Molecular Insights into Oral Malignancy

The Limitations of Artificial Intelligence in Head and Neck Oncology

Artificial intelligence (AI) is revolutionizing head and neck oncology, offering innovations in tumor detection, treatment planning, and patient management. However, its integration into clinical practice is hindered by several limitations. These include clinician mistrust due to a lack of understanding of AI mechanisms, biases in algorithm development, and the potential over-reliance on technology, which may undermine clinical expertise. Data-related challenges, such as inconsistent quality and limited representativeness of datasets, further complicate AI's application. Ethical, legal, and privacy concerns also pose significant barriers. Addressing these issues through transparent AI systems, clinician education, and clear regulations is essential for ensuring responsible, equitable use in head and neck oncology. This manuscript explores the limitations of AI in head and neck oncology.

SM, Subramanium N, Srinath BS. The Chimeric Antero-Lateral Thigh Flap and Vastus Lateralis Muscle Flap for the Infratemporal Fossa Reconstruction in Oral Cancer Defects

Objectives

To evaluate the effectiveness of the chimeric Free Anterolateral Thigh (FALT) and vastus lateralis muscle (VLM) flap for reconstructing extensive defects in advanced oral squamous cell carcinoma (OSCC), particularly those involving the infratemporal fossa (ITF) and masticator space.

Methods

A retrospective study was conducted at Sri Shankara Cancer Hospital, Bangalore, from January 2023 to June 2024. It included 22 patients with T4a and T4b OSCC who underwent curative ablative surgery, ITF clearance, and reconstruction using the chimeric FALT-VLM flap. The surgical technique involved harvesting a skin paddle based on a single perforator and a separate vastus lateralis muscle from the same donor site. The reconstruction aimed to provide oral cavity lining, oro-cervical separation, and ITF obliteration.

Results

Patient age ranged from 38 to 76 years (mean 53.6). The majority had buccal mucosa (54.5%) and retromolar trigone (36.3%) cancers. The FALT skin paddle size varied from 94.2 to 408.2 cm², with muscle bulk between 201.0 and 391.9 cm³. Complications included seroma and hematoma in 9.1% of cases, with 81.8% showing no complications. No donor site morbidity was noted. Post-operative mouth opening ranged between 2.5 and 3.5 cm. Most patients (72.7%) received adjuvant radiotherapy. All maintained local-regional control status.

Conclusion

The chimeric FALT-VLM flap is a robust technique for reconstructing complex oral cancer defects, effectively addressing both functional and aesthetic needs. This approach, combining skin and muscle components with independent vascular supplies, represents a significant advancement in reconstructive surgery for advanced OSCC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-024-05286-3.

Evaluation of Methylation and Changes in the Transcriptomics and Proteomics of the GRHL3, PHLDA3, and in Patients with Head and Neck Squamous Cell Carcinoma

Introduction

Head and Neck Squamous Cell Carcinoma (HNSCC) is the sixth most common malignancy in the world. High mortality and severe complications are critical features of head and neck cancer. Changes in intracellular signaling pathways are a general tumor formation and progression mechanism. Due to the objectivity that the PI3K pathway plays a critical role in HNSCC. the negative regulators involved in this pathway such as GRHL3, PHLDA3, which have been reported to reduce their expression in malignancies, can achieve significant results in the detection, prognosis, and targeted treatment of HNSCC if changes in transcriptome, proteome, and methylation levels of these genes are observed.

Method

45 fresh head and neck cancer cells and 45 control samples were collected. Protein expression was also studied using Western blot. Additionally, promoter methylation was investigated using the qMSP method to observe changes in the regulatory regions.

Results

The results indicate a significant decrease in GRHL3 expression and a significant increase in PHLDA3 expression. Notably, these expression changes were not confirmed at the protein level. Additionally, methylation analysis revealed hypermethylation of the promoter region in GRHL3 and hypomethylation in PHLDA3.

Conclusion

This study is the first to examine the genes GRHL3 and PHLDA3 at the transcriptome, proteome, and promoter methylation levels. Based on the results, we hope that further studies will confirm the potential of GRHL3 and PHLDA3 as prognostic biomarkers.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-024-05057-0.

Saliva in Balancing Oral and Systemic Health, Oral Cancer, and Beyond: A Narrative Review

Saliva plays a multifaceted role in oral health and systemic well-being. It supports digestion, protects oral tissues, maintains a healthy oral microbiome, and facilitates wound healing. Additionally, saliva serves as a diagnostic tool that reflects systemic health and disease/therapeutic states. Furthermore, although saliva shows a protective effect against oral cancer development, once tumor formation occurs, it may be involved in tumor progression and metastasis via exosomes and microRNAs. This review discusses the essential role of saliva; its relationship with the development, progression, and metastasis of head and neck squamous cell carcinoma (HNSCC); liquid biopsy tools for early diagnosis and monitoring of HNSCC; and the potential of exosomes as therapeutic agents.

Identification of Stage-Specific microRNAs that Govern the Early Stages of Sequential Oral Oncogenesis by Strategically Bridging Human Genetics with Epigenetics and Utilizing an Animal Model

Oral squamous cell carcinoma (OSCC) is a highly prevalent and aggressive malignancy, with mortality rates reaching 60%, mainly due to its excessive diagnostic delay. MiRNAs, a class of crucial epigenetic gene-expression regulators, have emerged as potential diagnostic biomarkers, with >200 molecules exhibiting expressional dysregulation in OSCC. We had previously established an in silico methodology for the identification of the most disease-specific molecules by bridging genetics and epigenetics. Here, we identified the stage-specific miRNAs that govern the asymptomatic early stages of oral tumorigenesis by exploiting seed-matching and the reverse interplay between miRNA levels and their target genes' expression. Incorporating gene-expression data from our group's experimental hamster model of sequential oral oncogenesis, we bioinformatically detected the miRNAs that simultaneously target/regulate >75% of the genes that are characteristically upregulated or downregulated in the consecutive stages of hyperplasia, dysplasia, and early invasion, while exhibiting the opposite expressional dysregulation in OSCC-derived tissue and/or saliva specimens. We found that all stages share the downregulation of miR-34a-5p, miR124-3p, and miR-125b-5p, while miR-1-3p is under-expressed in dysplasia and early invasion. The malignant early-invasion stage is distinguished by the downregulation of miR-147a and the overexpression of miR-155-5p, miR-423-3p, and miR-34a-5p. The identification of stage-specific miRNAs may facilitate their utilization as biomarkers for presymptomatic OSCC diagnosis.

C-Jun Transcription Factor Oncogenic Activation in Oral Carcinoma

INTRODUCTION

Oral carcinogenetic is based on a variety of genomic imbalances (gross chromosome or specific gene alterations) that drive the normal oral mucosa to its neoplastic/dysplastic epithelial form and finally to a totally malignant tissue transformation. In this multi-step procedure, down-regulation of suppressor genes combined with overactivation of oncogenes are two crucial and partially early genetic events involved in the onset and progression of neoplastic/malignant epithelia transformation. More specifically, deregulation of strong transcription factors negatively affects the normal expression of a broad spectrum of genes that are involved in cell proliferation and signalling transduction to the nucleus.

OBJECTIVE

The purpose of the current molecular review was to explore the c-Jun (chromosome location: 1p32-p31) transcription factor transformation mechanisms to oncogene in oral squamous cell carcinoma (OSCC).

MATERIAL AND METHOD

A systematic review of the literature was carried out by searching in PubMed international database. The year 2010 was set as a prominent time limit for the publication date of the articles in the majority of them, whereas specific references of great importance and historical value in the field of the c-Jun gene discovery and analysis were also included. The following keywords were used: c-Jun, oncogene, signaling pathway, oral, carcinoma, transcription. A pool of 45 important articles were selected for the present study at the basis of combining molecular knowledge with new targeted therapeutic strategies.

RESULTS

C-Jun - as a part of the c-Jun/c-Fos transcription factors' complex -critically regulates the expression levels in a variety of genes inside the cellular microenvironment. A broad spectrum of malignancies, including OSCC, demonstrate c-Jun alterations driving the gene to its oncogenic phenotype. Interestingly, c-Jun oncogenic activation is mediated by high-risk human papilloma virus (HR-HPV) persistent infection in significant subsets of these malignancies.

CONCLUSIONS

C-Jun was the first oncogene - acting as a strong transcription factor - that was discovered and cloned 35 years ago. C-Jun is the living history of oncogenes and its discovery marks a significant step in the evolution of molecular biology.

Salivary miRNAs as auxiliary liquid biopsy biomarkers for diagnosis in patients with oropharyngeal squamous cell carcinoma: a systematic review and meta-analysis

Objective: The healthcare system needs a novel approach to improve and diagnose early oropharyngeal squamous cell carcinoma against its low survival rate. We conduct a systematic review and a comprehensive meta-analysis for the diagnostic role of blood and salivary microRNAs (miRNAs). Methods: An unbiased and thorough literature search in PubMed yielded appropriate data from qualified articles regarding different miRNA biomarkers, method of extraction, research location, and year of publication. Stata was used to calculate the sensitivity, specificity, diagnostic odds ratio, and summary receiver operating characteristic curve. Results: We included 9 studies with 399 qualified oropharyngeal squamous cell carcinoma patients, which yielded a high diagnostic accuracy of blood miRNAs in combination with salivary miRNAs with a sensitivity of 0.70 (p < 0.001), specificity of 0.75 (p = 0.26), diagnostic odds ratio of 7, and an area under the curve of 0.78. Conclusion: Combined blood- and saliva-derived miRNAs demonstrated a high diagnostic accuracy in detecting oropharyngeal squamous cell carcinoma. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024509424.

HOXA1 3'UTR Methylation Is a Potential Prognostic Biomarker in Oral Squamous cell Carcinoma

BACKGROUND

HOXA1 is a prognostic marker and a potential predictive biomarker for radioresistance in head and neck tumors. Its overexpression has been associated with promoter methylation and a worse prognosis in oral squamous cell carcinoma (OSCC) patients. However, opposite outcomes are also described. The effect of the methylation of this gene on different gene regions, other than the promoter, remains uncertain. We investigated the methylation profile at different genomic regions of HOXA1 in OSCC and correlated differentially methylated CpG sites with clinicopathological data.

METHODS

The HOXA1 DNA methylation status was evaluated by analyzing data from The Cancer Genome Atlas and three Gene Expression Omnibus datasets. Significant differentially methylated CpG sites were considered with a |∆β| ≥ 0.10 and a Bonferroni-corrected p-value < 0.01. Differentially methylated CpGs were validated by pyrosequencing using two independent cohorts of 15 and 47 OSCC patients, respectively.

RESULTS

Compared to normal tissues, we found significantly higher DNA methylation levels in the 3'UTR region of HOXA1 in OSCC. Higher methylation levels in tumor samples were positively correlated with smoking habits and patients' overall survival.

CONCLUSIONS

Our findings suggest that HOXA1 gene body methylation is a promising prognostic biomarker for OSCC with potential clinical applications in patient monitoring.

Review of Disease-Specific microRNAs by Strategically Bridging Genetics and Epigenetics in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most prevalent human malignancies and a global health concern with a poor prognosis despite some therapeutic advances, highlighting the need for a better understanding of its molecular etiology. The genomic landscape of OSCC is well-established and recent research has focused on miRNAs, which regulate gene expression and may be useful non-invasive biomarkers or therapeutic targets. A plethora of findings regarding miRNA expression have been generated, posing challenges for the interpretation and identification of disease-specific molecules. Hence, we opted to identify the most important regulatory miRNAs by bridging genetics and epigenetics, focusing on the key genes implicated in OSCC development. Based on published reports, we have developed custom panels of fifteen major oncogenes and five major tumor suppressor genes. Following a miRNA/target gene interaction analysis and a comprehensive study of the literature, we selected the miRNA molecules which target the majority of these panels that have been reported to be downregulated or upregulated in OSCC, respectively. As a result, miR-34a-5p, miR-155-5p, miR-124-3p, miR-1-3p, and miR-16-5p appeared to be the most OSCC-specific. Their expression patterns, verified targets, and the signaling pathways affected by their dysregulation in OSCC are thoroughly discussed.

Establishment of anti-DKK3 peptide for the cancer control in head and neck squamous cell carcinoma (HNSCC)

Background

Head and neck squamous cell carcinoma (HNSCC) is the most common malignant tumor of the head and neck. We identified cancer-specific genes in HNSCC and focused on DKK3 expression. DKK3 gene codes two isoforms of proteins (secreted and non-secreted) with two distinct cysteine rich domains (CRDs). It is reported that DKK3 functions as a negative regulator of oncogenic Wnt signaling and, is therefore, considered to be a tumor suppressor gene. However, our series of studies have demonstrated that DKK3 expression is specifically high in HNSCC tissues and cells, and that DKK3 might determine the malignant potentials of HNSCC cells via the activation of Akt. Further analyses strongly suggested that both secreted DKK3 and non-secreted DKK3 could activate Akt signaling in discrete ways, and consequently exert tumor promoting effects. We hypothesized that DKK3 might be a specific druggable target, and it is necessary to establish a DKK3 inhibitor that can inhibit both secreted and non-secreted isoforms of DKK3.

Methods

Using inverse polymerase chain reaction, we generated mutant expression plasmids that express DKK3 without CRD1, CRD2, or both CRD1 and CRD2 (DKK3ΔC1, DKK3ΔC2, and DKK3ΔC1ΔC2, respectively). These plasmids were then transfected into HNSCC-derived cells to determine the domain responsible for DKK3-mediated Akt activation. We designed antisense peptides using the MIMETEC program, targeting DKK3-specific amino acid sequences within CRD1 and CRD2. The structural models for peptides and DKK3 were generated using Raptor X, and then a docking simulation was performed using CluPro2. Afterward, the best set of the peptides was applied into HNSCC-derived cells, and the effects on Akt phosphorylation, cellular proliferation, invasion, and migration were assessed. We also investigated the therapeutic effects of the peptides in the xenograft models.

Results

Transfection of mutant expression plasmids and subsequent functional analyses revealed that it is necessary to delete both CRD1 and CRD2 to inhibit Akt activation and inhibition of proliferation, migration, and invasion. The inhibitory peptides for CRD1 and CRD2 of DKK3 significantly reduced the phosphorylation of Akt, and consequently suppressed cellular proliferation, migration, invasion and in vivo tumor growth at very low doses.

Conclusions

This inhibitory peptide represents a promising new therapeutic strategy for HNSCC treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02783-9.