Targeting cellular metabolism in head and neck cancer precision medicine era: A promising strategy to overcome therapy resistance

Prognostic and therapeutic insights from lactate metabolism and tumor immune microenvironment in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) exhibits a poor prognosis, particularly in advanced stages characterized by high recurrence and metastasis rates. This study investigates the role of lactate metabolism in HNSCC, aiming to develop a prognostic model to predict immunotherapy outcomes. Genomic and clinical data from The Cancer Genome Atlas and Gene Expression Omnibus databases were analyzed, focusing on 233 lactate metabolism-related genes (LMGs). Differential expression and Cox regression analyses identified two significant prognostic genes: glycogen phosphorylase L (PYGL) and solute carrier family 16 member 3 (SLC16 A3, encoding MCT4). A lactate risk score (LRS) model constructed from these genes demonstrated robust predictive accuracy across multiple validation datasets. Multivariate analysis validated LRS as an independent prognostic factor, and a nomogram integrating LRS with clinical parameters further improved survival prediction accuracy. Immune infiltration analyses revealed distinct immune landscapes between high- and low-risk groups. Elevated levels of CD4 naïve T cells, resting NK cells, M0 macrophages, and activated mast cells characterized the high-risk group, whereas naive B cells, plasma cells, CD8 T cells, T follicular helper cells, regulatory T cells, gamma delta T cells, resting dendritic cells, resting mast cells, and eosinophils predominated in the low-risk group. Additionally, molecular docking suggested valproic acid as a potential inhibitor of MCT4. Immunohistochemical analyses showed increased PYGL and MCT4 expression correlated with advanced tumor stage, alongside decreased expression of CXCL9 and CXCL10. These findings highlight the critical role of lactate metabolism in HNSCC progression and immunotherapy resistance, identifying PYGL and MCT4 as promising therapeutic targets.

Multidimensional insights into squalene epoxidase drug development: in vitro mechanisms, in silico modeling, and in vivo implications

INTRODUCTION

Squalene epoxidase (SQLE) is a pivotal enzyme in sterol biosynthesis, catalyzing the conversion of squalene to 2,3-oxidosqualene. Beyond its core role in cholesterol homeostasis, SQLE is implicated in cancer, hypercholesterolemia, and fungal infections, positioning it as a valuable therapeutic target.

AREAS COVERED

We conducted a comprehensive literature search across primary databases to gather in vitro, in silico, and in vivo evidence on SQLE. This review explores the enzyme's structural and functional features, including substrate specificity and catalytic mechanisms, and examines inhibitor interactions. Computational methods predict enzyme - inhibitor dynamics, guiding drug design, while in vivo investigations clarify SQLE's role in metabolic disorders and tumorigenesis. Challenges include drug resistance and study discrepancies, but emerging technologies, such as cryo-electron microscopy and CRISPR editing, offer new avenues for deeper exploration.

EXPERT OPINION

SQLE is an underexplored yet promising therapeutic target, with particular relevance to oxidative stress, ferroptosis, and gut microbiota research. Overcoming current barriers through advanced technologies and multidisciplinary strategies could propel SQLE-targeted treatments into clinical practice, supporting precision medicine and broader translational applications.

Synthesis and pharmacological evaluation of natural product diphyllin derivatives against head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is one of the most common malignant tumors, but clinical drug treatments are limited. The natural product diphyllin was identified as a lead compound suppressing the proliferation of HNSCC cells through phenotypic screening of natural product library. However, further developments of diphyllin as an anti-HNSCC agent were restricted by the weak bioactivity and poor metabolic stability. Herein, we designed and synthesized two series of novel diphyllin derivatives that were achieved by introducing various pyranose rings or hydrophilic groups to block the easily metabolic C-4 site with the aim to improve antitumor activity and drug-like properties. Among these compounds, compound A3 showed the most potent inhibitory effects against HNSCC cells with IC50 values ranging from 4.37 to 77.81 nM and much less potent cytotoxicity against normal cells (IC50 > 10 μM). Mechanistically, it effectively inhibited cell proliferation and migration and induced the cell cycle arrest and apoptosis in a concentration-dependent manner. Besides, A3 possessed greatly improved pharmacokinetic properties including over 10-fold higher plasma exposure (AUC0-t: 541 vs 43.6 h∗ng/mL) and better oral bioavailability (F: 20.85 % vs 2.70 %), lower systemic plasma clearance (CL:1897 vs 24523 mL/h/kg), as well as longer half-life (T1/2: 0.530 vs 0.108 h) when compared to diphyllin. In a tumor cell xenograft model, A3 significantly suppressed the CAL27 tumor growth with a TGI of 42.2 % without obvious safety concern, which is superior to that of diphyllin (TGI = 23.3 %), suggesting great potential for treatment of HNSCC.

Portable multi-parametric microscopy for noninvasive metabolic and vascular imaging of orthotopic tongue cancer models in vivo

Significance

Precise imaging of tumor metabolism with its vascular microenvironment becomes emerging critical for cancer research because increasing evidence shows that the key attribute that allows a tumor to survive therapies is metabolic and vascular reprogramming. However, there are surprisingly few imaging techniques available to provide a systems-level view of tumor metabolism and vasculature in vivo on small animals for cancer discoveries.

Aim

We aim to develop a new multi-parametric microscope that can faithfully recapitulate in vivo metabolic and vascular changes with a wide field of view and microscope-level resolution to advance cancer-related investigations. To maximize the ease and accessibility of obtaining in vivo tissue metabolism and vasculature measurements, we aim to develop our new metabolic imaging tool with minimal cost and size, allowing one to easily quantify tissue metabolic and vascular endpoints together in vivo, advancing many critical biomedical inquiries.

Approach

We have combined fluorescence microscopy and dark-field microscopy in a re-emission geometry into one portable microscope to image the key metabolic and vascular endpoints on the same tissue site. The portable microscope was first characterized by tissue-mimicking phantoms. Then the multi-parametric system was demonstrated on small animals to image glucose uptake (using 2-NBDG) and mitochondrial membrane potential (using TMRE) along with vascular parameters (oxygen saturation and hemoglobin contents) of orthotopic tongue tumors in vivo.

Results

Our phantom studies demonstrated the capability of the portable microscope for effective measurements of several key vascular and metabolic parameters with a comparable accuracy compared with our former reported benchtop spectroscopy and imaging systems. Our in vivo animal studies revealed increased glucose uptake and mitochondrial membrane potential along with reduced vascular oxygenation in tongue tumors compared with normal tongue tissues. The spatial analysis of metabolic and vascular images showed a more heterogeneous metabolic and oxygenation profile in tongue tumors compared with normal tongue tissues.

Conclusions

Our in vivo animal studies demonstrated the capability of our portable multi-parametric microscope for imaging the key metabolic and vascular parameters at the same tissue site with about one hour delay using an orthotopic tongue tumor model in vivo. Our study showed the potential of a portable functional microscope to noninvasively evaluate tumor biology using orthotopic tongue cancer models for future head and neck cancer research.

Mitochondrial-related drug resistance lncRNAs as prognostic biomarkers in laryngeal squamous cell carcinoma

Laryngeal squamous cell carcinoma (LSCC) is a common malignant tumor of the head and neck that significantly impacts patients' quality of life, with chemotherapy resistance notably affecting prognosis. This study aims to identify prognostic biomarkers to optimize treatment strategies for LSCC. Using data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO), combined with mitochondrial gene database analysis, we identified mitochondrial lncRNAs associated with drug resistance genes. Key long non-coding RNAs (lncRNAs) were selected through univariate Cox regression and Lasso regression, and a multivariate Cox regression model was constructed to predict prognosis. We further analyzed the differences in immune function and biological pathway enrichment between high- and low-risk groups, developed a nomogram, and compared drug sensitivity. Results showed that the prognostic model based on seven mitochondrial lncRNAs could serve as an independent prognostic factor, with Area Under the Curve (AUC) values of 0.746, 0.827, and 0.771 at 1, 3, and 5 years, respectively, outperforming some existing models, demonstrating high predictive performance. Significant differences were observed in immune function and drug sensitivity between the high- and low-risk groups. The risk prediction model incorporating seven drug resistance-related mitochondrial lncRNAs can accurately and independently predict the prognosis of LSCC patients.

Glutamine and serum starvation alters the ATP production, oxidative stress, and abundance of mitochondrial RNAs in extracellular vesicles produced by cancer cells

Induction of autophagy represents an effective survival strategy for nutrient-deprived or stressed cancer cells. Autophagy contributes to the modulation of communication within the tumor microenvironment. Here, we conducted a study of the metabolic and signaling implications associated with autophagy induced by glutamine (Gln) and serum starvation and PI3K/mTOR inhibitor and autophagy inducer NVP-BEZ235 (BEZ) in the head and neck squamous cell carcinoma (HNSCC) cell line FaDu. We compared the effect of these different types of autophagy induction on ATP production, lipid peroxidation, mitophagy, RNA cargo of extracellular vesicles (EVs), and EVs-associated cytokine secretome of cancer cells. Both BEZ and starvation resulted in a decline in ATP production. Simultaneously, Gln starvation enhanced oxidative damage of cancer cells by lipid peroxidation. In starved cells, there was a discernible fragmentation of the mitochondrial network coupled with an increase in the presence of tumor susceptibility gene 101 (TSG101) on the mitochondrial membrane, indicative of the sorting of mitochondrial cargo into EVs. Consequently, the abundance of mitochondrial RNAs (mtRNAs) in EVs released by FaDu cells was enhanced. Notably, mtRNAs were also detectable in EVs isolated from the serum of both HNSCC patients and healthy controls. Starvation and BEZ reduced the production of EVs by cancer cells, yet the characteristic molecular profile of these EVs remained unchanged. We also found that alterations in the release of inflammatory cytokines constitute a principal response to autophagy induction. Importantly, the specific mechanism driving autophagy induction significantly influenced the composition of the EVs-associated cytokine secretome.

Application of metabolomics in oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a prevalent malignancy affecting the head and neck region. The prognosis for OSCC patients remains unfavorable due to the absence of precise and efficient early diagnostic techniques. Metabolomics offers a promising approach for identifying distinct metabolites, thereby facilitating early detection and treatment of OSCC.

OBJECTIVE

This review aims to provide a comprehensive overview of recent advancements in metabolic marker identification for early OSCC diagnosis. Additionally, the clinical significance and potential applications of metabolic markers for the management of OSCC are discussed.

RESULTS

This review summarizes metabolic changes during the occurrence and development of oral squamous cell carcinoma and reviews prospects for the clinical application of characteristic, differential metabolites in saliva, serum, and OSCC tissue. In this review, the application of metabolomic technology in OSCC research was summarized, and future research directions were proposed.

CONCLUSION

Metabolomics, detection technology that is the closest to phenotype, can efficiently identify differential metabolites. Combined with statistical data analyses and artificial intelligence technology, it can rapidly screen characteristic biomarkers for early diagnosis, treatment, and prognosis evaluations.

Transcription Factors and Markers Related to Epithelial-Mesenchymal Transition and Their Role in Resistance to Therapies in Head and Neck Cancers

Head and neck cancers (HNCs) are heterogeneous and aggressive tumors of the upper aerodigestive tract. Although various histological types exist, the most common is squamous cell carcinoma (HNSCC). The incidence of HNSCC is increasing, making it an important public health concern. Tumor resistance to contemporary treatments, namely, chemo- and radiotherapy, and the recurrence of the primary tumor after its surgical removal cause huge problems for patients. Despite recent improvements in these treatments, the 5-year survival rate is still relatively low. HNSCCs may develop local lymph node metastases and, in the most advanced cases, also distant metastases. A key process associated with tumor progression and metastasis is epithelial-mesenchymal transition (EMT), when poorly motile epithelial tumor cells acquire motile mesenchymal characteristics. These transition cells can invade different adjacent tissues and finally form metastases. EMT is governed by various transcription factors, including the best-characterized TWIST1 and TWIST2, SNAIL, SLUG, ZEB1, and ZEB2. Here, we highlight the current knowledge of the process of EMT in HNSCC and present the main protein markers associated with it. This review focuses on the transcription factors related to EMT and emphasizes their role in the resistance of HNSCC to current chemo- and radiotherapies. Understanding the role of EMT and the precise molecular mechanisms involved in this process may help with the development of novel anti-cancer therapies for this type of tumor.

PRI-724 and IWP-O1 Wnt Signaling Pathway Inhibitors Modulate the Expression of Glycolytic Enzymes in Tongue Cancer Cell Lines

The dysregulation of energetic metabolism is one of the hallmarks of cancer cells. Indeed, the growth of head and neck squamous cell carcinoma (HNSCC) cells depends heavily on glycolytic activity, which can be considered a potential therapeutic target. Wnt signaling is one of the pathways that undergoes upregulation in HNSCC. Our previous studies have shown that Wnt signaling inhibitors-PRI-724 and IWP-O1-attenuate tongue SCC survival and reduce glucose uptake and lactate release. The aim of this research was to further evaluate the possible mechanisms of the previously observed effects. We assessed the effect of PRI-724 and IWP-O1 on the expression of selected glycolytic enzymes: phosphofructokinase M, pyruvate kinase M2, and lactate dehydrogenase. Relative transcript expression was assessed by real-time PCR, and protein levels by Western blot. Moreover, clinical data concerning mRNA and protein expression, gene promoter methylation, and HNSCC patients' survival time were analyzed by the UALCAN tool, and protein-protein interaction was assessed using the STRING database. Experimental and bioinformatic data confirmed the relation between Wnt signaling and glycolytic enzymes in tongue cancer cells and HNSCC clinical samples. Overall, the inhibition of glucose metabolism by Wnt signaling inhibitors is a promising mode of action against tongue cancer cells.

RNA-Based Liquid Biopsy in Head and Neck Cancer

Head and neck cancer (HNC) is a prevalent and diverse group of malignancies with substantial morbidity and mortality rates. Early detection and monitoring of HNC are crucial for improving patient outcomes. Liquid biopsy, a non-invasive diagnostic approach, has emerged as a promising tool for cancer detection and monitoring. In this article, we review the application of RNA-based liquid biopsy in HNC. Various types of RNA, including messenger RNA (mRNA), microRNA (miRNA), long non-coding RNA (lncRNA), small nuclear RNA (snRNA), small nucleolar RNA (snoRNA), circular RNA (circRNA) and PIWI-interacting RNA (piRNA), are explored as potential biomarkers in HNC liquid-based diagnostics. The roles of RNAs in HNC diagnosis, metastasis, tumor resistance to radio and chemotherapy, and overall prognosis are discussed. RNA-based liquid biopsy holds great promise for the early detection, prognosis, and personalized treatment of HNC. Further research and validation are necessary to translate these findings into clinical practice and improve patient outcomes.