Molecular biology of oral cavity squamous cell carcinoma

Dinaciclib Interrupts Cell Cycle and Induces Apoptosis in Oral Squamous Cell Carcinoma: Mechanistic Insights and Therapeutic Potential

Dinaciclib, a potent cyclin-dependent kinase (CDK) inhibitor, has demonstrated considerable antitumor effects in various malignancies. However, its impact on oral squamous cell carcinoma (OSCC), a predominant and highly aggressive form of head and neck squamous cell carcinoma (HNSC) with limited treatment options, remains underexplored. We conducted gene set enrichment analyses in HNSC patients that reinforced the relevance of these cell cycle-related genes to OSCC pathogenesis. Given the known dysregulation of cell cycle-related genes in HNSC patients, we hypothesized that Dinaciclib may inhibit OSCC growth by targeting overexpressed cyclins and CDKs, thereby disrupting cell cycle progression and inducing apoptosis. This study investigated Dinaciclib's effects on cell proliferation, cell cycle progression, and apoptosis in the OSCC cell lines Ca9-22, OECM-1, and HSC-3. Our results demonstrated that Dinaciclib significantly reduces OSCC cell proliferation in a dose-dependent manner. Flow cytometry and Western blot analyses showed that Dinaciclib induces cell cycle arrest at the G1/S and G2/M transitions by downregulating Cyclins A, B, D, and E, along with CDKs 1 and 2-key regulators of these checkpoints. Furthermore, Dinaciclib treatment upregulated apoptotic markers, such as cleaved-caspase-3 and cleaved-PARP, confirming its pro-apoptotic effects. In conclusion, these findings highlight Dinaciclib's therapeutic promise in OSCC by simultaneously disrupting cell cycle progression and inducing apoptosis. These results support further exploration of Dinaciclib as a viable monotherapy or combination treatment in OSCC and other HNSC subtypes to improve patient outcomes.

Genome-Wide DNA Methylation Confirms Oral Squamous Cell Carcinomas in Proliferative Verrucous Leukoplakia as a Distinct Oral Cancer Subtype: A Case-Control Study

BACKGROUND/OBJECTIVES

Oral cancers in patients with proliferative verrucous leukoplakia (PVL-OSCC) exhibit different clinical and prognostic outcomes from those seen in conventional oral squamous cell carcinomas (cOSSCs). The aim of the present study is to compare the genome-wide DNA methylation signatures in fresh frozen tissues between oral squamous cell carcinomas in patients with PVL and cOSCC using the Illumina Infinium MethylationEPIC BeadChip.

METHODS

This case-control study was carried out at the Stomatology and Maxillofacial Surgery Department of the General University Hospital of Valencia. For the epigenomic study, unsupervised exploratory bioinformatic analyses were performed using principal component and heatmap analysis. Supervised differential methylation analyses were conducted using a rank-based regression model and a penalized logistic regression model to identify potential prognostic biomarkers.

RESULTS

The unsupervised analyses of the global methylation profiles did not allow us to differentiate between the distinct oral cancer groups. However, the two supervised analyses confirmed the existence of two oral carcinoma phenotypes. We identified 21 differentially methylated CpGs corresponding to 14 genes. Among them, three CpGs had not been previously assigned to any known gene, and the remaining were associated with genes unrelated to oral cancer. The AGL, WRB, and ARL15 genes were identified as potential prognostic biomarkers.

CONCLUSIONS

This study emphasizes the significant role of epigenetic dysregulation in OSCC, particularly in cases preceded by PVL. We have provided data on differential methylation genes that could be involved in the molecular carcinogenesis of PVL-OSCC.

Association of Fusobacterium nucleatum Levels by ddPCR in Oral Rinse Samples With Periodontal Disease in Oral Squamous Cell Carcinoma Patients and in Controls

BACKGROUND

The role of microbiome, particularly Fusobacterium nucleatum (Fn), in periodontal disease and oral squamous cell carcinoma (OSCC) has been recently explored. This study aimed to evaluate the Fn presence and its levels in oral rinse samples from Brazilian OSCC patients and healthy individuals and its association with sociodemographic, clinical, and oral health features.

METHODS

In this case-control study, 80 participants were included, 31 OSCC patients and 49 individuals without a cancer history. Clinical data were collected, and an oral exam was done on a subset of the cohort. Fn levels were evaluated by droplet digital PCR (ddPCR) in oral rinse samples and were categorized as Fn-high or Fn-low based on the median number of copies per reaction.

RESULTS

OSCC patients showed higher levels of Fn (68%, p = 0.03) than controls, and all OSCC cases were diagnosed with periodontal disease (100%, p = 1.0). In the univariate analysis, Fn-high level was more frequently present in OSCC cases compared to controls (p = 0.01). It was also observed that Fn-high level OSCC cases were significantly associated with self-reported non-white ethnicity (71.4%, p = 0.01) and had more infiltrative lesions (57.1%, p = 0.02) than Fn-low OSCC cases. Fn-high levels in oral rinse samples, were significantly more prevalent among OSCC than in controls.

CONCLUSIONS

In OSCC patients, Fn-high levels were associated with non-white ethnicity and lesions with infiltrative clinical aspects. Among OSCC cases, all had periodontal disease.

Rho GTPase activating protein 11A promotes tongue squamous cell carcinoma proliferation and is a transcriptional target of forkhead box M1

Background/purpose

Rho GTPase activating protein 11A (ARHGAP11A) can facilitate GTP hydrolysis in RhoA. The functions of ARHGAP11A in oral squamous cell carcinoma (OSCC) have not yet been explored. This study aimed to investigate the expression profile of ARHGAP11A in OSCC, its correlation with patient prognosis, its effect on cell-cycle progression, and the mechanisms by which it is dysregulated.

Materials and methods

Bioinformatics analysis was conducted using data from The Cancer Genome Atlas-Head and Neck Squamous Cell Carcinoma (TCGA-HNSC). Lentiviruses carrying ARHGAP11A shRNAs were employed to determine the effects of ARHGAP11A knockdown on tumor cell proliferation and cell-cycle progression. Dual-luciferase reporter assays were utilized to examine how FOXM1 transcriptionally regulates ARHGAP11A expression.

Results

ARHGAP11A upregulation was associated with unfavorable overall survival (OS) in patients with TSCC (HR: 2.142, 95%CI: 1.224-3.749, P = 0.007), but not in patients with OSCC of sites other than the tongue. ARHGAP11A knockdown inhibited the proliferation of TSCC cells in vitro and in vivo, and induced G1 phase arrest. ARHGAP11A knockdown increased GTP-RhoA but decreased p-RB levels, while it did not affect the total expression of RhoA and RB. ARHGAP11A knockdown increased p27 and decreased cyclin E1 expression. ARHGAP11A is transcriptionally activated by FOXM1 via multiple FOXM1 binding sites in the promoter regions in TSCC cells.

Conclusion

This study revealed the oncogenic role of ARHGAP11A in TSCC, highlighting its impact on cell-cycle control and tumor proliferation. Furthermore, the regulatory relationship between FOXM1 and ARHGAP11A provides new insights into the transcriptional networks in TSCC.

Aberrant expression of VASP serves as a potential prognostic biomarker and therapeutic target for oral squamous cell carcinoma

OBJECTIVE

To address the molecular markers linked to the development and progression of oral squamous cell carcinoma (OSCC), we sought to analyze the expression of vasodilator-stimulated phosphoproteins (VASP) in OSCC samples.

STUDY DESIGN

This study used 51 OSCC patients and The Cancer Genome Atlas-Head and Neck Squamous Cell Carcinoma (TCGA-HNSC) dataset to analyze VASP expression. The association between VASP mRNA expression and HNSCC clinicopathological features, tumor infiltration, functional roles, and gene co-expression of VASP also were evaluated.

RESULTS

Our study observed increased VASP mRNA expression in OSCC tumor tissues compared to normal tissues, supported by TCGA-HNSC dataset analysis. Elevated VASP levels correlated with advanced tumor stage, higher grade, nodal metastasis, and poor survival, indicating its potential as a prognostic marker. Protein analysis and immunohistochemistry confirmed these findings, and in silico analysis revealed VASP involvement in key cancer-related processes and its correlation with IL8, RAP1A expression, and tumor infiltration levels.

CONCLUSIONS

In conclusion, VASP emerges as a promising diagnostic and prognostic marker for OSCC within HNSCC, emphasizing the importance of exploring its regulatory mechanisms and therapeutic applications. The revealed pathways present avenues for targeted treatment in OSCC. Despite limitations, this study provides valuable insights with potential implications for improving patient outcomes.

Precision Medicine and Clinical Trials in Advanced and Metastatic Oral Cancer

Purpose

Oral cancer is a significant global health concern, with high morbidity and mortality rates, particularly in regions with prevalent tobacco usage such as Asia. Majority of oral cancers are detected at an advanced stage resulting in poor survival outcomes. Moreover, the treatment modalities of oral cancers have remained constant with surgery and concurrent chemoradiotherapy being mainstays of the treatment. This review provides a significant progress made in understanding the molecular landscape of oral cancers and the evolution of therapeutic strategies toward precision medicine.

Methods

A comprehensive literature review was conducted to gather recent studies on the molecular landscape of oral cancers, genomic insights, and clinical trials.

Results

Firstly, genomic insights into oral cancers, including key driver mutations and copy number alterations, are discussed in the context of personalized medicine approaches. Subsequently, advancements in therapeutic strategies, particularly focusing on clinical trials investigating immunotherapy and targeted agents, are highlighted.

Conclusion

Despite promising results, challenges persist in identifying reliable biomarkers for treatment response and resistance. Continued research efforts are warranted to validate biomarkers and optimize therapeutic interventions, with the goal of enhancing patient outcomes and reducing the global burden of oral cancer.

Role of Cathepsin B Expression in Oral Squamous Cell Carcinoma: A Comprehensive Review

This comprehensive review delves into the intricate landscape of oral squamous cell carcinoma (OSCC) by examining the role of cathepsin B expression in its pathogenesis. OSCC, a prevalent and clinically significant oral malignancy, poses a considerable global health burden, necessitating a thorough exploration of its underlying molecular mechanisms. Cathepsin B, a lysosomal cysteine protease, emerges as a critical player in OSCC, influencing tumour initiation, invasion, and metastasis. The review begins with a brief overview of OSCC, emphasizing its epidemiological and clinical features, followed by exploring the significance of studying cathepsin B expression in this context. In the manuscript, the structure and function of cathepsin B are elucidated, providing a foundation for understanding its aberrant expression in OSCC. Clinical studies revealing correlations with tumour grade and stage, along with prognostic significance, are scrutinized, offering insights into the potential diagnostic and prognostic utility of cathepsin B. The biological functions of cathepsin B in OSCC, including its impact on tumour invasion and modulation of apoptosis, are comprehensively discussed. The Therapeutic Implications section explores targeting cathepsin B as a potential strategy, emphasizing the need for future research to overcome associated challenges. In the Conclusion section, the review synthesizes key findings, delineates implications for future research, and highlights the potential impact of cathepsin B on OSCC diagnosis and treatment, contributing to the ongoing efforts to advance our understanding of this complex malignancy, which is associated with a high mortality rate and improve clinical outcomes.

DNA methylation-based depiction of the immune microenvironment and immune-associated long non-coding RNAs in oral cavity squamous cell carcinomas

Oral cavity squamous cell carcinoma (OSCC) is a complex and dynamic disease characterized by clinicopathological and molecular heterogeneity. Spatial and temporal heterogeneity of cell subpopulations has been associated with cancer progression and implicated in the prognosis and therapy response. Emerging evidence indicates that aberrant epigenetic profiles in OSCC may foster an immunosuppressive tumor microenvironment by modulating the expression of immune-related long non-coding RNAs (lncRNAs). DNA methylation analysis was performed in 46 matched OSCC and normal adjacent tissue samples using a genome-wide platform (Infinium HumanMethylation450 BeadChip). Reference-based computational deconvolution (MethylCIBERSORT) was applied to infer the immune cell composition of the bulk samples. The expression levels of genes encoding immune markers and differentially methylated lncRNAs were investigated using The Cancer Genome Atlas dataset. OSCC specimens presented distinct immune cell composition, including the enrichment of monocyte lineage cells, natural killer cells, cytotoxic T-lymphocytes, regulatory T-lymphocytes, and neutrophils. In contrast, B-lymphocytes, effector T-lymphocytes, and fibroblasts were diminished in tumor samples. The hypomethylation of three immune-associated lncRNAs (MEG3, MIR155HG, and WFDC21P) at individual CpG sites was confirmed by bisulfite-pyrosequencing. Also, the upregulation of a set of immune markers (FOXP3, GZMB, IL10, IL2RA, TGFB, IFNG, TDO2, IDO1, and HIF1A) was detected. The immune cell composition, immune markers alteration, and dysregulation of immune-associated lncRNAs reinforce the impact of the immune microenvironment in OSCC. These concurrent factors contribute to tumor heterogeneity, suggesting that epi-immunotherapy could be an efficient alternative to treat OSCC.

Ki-67 Expression as a Prognostic Marker: A Comparative Immunohistochemical Analysis of Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma

Introduction Oral dysplasia is a frequent precancerous condition that may lead to oral cancer. The histopathologic abnormalities exhibited in a chronic, progressive, and premalignant condition of the oral mucosa are referred to as oral epithelial dysplasia (OED). It might show up as erythroplakia, leukoplakia, or leukoerythroplakia. OED is a premalignancy histologic marker that predicts a higher likelihood of squamous cell carcinoma development. Aims and objectives The aim of this study is to identify an association between Ki-67 protein expression and histological grading of OED and oral squamous cell carcinoma (OSCC) and to compare the expression of Ki-67 in different grades of OED and OSCC with the prognosis. Materials and methods The current retrospective research is focused on evaluating epithelial dysplasia and analyzing the function of Ki-67 as a prognostic marker after receiving institutional ethical approval. Group I - normal oral mucosa (NOM), Group II - OED, and Group III - OSCC were included in the study. For statistical analysis, SPSS Statistics version 21.0 (IBM Corp. Released 2021. IBM SPSS Statistics for Windows, Version 28.0. Armonk, NY: IBM Corp) was utilized. The Cox regression model was employed to look at interactions between various prognostic variables. At p<0.05, differences were deemed statistically significant. Results Ki-67 expression was confined to the basal layers in the normal oral epithelium and in the basal, suprabasal, and spinous layers in OED. Ki-67 positive cells were mostly found on the perimeter of well, moderate, and poorly differentiated OSCC tumor nests with Ki-67 positive cells scattered throughout OSCC. According to statistical analysis, there is a substantial difference in expression between OED and NOM, OSCC and NOM, and OED and OSCC. Conclusion Our study showed that there is a progressive increase in Ki-67 expression across various grades of OED, and the highest expression was noted in OSCC. Early identification and prompt treatment will help in improving the quality of life of such patients.

Exosomics in oral cancer diagnosis, prognosis, and therapeutics - An emergent and imperative non-invasive natural nanoparticle-based approach

Exosomes- the natural nanoparticles belonging to heterogeneous vesicles are released via nearly all sorts of cells, including tumour cells, to oprate intercellular communication. Selective packaging of exosomes amid nucleic acids, phospholipids, and proteins makes them ideal for intercellular communications occurring among different cells. The existence of exosomes has been validated in various biofluids, including saliva. Being non-invasive and in direct contact with oral malignant cells, saliva establishes itself as a preeminent source of early cancer biomarkers. In context, the role and providence of both recipient and donor secreting cells are persuaded through exosomal cargo.Several studies have emphasized the influence of exosomal contents in different stages of cancer development, reconciling interactions between tumour cells and their surrounding niche. More explicitly, a transformation of exosomal contents such as nucleic acids, lipids, and proteins can endorse tumour progression and help ascertain a secluded pre-metastatic niche crammed with substances that errand cancer cell proliferation,angiogenesis, metastasis, and drug resistance. The blooming field of exosomes has directed the evolution of high-end isolation and characterization techniques along with the development of an entirely new field- exosomics that comprises complete analysis of exosomal cargo in various physiological conditions, including oral cancer. Researchers have discovered multiple pathways involved in exosome biogenesis to understand numerous events associated with cancer progression. Tissue-specific packaging of exosomes makes them a novel source of prognostic and diagnostic biomarkers and potential therapeutic targets. The extent of the current review confers the contemporary perception of the versatile task of exosomes, especially salivary exosomes, as potential biomarkers in the progression and diagnosis as well as therapeutics of oral cancers and their potential employment in clinical applications.

Liquid Biopsy in Squamous Cell Carcinoma of the Esophagus and of the Head and Neck

Squamous cell carcinomas of the esophagus (ESCC) and of the head and neck (HNSCC) are two neoplasms that share common risk factors and have the same embryological origin, but a very different prognosis, the 5-year survival of HNSCC being almost double (40–50%) compared to the 5-year survival of ESCC (20%). Current guidelines emphasize the importance of screening for ESCC in patients diagnosed with head and neck cancers. A liquid biopsy is a novel tool for diagnosis, prognostic stratification, and personalized therapy. Liquid biopsy biomarkers for these two malignancies could help both their early detection, facilitate residual disease identification, and provide prognosis information. The present systematic review of the literature was aimed at describing the liquid biopsy biomarkers present in these two malignancies, with an emphasis on potential clinical applications.

Molecular drivers of oral cavity squamous cell carcinoma in non-smoking and non-drinking patients: what do we know so far?

Oral cavity squamous cell carcinoma (OCSCC) is one of the most common head and neck cancers worldwide. It is well known that risk factors for OCSCC include tobacco and excess alcohol consumption. However, in recent years, OCSCC incidence has been increasing in patients without these traditional risk factors. The cause of this increase is unclear and various genetic, environmental, and infectious factors have been hypothesized to play a role. Additionally, there are expert opinions that oral cancer in non-smoking, non-drinking (NSND) patients have a distinct phenotype resulting in more aggressive disease presentation and poorer prognosis. In this review, we summarize the current state of knowledge for oral cavity cancer in patients without traditional risk factors.

Identification of Candidate Target Genes and Immune Cells in Oral Squamous Cell Carcinoma

Background

The advance of new treatment strategies for more effective management of oral cancer requires identification of novel biological targets. Therefore, the purpose of this study is to identify novel biomarkers associated with oral tumorigenesis and prognostic signature by comparing gene expression profile of oral squamous cell carcinomas (OSCCs).

Methods

Four datasets including GSE25099, GSE30784, GSE37991, and GSE41613 were collected from Gene Expression Omnibus (GEO) database. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, Cox model analysis, identification of key genes, and Kaplan-Meier analysis were also performed. The xCell was utilized to analyze the infiltration levels of immune cells.

Results

A total of 235 differentially expressed genes (DEGs) were found to be dysregulated in OSCC. These genes were mainly enriched in ECM receptor interaction and focal adhesion. Cox regression analysis identified 10 genes considered as key genes. Kaplan-Meier analysis showed that low expression of SERPINE1 (also known as PAI-1), high expression of CD1C, and C-X3-C motif chemokine receptor 1 (CX3CR1) were associated with well prognostic status in OSCC patients. In addition, we constructed a 3-immune-cell signature (myeloid dendritic cell, T cell CD4⁺ central memory, and common myeloid progenitor) that may be used to predict the survival status of OSCC patients.

Conclusion

Three key genes and 3-immune-cell signature were potential biomarkers for the prognosis of OSCC, and they may serve as potential targets for the treatment of OSCC patients.

Molecular landscape of head and neck cancer and implications for therapy

Head and neck squamous cell carcinomas (HNSCC) arising from the oral cavity, pharynx, and larynx constitute the 6^th most common human cancer. Human papillomavirus (HPV)-positive tumours are distinct from HPV-negative counterparts, with HPV status affording clear clinical utility, prognostic benefit and better treatment outcomes. In contrast to their HPV-positive counterparts, HPV-negative tumours are characterized by high mutational load and chromosomal aberrations, with varying copy number alteration (CNA) profiles. HNSCC are distinct tumours at the chromosomal, gene and expression levels, with additional insight gained from immune profiling. Based on mutational analyses, HNSCC are categorized as HPV-positive, HPV-negative CNA-silent, and HPV-negative CNA-high tumours. Furthermore, gene expression profiling segregates these tumours into atypical, classical, basal, and mesenchymal, with clear differences observed between tumours of the oral cavity, oropharynx, hypopharynx and larynx. Additional immune profiling further classifies tumours as either immune-active or immune-exhausted. The clinical utility and impact of these tumour molecular subtypes however remains to be determined. HNSCC harbor high levels of somatic mutations. They display loss at 3p and 18q and gain at 3q and 8q, with mutations in CDKN2A, TP53, CCND1, EGFR, PIK3CA, PTEN, NOTCH1, NSD1, FAT1, AJUBA and KMT2D. Important pathways include the p53 and RB pathways which are involved in cell cycle control and are frequently lost in HPV-negative tumours, the WNT-β-catenin pathway related to the mesenchymal subtype and smoking etiology, and the PI3K pathway which includes the most common genetic alteration in HPV-positive HNSCC. Understanding the mutational, genomic and transcriptomic landscape of HNSCC has leveraged better therapeutic approaches to manage this group of diseases, and it is hoped that additional insight into the molecular subtypes of HNSCC and its specific subsites will further drive improved strategies to stratify and treat patients with this debilitating disease.

Contribution of Genomics to the Surgical Management and Study of Oral Cancer

Background

Oral squamous cell carcinoma (OSCC) is the most frequent type of tumor arising from the oral cavity. Surgery is the cornerstone of the treatment of these cancers. Tumor biology has long been overlooked as an important contributor to the outcome of surgical procedures, but recent studies are challenging this concept. Molecular analyses of tumor DNA or RNA provide a rich source of information about the biology of OSCC.

Methods

We searched for relevant articles using PubMed. We examined in particular the prospect of applying molecular methods for minimally invasive exploration of OSCC biology.

Results

We examined five potential applications of genomics to the surgical management and study of OSCC: i) assessing oral potentially malignant lesions; ii) tumor staging prior to surgery; iii) predicting postoperative risk in locally advanced tumors; iv) measuring minimal residual disease and optimizing the longitudinal monitoring of OSCC; and v) predicting the efficacy of medical treatment.

Conclusions

Genomic information can be harnessed in order to identify new biomarkers that could improve the staging, choice of therapy and management of OSCC. The identification of new biomarkers is awaited for better personalization of the surgical treatment of OSCC.

Preclinical Evaluation of the Association of the Cyclin-Dependent Kinase 4/6 Inhibitor, Ribociclib, and Cetuximab in Squamous Cell Carcinoma of the Head and Neck

Simple Summary

We previously showed that ribociclib induces cell cycle arrest in some human papillomavirus (HPV)-negative squamous cell carcinomas of the head and neck (SCCHN) models. However, in vivo, ribociclib has only a cytostatic effect, suggesting that its activity needs to be optimized in combination with other treatments. We investigated the activity of ribociclib in combination with cetuximab in several HPV-negative SCCHN patient-derived tumor xenograft (PDTX) models. We found that the combination of cetuximab and ribociclib was not significantly more active than cetuximab monotherapy. In addition, our observations also suggest that the combination of cetuximab with a cyclin-dependent kinase (CDK) 4/6 inhibitor may reduce the activity of the CDK4/6 inhibitor in some cetuximab-resistant models. Our work has significant clinical implications since combinations of anti-epidermal growth factor receptor (EGFR) therapy and CDK4/6 inhibitors are currently being investigated in clinical trials.

Abstract

Epidermal growth factor receptor (EGFR) overexpression is observed in 90% of human papillomavirus (HPV)-negative squamous cell carcinomas of the head and neck (SCCHN). Cell cycle pathway impairments resulting in cyclin-dependent kinase (CDK) 4 and 6 activation, are frequently observed in SCCHN. We investigated the efficacy of ribociclib, a CDK4/6 inhibitor, in combination with cetuximab, a monoclonal antibody targeting the EGFR, in HPV-negative SCCHN patient-derived tumor xenograft (PDTX) models. The combination of cetuximab and ribociclib was not significantly more active than cetuximab monotherapy in all models investigated. In addition, the combination of cetuximab and ribociclib was less active than ribociclib monotherapy in the cetuximab-resistant PDTX models. In these models, a significant downregulation of the retinoblastoma (Rb) protein was observed in cetuximab-treated mice. We also observed Rb downregulation in the SCCHN cell lines chronically exposed and resistant to cetuximab. In addition, Rb downregulation induced interleukin 6 (Il-6) secretion and the Janus kinase family member/signal transducer and activator of transcription (JAK/STAT) pathway activation that might be implicated in the cetuximab resistance of these cell lines. To conclude, cetuximab is not an appropriate partner for ribociclib in cetuximab-resistant SCCHN models. Our work has significant clinical implications since the combination of anti-EGFR therapy with CDK4/6 inhibitors is currently being investigated in clinical trials.

Possible applications of salvianolic acid B against different cancers

Cancer is the second death causing disease worldwide after cardiovascular abnormalities. The difficulty in treating tumor cells with more precise targeted interventions and recurrence of cancer after treatment may pose great difficulty in developing sustainable therapeutic regimens. These limitations have prompted the need to explore several compounds with ability to cease tumor growth while at the same time induce apoptosis of tumor cells. Several studies have emphasized the use of natural compounds as antitumor agents due to their high efficacy against cancer cells and low toxicity in normal cells. Salvianolic acid B (SAB), a naturally occurring phenolic compound extracted from the radix of Chinese herb Salvia miltiorrhiza can induce apoptosis in different types of tumor cells. It can be used to treat cardiovascular and neurodegenerative disorders, hepatic fibrosis, and cancers. Several studies have shown that SAB can mitigate tumorigenesis by modulating MAPK, PI3K/AKT, and NF-ĸB signaling pathways. It also sensitizes the tumor cells to different anti-cancer agents by reversing the multi-drug resistance mechanisms found in tumor cells. This review summarizes the studies showing antitumor potential of SAB in different types of cancer cell lines, animal models and highlights the possible mechanisms through which SAB can induce apoptosis, inhibit growth and metastasis in tumor cells. Moreover, the possible role of nano-technological approaches to induce targeted delivery of SAB to eradicate tumor cells has been also discussed.

Gene expression analysis of autofluorescence margins in leukoplakia and oral carcinoma: A pilot study

OBJECTIVES

Autofluorescence is considered a useful technique in the early detection of oral mucosal alterations. However, its efficacy to discriminate tumor margins is still under debate. The purpose of this pilot study was to confirm the existence of molecular divergence from the center of a lesion compared to white light and autofluorescence (VELscope^TM ) visualized margins in leukoplakia and oral carcinoma.

MATERIALS AND METHODS

Molecular divergence from the center of the lesion to white light and VELscope^TM defined margins was compared in patients with leukoplakia (n = 3) and oral carcinoma (n = 4). Expression profiling of 45 selected genes was performed through custom-made TaqMan arrays. Gene Ontology was used for biological pathway analysis.

RESULTS

Irrespective of pathology, the greatest molecular divergence existed between the center of the lesion and both white light and VELscope^TM margins. VELscope^TM and white light margins were also molecularly distinct in oral carcinoma samples. Indeed, the white light margin retained molecular abnormalities observed in the center of the lesion thus suggesting the existence of a "partially transformed" cell population.

CONCLUSION

Despite the limited low number of patients, our data confirm the benefit of combining autofluorescence with conventional oral examination in identifying surgical margins during biopsy procedures for leukoplakia and oral carcinoma.