Prognostic and Clinicopathological Significance of the Aberrant Expression of β-Catenin in Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

WNT3 promotes chemoresistance to 5-Fluorouracil in oral squamous cell carcinoma via activating the canonical β-catenin pathway

BACKGROUND

5-Fluorouracil (5FU) is a primary chemotherapeutic agent used to treat oral squamous cell carcinoma (OSCC). However, the development of drug resistance has significantly limited its clinical application. Therefore, there is an urgent need to determine the mechanisms underlying drug resistance and identify effective targets. In recent years, the Wingless and Int-1 (WNT) signaling pathway has been increasingly studied in cancer drug resistance; however, the role of WNT3, a ligand of the canonical WNT signaling pathway, in OSCC 5FU-resistance is not clear. This study delved into this potential connection.

METHODS

5FU-resistant cell lines were established by gradually elevating the drug concentration in the culture medium. Differential gene expressions between parental and resistant cells underwent RNA sequencing analysis, which was then substantiated via Real-time quantitative PCR (RT-qPCR) and western blot tests. The influence of the WNT signaling on OSCC chemoresistance was ascertained through WNT3 knockdown or overexpression. The WNT inhibitor methyl 3-benzoate (MSAB) was probed for its capacity to boost 5FU efficacy.

RESULTS

In this study, the WNT/β-catenin signaling pathway was notably activated in 5FU-resistant OSCC cell lines, which was confirmed through transcriptome sequencing analysis, RT-qPCR, and western blot verification. Additionally, the key ligand responsible for pathway activation, WNT3, was identified. By knocking down WNT3 in resistant cells or overexpressing WNT3 in parental cells, we found that WNT3 promoted 5FU-resistance in OSCC. In addition, the WNT inhibitor MSAB reversed 5FU-resistance in OSCC cells.

CONCLUSIONS

These data underscored the activation of the WNT/β-catenin signaling pathway in resistant cells and identified the promoting effect of WNT3 upregulation on 5FU-resistance in oral squamous carcinoma. This may provide a new therapeutic strategy for reversing 5FU-resistance in OSCC cells.

Biological biomarkers of oral cancer

The oral squamous cell carcinoma (OSCC) 5 year survival rate of 41% has marginally improved in the last few years, with less than a 1% improvement per year from 2005 to 2017, with higher survival rates when detected at early stages. Based on histopathological grading of oral dysplasia, it is estimated that severe dysplasia has a malignant transformation rate of 7%-50%. Despite these numbers, oral dysplasia grading does not reliably predict its clinical behavior. Thus, more accurate markers predicting oral dysplasia progression to cancer would enable better targeting of these lesions for closer follow-up, especially in the early stages of the disease. In this context, molecular biomarkers derived from genetics, proteins, and metabolites play key roles in clinical oncology. These molecular signatures can help predict the likelihood of OSCC development and/or progression and have the potential to detect the disease at an early stage and, support treatment decision-making and predict treatment responsiveness. Also, identifying reliable biomarkers for OSCC detection that can be obtained non-invasively would enhance management of OSCC. This review will discuss biomarkers for OSCC that have emerged from different biological areas, including genomics, transcriptomics, proteomics, metabolomics, immunomics, and microbiomics.

Prognostic Significance of β-Catenin in Relation to the Tumor Immune Microenvironment in Oral Cancer

The aim of this study was to investigate the prognostic relevance of β-catenin expression in oral squamous cell carcinoma (OSCC) and to explore relationships with the tumor immune microenvironment. Expression of β-catenin and PD-L1, as well as lymphocyte and macrophage densities, were evaluated by immunohistochemistry in 125 OSCC patient specimens. Membranous β-catenin expression was detected in 102 (81.6%) and nuclear β-catenin in 2 (1.6%) tumors. There was an association between β-catenin expression, tumoral, and stromal CD8+ T-cell infiltration (TIL) and also the type of tumor immune microenvironment (TIME). Tumors harboring nuclear β-catenin were associated with a type II TIME (i.e., immune ignorance defined by a negative PD-L1 expression and low CD8+ TIL density), whereas tumors with membranous β-catenin expression were predominantly type IV (i.e., immune tolerance defined by negative PD-L1 and high CD8+ TIL density). Combined, but not individual, high stromal CD8+ TILs and membranous β-catenin expression was independently associated with better disease-specific survival (HR = 0.48, p = 0.019). Taken together, a combination of high stromal CD8+ T-cell infiltration and membranous β-catenin in the tumor emerges as an independent predictor of better survival in OSCC patients.

Prognostic and Clinicopathological Significance of Epidermal Growth Factor Receptor (EGFR) Expression in Oral Squamous Cell Carcinoma: Systematic Review and Meta-Analysis

The aim of this systematic review and meta-analysis was to evaluate the current evidence in relation to the clinicopathological and prognostic significance of epidermal growth factor receptor (EGFR) overexpression in patients with oral squamous cell carcinoma (OSCC). We searched MEDLINE/PubMed, Embase, Web of Science, and Scopus for studies published before November 2022. We evaluated the quality of primary-level studies using the QUIPS tool, conducted meta-analyses, examined inter-study heterogeneity via subgroup analyses and meta-regressions, and performed small-study effects analyses. Fifty primary-level studies (4631 patients) met the inclusion criteria. EGFR overexpression was significantly associated with poor overall survival (hazard ratio [HR] = 1.38, 95% confidence intervals [CI] = 1.06-1.79, p = 0.02), N+ status (odds ratio [OR] = 1.37, 95%CI = 1.01-1.86, p = 0.04), and moderately-poorly differentiated OSCC (OR = 1.43, 95% CI = 1.05-1.94, p = 0.02). In addition, better results were obtained by the application of a cutoff point ≥10% tumor cells with EGFR overexpression (p < 0.001). In conclusion, our systematic review and meta-analysis supports that the immunohistochemical assessment of EGFR overexpression may be useful as a prognostic biomarker for OSCC.

Immunohistochemical Expression of E-Cadherin and β-Catenin in Oral Squamous Cell Carcinoma

Background

The E-cadherin/β-catenin protein complexes are actively involved in the epithelial-to-mesenchymal transition. Alterations in cadherin or catenin expression or function, play important roles in the development of invasive or metastatic phenotypes of cancers.

Objectives

The aim of this study was to assess the expression of E-cadherin and β-catenin in oral squamous cell carcinoma (OSCC) patients and to compare this with their clinico-pathological parameters.

Materials and Methods

This was a cross-sectional study to assess the immunohistochemical expression of E-cadherin and β-catenin in 41 cases of OSCC. Data were analyzed using version 26 of SPSS software. Qualitative data were compared using chi-square statistics. Quantitative data were summarized using mean, standard deviation, and confidence interval and compared using a one-way analysis of variance test. The level of significance was set at P < 0.05.

Results

Overall, 95.1% of the cases had positive membrane expression for E-cadherin, while cytoplasmic staining was seen in 90.2% cases. Positive nuclear staining was seen in 46.3% cases. There was a decrease in the percentage of cytoplasmic and nuclear expression of E-cadherin as the OSCC became more poorly differentiated (χ2 = 13.96, P = 0.016). Also, a decrease in the percentage of nuclear expression of β-catenin in poorly differentiated cases was seen. However, no statistically significant difference was seen in the expression of β-catenin between the different histologic grades (χ2 = 4.8, P = 0.4).

Conclusion

This study shows a reduction in the expression of E-cadherin and β-catenin as OSCC becomes less differentiated.

Prognostic and Clinicopathological Significance of the Loss of Expression of Retinoblastoma Protein (pRb) in Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aims to evaluate the scientific evidence on the implications of retinoblastoma protein (pRb) alterations in oral cancer, in order to determine its prognostic and clinicopathological significance. PubMed, Embase, Web of Science, and Scopus were searched for studies published before February 2022, with no restrictions by publication date or language. The quality of the studies using the Quality in Prognosis Studies tool (QUIPS tool). Meta-analysis was conducted to achieve the proposed objectives, as well as heterogeneity, subgroup, meta-regression, and small study-effects analyses. Twenty studies that met the inclusion criteria (2451 patients) were systematically reviewed and meta-analyzed. Our results were significant for the association between the loss of pRb expression and a better overall survival (HR = 0.79, 95%CI = 0.64-0.98, p = 0.03), whereas no significant results were found for disease-free survival or clinico-pathological parameters (T/N status, clinical stage, histological grade). In conclusion, our evidence-based results demonstrate that loss of pRb function is a factor associated with improved survival in patients with OSCC. Research lines that should be developed in the future are highlighted.

Clinicopathological and prognostic value of chemokine receptor CCR7 expression in head and neck squamous cell carcinoma: a systematic review and meta-analysis

OBJECTIVES

This study aimed to identify the clinicopathological characteristics and prognostic value of CC chemokine receptor 7 (CCR7) expression in patients with head and neck squamous cell carcinoma (HNSSC).

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed in this meta-analysis. Up to the 2^nd of July 2022 a search was conducted using five databases: PubMed, Embase, Scopus, ProQuest, and Web of Science. The methodological standards for the epidemiological research scale were used to assess the quality of the included articles, and Stata software was used to synthesise the meta-analysis.

RESULTS

We considered 13 of the 615 studies which included 1005 HNSCC patients. High expression of CCR7 increased the pooled odds ratio (OR) of advanced stage, tumour size, metastasis and recurrence by 2.82 [95% confidence interval (CI) 1.84 to 4.33], 2.48 (95% CI 1.68, to 3.67), 3.57, 95% CI 2.25 to 5.05) and 3.93 (95% CI 2.03 to 7.64), respectively. High CCR7 reduced overall patient survival [hazard ratio 2.62 (95% CI 1.59 to 4.32)].

CONCLUSION

This study showed that high expression of CCR7 in HNSCC tumours was significantly associated with worse clinicopathological and survival outcomes, suggesting that CCR7 and its pathway could be potential therapeutic strategies for HNSCC.

FOXM1 is regulated by DEPDC1 to facilitate development and metastasis of oral squamous cell carcinoma

The Disheveled, EGL-10, Pleckstrin domain containing 1 (DEPDC1) is a new oncogene that has recently been described. The mechanisms and functions of its expression are yet to be determined in oral squamous cell carcinoma (OSCC). In the present study, the impact of DEPDC1 on the growth and development of OSCC was investigated using animal models, cell lines and human tissue samples. Elevated DEPDC1 expression within cancer cell lines and human OSCC has been identified. Mechanistic examination showed that restored DEPDC1 expression in vivo and in vitro stimulated OSCC tumour development. In addition, FOXM1 interacts with DEPDC1 as indicated by co-immunoprecipitation and immunofluorescence testing. Functionally, DEPDC1 facilitated Wnt/β-catenin signal transduction and β-catenin protein nuclear expression. In summary, the DEPDC1, interacting with FOXM1 via Wnt/β-catenin signaling, the closely regulated OSCC pathogenesis, suggesting that targeting the novel DEPDC1/FOXM1/β-catenin complex is an essential OSCC therapeutic approach.

Hallmarks of Cancer Applied to Oral and Oropharyngeal Carcinogenesis: A Scoping Review of the Evidence Gaps Found in Published Systematic Reviews

Simple Summary

This scoping review of systematic reviews aims to accurately assess the degree of existing scientific evidence on the cancer hallmarks proposed in 2011 by Hanahan and Weinberg, in the form of systematic reviews and meta-analyses, applied to oral potentially malignant disorders, oral cavity and oropharyngeal squamous cell carcinomas, in order to point out gaps in evidence and lines of research that should be implemented in the future to improve the malignant transformation prediction, diagnosis and/or prognosis of these diseases.

Abstract

In 2000 and 2011, Hanahan and Weinberg published two papers in which they defined the characteristics that cells must fulfil in order to be considered neoplastic cells in all types of tumours that affect humans, which the authors called “hallmarks of cancer”. These papers have represented a milestone in our understanding of the biology of many types of cancers and have made it possible to reach high levels of scientific evidence in relation to the prognostic impact that these hallmarks have on different tumour types. However, to date, there is no study that globally analyses evidence-based knowledge on the importance of these hallmarks in oral and oropharyngeal squamous cell carcinomas. For this reason, we set out to conduct this scoping review of systematic reviews with the aim of detecting evidence gaps in relation to the relevance of the cancer hallmarks proposed by Hanahan and Weinberg in oral and oropharyngeal cancer, and oral potentially malignant disorders, and to point out future lines of research in this field.

Prognostic and Clinicopathological Significance of Telomerase Reverse Transcriptase Upregulation in Oral Cancer: A Systematic Review and Meta-Analysis

The aim of this systematic review and meta-analysis was to evaluate the current evidence on the prognostic and clinicopathological significance value of telomerase reverse transcriptase (TERT) upregulation in patients with oral squamous cell carcinoma (OSCC). PubMed, Embase, Web of Science, and Scopus were searched for studies published before April 2022, not restricted by date or publication language. The methodological quality of primary-level studies was critically assessed using the Quality in Prognosis Studies (QUIPS) tool. We carried out meta-analyses, explored heterogeneity and its sources, and performed subgroup, meta-regression, sensitivity, and small-study effects analyses. Twenty-one studies (1698 patients) met inclusion criteria. TERT protein overexpression was significantly associated with worse overall survival (hazard ratio [HR] = 3.01, 95% CI = 1.70−5.35, p < 0.001), disease-free survival (HR = 4.03, 95% CI = 1.80−9.05, p = 0.001), and higher histological grade OSCC (odds ratio [OR] = 3.20, 95% CI = 1.83−5.62, p < 0.001). These large effect sizes were consistently obtained by homogeneous subgroups (p > 0.10, I2 = 0.0, respectively), which reflects a high quality of evidence. On the other hand, TERT gene mutations obtained constantly nonsignificant null effect sizes for all outcomes investigated, evidencing no prognostic or clinicopathological value. In conclusion, our findings indicate that TERT upregulation is a prognostic indicator of poor survival in oral cancer. Our findings support the immunohistochemical assessment of TERT overexpression, which could probably be incorporated into the prognostic evaluation of OSCC.

Temporal Bone Squamous Cell Carcinoma: Molecular Markers Involved in Carcinogenesis, Behavior, and Prognosis: A Systematic Review

Temporal bone squamous cell carcinoma (TBSCC) is an uncommon malignancy with a poor prognosis in advanced cases. The dismal outcome of advanced TBSSC cases is largely due to the cancer’s local aggressiveness and the complex anatomy of this region, as well as to persistent pitfalls in diagnosis and treatment. Molecular changes occur in malignancies before any morphological changes become visible, and are responsible for the disease’s clinical behavior. The main purpose of this critical systematic review is to assess the level of knowledge on the molecular markers involved in the biology, behavior, and prognosis of TBSCC. A search (updated to March 2022) was run in PubMed, Scopus, and Web of Science electronic databases without publication date limits for studies investigating molecular markers in cohorts of patients with primary TBSCC. The search terms used were: “temporal bone” OR “external auditory canal” OR “ear”, AND “cancer” OR “carcinoma” OR “malignancy”. We preliminarily decided not to consider series with less than five cases. Twenty-four case series of TBSCC were found in which different analytical techniques had been used to study the role of several biomarkers. In conclusion, only very limited information on the prognostic role of molecular markers in TBSCC are currently available; prospective, multi-institutional, international prognostic studies should be planned to identify the molecular markers involved in the clinical behavior and prognosis of TBSCC. A further, more ambitious goal would be to find targets for therapeutic agents able to improve disease-specific survival in patients with advanced TBSCC.