Dysplastic features relevant to malignant transformation in atrophic epithelium of oral submucous fibrosis: A preliminary study

Immuno-oncologic signature of malignant transformation in oral squamous cell carcinoma

OBJECTIVE

The purpose of this study is to identify the immuno-oncologic (IO) signature at the surgical tumor margin (TM) of oral squamous cell carcinoma (OSCC) that is involved in the process of malignant transformation.

STUDY DESIGN

Under institutional review board approval, TM of 73 OSCC were investigated using immunohistochemistry for the immune biomarker, programmed death ligand-1 (PD-L1). NanoString 770 IO-focused gene set was analyzed in 5 pairs of TM and invasive tumor (T). PD-L1 regulation in response to interferon-gamma (IFN-γ) was investigated in an oral potentially malignant cell line (OPMC).

RESULTS

Programmed death ligand-1 expression in the epithelial margin directly correlated with its expression in the underlying immune cells (P = .0082). Differential gene expression showed downregulation of PD-L1 and IFN-γ 6 gene signature in the TM relative to T pair.CD8 and macrophages were higher in TM. CNTFR, LYZ, C7, RORC, and FGF13 downregulation in T relative to TM. TDO2, ADAM12, MMP1, LAMC2, MB21D1, TYMP, OASL, COL5A1, exhausted_CD8, Tregs,and NK_CD56dim were upregulated in T relative to TM. Finally, IFN-γ induced upregulation of PD-L1 in the OPMC.

CONCLUSIONS

Our work suggests a role for IFN-γ in PD-L1 upregulation in OPMC and presents novel IO transcriptional signatures for frankly invasive OSCC relative to TM.

Organic Acids Derived from Saliva-amalgamated Betel Quid Filtrate Are Predicted as a Ten-eleven Translocation-2 Inhibitor

There is a lack of evidence regarding the use of betel quid (BQ) and its potential contribution to oral cancer. Limited attention has been directed towards investigating the involvement of BQ-derived organic acids in the modulation of metabolic-epigenomic pathways associated with oral cancer initiation and progression. We employed novel protocol for preparing saliva-amalgamated BQ filtrate (SABFI) that mimics the oral cavity environment. SABFI and saliva control were further purified by an in-house developed vertical tube gel electrophoresis tool. The purified SABFI was then subjected to liquid chromatography-high resolution mass spectrometry analysis to identify the presence of organic acids. Profiling of SABFI showed a pool of prominent organic acids such as citric acid. malic acid, fumaric acid, 2-methylcitric acid, 2-hydroxyglutarate, cis-aconitic acid, succinic acid, 2-hydroxyglutaric acid lactone, tartaric acid and β-ketoglutaric acid. SABFI showed anti-proliferative and early apoptosis effects in oral cancer cells. Molecular docking and molecular dynamics simulations predicted that SABFI-derived organic acids as potential inhibitors of the epigenetic demethylase enzyme, Ten-Eleven Translocation-2 (TET2). By binding to the active site of α-ketoglutarate, a known substrate of TET2, these organic acids are likely to act as competitive inhibitors. This study reports a novel approach to study SABFI-derived organic acids that could mimic the chemical composition of BQ in the oral cavity. These SABFI-derived organic acids projected as inhibitors of TET2 and could be explored for their role oral cancer.

Assessment of Oral Lesions With Tobacco Usage: A Cross-Sectional Clinicopathological Study in Sri Ganganagar, Rajasthan, India

Background Tobacco usage in the form of smoking or chewing has increased the risk of oral potentially malignant disorders (OPMDs) and oral cancer. These deleterious habits are also related to changes in dentition and the oral mucosa. Aim The aim of our study was to evaluate the oral changes associated with tobacco usage among residents of Sri Ganganagar. Materials and methods This study was conducted among the residents of Sri Ganganagar, Rajasthan, India, using stratified cluster random sampling, prestructured questionnaires, and detailed oral examination. A total of 100 patients with a previous history of tobacco usage were enrolled in this study after obtaining informed consent. Age- and gender-matched controls were also evaluated to correlate the findings. Clinical details were documented, including the Oral Hygiene Index-Simplified (OHI-S), Decayed-Missing-Filled Teeth (DMFT) index, Community Periodontal Index (CPI), loss of attachment, dental findings, and oral mucosal changes. Suspicious lesions were stained with toluidine blue, and a biopsy was performed for histopathological evaluation. The tabulated results were statistically analyzed using the Statistical Package for the Social Sciences (SPSS) version 21.0 (IBM SPSS Statistics, Armonk, NY, USA) for significance. Results Attrition, abrasion, and erosion of teeth were more frequent in tobacco users than in controls. Smoker's palate, tobacco pouch keratosis, and leukoplakia were commonly noted mucosal lesions. The mean values of the parameters of the DMFT score (3.560), CPI score (2.190), and loss of attachment score (0.542) were higher among tobacco users, and it was statistically significant (P value < 0.05). Out of 100 patients, 17 had suspicious lesions. It included seven cases of oral submucous fibrosis (OSMF), two cases of tobacco pouch keratosis, and eight cases of leukoplakia. Toluidine blue staining and biopsy were performed. Histopathological examination of suspicious lesions revealed hyperkeratosis, various grades of epithelial dysplasia, and differing inflammatory responses. Out of 17 biopsied cases, there were two cases of hyperkeratosis with severe epithelial dysplasia, four cases of hyperkeratosis with moderate epithelial dysplasia, two cases of hyperkeratosis with mild dysplasia, two cases of superficially invasive squamous cell carcinoma, five cases of advanced OSMF, and two cases of moderately advanced OSMF. Conclusion Tobacco usage produces visible changes in dentition and latent alterations in the oral mucosa. Suspicious lesions should always be referred for histopathological examination to identify oral potentially malignant disorders and oral cancer so that prompt treatment could be initiated. Patient education is mandatory to avoid the usage of tobacco in any form.

Serum aflatoxin B1 antibody titer, percent hemolysis and transaminases in oral submucous fibrosis

Introduction

Areca nut is deeply rooted sociocultural habit in India. Areca nut reported to be infested by fungi during the field and storage conditions. Areca nut alkaloids, nitrosamines, tobacco and aflatoxin are cytotoxic, immunotoxic to red blood cell and epithelial cell. Hence, the present study was conducted to assess the serum aflatoxin B₁ (AFB₁) antibody titer, percent hemolysis and transaminases in oral submucous fibrosis (OSMF) patients.

Materials and Methods

In this study, 128 participants of which 88 were suffering from OSMF. Twenty participants were areca nut habitual without OSMF (habitual control) and 20 participants without any habit (healthy control). For the detection of AFB₁ antibody titer, AFB₁ antigen (Sigma) A6636 from Aspergillus flavus was used. Percent hemolysis was estimated as per the procedure described by Mathuria and Verma. Serum Glutamic oxalo acetic transaminase (SGOT) and Serum Glutamic pyruvic transaminase (SGPT) were estimated by the optimized ultraviolet method using the enzyme-linked immunosorbent assay kit.

Results

Mean SGOT, SGPT, percent hemolysis and AFB₁ antibody titer were significantly higher in participants with OSMF than the habitual and healthy controls. AFB₁ antibody titer and % hemolysis in both OSMF and habitual without OSMF were showed significant correlation, i.e., increased AFB₁ antibody titer with increased % hemolysis.

Conclusions

A study result demonstrates that aflatoxin causes increase in serum transaminases which is indicative of liver damage in OSMF. The combined toxic effects of areca nut alkaloids, tobacco and AFB₁ on red blood cell (RBC) cell wall might be responsible for increased percent hemolysis in OSMF and habitual control.

Conspicuous and frank dilated vascular spaces: A marker of malignant transformation in oral submucous fibrosis

Histo-morphological alterations observed at mucosal surgical margins can be envisaged as potential markers of malignant transformation. In this paper, we have presented a very striking observation at the mucosal surgical margins of oral squamous cell carcinoma arising in the background of oral submucous fibrosis (OSCC-OSMF). Out of 38 cases of OSCC-OSMF, 22 (57.89%) showed conspicuous large dilated vascular spaces lined by endothelial cells in the background of dense fibrosis. These large dilated areas were engorged with red blood cells and were located at the juxta-epithelial and submucosal regions. Since surgical margin tissues are biologically close to malignant transformation, we proposed this unique feature as a potential predictive marker for oral submucous fibrosis that will aid in the early detection of OSCC. Future cohort studies are warranted to prove the authenticity of the present observations.

Oral Potentially Malignant Disorders (OPMD): What is the clinical utility of dysplasia grade?

INTRODUCTION

Oral epithelial dysplasia is considered a potential histologic precursor of subsequent squamous cell cancer. As standard clinical practice, pathologists grade dysplasia to assess risk for progression to malignancy. Except for the most advanced grade, severe dysplasia, dysplasia grading has failed to correlate well with the risk to develop invasive cancer. The questions of what process dysplasia grading best represents and what clinical utility dysplasia grading may have are explored.

AREAS COVERED

This narrative review is based on PubMed search with emphasis on papers since 2010. Epithelial dysplasia as a precursor lesion of cancer and dysplasia grading as a risk assessment tool for progression to cancer are discussed. The close clinical association of dysplasia with known carcinogens, alcohol, and tobacco products is presented.

EXPERT OPINION

Oral epithelial dysplasia is often, associated with prolonged exposure to tobacco and alcohol products. With reduction of carcinogen exposure, dysplasia is known to regress in some cases. It is proposed that histologic dysplasia grade together with macroscopic images of dysplastic clinical lesions be used as an educational tool to incentivize patients to reduce their known carcinogen exposure. This strategy has the potential to reduce lesion progression thereby reducing the disease burden of oral cancer.

Readdressing dysplasia at surgical margins as predictive biomarker of malignant transformation

Clinical, histological and molecular alterations observed at surgical margins could be regarded as predictive markers of malignant transformation. However, there are contrasting views on usefulness of oral epithelial dysplasia (OED) in predicting malignant transformation. In this regard, investigation of OED status at surgical margins could give an interesting perspective to this notion. We searched the reputed databases to retrieve the original research articles wherein the OED status was investigated at the mucosal surgical margins of oral squamous cell carcinoma (OSCC). Intriguingly, in all the studies, number of cases in 'no dysplasia' category was higher than other grades of dysplasia. In our institutional experience of 92 cases of OSCC, 75 (82%) cases showed no evidence of dysplasia at surgical margins. Thus, we conclude that dysplasia status at surgical margins does not support the OED as potential marker of malignant transformation.

Proliferative ability and accumulation of cancer stem cells in oral submucous fibrosis epithelium

OBJECTIVES

The driving force of the malignant transformation of epithelial cells during oral submucous fibrosis (OSF) is an unsettled debate. We hypothesized that the expression and accumulation of cancer stem cells (CSCs) are accompanied by epithelial atrophy in OSF.

MATERIALS AND METHODS

The expression levels of Ki67 (proliferation marker), SOX2, and Bmi1 (CSC marker) in the epithelium during the early, middle, and late stages of OSF were measured by immunohistochemistry. At the same time, we focused on the expression of three proteins in OSF patients with benign hyperkeratosis and epithelial dysplasia.

RESULTS

The clinical cohort study showed upregulated expression of the proliferation-associated protein Ki67 in atrophic epithelium in patients with OSF. The expression levels of SOX2 and Bmi1 showed an increasing trend in the progression of OSF. Ki67, SOX2, and Bmi1 were highly expressed in OSF tissues with dysplasia. Moreover, the three proteins were located at the epithelial and mesenchymal junctions, and their expression showed a positive correlation with each other.

CONCLUSION

The results suggest that CSC accumulation could be accompanied by epithelial atrophy during OSF, which may be responsible for the driving forces for OSF carcinogenesis.

The Stromal Dictators in a Concomitant Case of Oral Submucous Fibrosis - Oral Squamous Cell Carcinoma

Oral submucous fibrosis (OSMF) is a potentially malignant disorder, characterized by alteration in the connective tissue stroma. Its association with oral squamous cell carcinoma (OSCC) has been recognized and conferred a special status as a distinct disease entity with improved prognosis as compared to conventional squamous cell carcinoma. Such cases of concomitant presentation of OSMF and OSCC have not yet been defined, leading to ambiguity regarding the evaluation. The concomitant occurrence of OSMF-OSCC is associated with histopathological features, unlike OSMF, yet similar to an aggressive presentation of OSCC. An indepth evaluation of the connective tissue, along with other tumor characteristics such as tissue hypoxia, inflammatory cell population, neoangiogenesis, and stromal cells fortify the possibility of these cases of concomitance being as aggressive, if not more, as compared to conventional OSCC. Thus, recognizing such cases along with the evaluation of probable prognostic indicators is necessary to improve the current understanding of tumorigenesis and progression in concomitant cases of OSMF-OSCC.

DNA content abnormality in oral submucous fibrosis concomitant leukoplakia: A preliminary evaluation of the diagnostic and clinical implications

Oral submucous fibrosis (OSF) is an insidious chronic oral and oropharyngeal potentially malignant disorder. Our previously studies reported that DNA image cytometry (ICM) using brushing added in the diagnosis of high-grade dysplasia and staging of oral leukoplakia (OLK). This preliminary study aimed to investigate the abnormal rate of DNA content in 30 cases of OSF including three cases of OSF concomitant OLK and evaluate their the diagnostic and clinical implications with special emphasis on the OSF concomitant OLK. Brushing and biopsy sample form each patient was processed by DNA-ICM and histological examination, respectively. The results of DNA-ICM analysis showed that all the lesions from the 27 patients with OSF only were identified as normal DNA content. Strikingly, two of three cases of OSF concomitant OLK were identified as abnormal DNA content, and one case of whom progressed to early oral squamous cell carcinoma at the follow-up of 31 months. Collectively, this preliminary evaluation revealed that DNA content abnormality was hardly observed in OSF only; however, it may be usually observed in OSF concomitant OLK, whom should be monitored on a priority basis for early detection of carcinoma. Multicenter large studies are needed to validate the findings of the current study.

Ki67, CD105 and α-smooth muscle actin expression in disease progression model of oral submucous fibrosis

AIM

The aim of this study was to investigate the expression of Ki67, CD105 and α-smooth muscle actin (α-SMA) expression in oral submucous fibrosis (OSF) and oral squamous cell carcinoma in the background of OSF (OSCC-SMF).

METHODS

The study was carried out on paraffin-embedded tissues of 30 normal oral mucosa (NOM), 50 OSF cases and 105 OSCC-SMF. The immunohistochemistry was carried out to evaluate the expression of Ki67, CD105 and α-SMA antigen.

RESULTS

Ki67 labelling index (LI), CD105 and α-SMA expression showed increasing trend from NOM, low-risk epithelial dysplasia (LRED), high-risk epithelial dysplasia (HRED), well-differentiated squamous cell carcinoma (WDSCC), moderately differentiated squamous cell carcinoma to poorly differentiated squamous cell carcinoma. However, there was no significant difference of α-SMA expression between HRED and WDSCC. In OSCC-SMF, Ki67 LI, CD105 and α-SMA were significantly higher in advanced clinical TNM stage, metastasis and less than 3 years patient survival as compared with early clinical TNM stage, non-metastasis and 3 years or more patient survival.

CONCLUSION

Ki67 LI, α-SMA and CD105 expression alone or together correspond with the disease progression model of SMF. Hence, expression of these markers can be used as a predictive marker of clinical outcome of OSCC-SMF.

Ki67, CD105, and α-SMA expression supports the transformation relevant dysplastic features in the atrophic epithelium of oral submucous fibrosis

Background

The grading of oral epithelial dysplasia is not possible in the atrophic epithelium of oral submucous fibrosis (OSMF). Recently, we found that features such as increased basal cell layer hyperplasia, abnormal superficial mitosis, increased nuclear-cytoplasmic ratio, increased nuclear size, and hyperchromasia represent transformation-relevant dysplastic features in the atrophic epithelium of OSMF. The presence of these features can be considered a high-risk feature for patients. However, these findings have not been tested and authenticated using markers relevant to oral carcinogenesis.

Method

Paraffin-embedded tissues from 30 normal oral mucosa (NOM) and 50 OSMF were retrieved from 2008 to 2016 and subjected to immunohistochemical expression using Ki67, CD105 and α-SMA antibodies.

Results

Ki67 LI showed significant increases from NOM (12.47±2.34) to LRED (23.47±3.75) to HRED (34.31±7.31) (<0.0001). Similarly, MVD was increased significantly from NOM (3.53±5.17) to LRED (27.57±12.25) to HRED (46.18±12.55) (p<0.0001). The expression of α-SMA was significantly increased from LRED (0.21±0.41) to HRED (1.13±0.56) (<0.0001). The Ki67 LI and α-SMA; MVD and α-SMA; and Ki67Ki67 LI and MVD in NOM, LRED and HRED showed a statistically significant positive correlation (P<0.0001). The increase in Ki67 LI was directly proportional to MVD and α-SMA expression from NOM to LRED to HRED (P<0.0001). The connective tissue stroma of NOM lacks α-SMA expression. Mild myofibroblast expression was noted in 4 cases of LRED (14.28%) and in 18 cases of HRED (81.81%). Moderate expression was noted only in 4 cases of HRED (22.22%).

Conclusion

Ki67 LI, CD105, and α-SMA expression showed significant differences between normal, LRED and HRED. These findings further support that features such as increased basal cell layer hyperplasia, abnormal superficial mitosis, increased nuclear-cytoplasmic ratio, and hyperchromasia could be transformation-relevant dysplastic features.