Immunohistochemical expression of p16 protein in oral squamous cell carcinoma and lichen planus

A Molecular Hypothesis on Malignant Transformation of Oral Lichen Planus: A Systematic Review and Meta-Analysis of Cancer Hallmarks Expression in This Oral Potentially Malignant Disorder

We aimed to qualitatively and quantitatively analyze, through a systematic review and meta-analysis, the current evidence on the differential expression of the hallmarks of cancer in oral lichen planus (OLP) samples, in order to know the earliest molecular mechanisms that could be involved in the malignant transformation of this oral potentially malignant disorder. We searched MEDLINE/PubMed, Embase, Web of Science, and Scopus for studies published before November 2023. We evaluated the methodological quality of studies and carried out meta-analyses to fulfill our objectives. Inclusion criteria were met by 110 primary-level studies, with 7065 OLP samples, in which the expression of 104 biomarkers were analyzed through immunohistochemistry. Most OLP samples showed sustained cell proliferation signaling (65.48%, 95%CI = 51.87-78.02), anti-apoptotic pathways (55.93%, 95%CI = 35.99-75.0), genome instability (48.44%, 95%CI = 13.54-84.19), and tumor-promoting inflammation events (83.10%, 95%CI = 73.93-90.74). Concurrently, OLP samples also harbored tumor growth suppressor mechanisms (64.00%, 95%CI = 53.27-74.12). In conclusion, current evidence indicates that molecular mechanisms promoting hyperproliferative signaling, an antiapoptotic state with genomic instability, and an escape of epithelial cells from immune destruction, are developed in LP-affected oral mucosa. It is plausible that these events are due to the actions exerted by the chronic inflammatory infiltrate. Malignant transformation appears to be prevented by tumor suppressor genes, which showed consistent upregulation in OLP samples.

Prognostic value of CD44 expression in oral squamous cell carcinoma: A meta-analysis

CD44 as a marker of cancer stem cells (CSCs) may be correlated with tumor growth, cell migration, metastasis and chemo-radiotherapy resistance of cancers. However, the prognostic value of CD44 in oral squamous cell carcinoma(OSCC) remains controversial. Therefore, the purpose of the current study was to evaluate the correlation of CD44 expression with the prognosis of OSCC through a meta-analysis. We systematically searched PubMed, Scopus, ISI Web of Science, Embase and Cochrane Central databases for relevant studies up to November 2022. We included 11 articles with immunohistochemistry (IHC) method involving 1084 OSCC patients. Hazard ratios (HRs) with 95 % confidence intervals (95 % CIs) were calculated to assess the association between CD44 expression and overall survival (OS) and disease-free survival (DFS). Results showed that high expression of CD44 was a poor prognostic marker for OS in OSCC patients (HR: 1.71, 95 % CI: 1.18-2.47). Also results for DFS demonstrated that in patients with high CD44 expression who received treatment, the probability of tumor recurrence or death was 1.66 times and in the worst case this ratio can reach 2.39 (HR: 1.66, 95 % CI: 1.15-2.39). High CD44 expression associated with metastasis to lymph nodes and distant metastasis, poorer survival of the patients, tumor recurrence, higher tumor stage and grade and aggressive clinicopathological features. Therefore CD44 can be used as a valuable independent marker in predicting the prognosis of OSCC patients.

Oral squamous cell carcinomas: state of the field and emerging directions

Oral squamous cell carcinoma (OSCC) develops on the mucosal epithelium of the oral cavity. It accounts for approximately 90% of oral malignancies and impairs appearance, pronunciation, swallowing, and flavor perception. In 2020, 377,713 OSCC cases were reported globally. According to the Global Cancer Observatory (GCO), the incidence of OSCC will rise by approximately 40% by 2040, accompanied by a growth in mortality. Persistent exposure to various risk factors, including tobacco, alcohol, betel quid (BQ), and human papillomavirus (HPV), will lead to the development of oral potentially malignant disorders (OPMDs), which are oral mucosal lesions with an increased risk of developing into OSCC. Complex and multifactorial, the oncogenesis process involves genetic alteration, epigenetic modification, and a dysregulated tumor microenvironment. Although various therapeutic interventions, such as chemotherapy, radiation, immunotherapy, and nanomedicine, have been proposed to prevent or treat OSCC and OPMDs, understanding the mechanism of malignancies will facilitate the identification of therapeutic and prognostic factors, thereby improving the efficacy of treatment for OSCC patients. This review summarizes the mechanisms involved in OSCC. Moreover, the current therapeutic interventions and prognostic methods for OSCC and OPMDs are discussed to facilitate comprehension and provide several prospective outlooks for the fields.

Comparison of Immunohistochemical Markers in Oral Submucous Fibrosis and Oral Submucous Fibrosis Transformed to Oral Squamous Cell Carcinoma-A Systematic Review and Meta-Analysis

The objective of the study was to compare the expression of immunohistochemical (IHC) markers of oral submucous fibrosis (OSMF) (non-transformed group) to those of oral squamous cell carcinoma (OSCC) transformed from OSMF (transformed group). The search for comparative cross-sectional studies was carried out in PubMed and Scopus abiding to the PICO criteria, where expression of IHC markers in OSMF were compared with that of OSCC transformed from OSMF. The cellular distribution, number of positive cases, staining intensity, and mean immunoreactive score (IRS) of each IHC marker were evaluated in both groups. A total of 14 studies were included in the systematic review, in which immunoexpression of 15 epithelial and 4 connective tissue biomarkers were evaluated. Expression of β1-integrin, OCT-3, CD1a, CD207, survivin, Dickkopf-1, COX-2, hTERT, CTGF, MDM2, Ki-67, and α-SMA were increased during transformation of OSMF to OSCC. Conversely, expression of PTEN and lysyl oxidase decreased during transformation of OSMF to OSCC. Expression of a group of epithelial markers, such as COX2, hTERT, CTGF, survivin, MDM2, and p53, was 38 times lower in the non-transformed group cases compared to transformed group cases (95% CI: 58% to 10%; p = 0.01; and I² = 90%). Meta-analysis of all markers involved in cell metabolism/apoptosis, which included β1-integrin along with the above markers also suggested 42 times lower expression in the non-transformed group as compared to the transformed group (95% CI: 58% to 10%; p = 0.01; and I² = 90%). Sub-group analyses on cytoplasmic and nuclear epithelial markers were inconclusive. Meta-analysis of connective tissue markers was also inconclusive. No publication bias was found. Instead of delving into numerous markers without a strong basis for their use, it is advisable to further study the markers identified in this study to explore their clinical utility.

Worst Pattern of Invasion as a Predictor of Nodal Metastasis in Early-Stage Oral Squamous Cell Carcinoma

About one-third of early stage oral cancer patients have occult nodal metastasis. High grade worst pattern of invasion (WPOI) is associated with an increased risk of nodal metastasis and poor prognosis. However, it still remains unanswered whether to perform an elective neck dissection for clinically node-negative disease or not. This study aims to evaluate the role of histological parameters including WPOI in predicting nodal metastasis in early-stage oral cancers. This analytical observational study comprised 100 patients of early-stage, node-negative, oral squamous cell carcinoma, admitted in the Surgical Oncology Department from April, 2018 till the sample size was reached. The socio-demographic data, clinical history, and findings of clinical and radiological examination were noted. The association of nodal metastasis with various histological parameters like tumour size, degree of differentiation, depth of invasion (DOI), WPOI, perineural invasion (PNI), lymphovascular invasion (LVI) and lymphocytic response was determined. SPSS 20.0 statistical tool; student's 't' test and chi-square tests were applied. While the buccal mucosa was the commonest site, the rate of occult metastasis was highest in the tongue. Nodal metastasis was not significantly associated with age, sex, smoking and primary site. While the nodal positivity was not significantly associated with tumour size, pathological stage, DOI, PNI and lymphocytic response, it was associated with LVI, degree of differentiation and WPOI. Increasing WPOI grade correlated significantly with the nodal stage, LVI and PNI, but not with DOI. WPOI is not only a significant predictor of occult nodal metastasis but can also be a novel therapeutic tool in the management of early-stage oral cancers. In patients with an aggressive WPOI pattern or other high-risk histological parameters, the neck can be addressed with either elective neck dissection or radiotherapy after wide excision of the primary tumor; otherwise, an active surveillance approach can be followed.

Expression Profiles of CDKN2A, MDM2, E2F2 and LTF Genes in Oral Squamous Cell Carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is one of the most commonly detected neoplasms worldwide. Not all mechanisms associated with cell cycle disturbances are known in OSCC. Examples of genes involved in the control of the cell cycle are CDKN2A, MDM2, E2F2 and LTF. The aim of this study was to examine the possible association between CDKN2A, MDM2, E2F2 and LTF mRNA expression and influence on clinical variables.

METHODS

The study group consisted of 88 Polish patients. The gene expression levels were assessed by quantitative reverse transcription PCR.

RESULTS

We found no statistically significant differences in the expression level of CDKN2A, MDM2, E2F2 and LTF genes in tumour samples compared to margin samples. No association was found between the gene expression levels and clinical parameters, except E2F2. The patients with G2 tumours had a significantly higher gene expression level of E2F2 than patients with low-grade G1 tumours.

CONCLUSIONS

We have not demonstrated that a change in expression profiles of genes has a significant impact on the pathogenesis of OSCC. It may also be useful to conduct further studies on the use of E2F2 expression profile changes as a factor to describe the invasiveness and dynamics of OSCC development.

The genomic and proteomic landscape in oral lichen planus versus oral squamous cell carcinoma: a scoping review

BACKGROUND

Oral lichen planus (OLP), a World Health Organization (WHO)-classified oral potentially malignant condition, confers a 1% risk of transformation to oral squamous cell carcinoma (OSCC). There does not appear to be a consensus understanding of the underlying molecular events. This scoping review aimed to identify critical molecular pathways and highlight gaps in existing knowledge on malignant transformation in OLP.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) guidelines, a comprehensive literature search and methodical screening identified 61 relevant studies detailing molecular differences between OLP and OSCC.

RESULTS

Molecular changes shared between OLP and OSCC included those affecting cellular proliferation (altered p53 expression, hypermethylation of p16/CDKN2A, MYC gains, increased ki-67), apoptosis (increased bcl-2 and survivin expression), extracellular matrix (ECM) remodeling (increased matrix metalloproteinase [MMP] expression), and transcriptional control (altered bmi1 and microRNA [miRNA] expression). In addition, some molecular alterations accumulated incrementally from control to OLP to OSCC or were present in higher-risk erosive variants of OLP or transformed OLP. Few studies included rigorous diagnostic inclusion criteria or unbiased discovery methods.

CONCLUSIONS

Results of this review support the potentially malignant nature of OLP and imply that molecular events associated with malignant transformation may be heterogeneous. In addition, findings in this review highlight the need for additional studies using rigorous diagnostic inclusion criteria and unbiased discovery methods to further understand this process.

Immunohistochemical Evaluation of Transforming Growth Factor-β Expression in Oral Lichen Planus

Background: In oral lichen planus (OLP), which is a persistent inflammatory condition of the autoimmune system, cytotoxic T lymphocytes are triggered against epithelial cells. OLP resists treatment more than its cutaneous counterpart and potentially transforms into malignancy as oral squamous cell carcinoma (OSCC). Transforming growth factor β (TGF-β) is produced by various cells, such as leukocytes and epithelial cells, whereby epithelial-mesenchymal-epithelialn (EMT) forms the phenotype of invasive cancerous cells and promotes tumors. Objectives: We investigated the role of TGF-β in the pathogenesis and biological behavior of dysplastic and non-dysplastic OLP. Methods: Thirty samples of erosive/atrophic OLP (15 dysplastic and 15 non-dysplastic) and 10 samples of normal mucosa of the oral cavity were immunohistochemically examined for the expression of TGF-β. Statistical analysis was performed using the Kruskal-Wallis and chi-squared tests. Results: TGF-β expressed to varying degrees in the epithelium of the studied groups. The groups significantly differed in terms of the expression of TGF-β. In pairwise comparisons, the dysplastic OLP group showed significantly higher immunoreactivity than the normal and non-dysplastic groups, although there was no significant difference between the normal and non-dysplastic OLP groups. The expression of TGF-β in the sub-epithelial lymphocytes of the dysplastic and non-dysplastic OLP groups showed a statistically significant difference. Conclusions: According to the results, TGF-β, as a marker of the inflammatory process in chronic inflammatory conditions, was expressed in epithelial cells and sub-epithelial lymphocytes of all OLPs. This suggests a possible role of this marker in the pathogenesis of OLP. In addition, the increased expression of TGF-β, a marker also involved in carcinogenesis, in the epithelial keratinocytes indicates the role it might play in the development of carcinoma in OLP.

Markers associated with malignant transformation of oral lichen planus: A review article

Oral lichen planus (OLP) is one of the autoimmune diseases associated with chronic inflammation that involves several complications including the potential for malignant transformation into oral squamous cell carcinoma. Pathogenesis of OLP are yet to be fully comprehended however, it has been demonstrated that the epithelial cells in OLP lesions are affected by cytotoxic T lymphocytes leading to immunological reactions. Various factors are reported to act as diagnostic markers for predicting and monitoring the cancerous progression. Hence, in this review, we summarize and present the latest studies regarding the predictive markers associated with malignant potential of OLP.

Evaluation of HPV and EBV in OSCC and the expression of p53, p16, E-cadherin, COX-2, MYC, and MLH1

OBJECTIVE

This study aimed to evaluate the presence of human papillomavirus (HPV) and Epstein-Barr virus (EBV) and the expression of p53, p16, E-cadherin, COX-2, MLH1, and MYC in oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

One hundred OSCC specimens were submitted to in situ hybridization for HPV and EBV, and immunohistochemistry for detection of the human proteins.

RESULTS

Thirty-one cases showed HPV in tumor tissue. EBV was not detected in any case investigated. The HPV(+) group demonstrated an increase of staining scores for nuclear p16 (p = .047), cytoplasmic MYC (p = .002), while a decrease for nuclear MLH1 (p = .048), suggesting that HPV may upregulate the expression of the first two proteins and down-regulate the latter.

CONCLUSION

Our findings reinforce the hypothesis of the HPV-related oral carcinogenesis involving the expression of p16 and MYC, and MLH1 suppression. Exclusively cytoplasmic stainings for p16, MLH1, and MYC were also associated with more advanced tumors. Finally, in view of the lack of studies correlating the HPV or EBV infection to the expression of oncoproteins, more researches assessing a broader panel of markers and employing different approaches are still necessary in order to understand the role of these viruses as well as the molecular mechanisms involved in the development and progression of oral carcinomas.

Molecular biology of oral cavity squamous cell carcinoma

Oral cavity squamous cell carcinoma (OCSCC) is a heterogeneous and complex disease that arises due to dysfunction of multiple molecular signaling pathways. Recent advances in high-throughput genetic sequencing technologies coupled with innovative analytical techniques have begun to characterize the molecular determinants driving OCSCC. An understanding of the key molecular signaling networks underlying the initiation and progression of is essential for informing treatment of the disease. In this chapter, we discuss recent findings of key genes altered in OCSCC and potential treatments targeting these genes.

Promoter DNA Methylation and mRNA Expression Level of p16 Gene in Oral Squamous Cell Carcinoma: Correlation with Clinicopathological Characteristics

The aim of this study was to investigate the relationship between p16 methylation and its expression in oral squamous cell carcinoma (OSCC). Also the contribution of clinicopathological factors, HPV infection and smoking in p16 expression and promoter methylation has been investigated. In this study 67 consecutive OSCC patients and 59 normal individuals were enrolled. All patients were candidates for surgery of oral cavity and fresh tumor biopsies were collected and processed for DNA and RNA extraction. Normal gingival tissues were collected from individuals referred to dentistry clinic and considered as controls. All the cases and controls were checked for HPV infection and then promoter methylation and expression of p16 gene were determined using Methylation-specific PCR (MSP) and real-time PCR (QPCR), respectively. Methylation of p16 in tumors and normal tissues were 59.7 and 38.9%, respectively. Most of hypermethylated samples (>82%) were in high grades. P16 methylation was comparable in HPV+ and HPV- patients or smokers. P16 was overexpressed (~3 fold; p = 0.044) in HPV+ tumors, but it was significantly down-regulated in smoker patients (40% of all tumors). Comparison of P16 expression in OSCC tumors with different degrees of promoter methylation further suggest the relationship of methylation rate and down-regulation of P16 expression. The p16 methylation and expression was differentially affected in patients with HPV infection and the smoker cases. Regardless of the influence of environmental factors, it appears that P16 status is useful for classifying patients with OSCC and for influencing treatment strategies in accordance with this classification. Moreover, targeting the upregulation of p16 could be a promising therapeutic option.

Increased expression of p16 in both oral and genital lichen planus

Background

Lichen Planus, LP, is an inflammatory disease of possible autoimmune origin affecting mainly oral and genital mucosa and skin. According to the WHO oral LP is considered a potentially malignant disorders. The p16 tumour suppressor protein can act as an inhibitor of cyclin dependent kinases 4 and 6 and thus down regulate cell cycle progression. Since the discovery of p16 several studies have evaluated its expression in various forms of human cancers. The aim of this study was to evaluate and compare the expression of p16 in oral and genital LP and corresponding healthy mucosa.

Material and Methods

A total of 76 cases of oral LP (OLP), 34 cases of genital LP (GLP), 12 cases of healthy oral and 9 cases of healthy genital mucosa were analysed by the use of immunohistochemistry.

Results

Data showed p16 to be highly expressed in both oral and genital LP, higher than in oral (p=0.000), and genital controls (p=0.002).

Conclusions

Results suggest that the over-expression of p16 seen in LP play a part in the histopathology of the disease.

Key words:p16, inflammation, oral, genital, lichen planus, malignant risk.

Oral lichen planus and malignant transformation: The role of p16, Ki-67, Bub-3 and SOX4 in assessing precancerous potential

The association of oral lichen planus (OLP) lesions with malignant transformation risk has remained a controversial topic and is of clinical importance. Therefore, the present study evaluated the expression levels of p16, Ki-67, budding uninhibited by benzimidazoles 3 (Bub-3) and sex-determining region Y-related high mobility group box 4 (SOX4), and their roles as precancerous biomarkers in OLP. A retrospective study was performed, in which tissue blocks of OLP, oral dysplasia (OD), cutaneous lichen planus (CLP) and oral fibrous hyperplasia (OFH) were used (n=120). A positivity index (PI) for p16, BUB3, Ki-67 and SOX4 expression was calculated in each group. The PI for p16 was 20.65% for OLP, 7.85% for OD, 86.59% for CLP and 11.8% for OFH, and the difference between these groups was statistically significant (P<0.001). PIs of Ki-67 were indicated as 11.6% for OLP, 14.4% for OD, 8.24% for CLP and 5.5% for OFH, and a statistically significant difference was observed between the groups (P<0.001). Notably, the expression levels of BUB3 were not statistically different among groups. The highest expression levels of SOX4 were identified in CLP (P<0.001 vs. OLP/CLP; P=0,001 vs. CLP/OD). The determined expression levels of p16 and Ki-67 suggest that specific OLP lesions may have an intermediate malignant potential and should be carefully followed up. The intense SOX4 staining in CLP indicated a different proliferation pattern of epithelium compared with oral mucosa cells. These findings suggest that SOX4 expression may also be associated with the different clinical courses of OLP and CLP.

Markers of Oral Lichen Planus Malignant Transformation

Oral lichen planus (OLP) is a chronic inflammatory disease of unknown etiology with significant impact on patients' quality of life. Malignant transformation into oral squamous cell carcinoma (OSCC) is considered as one of the most serious complications of the disease; nevertheless, controversy still persists. Various factors seem to be involved in the progression of malignant transformation; however, the mechanism of this process is not fully understood yet. Molecular alterations detected in OLP samples might represent useful biomarkers for predicting and monitoring the malignant progression. In this review, we discuss various studies which highlight different molecules as ominous predictors of OLP malignant transformation.

Expression of p63 and CD44 in oral squamous cell carcinoma and correlation with clinicopathological parameters

Squamous cell carcinoma (SCC) is the sixth most frequent malignant tumor of the head and neck region. Despite advances in therapeutic options over the last decades, the rate of mortality and morbidity has not been improved markedly. A small subset of cells, cancer stem cells (CSCs), with self-renewal properties have become a major focus of current cancer research. CD44 and p63 are identified as candidate stem cell markers in normal squamous epithelium and SCC. The role of these markers in oral squamous cell carcinoma (OSCC) is still debatable. The aim of this study was to evaluate immunohistochemical expression of these markers in OSCC samples and also correlates the expression of these markers with some clinicopathological parameters of prognostic significance including histological grading, TNM staging, overall survival (OS) rate as well as patients' age, gender, and tumor location. CD44 and p63 were expressed in all studied lesions with different degrees. Statistically significant difference was observed between CD44 and p63 expression with tumor grade and stage with higher expression in high grade and advanced OSCCs. No significant relationship was detected between markers immunoreactivity and patients age, gender, tumor location as well as OS. These markers can possibly advance our understanding of the initiating mechanisms and pathogenesis of OSCC and also result in novel therapeutic target in cancer treatment.

In situ carcinoma developed over oral lichen planus: a case report with analysis of BUB3, p16, p53, Ki67 and SOX4 expression

Oral lichen planus (OLP) represents a common mucocutaneous disease. Various authors have suggested that OLP has malignant potential; however, the mechanisms involved in malignant transformation have not yet been elucidated. A 79-year-old man presented a white lesion for five months in the buccal mucosa diagnosed as OLP. After two months using 0.05% clobetasol ointment for treatment, the lesion became ulcerated. A new biopsy of the same lesion was performed, and histological analysis showed an in situ oral carcinoma (ISOC). An immunohistochemistry panel was performed, and p16 expression was negative in OLP, however, it showed weak cytoplasmic staining in ISOC. There was strong nuclear BUB3 staining in both OLP and ISOC areas. p53 showed less intense nuclear staining in both regions. Ki67 was negative in OLP area, but showed nuclear staining in the ISOC. SOX4 was negative in both studied areas. BUB3 expression, first reported in this case, and the p16 expression may suggest some influence of these genes on pathogenesis or malignant potential of OLP.

P16INK4A and survivin: Diagnostic and prognostic markers in cervical intraepithelial neoplasia and cervical squamous cell carcinoma

OBJECTIVE

To explore the the correlations of p16INK4A (p16) and survivin expressions with cervical intraepithelial neoplasia (CIN) and cervical squamous cell carcinoma.

METHODS

The p16 and survivin expressions were detected in 50 cervical squamous cell carcinoma tissues, 150 various grades of CIN tissues and 30 normal cervical tissues using immunohistochemistry. All data were analyzed applying SPSS 17.0 software.

RESULTS

The p16 and survivin expressions showed the presence of statistical significance in cervical cancer, CINI, CINII, CINIII and normal cervical tissues (P<0.05), and the comparison also revealed statistical significance among groups (all P<0.05); the p16 and survivin expressions were positively correlated with the grade of cervical diseases (both P<0.05). Moreover, p16 protein was associated with CIN grade and lymph node metastases in cervical cancer (all P<0.05); survivin protein was also related with clinical stages, CIN grade and lymph node metastases (all P<0.05); the p16 and survivin expressions were positively correlated with cervical cancer (r=0.854, P<0.001), and associated with poor prognosis of cervical cancer.

CONCLUSION

Briefly, p16 and survivin expression may be correlated with the clinico-pathological and prognosis of cervical cancer.