 mRNA complexes, with the consequent reduction in mRNA translation and CCNE1 protein expression. Our findings suggest that mTORi reverts the adaptive resistance to palbociclib. This provides a multimodal therapeutic option for HNSCC by cotargeting mTOR and CDK4/6, which in turn may halt the emergence of palbociclib resistance.

SIGNIFICANCE

A kinome-wide CRISPR/Cas9 screen identified cell-cycle inhibition as a synthetic lethal target of mTORis. A combination of mTORi and palbociclib, a CDK4/6-specific inhibitor, showed strong synergistic effects in HNSCC. Mechanistically, mTORis inhibited palbociclib-induced increase in CCNE1.

Exploiting new strategies in combating head and neck carcinoma: A comprehensive review on phytochemical approaches passing through PI3K/Akt/mTOR signaling pathway

Recently, malignant neoplasms have growingly caused human morbidity and mortality. Head and neck cancer (HNC) constitutes a substantial group of malignancies occurring in various anatomical regions of the head and neck, including lips, mouth, throat, larynx, nose, sinuses, oropharynx, hypopharynx, nasopharynx, and salivary glands. The present study addresses the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway as a possible therapeutic target in cancer therapy. Finding new multitargeting agents capable of modulating PI3K/Akt/mTOR and cross-linked mediators could be viewed as an effective strategy in combating HNC. Recent studies have introduced phytochemicals as multitargeting agents and rich sources for finding and developing new therapeutic agents. Phytochemicals have exhibited immense anticancer effects, including targeting different stages of HNC through the modulation of several signaling pathways. Moreover, phenolic/polyphenolic compounds, alkaloids, terpenes/terpenoids, and other secondary metabolites have demonstrated promising anticancer activities because of their diverse pharmacological and biological properties like antiproliferative, antineoplastic, antioxidant, and anti-inflammatory activities. The current review is mainly focused on new therapeutic strategies for HNC passing through the PI3K/Akt/mTOR pathway as new strategies in combating HNC.

Dichloroacetate for Cancer Treatment: Some Facts and Many Doubts

Rarely has a chemical elicited as much controversy as dichloroacetate (DCA). DCA was initially considered a dangerous toxic industrial waste product, then a potential treatment for lactic acidosis. However, the main controversies started in 2008 when DCA was found to have anti-cancer effects on experimental animals. These publications showed contradictory results in vivo and in vitro such that a thorough consideration of this compound's in cancer is merited. Despite 50 years of experimentation, DCA's future in therapeutics is uncertain. Without adequate clinical trials and health authorities' approval, DCA has been introduced in off-label cancer treatments in alternative medicine clinics in Canada, Germany, and other European countries. The lack of well-planned clinical trials and its use by people without medical training has discouraged consideration by the scientific community. There are few thorough clinical studies of DCA, and many publications are individual case reports. Case reports of DCA's benefits against cancer have been increasing recently. Furthermore, it has been shown that DCA synergizes with conventional treatments and other repurposable drugs. Beyond the classic DCA target, pyruvate dehydrogenase kinase, new target molecules have also been recently discovered. These findings have renewed interest in DCA. This paper explores whether existing evidence justifies further research on DCA for cancer treatment and it explores the role DCA may play in it.

Celecoxib and sulindac sulfide elicit anticancer effects on PIK3CA-mutated head and neck cancer cells through endoplasmic reticulum stress, reactive oxygen species, and mitochondrial dysfunction

Gain-of-function mutation in the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) catalytic subunit alpha gene (PIK3CA) is a significant factor in head and neck cancer (HNC). Patients with HNC harboring PIK3CA mutations receive therapeutic benefits from the use of non-steroidal anti-inflammatory drugs (NSAIDs). However, the molecular mechanisms underlying these effects remain unknown. Here, we examined the Detroit562 and FaDu cell lines as HNC models with and without a hyperactive PIK3CA mutation (H1047R), respectively, regarding their possible distinct responses to the NSAIDs celecoxib and sulindac sulfide (SUS). Detroit562 cells exhibited relatively high PI3K/Akt pathway-dependent cyclooxygenase-2 (COX-2) expression, associated with cell proliferation. Celecoxib treatment restricted cell proliferation and upregulated endoplasmic reticulum (ER) stress-related markers, including GRP78, C/EBP-homologous protein, activating transcription factor 4, death receptor 5, and reactive oxygen species (ROS). These effects were much stronger in Detroit562 cells than in FaDu cells and were largely COX-2-independent. SUS treatment yielded similar results. Salubrinal (an ER stress inhibitor) and N-acetyl-L-cysteine (a ROS scavenger) prevented NSAID-induced ROS generation and ER stress, respectively, indicating crosstalk between ER and oxidative stress. In addition, celecoxib and/or SUS elevated cleaved caspase-3 levels, Bcl-2-associated X protein/Bcl-2-interacting mediator of cell death expression, and mitochondrial damage, which was more pronounced in Detroit562 than in FaDu cells. Salubrinal and N-acetyl-L-cysteine attenuated celecoxib-induced mitochondrial dysfunction. Collectively, our results suggest that celecoxib and SUS efficiently suppress activating PIK3CA mutation-harboring HNC progression by inducing ER and oxidative stress and mitochondrial dysfunction, leading to apoptotic cell death, further supporting NSAID treatment as a useful strategy for oncogenic PIK3CA-mutated HNC therapy.

Integrating GEO, network pharmacology, and in vitro assays to explore the pharmacological mechanism of Bruceae Fructus against laryngeal cancer

The goal of this study is to look into the pharmacological mechanism of Bruceae Fructus in conjunction with GEO, network pharmacology, and in vitro assays for the treatment of laryngeal cancer to provide theoretical support for its therapeutic use. The active components and matching targets of Bruceae Fructus were retrieved from the TCMSP database, while genes linked with laryngeal cancer were obtained from the GEO, GeneCards, DisGeNET, and DrugBank databases. Besides, the components and targets were supplemented by literatures in PubMed database. Cytoscape software was used to create the active ingredients-target network diagram. The String database was used to build the PPI network. Following that, the core targets were subjected to GO enrichment and KEGG pathway analysis using the DAVID database. Finally, AutoDock was used to perform molecular docking between the core components and the core targets. To investigate the biological effects of beta-sitosterol, the viability of laryngeal cancer cells was assessed after beta-sitosterol therapy using the MTS technique. Following that, how beta-sitosterol affected colony formation after 14 days of culture of treated cells was researched. Flow cytometry was utilized to detect apoptosis to examine the influence of beta-sitosterol on laryngeal cancer cell apoptosis, and then detected mRNA and protein expression levels of 10 key genes by RT-qPCR and Western Blot assay. There were 1258 laryngeal cancer-related genes and 15 Bruceae Fructus components, with beta-sitosterol and luteolin serving as key components. Bruceae Fructus' primary targets against laryngeal cancer were IL6, JUN, TNF, IL2, IL4, IFNG, RELA, TP53, CDKN1A, and AKT1. GO enrichment yielded 41 CC, 78 MF, and 383 BP. Platinum drug resistance, the PI3K-Akt signaling pathway, the p53 signaling pathway, apoptosis, the HIF-1 signaling pathway, and 147 additional pathways have been added to KEGG. The results of molecular docking revealed that the core components had a high affinity for the core target. The results of the cell experiment indicate that beta-sitosterol suppressed Hep-2 cell activity in a concentration-dependent manner. Besides, beta-sitosterol has powerful antiproliferative properties in Hep-2 cells. Flow cytometry results showed that beta-sitosterol promoted laryngeal cancer cell apoptosis in a concentration-dependent manner. The results of RT-qPCR and Western Blot assay showed that the mRNA and protein expression levels of TP53, JUN, TNF-α, CDKN1A, and IL-2 were significantly up-regulated after beta-sitosterol treatment, while the mRNA and protein expression levels of RELA, AKT1, IL-6, IFNG, and IL-4 were significantly down-regulated. This study integrating GEO, network pharmacology, and in vitro assays investigated the probable mechanism of Bruceae Fructus' anti-laryngeal cancer activity, which can give a theoretical foundation for additional future animal experiments.

Personalized Biomarker-Based Umbrella Trial for Patients With Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma: KCSG HN 15-16 TRIUMPH Trial

PURPOSE

A precise oncologic approach for head and neck squamous cell carcinoma (HNSCC) is necessary. We performed a genomic profile-based umbrella trial for the patients with platinum-refractory recurrent and/or metastatic HNSCC.

METHODS

In this multicenter, open-label, single-arm phase II trial, we performed targeted next-generation sequencing (NGS). Patients were assigned to each treatment arm on the basis of their matching genomic profiles: arm 1, alpelisib, a PIK3CA inhibitor; arm 2, poziotinib, an epidermal growth factor receptor/HER2 inhibitor; arm 3, nintedanib, an fibroblast growth factor receptor inhibitor; and arm 4, abemaciclib, a CDK4/6 inhibitor. If there was no matching target, patients were allocated to arm 5, duvalumab ± tremelimumab, anti-PD-L1/cytotoxic T-cell lymphocyte-4 inhibitor. When progressive disease (PD) occurred in arms 1-4, cross over to arm 5 was allowed. The primary end point was disease control rate (DCR) in arm 1 and overall response rate (ORR) in arms 2-5 by investigator assessment.

RESULTS

Between October 2017 and August 2020, 203 patients were enrolled, including crossover. In arm 1, the ORR was 21.2% and DCR was 65.6%. The ORR was 0% for arm 2, 42.9% for arm 3, 0% for arm 4, and 15.6% for arm 5. In the case of PD with durvalumab, tremelimumab was added, and the ORR for durvalumab + tremelimumab was 2.2%. The median progression-free survival was 3.4, 3.2, 5.6, 1.6, and 1.7 months for each arm, respectively. The median overall survival was 12.4, 6.1, 11.1, 9.1, and 12.7 months, respectively. Overall, the toxicity profiles were manageable, and there were no treatment-related deaths.

CONCLUSION

To our knowledge, this study is the first biomarker-driven umbrella trial for platinum-refractory HNSCC using matched molecular targeted agents. We found that NGS-based genomic phenotyping was methodologically feasible and applicable.

Different Impacts of DNA-PK and mTOR Kinase Inhibitors in Combination with Ionizing Radiation on HNSCC and Normal Tissue Cells

Despite substantial advancements in understanding the pathomechanisms of head and neck squamous cell carcinoma (HNSCC), effective therapy remains challenging. The application of kinase inhibitors (KIs) in HNSCC, specifically mTOR and DNA-PK inhibitors, can increase radiosensitivity and therefore presents a promising strategy when used simultaneously with ionizing radiation (IR) in cancer treatment. Our study focused on the selective DNA-PK-inhibitor AZD7648; the selective mTOR-inhibitor Sapanisertib; and CC-115, a dual inhibitor targeting both mTOR and DNA-PK. The impact of these KIs on HNSCC and normal tissue cells was assessed using various analytical methods including cell death studies, cell cycle analysis, real-time microscopy, colony-forming assays and immunohistochemical staining for γH2AX and downstream mTOR protein p-S6. We detected a strong inhibition of IR-induced DNA double-strand break (DSB) repair, particularly in AZD7648-treated HNSCC, whereas normal tissue cells repaired DNA DSB more efficiently. Additionally, AZD7648 + IR treatment showed a synergistic decline in cell proliferation and clonogenicity, along with an elevated G2/M arrest and cell death in the majority of HNSCC cell lines. CC-115 + IR treatment led to an elevation in G2/M arrest, increased cell death, and a synergistic reduction in cell proliferation, though the effect was notably lower compared to the AZD7648 + IR- treated group. Sapanisertib led to a high cellular toxicity in both HNSCC and normal tissue cells, even in non-irradiated cells. Regarding cell proliferation and the induction of apoptosis and necrosis, Sapanisertib + IR was beneficial only in HPV+ HNSCC. Overall, this study highlights the potential of AZD7648 as a radiosensitizing agent in advanced-stage HPV-positive and negative HNSCC, offering a promising therapeutic strategy. However, the dual mTOR/DNA-PK-I CC-115 did not provide a distinct advantage over the use of selective KIs in our investigations, suggesting limited benefits for its application in KI + IR therapy. Notably, the selective mTOR-inhibitor Sapanisertib was only beneficial in HPV+ HNSCC and should not be applied in HPV- cases.

β1 integrin mediates unresponsiveness to PI3Kα inhibition for radiochemosensitization of 3D HNSCC models

Phosphoinositide 3-kinase (PI3K)-α represents a key intracellular signal transducer involved in the regulation of key cell functions such as cell survival and proliferation. Excessive activation of PI3Kα is considered one of the major determinants of cancer therapy resistance. Despite preclinical and clinical evaluation of PI3Kα inhibitors in various tumor entities, including head and neck squamous cell carcinoma (HNSCC), it remains elusive how conventional radiochemotherapy can be enhanced by concurrent PI3K inhibitors and how PI3K deactivation mechanistically exerts its effects. Here, we investigated the radiochemosensitizing potential and adaptation mechanisms of four PI3K inhibitors, Alpelisib, Copanlisib, AZD8186, and Idelalisib in eight HNSCC models grown under physiological, three-dimensional matrix conditions. We demonstrate that Alpelisib, Copanlisib and AZD8186 but not Idelalisib enhance radio- and radiochemosensitivity in the majority of HNSCC cell models (= responders) in a manner independent of PIK3CA mutation status. However, Alpelisib promotes MAPK signaling in non-responders compared to responders without profound impact on Akt, NFκB, TGFβ, JAK/STAT signaling and DNA repair. Bioinformatic analyses identified unique gene mutations associated with extracellular matrix to be more frequent in non-responder cell models than in responders. Finally, we demonstrate that targeting of the cell adhesion molecule β1 integrin on top of Alpelisib sensitizes non-responders to radiochemotherapy. Taken together, our study demonstrates the sensitizing potential of Alpelisib and other PI3K inhibitors in HNSCC models and uncovers a novel β1 integrin-dependent mechanism that may prove useful in overcoming resistance to PI3K inhibitors.

Very rare tumour of the palatine tonsil: a molecular approach

Mucoepidermoid cancer (MEC) is extremely rare in the palatine tonsil with only three adequately described cases in the literature.We describe a woman in her late 70s with vague pharyngeal discomfort who underwent tonsillectomy, lymph node dissection of the neck and radiotherapy for MEC with loco-regional lymph node metastasis of the palatine tonsil. To confirm this extremely rare diagnosis and to gain deeper insight in the molecular oncogenesis, an extensive molecular study including next-generation sequencing and immunohistochemistry was performed. Immunoreactivity for p16 protein and real-time PCR showed high-risk oncogenic human papillomavirus 16 DNA and mutations in the BRAF, BARD and DNMT3A genes. Tumour mutational burden was low. After a follow-up of 7 years the patient is still alive and well without any residual or disseminated disease.

Immune Escape Strategies in Head and Neck Cancer: Evade, Resist, Inhibit, Recruit

Head and neck cancers (HNCs) arise from the mucosal lining of the aerodigestive tract and are often associated with alcohol use, tobacco use, and/or human papillomavirus (HPV) infection. Over 600,000 new cases of HNC are diagnosed each year, making it the sixth most common cancer worldwide. Historically, treatments have included surgery, radiation, and chemotherapy, and while these treatments are still the backbone of current therapy, several immunotherapies have recently been approved by the Food and Drug Administration (FDA) for use in HNC. The role of the immune system in tumorigenesis and cancer progression has been explored since the early 20th century, eventually coalescing into the current three-phase model of cancer immunoediting. During each of the three phases-elimination, equilibrium, and escape-cancer cells develop and utilize multiple strategies to either reach or remain in the final phase, escape, at which point the tumor is able to grow and metastasize with little to no detrimental interference from the immune system. In this review, we summarize the many strategies used by HNC to escape the immune system, which include ways to evade immune detection, resist immune cell attacks, inhibit immune cell functions, and recruit pro-tumor immune cells.

The role of ultrasonographic findings for PIK3CA-mutated, hormone receptor-positive, human epidermal growth factor receptor-2-negative breast cancer

To determine whether ultrasound (US) features of breast cancer are associated with Breast Imaging and Reporting Data System molecular subtype, histologic grade, and hormone receptor status as well as to assess the predictive value of these features. Retrospective analysis of the medical records of 220 consecutive patients with invasive breast cancer was reviewed according to the PIK3CA-mutated molecular tumor subtype. US findings of all patients were analyzed. Breast tumors harboring a PIK3CA-mutation were large and exhibited liquefied necrosis and posterior echo attenuation in the nodule. Moreover, such tumors were lobulated and calcified. The aspect ratio of the PIK3CA-mutant was more likely >1. The average nodule elasticity (7.479 ± 0.993 m/s) was measured using US shear wave elastography. Microcalcification was easier to detect inside the nodule using a fluorescence technique. Measurement of the nodule blood flow spectrum showed that the internal blood flow resistance index of nodules was lower than that of other types of breast cancer. The sonographic features of PIK3CA-mutated breast cancers were strongly associated with extensive and liquefied necrosis. The ability to predict molecular subtypes, particularly using US to detect the triple-negative subtype, may play an important role in early management and 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.

Role of tissue markers associated with tumor microenvironment in the progression and immune suppression of oral squamous cell carcinoma

Head and neck cancers (HNC) continues to dominate major cancers contributing to  mortality worldwide. Squamous cell carcinoma is the major type of HNC. Oral Squamous Cell Carcinoma grouped under HNC is a malignant tumor occurring in the oral cavity. The primary risk factors of OSCC are tobacco, alcohol consumption, etc. This review focuses on modulations, mechanisms, growth and differentiation of oral squamous cell carcinoma. Cancer cell surrounds itself with a group of elements forming a favorable environment known as tumor microenvironment (TME). It consists of numerous cells which includes immune cells, blood cells and acellular components that are responsible for the progression, immunosuppression, metastasis and angiogenesis of cancer. This review highlights the most important tissue biomarkers (mTOR, CAF, FOXp3, CD163, CD33, CD34) that are associated with TME cells. mTOR remains as the primary regulator responsible in cancer and its importance towards immune-suppression is highlighted. Tumor-associated macrophages associated with cancer development and its relationship with immunomodulatory mechanism and Tregs, which are potential blockers of immune response and its mechanism and aberrations are discussed. Cancer-associated fibroblasts that are a part of TME and their role in evading the immune response and myeloid derived suppressor cells that have slight control over the immune response and their mechanism in the tumor progression is further explained. These markers have been emphasised as therapeutic targets and are currently in different stages of clinical trials.

Molecular pathways modulated by phytochemicals in head and neck cancer

In the last few years, natural dietary phytochemicals have shown immense potential in the suppression and incidence of Head and Neck Cancer (HNC). From various in-vitro, animal, and epidemiological studies it is now clear that intake of foods rich in dietary phytochemicals lower the risk of HNC. These phytochemicals have been reported to target different stages of Head and Neck cancer (initiation to promotion) by modulating many cellular signaling pathways. A single phytochemical may target different pathways simultaneously or a single pathway may be targeted by a diversity of phytochemicals. This review highlights the molecular pathways modulated by a large number of phytochemicals relevant to HNC with an intent to identify specific signaling pathways that could be therapeutically targeted. Therefore, relevant literature was screened and scrutinized for molecular details. We have focused on the complexity of the molecular mechanisms that are modulated by various phytochemicals and the role they can play in better clinical efficacy and management of head and neck cancer. In-depth knowledge of these molecular mechanisms can lead to innovative therapeutic strategies using phytochemicals alone or along with available treatments for various cancers including HNC. Molecular pathways modulated by Phytochemicals.

A Network Landscape of HPVOPC Reveals Methylation Alterations as Significant Drivers of Gene Expression via an Immune-Mediated GPCR Signal

HPV-associated oropharynx carcinoma (HPVOPC) tumors have a relatively low mutational burden. Elucidating the relative contributions of other tumor alterations, such as DNA methylation alterations, alternative splicing events (ASE), and copy number variation (CNV), could provide a deeper understanding of carcinogenesis drivers in this disease. We applied network propagation analysis to multiple classes of tumor alterations in a discovery cohort of 46 primary HPVOPC tumors and 25 cancer-unaffected controls and validated our findings with TCGA data. We identified significant overlap between differential gene expression networks and all alteration classes, and this association was highest for methylation and lowest for CNV. Significant overlap was seen for gene clusters of G protein-coupled receptor (GPCR) pathways. HPV16-human protein interaction analysis identified an enriched cluster defined by an immune-mediated GPCR signal, including CXCR3 cytokines CXCL9, CXCL10, and CXCL11. CXCR3 was found to be expressed in primary HPVOPC, and scRNA-seq analysis demonstrated CXCR3 ligands to be highly expressed in M2 macrophages. In vivo models demonstrated decreased tumor growth with antagonism of the CXCR3 receptor in immunodeficient but not immunocompetent mice, suggesting that the CXCR3 axis can drive tumor proliferation in an autocrine fashion, but the effect is tempered by an intact immune system. In conclusion, methylation, ASE, and SNV alterations are highly associated with network gene expression changes in HPVOPC, suggesting that ASE and methylation alterations have an important role in driving the oncogenic phenotype. Network analysis identifies GPCR networks, specifically the CXCR3 chemokine axis, as modulators of tumor-immune interactions that may have proliferative effects on primary tumors as well as a role for immunosurveillance; however, CXCR3 inhibition should be used with caution, as these agents may both inhibit and stimulate tumor growth considering the competing effects of this cytokine axis. Further investigation is needed to explore opportunities for targeted therapy in this setting.

p-mTOR, p-ERK and PTEN Expression in Tumor Biopsies and Organoids as Predictive Biomarkers for Patients with HPV Negative Head and Neck Cancer

BACKGROUND

Survival rates of head and neck squamous cell carcinoma (HNSCC) have only marginally improved in the last decades. Hence there is a need for predictive biomarkers for long-time survival that can help to guide treatment decisions and might lead to the development of new therapies. The phosphatidylinositol 3-kinase (PI3K)/AKT/mTOR signaling pathway is the most frequently altered pathway in HNSCC, genes are often mutated, amplificated and overexpressed causing aberrant signaling affecting cell growth and differentiation. Numerous genetic alterations of upstream and downstream factors have currently been clarified. However, their predictive value has yet to be established. Therefore we assess the predictive value of p-mTOR, p-ERK and PTEN expression.

METHODS

Tissue microarrays (TMA's) of HPV-negative patients with oropharyngeal (n = 48), hypopharyngeal (n = 16) or laryngeal (n = 13) SCC, treated with primary chemoradiation (cisplatin/carboplatin/cetuximab and radiotherapy), were histologically stained for p-mTOR, PTEN and p-ERK. Expression was correlated to overall survival (OS), disease free survival (DFS) and locoregional control (LRC). Also p-mTOR was histologically stained in a separate cohort of HNSCC organoids (n = 8) and correlated to mTOR-inhibitor everolimus response.

RESULTS

High p-mTOR expression correlated significantly with worse OS in multivariate analysis in the whole patient cohort [Hazar Ratio (HR) 1.06, 95%CI 1.01-1.11, p = 0.03] and in the cisplatin/carboplatin group with both worse OS (HR 1.09, 95%CI 1.02-1.16, p = 0.02) and DFS (HR 1.06, 95%CI 1.00-1.12, p = 0,04). p-ERK expression correlated significantly with DFS in univariate analysis in the whole patient cohort (HR 1.03, 95%CI 1.00-1.05, p = 0.04) and cisplatin/carboplatin group (HR 1.03, 95%CI 1.00-1.07, p = 0.04). PTEN-expression did not correlate with OS/DFS/LRC. Better organoid response to everolimus correlated significantly to higher p-mTOR expression (Rs = - 0.731, p = 0.04).

CONCLUSIONS

High p-mTOR expression predicts and high p-ERK expression tends to predict worse treatment outcome in HPV negative HNSCC patients treated with chemoradiation, providing additional evidence that these markers are candidate prognostic biomarkers for survival in this patient population. Also this study shows that the use of HNSCC organoids for biomarker research has potential. The role of PTEN expression as prognostic biomarker remains unclear, as consistent evidence on its prognostic and predictive value is lacking.

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.

Network pharmacological analysis and experimental study of cucurbitacin B in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a malignant tumor with a high incidence and poor prognosis. Cucurbitacin B (CuB) is a tetracyclic triterpenoid small-molecule compound extracted from plants, such as Cucurbitaceae and Brassicaceae, which has powerful anticancer effects. However, the effect and mechanism of CuB on OSCC remain unclear. Within the framework of the current study, network pharmacology was used to analyze the relationship between CuB and OSCC. The network pharmacology analysis showed that CuB and OSCC share 134 common targets; among them, PIK3R1, SRC, STAT3, AKT1, and MAPK1 are the key targets. The molecular docking analysis showed that CuB binds five target proteins. The results of the enrichment analysis showed that CuB exerted effects on OSCC through various pathways; of these pathways, PI3K-AKT was the most important pathway. The results of the in vitro cell experiments showed that CuB could inhibit the proliferation and migration of SCC25 and CAL27 cells, block the cell cycle in the G2 phase, induce cell apoptosis, and regulate the protein expression of the PI3K-AKT signaling pathway. The results of the in vivo animal experiments showed that CuB could inhibit 4NQO-induced oral cancer in mice. Therefore, network pharmacology, molecular docking, cell experiments, and animal experiments showed that CuB could play a role in OSCC by regulating multiple targets and pathways.

Circulating tumour DNA alterations: emerging biomarker in head and neck squamous cell carcinoma

Head and Neck cancers (HNC) are a heterogeneous group of upper aero-digestive tract cancer and account for 931,922 new cases and 467,125 deaths worldwide. About 90% of these cancers are of squamous cell origin (HNSCC). HNSCC is associated with excessive tobacco and alcohol consumption and infection with oncogenic viruses. Genotyping tumour tissue to guide clinical decision-making is becoming common practice in modern oncology, but in the management of patients with HNSCC, cytopathology or histopathology of tumour tissue remains the mainstream for diagnosis and treatment planning. Due to tumour heterogeneity and the lack of access to tumour due to its anatomical location, alternative methods to evaluate tumour activities are urgently needed. Liquid biopsy approaches can overcome issues such as tumour heterogeneity, which is associated with the analysis of small tissue biopsy. In addition, liquid biopsy offers repeat biopsy sampling, even for patients with tumours with access limitations. Liquid biopsy refers to biomarkers found in body fluids, traditionally blood, that can be sampled to provide clinically valuable information on both the patient and their underlying malignancy. To date, the majority of liquid biopsy research has focused on blood-based biomarkers, such as circulating tumour DNA (ctDNA), circulating tumour cells (CTCs), and circulating microRNA. In this review, we will focus on ctDNA as a biomarker in HNSCC because of its robustness, its presence in many body fluids, adaptability to existing clinical laboratory-based technology platforms, and ease of collection and transportation. We will discuss mechanisms of ctDNA release into circulation, technological advances in the analysis of ctDNA, ctDNA as a biomarker in HNSCC management, and some of the challenges associated with translating ctDNA into clinical and future perspectives. ctDNA provides a minimally invasive method for HNSCC prognosis and disease surveillance and will pave the way in the future for personalized medicine, thereby significantly improving outcomes and reducing healthcare costs.

Estrogen promotes Epithelial ovarian cancer cells proliferation via down-regulating expression and activating phosphorylation of PTEN

Epithelial ovarian cancer (EOC) is the most common of cancer death among malignant tumors in women, its occurrence and development are strongly linked to estrogen. Having identified the phosphatase and tensin homologue (PTEN) is a potent tumor suppressor regulating cell proliferation, migration, and survival. Meanwhile, there is a correlation between PTEN protein expression and estrogen receptor expression in EOC. However, no study has amplified on the molecular regulatory mechanism and function between estrogen and PTEN in the development of EOC. In this research, we found that PTEN shows a low expression level in EOC tissues and estrogen decreased PTEN expression via the estrogen receptor 1 (ESR1) in EOC cells. Knockdown of PTEN enhanced the proliferation and migration level of EOC cells driven by estrogen. Moreover, PTEN was also phosphorylated by G protein-coupled receptor 30 (GPR30)-Protein kinase C (PKC) signaling pathway upon estrogen stimulation. Inhibiting the phosphorylation of PTEN weakened the proliferation and migration of estrogen induced-EOC cells estrogen and decreased the phosphorylation of Protein kinase B (AKT) and Mammalian target of rapamycin (mTOR). These results indicated that estrogen decreased PTEN expression level via the ESR1 genomic pathway and phosphorylated PTEN via the GPR30-PKC non-genomic pathway to activate the PI3K/AKT/mTOR signaling pathway, thereby determining the fate of EOC cells.

Spatial tissue proteomics reveals distinct landscapes of heterogeneity in cutaneous papillomavirus-induced keratinocyte carcinomas

Infection with certain cutaneous human papillomaviruses (HPV), in conjunction with chronic ultraviolet (UV) exposure, are the major cofactors of non-melanoma skin cancer (NMSC), the most frequent cancer type worldwide. Cutaneous squamous cell carcinomas (SCCs) as well as tumors in general represent three-dimensional entities determined by both temporal and spatial constraints. Whole tissue proteomics is a straightforward approach to understand tumorigenesis in better detail, but studies focusing on different progression states toward a dedifferentiated SCC phenotype on a spatial level are rare. Here, we applied an innovative proteomic workflow on formalin-fixed, paraffin-embedded (FFPE) epithelial tumors derived from the preclinical animal model Mastomys coucha. This rodent is naturally infected with its genuine cutaneous papillomavirus and closely mimics skin carcinogenesis in the context of cutaneous HPV infections in humans. We deciphered cellular networks by comparing diverse epithelial tissues with respect to their differentiation level and infection status. Our study reveals novel regulatory proteins and pathways associated with virus-induced tumor initiation and progression of SCCs. This approach provides the basis to better comprehend the multistep process of skin carcinogenesis.

Tumor microenvironmental modification by the current target therapy for head and neck squamous cell carcinoma

Current clinical and observational evidence supports the EXTREME regimen as one of the standards of care for patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) followed by the administration of immune checkpoint inhibitors (ICIs). In addition to the inhibition of the epidermal growth factor receptor (EGFR) pathway, cetuximab-mediated EGFR blockade has been shown to modulate tumor microenvironment (TME) characteristics, such as antibody-dependent cellular cytotoxicity (ADCC) activity, cytotoxic T-lymphocyte (CTL) infiltration into the tumor, anti-angiogenesis activity, and cytokine secretion via associated natural killer (NK) cells, etc.. On the other hand, there are reports that nivolumab affects the TME via Programmed cell death 1 (PD-1) inhibition, Interleukin-10 upregulation via T-cells, myeloid-derived suppressor cell-mediated immune escape induction, and tumor vessel perfusion by promoting CD8 + T-cell accumulation and Interferon-γ production in treatment-sensitive tumor cells. Actually, nivolumab administration can give T cells in the TME both immune superiority and inferiority. HNSCC treatment using cetuximab increases the frequency of FoxP3 + intratumoral effector regulatory T cells (Tregs) expressing CTL associated antigen (CTLA)-4, and targeting CTLA-4 + Tregs using ipilimumab restores the cytolytic function of NK cells, which mediate ADCC activity. Treg-mediated immune suppression also contributes to clinical response to cetuximab treatment, suggesting the possibility of the addition of ipilimumab or the use of other Treg ablation strategies to promote antitumor immunity. Moreover, also in hyper progression disease (HPD), intratumoral frequency of FoxP3 + effector Tregs expressing CTLA-4 is increased. Therefore, combination treatment with cetuximab plus anti-CTLA-4 antibody ipilimumab for HNSCC and this combination therapy after nivolumab administration for HPD may be expected to result in a higher tumor-control response. Based on the above evidence, we here suggest the efficacy of using these therapeutic strategies for patients with local-advanced, recurrent, and metastatic HNSCC and patients who do not respond well to nivolumab administration.

PI3K/AKT/mTOR Signaling Pathway in HPV-Driven Head and Neck Carcinogenesis: Therapeutic Implications

High-risk human papillomaviruses (HR-HPVs) are the causal agents of cervical, anogenital and a subset of head and neck carcinomas (HNCs). Indeed, oropharyngeal cancers are a type of HNC highly associated with HR-HPV infections and constitute a specific clinical entity. The oncogenic mechanism of HR-HPV involves E6/E7 oncoprotein overexpression for promoting cell immortalization and transformation, through the downregulation of p53 and pRB tumor suppressor proteins, among other cellular targets. Additionally, E6/E7 proteins are involved in promoting PI3K/AKT/mTOR signaling pathway alterations. In this review, we address the relationship between HR-HPV and PI3K/AKT/mTOR signaling pathway activation in HNC with an emphasis on its therapeutic importance.

Circulating CD137+ T Cell Levels Are Correlated with Response to Pembrolizumab Treatment in Advanced Head and Neck Cancer Patients

Pembrolizumab, an anti-PD-1 antibody, has been approved as first-line treatment for recurrent or metastatic head and neck squamous cell carcinoma ((R/M) HNSCC). However, only a minority of patients benefit from immunotherapy, which highlights the need to identify novel biomarkers to optimize treatment strategies. CD137⁺ T cells have been identified as tumour-specific T cells correlated with immunotherapy responses in several solid tumours. In this study, we investigated the role of circulating CD137⁺ T cells in (R/M) HNSCC patients undergoing pembrolizumab treatment. PBMCs obtained from 40 (R/M) HNSCC patients with a PD-L1 combined positive score (CPS) ≥1 were analysed at baseline via cytofluorimetry for the expression of CD137, and it was found that the percentage of CD3⁺CD137⁺ cells is correlated with the clinical benefit rate (CBR), PFS, and OS. The results show that levels of circulating CD137⁺ T cells are significantly higher in responder patients than in non-responders (p = 0.03). Moreover, patients with CD3⁺CD137⁺ percentage ≥1.65% had prolonged OS (p = 0.02) and PFS (p = 0.02). Multivariate analysis, on a combination of biological and clinical parameters, showed that high levels of CD3⁺CD137⁺ cells (≥1.65%) and performance status (PS) = 0 are independent prognostic factors of PFS (CD137⁺ T cells, p = 0.007; PS, p = 0.002) and OS (CD137⁺ T cells, p = 0.006; PS, p = 0.001). Our results suggest that levels of circulating CD137⁺ T cells could serve as biomarkers for predicting the response of (R/M) HNSCC patients to pembrolizumab treatment, thus contributing to the success of anti-cancer treatment.

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.

YBX1 integration of oncogenic PI3K/mTOR signalling regulates the fitness of malignant epithelial cells

In heterogeneous head and neck cancer (HNC), subtype-specific treatment regimens are currently missing. An integrated analysis of patient HNC subtypes using single-cell sequencing and proteome profiles reveals an epithelial-mesenchymal transition (EMT) signature within the epithelial cancer-cell population. The EMT signature coincides with PI3K/mTOR inactivation in the mesenchymal subtype. Conversely, the signature is suppressed in epithelial cells of the basal subtype which exhibits hyperactive PI3K/mTOR signalling. We further identify YBX1 phosphorylation, downstream of the PI3K/mTOR pathway, restraining basal-like cancer cell proliferation. In contrast, YBX1 acts as a safeguard against the proliferation-to-invasion switch in mesenchymal-like epithelial cancer cells, and its loss accentuates partial-EMT and in vivo invasion. Interestingly, phospho-YBX1 that is mutually exclusive to partial-EMT, emerges as a prognostic marker for overall patient outcomes. These findings create a unique opportunity to sensitise mesenchymal cancer cells to PI3K/mTOR inhibitors by shifting them towards a basal-like subtype as a promising therapeutic approach against HNC.

PI3K pathway mutation predicts an activated immune microenvironment and better immunotherapeutic efficacy in head and neck squamous cell carcinoma

BACKGROUND

PI3K pathway is the most frequently mutated pathway in head and neck squamous cell carcinoma (HNSC), which plays a crucial role in tumorigenesis and progression. In the present study, we aimed to investigate the role of PI3K pathway mutation in clinical prognosis prediction and the relationship with immune microenvironment and response rate to immunotherapy.

METHODS

We collected 129 samples with immunotherapy information from MSKCC-2019 cohort as well as 501 and 40 samples from TCGA-HNSC and MD-Anderson non-immunotherapy cohorts, respectively. Somatic mutation data was utilized to characterize the mutational status of the PI3K pathway. Subsequently, we further analyzed the differences in prognosis, immunotherapy response, genomic alterations, functional characteristics, and immune microenvironment between the mutation and wild groups.

RESULTS

The Kaplan-Meier survival curves displayed that PI3K pathway mutation predicted observably prolonged overall survival (OS) in the immunotherapy cohort MSKCC-2019 (p = 0.012) but did not reach statistical significance in the non-immunotherapy cohorts TCGA-HNSC (p = 0.68) and MD-Anderson (p = 0.68). After incorporating several clinicopathologic features such as age, gender, and tumor mutation burden (TMB), the results of multivariate Cox regression analysis also demonstrated that the PI3K pathway mutation could indicate better immunotherapy outcomes in HNSC patients with a hazard ratio (HR) of 0.533 (95% CI: 0.313-0.910; p = 0.021) in the immunotherapy cohort MSKCC-2019, compared with 0.888 (95% CI: 0.636-1.241; p = 0.487) and 1.939 (95% CI: 0.483-7.781; p = 0.351) in the non-immunotherapy cohorts TCGA-HNSC and MD-Anderson. In addition, the results of the subclass mapping (SubMap) and the tumor immune dysfunction and exclusion (TIDE) also consistently suggested that patients in the mutation group are more likely to benefit from immunotherapy. And further studies showed that the mutation group owned significantly higher TMB, activated immune-related pathways, richer abundance of immune cells, and higher expression levels of immunomodulators. To improve the prognosis of the wild group, we identified five relatively sensitive potential drugs for the wild group, including "BMS-536924," "linsitinib," "NVP-TAE684," "PLX-4720," and "clonazepam."

CONCLUSIONS

The PI3K pathway mutation status could be considered as a potential biomarker to predict better immunotherapeutic efficacy and clinical outcomes after immunotherapy in HNSC patients.

Effect of Opioid Receptor Activation and Blockage on the Progression and Response to Treatment of Head and Neck Squamous Cell Carcinoma

Recent studies suggest that opioids have a role in the progression of HNSCC mediated by mu opioid receptors (MOR), however, the effects of their activation or blockage remains unclear. Expression of MOR-1 was explored in seven HNSCC cell lines using Western blotting (WB). XTT cell proliferation and cell migration assays were performed on four selected cell lines (Cal-33, FaDu, HSC-2, and HSC-3), treated with opiate receptor agonist (morphine), antagonist (naloxone), alone and combined with cisplatin. All four selected cell lines display an increased cell proliferation and upregulation of MOR-1 when exposed to morphine. Furthermore, morphine promotes cell migration, while naloxone inhibits it. The effects on cell signaling pathways were analyzed using WB, demonstrating morphine activation of AKT and S6, key proteins in the PI3K/AKT/mTOR axis. A significant synergistic cytotoxic effect between cisplatin and naloxone in all cell lines is observed. In vivo studies of nude mice harboring HSC3 tumor treated with naloxone demonstrate a decrease in tumor volume. The synergistic cytotoxic effect between cisplatin and naloxone is observed in the in vivo studies as well. Our findings suggest that opioids may increase HNSCC cell proliferation via the activation of the PI3K/Akt/mTOR signaling pathway. Moreover, MOR blockage may chemo-sensitize HNSCC to cisplatin.

Statins block mammalian target of rapamycin pathway: a possible novel therapeutic strategy for inflammatory, malignant and neurodegenerative diseases

Inflammation plays a critical role in several diseases such as cancer, gastric, heart and nervous system diseases. Data suggest that the activation of mammalian target of rapamycin (mTOR) pathway in epithelial cells leads to inflammation. Statins, the inhibitors of the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA), seem to be able to inhibit the mTOR. Statins are considered to have favorable effects on inflammatory diseases by reducing the complications caused by inflammation and by regulating the inflammatory process and cytokines secretion. This critical review collected data on this topic from clinical, in vivo and in vitro studies published between 1998 and June 2022 in English from databases including PubMed, Google Scholar, Scopus, and Cochrane libraries.

HSF1 activates the FOXO3a-ΔNp63α-CDK4 axis to promote head and neck squamous cell carcinoma cell proliferation and tumour growth

Head and neck squamous cell carcinoma (HNSCC) is one of the most prevalent cancers worldwide. Heat shock factor 1 (HSF1) is a conserved transcriptional factor that plays a critical role in maintaining cellular proteostasis. However, the role of HSF1 in HNSCC development remains largely unclear. Here, we report that HSF1 promotes forkhead box protein O3a (FOXO3a)-dependent transcription of ΔNp63α (p63 isoform in the p53 family; inhibits cell migration, invasion, and metastasis), which leads to upregulation of cyclin-dependent kinase 4 expression and HNSCC tumour growth. Ablation of HSF1 or treatment with KRIBB11, a specific pharmacological inhibitor of HSF1, significantly suppresses ΔNp63α expression and HNSCC tumour growth. Clinically, the expression of HSF1 is positively correlated with the expression of ΔNp63α in HNSCC tumours. Together, this study demonstrates that the HSF1-ΔNp63α pathway is critically important for HNSCC tumour growth.

Mutational profiles of head and neck squamous cell carcinomas based upon human papillomavirus status in the Veterans Affairs National Precision Oncology Program

BACKGROUND

Patients with advanced head and neck squamous cell carcinoma (HNSCC) associated with human papillomavirus (HPV) demonstrate favorable clinical outcomes compared to patients bearing HPV-negative HNSCC. We sought to characterize the association between HPV status and mutational profiles among patients served by the Veterans Health Administration (VHA).

METHODS

We performed a retrospective analysis of all Veterans with primary HNSCC tumors who underwent next-generation sequencing (NGS) through the VHA's National Precision Oncology Program between July 2016 and February 2019. HPV status was determined by clinical pathology reports of p16 immunohistochemical staining; gene variant pathogenicity was classified using OncoKB, an online precision oncology knowledge database, and mutation frequencies were compared using Fisher's exact test.

RESULTS

A total of 79 patients met inclusion criteria, of which 48 (60.8%) had p16-positive tumors. Patients with p16-negative HNSCC were more likely to have mutations in TP53 (p < 0.0001), and a trend towards increased mutation frequency was observed within NOTCH1 (p = 0.032) and within the composite CDK/Rb pathway (p = 0.065). Mutations in KRAS, NRAS, HRAS, and FBXW7 were exclusively identified within p16-positive tumors, and a trend towards increased frequency was observed within the PI3K pathway (p = 0.051). No difference in overall mutational burden was observed between the two groups.

CONCLUSIONS

In accordance with the previous studies, no clear molecular basis for improved prognosis among patients harboring HPV-positive disease has been elucidated. Though no targeted therapies are approved based upon HPV-status, current efforts to trial PI3K inhibitors and mTOR inhibitors across patients with HPV-positive disease bear genomic rationale based upon the current findings.

Co-Targeting the EGFR and PI3K/Akt Pathway to Overcome Therapeutic Resistance in Head and Neck Squamous Cell Carcinoma: What about Autophagy?

Resistance to EGFR-targeted therapy is a major obstacle on the road to effective treatment options for head and neck cancers. During the search for underlying mechanisms and regulators of this resistance, there were several indications that EGFR-targeted therapy resistance is (partially) mediated by aberrant signaling of the PI3K/Akt pathway. Genomic alterations in and/or overexpression of major components of the PI3K/Akt pathway are common in HNSCC tumors. Therefore, downstream effectors of the PI3K/Akt pathway serve as promising targets in the search for novel therapeutic strategies overcoming resistance to EGFR inhibitors. As both the EGFR/Ras/Raf/MAPK and the PI3K/Akt pathway are involved in autophagy, combinations of EGFR and PI3K/Akt pathway inhibitors can induce an autophagic response in tumor cells. This activation of autophagy can be seen as a "double-edge sword", depending on the cellular context. Autophagy is largely known as a cytoprotective mechanism, but it can also be a mechanism of programmed (autophagic) cell death. The activation of autophagy during anti-cancer treatment is, therefore, not necessarily a bad sign. However, in HNSCC, the role of therapy-induced autophagy as an anti-tumor mechanism is still largely unclear. Further research is warranted to understand the potential of combination treatments targeting both the EGFR and PI3K/Akt pathway.

LINE-1 hypomethylation is associated with poor outcomes in locoregionally advanced oropharyngeal cancer

BACKGROUND AND PURPOSE

Currently, human papillomavirus (HPV) positivity represents a strong prognostic factor for both reduced risk of relapse and improved survival in patients with oropharyngeal squamous cell carcinoma (OPSCC). However, a subset of HPV-positive OPSCC patients still experience poor outcomes. Furthermore, HPV-negative OPSCC patients, who have an even higher risk of relapse, are still lacking suitable prognostic biomarkers for clinical outcome. Here, we evaluated the prognostic value of LINE-1 methylation level in OPSCC patients and further addressed the relationship between LINE-1 methylation status and p53 protein expression as well as genome-wide/gene-specific DNA methylation.

RESULTS

In this study, DNA was extracted from 163 formalin-fixed paraffin-embedded tissue samples retrospectively collected from stage III-IVB OPSCC patients managed with curative intent with up-front treatment. Quantitative methylation-specific PCR revealed that LINE-1 hypomethylation was directly associated with poor prognosis (5-year overall survival-OS: 28.1% for LINE-1 methylation < 35% vs. 69.1% for ≥ 55%; p < 0.0001). When LINE-1 methylation was dichotomized as < 55% versus ≥ 55%, interaction with HPV16 emerged: compared with hypermethylated HPV16-positive patients, subjects with hypomethylated HPV16-negative OPSCC reported an adjusted higher risk of death (HR 4.83, 95% CI 2.24-10.38) and progression (HR 4.54, 95% CI 2.18-9.48). Tumor protein p53 (TP53) gene is often mutated and overexpressed in HPV-negative OPSCC. Since p53 has been reported to repress LINE-1 promoter, we then analyzed the association between p53 protein expression and LINE-1 methylation levels. Following p53 immunohistochemistry, results indicated that among HPV16-negative patients with p53 ≥ 50%, LINE-1 methylation levels declined and remained stable at approximately 43%; any HPV16-positive patient reported p53 ≥ 50%. Finally, DNA methylation analysis demonstrated that genome-wide average methylation level at cytosine-phosphate-guanine sites was significantly lower in HPV16-negative OPSCC patients who relapsed within two years. The subsequent integrative analysis of gene expression and DNA methylation identified 20 up-regulated/hypomethylated genes in relapsed patients, and most of them contained LINE-1 elements in their promoter sequences.

CONCLUSIONS

Evaluation of the methylation level of LINE-1 may help in identifying the subset of OPSCC patients with bad prognosis regardless of their HPV status. Aberrant LINE-1 hypomethylation might occur along with TP53 mutations and lead to altered gene expression in OPSCC.

Cryo-EM structures of cancer-specific helical and kinase domain mutations of PI3Kα

Phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases that perform multiple and important cellular functions. The protein investigated here belongs to class IA of the PI3Ks; it is a dimer consisting of a catalytic subunit, p110α, and a regulatory subunit, p85α, and is referred to as PI3Kα. The catalytic subunit p110α is frequently mutated in cancer. The mutations induce a gain of function and constitute a driving force in cancer development. About 80% of these mutations lead to single-amino-acid substitutions in one of three sites of p110α: two in the helical domain of the protein (E542K and E545K) and one at the C-terminus of the kinase domain (H1047R). Here, we report the cryo-electron microscopy structures of these mutants in complex with the p110α-specific inhibitor BYL-719. The H1047R mutant rotates its sidechain to a new position and weakens the kα11 activation loop interaction, thereby reducing the inhibitory effect of p85α on p110α. E542K and E545K completely abolish the tight interaction between the helical domain of p110α and the N-terminal SH2 domain of p85α and lead to the disruption of all p85α binding and a dramatic increase in flexibility of the adaptor-binding domain (ABD) in p110α. Yet, the dimerization of PI3Kα is preserved through the ABD-p85α interaction. The local and global structural features induced by these mutations provide molecular insights into the activation of PI3Kα, deepen our understanding of the oncogenic mechanism of this important signaling molecule, and may facilitate the development of mutant-specific inhibitors.

Uncovering novel mutational signatures by de novo extraction with SigProfilerExtractor

Mutational signature analysis is commonly performed in cancer genomic studies. Here, we present SigProfilerExtractor, an automated tool for de novo extraction of mutational signatures, and benchmark it against another 13 bioinformatics tools by using 34 scenarios encompassing 2,500 simulated signatures found in 60,000 synthetic genomes and 20,000 synthetic exomes. For simulations with 5% noise, reflecting high-quality datasets, SigProfilerExtractor outperforms other approaches by elucidating between 20% and 50% more true-positive signatures while yielding 5-fold less false-positive signatures. Applying SigProfilerExtractor to 4,643 whole-genome- and 19,184 whole-exome-sequenced cancers reveals four novel signatures. Two of the signatures are confirmed in independent cohorts, and one of these signatures is associated with tobacco smoking. In summary, this report provides a reference tool for analysis of mutational signatures, a comprehensive benchmarking of bioinformatics tools for extracting signatures, and several novel mutational signatures, including one putatively attributed to direct tobacco smoking mutagenesis in bladder tissues.

An ErbB Lineage Co-Regulon Harbors Potentially Co-Druggable Targets for Multimodal Precision Therapy in Head and Neck Squamous Cell Carcinoma

The ErbB lineage of oncogenic receptor tyrosine kinases is frequently overexpressed in head and neck squamous cell carcinomas. A common co-regulon triggered by the ErbB proteins; involving shared signaling circuitries; may harbor co-druggable targets or response biomarkers for potential future multimodal precision therapy in ErbB-driven head and neck squamous cell carcinoma. We here present a cohort-based; genome-wide analysis of 488 head and neck squamous cell carcinomas curated as part of The Cancer Genome Atlas Project to characterize genes that are significantly positively co-regulated with the four ErbB proteins and those that are shared among all ErbBs denoting a common ErbB co-regulon. Significant positive gene correlations involved hundreds of genes that were co-expressed with the four ErbB family members (q < 0.05). A common; overlapping co-regulon consisted of a core set of 268 genes that were uniformly co-regulated with all four ErbB genes and highly enriched for functions in chromatin organization and histone modifications. This high-priority set of genes contained ten putative antineoplastic drug-gene interactions. The nature and directionality of these ten drug-gene associations was an inhibiting interaction for seven (PIK3CB; PIK3C2B; HDAC4; FRK; PRKCE; EPHA4; and DYRK1A) of them in which the drug decreases the biological activity or expression of the gene target. For three (CHD4; ARID1A; and PBRM1) of the associations; the directionality of the interaction was such that the gene predicted sensitivit y to the drug suggesting utility as potential response biomarkers. Drug-gene interactions that predicted the gene product to be reduced by the drug included a variety of potential targeted molecular agent classes. This unbiased genome-wide analysis identified a target-rich environment for multimodal therapeutic approaches in tumors that are putatively ErbB-driven. The results of this study require preclinical validation before ultimately devising lines of combinatorial treatment strategies for ErbB-dependent head and neck squamous cell carcinomas that incorporate these findings.

Genomic and Immune Approach in Platinum Refractory HPV-Negative Head and Neck Squamous Cell Carcinoma Patients Treated with Immunotherapy: A Novel Combined Profile

Introduction: Only a minority of patients with platinum refractory head and neck squamous cell carcinoma (PR/HNSCC) gain some lasting benefit from immunotherapy. Methods: The combined role of the comprehensive genomic (through the FoundationOne Cdx test) and immune profiles of 10 PR/HNSCC patients treated with the anti-PD-1 nivolumab was evaluated. The immune profiles were studied both at baseline and at the second cycle of immunotherapy, weighing 20 circulating cytokines/chemokines, adhesion molecules, and 14 soluble immune checkpoints dosed through a multiplex assay. A connectivity map was obtained by calculating the Spearman correlation between the expression profiles of circulating molecules. Results: Early progression occurred in five patients, each of them showing TP53 alteration and three of them showing a mutation/loss/amplification of genes involved in the cyclin-dependent kinase pathway. In addition, ERB2 amplification (1 patient), BRCA1 mutation (1 patient), and NOTCH1 genes alteration (3 patients) occurred. Five patients achieved either stable disease or partial response. Four of them carried mutations in PI3K/AKT/PTEN pathways. In the only two patients, with a long response to immunotherapy, the tumor mutational burden (TMB) was high. Moreover, a distinct signature, in terms of network connectivity of the circulating soluble molecules, characterizing responder and non-responder patients, was evidenced. Moreover, a strong negative and statistically significant (p-value ≤ 0.05) correlation with alive status was evidenced for sE-selectin at T1. Conclusions: Our results highlighted the complexity and heterogeneity of HNSCCs, even though it was in a small cohort. Molecular and immune approaches, combined in a single profile, could represent a promising strategy, in the context of precision immunotherapy.

The role of T-cells in head and neck squamous cell carcinoma: From immunity to immunotherapy

Head and neck squamous cell carcinoma (HNSCC) encompass a group of complex entities of tumours affecting the aerodigestive upper tract. The main risk factors are strongly related to tobacco and alcohol consumption, but also HPV infection is often associated. Surgery, radiotherapy and/or chemotherapy are the standard treatments, though the 5-year overall survival is less than 50%. The advances in genomics, molecular medicine, immunology, and nanotechnology have shed a light on tumour biology which helps clinical researchers to obtain more efficacious and less toxic therapies. Head and neck tumours possess different immune escape mechanisms including diminishing the immune response through modulating immune checkpoints, in addition to the recruitment and differentiation of suppressive immune cells. The insights into the HNSCC biology and its strong interaction with the tumour microenvironment highlights the role of immunomodulating agents. Recently, the knowledge of the immunological features of these tumours has paved the way for the discovery of effective biomarkers that allow a better selection of patients with odds of improving overall survival through immunotherapy. Specially biomarkers regarding immune checkpoint inhibitors antibodies, such as anti-PD-1/PD-L1 and anti-CTLA-4 in combination with standard therapy or as monotherapy. New immunotherapies to treat head and neck cancer carcinomas, such as CAR T cells and nanoparticles have been the center of attention and in this review, we discuss the necessity of finding targets for the T cell in the cancer cells to generate CAR T cells, but also the relevance of evaluating specificity and safety of those therapies.

Involvement of the p53-p16/RB pathway control mechanism in early-stage carcinogenesis in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma develops through a heterogeneous process involving human papillomavirus infection, smoking, and alcohol consumption. A comprehensive genomic analysis of head and neck squamous cell carcinomas to date has identified a few single driver gene mutations, the most frequent of which involve TP53 and CDKN2A/p16. To investigate the involvement of the tumorigenesis mechanism in early-stage carcinogenesis, HPV-derived genomes E6 and E7, which are carcinogens, and stem/progenitor-associated, polycomb (PcG) genes Bmi1 and TERT were induced into human stromal cells and immortalized as the head and neck squamous cell carcinoma model. We found that Bmi1 suppressed both the p16INK4a and p16/Rb-p53 pathway cross-talks. The E7 group showed that endogenous p53 is highly expressed and eludes chromosome number aberration, even on long-term observation. Bmi1 was predominantly expressed in early head and neck squamous cell carcinoma, and PcG was essential in early cancer development. Additionally, TP53 whole exon analysis revealed categories useful for estimating malignant potential, such as poor prognosis and high recurrence at the transection site. Therefore, understanding the p53-p16/RB pathway in head and neck squamous cell carcinoma is an essential factor to elucidate the early carcinogenesis of head and neck squamous cell carcinoma.

Targeting the Tumor Microenvironment through mTOR Inhibition and Chemotherapy as Induction Therapy for Locally Advanced Head and Neck Squamous Cell Carcinoma: The CAPRA Study

Simple Summary

The PI3K-AKT-mTOR pathway is dysregulated in 70% of head and neck squamous cell carcinoma (HNSCC) and linked to the tumor microenvironment. This weekly induction treatment combined the mTOR inhibitor everolimus with carboplatin-paclitaxel chemotherapy for locally advanced T3-4/N0-3 HNSCC. In 41 patients, safety profile was favorable and overall response rate was 75.6%. Translational data demonstrated specific target engagement with p-S6K decrease in tumor tissue and pro-immunogenic cytokine release in peripheral blood. Induction treatment with chemotherapy and mTOR inhibitors may provide new therapeutic options and rationale for combinations with immune oncology agents for locally advanced HNSCC.

Abstract

Mammalian target of rapamycin (mTOR) regulates cellular functions by integrating intracellular signals and signals from the tumor microenvironment (TME). The PI3K-AKT-mTOR pathway is activated in 70% of head and neck squamous cell carcinoma (HNSCC) and associated with poor prognosis. This phase I-II study investigated the effect of mTOR inhibition using weekly everolimus (30 mg for dose level 1, 50 mg for dose level 2) combined with weekly induction chemotherapy (AUC2 carboplatin and 60 mg/m² paclitaxel) in treatment-naïve patients with locally advanced T3-4/N0-3 HNSCC. Patients received 9 weekly cycles before chemoradiotherapy. Objectives were safety and antitumor activity along with tissue and blood molecular biomarkers. A total of 50 patients were enrolled. Among 41 evaluable patients treated at the recommended dose of 50 mg everolimus weekly, tolerance was good and overall response rate was 75.6%, including 20 major responses (≥50% reduction in tumor size). A significant decrease in expression of p-S6K (p-value: 0.007) and Ki67 (p-value: 0.01) was observed in post-treatment tumor tissue. Pro-immunogenic cytokine release (Th1 cytokines IFN-γ, IL-2, and TNF-β) was observed in the peripheral blood. The combination of everolimus and chemotherapy in HNSCC was safe and achieved major tumor responses. This strategy favorably impacts the TME and might be combined with immunotherapeutic agents.

Human Papillomavirus Integration Strictly Correlates with Global Genome Instability in Head and Neck Cancer

Human papillomavirus (HPV)-positive head and neck cancers, predominantly oropharyngeal squamous cell carcinoma (OPSCC), exhibit epidemiologic, clinical, and molecular characteristics distinct from those OPSCCs lacking HPV. We applied a combination of whole-genome sequencing and optical genome mapping to interrogate the genome structure of HPV-positive OPSCCs. We found that the virus had integrated in the host genome in two thirds of the tumors examined but resided solely extrachromosomally in the other third. Integration of the virus occurred at essentially random sites within the genome. Focal amplification of the virus and the genomic sequences surrounding it often occurred subsequent to integration, with the number of tandem repeats in the chromosome accounting for the increased copy number of the genome sequences flanking the site of integration. In all cases, viral integration correlated with pervasive genome-wide somatic alterations at sites distinct from that of viral integration and comprised multiple insertions, deletions, translocations, inversions, and point mutations. Few or no somatic mutations were present in tumors with only episomal HPV. Our data could be interpreted by positing that episomal HPV is captured in the host genome following an episode of global genome instability during tumor development. Viral integration correlated with higher grade tumors, which may be explained by the associated extensive mutation of the genome and suggests that HPV integration status may inform prognosis.

IMPLICATIONS

Our results indicate that HPV integration in head and neck cancer correlates with extensive pangenomic structural variation, which may have prognostic implications.

PI3K Inhibition for Squamous Cell Head and Neck Carcinoma

ABSTRACT

The phosphoinositide 3-kinase (PI3K) pathway is aberrantly activated in most head and neck squamous cell carcinomas, making it a prized target for targeted therapy development. Multiple PI3K inhibitors have been studied in early phase trials, with unfavorable risk-benefit ratios in molecularly unselected patient populations. Buparlisib, a potent pan-class I PI3K inhibitor, shows promising efficacy in combination with paclitaxel for advanced head and neck squamous cell carcinoma. Results of the phase III BURAN trial are awaited.

Characterization of tumor immune microenvironment and cancer therapy for head and neck squamous cell carcinoma through identification of a genomic instability-related lncRNA prognostic signature

Head and neck squamous cell carcinoma (HNSCC) represents one of the most prevalent and malignant tumors of epithelial origins with unfavorable outcomes. Increasing evidence has shown that dysregulated long non-coding RNAs (lncRNAs) correlate with tumorigenesis and genomic instability (GI), while the roles of GI-related lncRNAs in the tumor immune microenvironment (TIME) and predicting cancer therapy are still yet to be clarified. In this study, transcriptome and somatic mutation profiles with clinical parameters were obtained from the TCGA database. Patients were classified into GI-like and genomic stable (GS)-like groups according to the top 25% and bottom 25% cumulative counts of somatic mutations. Differentially expressed lncRNAs (DElncRNAs) between GI- and GS-like groups were identified as GI-related lncRNAs. These lncRNA-related coding genes were enriched in cancer-related KEGG pathways. Patients totaling 499 with clinical information were randomly divided into the training and validation sets. A total of 18 DElncRNAs screened by univariate Cox regression analysis were associated with overall survival (OS) in the training set. A GI-related lncRNA signature that comprised 10 DElncRNAs was generated through least absolute shrinkage and selection operator (Lasso)-Cox regression analysis. Patients in the high-risk group have significantly decreased OS vs. patients in the low-risk group, which was verified in internal validation and entire HNSCC sets. Integrated HNSCC sets from GEO confirmed the notable survival stratification of the signature. The time-dependent receiver operating characteristic curve demonstrated that the signature was reliable. In addition, the signature retained a strong performance of OS prediction for patients with various clinicopathological features. Cell composition analysis showed high anti-tumor immunity in the low-risk group which was evidenced by increased infiltrating CD8+ T cells and natural killer cells and reduced cancer-associated fibroblasts, which was convinced by immune signatures analysis via ssGSEA algorithm. T helper/IFNγ signaling, co-stimulatory, and co-inhibitory signatures showed increased expression in the low-risk group. Low-risk patients were predicted to be beneficial to immunotherapy, which was confirmed by patients with progressive disease who had high risk scores vs. complete remission patients. Furthermore, the drugs that might be sensitive to HNSCC were identified. In summary, the novel prognostic GILncRNA signature provided a promising approach for characterizing the TIME and predicting therapeutic strategies for HNSCC patients.

Anti-cancer therapeutic strategies based on HGF/MET, EpCAM, and tumor-stromal cross talk

As an intelligent disease, tumors apply several pathways to evade the immune system. It can use alternative routes to bypass intracellular signaling pathways, such as nuclear factor-κB (NF-κB), Wnt, and mitogen-activated protein (MAP)/phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR). Therefore, these mechanisms lead to therapeutic resistance in cancer. Also, these pathways play important roles in the proliferation, survival, migration, and invasion of cells. In most cancers, these signaling pathways are overactivated, caused by mutation, overexpression, etc. Since numerous molecules share these signaling pathways, the identification of key molecules is crucial to achieve favorable consequences in cancer therapy. One of the key molecules is the mesenchymal-epithelial transition factor (MET; c-Met) and its ligand hepatocyte growth factor (HGF). Another molecule is the epithelial cell adhesion molecule (EpCAM), which its binding is hemophilic. Although both of them are involved in many physiologic processes (especially in embryonic stages), in some cancers, they are overexpressed on epithelial cells. Since they share intracellular pathways, targeting them simultaneously may inhibit substitute pathways that tumor uses to evade the immune system and resistant to therapeutic agents.

Novel Systemic Treatment Modalities Including Immunotherapy and Molecular Targeted Therapy for Recurrent and Metastatic Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinomas (HNSCCs) are the sixth most common cancers worldwide. More than half of patients with HNSCC eventually experience disease recurrence and/or metastasis, which can threaten their long-term survival. HNSCCs located in the oral cavity and larynx are usually associated with tobacco and/or alcohol use, whereas human papillomavirus (HPV) infection, particularly HPV16 infection, is increasingly recognized as a cause of oropharyngeal HNSCC. Despite clinical, histologic, and molecular differences between HPV-positive and HPV-negative HNSCCs, current treatment approaches are the same. For recurrent disease, these strategies include chemotherapy, immunotherapy with PD-1-inhibitors, or a monoclonal antibody, cetuximab, that targets epidermal growth factor; these therapies can be administered either as single agents or in combination. However, these treatment strategies carry a high risk of toxic side effects; therefore, more effective and less toxic treatments are needed. The landscape of HNSCC therapy is changing significantly; numerous clinical trials are underway to test novel therapeutic options like adaptive cellular therapy, antibody-drug conjugates, new targeted therapy agents, novel immunotherapy combinations, and therapeutic vaccines. This review helps in understanding the various developments in HNSCC therapy and sheds light on the path ahead in terms of further research in this field.