Evaluation of COX-2, EGFR, and p53 as biomarkers of non-dysplastic oral leukoplakias

Evaluation of EGFR in prognostic characterization in histopathological variants of oral squamous cell carcinoma

AIM OF THE STUDY

Epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor of the Erb B family contributing to proliferation, invasion, and metastasis. EGFR overexpression is frequently associated with poor clinical outcome in malignant neoplasms.• To evaluate and compare immunoexpression of EGFR in histopathological variants of oral squamous cell carcinoma (OSCC).• To hypothesize the role of EGFR in determining biological behavior and prognostic course of histopathological variants of OSCC.

MATERIALS AND METHODS

The study comprised a total of 40 cases including 10 cases each of Squamous cell carcinoma, Verrucous carcinoma, Adenosquamous cell carcinoma, and Adenoid squamous cell carcinoma. EGFR immunoexpression was observed qualitatively as low (1), moderate (2) and strong (3) and quantitatively as score 1 for <10%, 2 for 10%-50%, and 3 for >50% positive cells. The resulting data were analyzed using SPSS software version 19. Data have been expressed as mean and standard deviation. Differences between the different variables were analyzed using ANOVA, and Pearson's Chi-square. (p ≤ 0.05).

RESULT

The study results revealed that the EFGR immunoexpression was highest in adenosquamous cell carcinoma followed by adenoid squamous cell carcinoma then conventional squamous cell carcinoma followed by lowest immunoexpression in verrucous carcinoma. The results were statistically significant. (p ≤ 0.05).

CONCLUSION

Expression of EGFR could be established as a valuable biomarker with significant association in predicting aggressive potential and treatment response in various histopathological variants of OSCC. Further studies where EGFR could be linked to predictive indicators and tumor prognosis could be undertaken.

Plant polysaccharides with anti-lung injury effects as a potential therapeutic strategy for COVID-19

When coronavirus disease 2019 (COVID-19) develops into the severe phase, lung injury, acute respiratory distress syndrome, and/or respiratory failure could develop within a few days. As a result of pulmonary tissue injury, pathomorphological changes usually present endothelial dysfunction, inflammatory cell infiltration of the lung interstitium, defective gas exchange, and wall leakage. Consequently, COVID-19 may progress to tremendous lung injury, ongoing lung failure, and death. Exploring the treatment drugs has important implications. Recently, the application of traditional Chinese medicine had better performance in reducing fatalities, relieving symptoms, and curtailing hospitalization. Through constant research and study, plant polysaccharides may emerge as a crucial resource against lung injury with high potency and low side effects. However, the absence of a comprehensive understanding of lung-protective mechanisms impedes further investigation of polysaccharides. In the present article, a comprehensive review of research into plant polysaccharides in the past 5 years was performed. In total, 30 types of polysaccharides from 19 kinds of plants have shown lung-protective effects through the pathological processes of inflammation, oxidative stress, apoptosis, autophagy, epithelial–mesenchymal transition, and immunomodulation by mediating mucin and aquaporins, macrophage, endoplasmic reticulum stress, neutrophil, TGF-β1 pathways, Nrf2 pathway, and other mechanisms. Moreover, the deficiencies of the current studies and the future research direction are also tentatively discussed. This research provides a comprehensive perspective for better understanding the mechanism and development of polysaccharides against lung injury for the treatment of COVID-19.

Role of Cyclooxygenase-2 in Head and Neck Tumorigenesis

The cyclooxygenase-2 (COX-2) is a potent enzyme that converts arachidonic acid to prostaglandins (PG), including PGE2, a key mediator of inflammation and angiogenesis. Importantly, COX-2 is activated in response to inflammatory stimuli, where it is also believed to promote the development and progression of head and neck cancers (HNC). COX-2 can mediate its protumorigenic effect through various mechanisms, such as inducing cell proliferation, inhibition of apoptosis, and suppressing the host’s immune response. Furthermore, COX-2 can induce the production of vascular endothelial growth factors, hence, promoting angiogenesis. Indeed, the ability of COX-2 inhibitors to selectively restrict the proliferation of tumor cells and mediating apoptosis provides promising therapeutic targets for cancer patients. Thus, in this comprehensive review, we summarized the reported differential expression patterns of COX-2 in different stages of head and neck carcinogenesis—from potentially premalignant lesions to invasive carcinomas. Furthermore, we examined the available meta-analysis evidence for COX-2 role in the carcinogenesis of HNC. Finally, further understanding of the biological processes of COX-2 and its role in orchestrating cell proliferation, apoptosis, and angiogenesis may give therapeutically beneficial insight to develop the management plan of HNC patients and improve their clinical outcomes.

Mast Cells and Blood Vessels Profile in Oral Carcinogenesis: An Immunohistochemistry Study

Background:

The objectives of the present study were to evaluate angiogenesis and mast cell density in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC).

Materials and Methods:

This was an observational, retrospective and quantitative study. The samples consisted of 60 tissue specimens from patients with squamous cell carcinoma, epithelial dysplasia and controls (n=20/group). Immunohistochemistry was performed using an anti-tryptase antibody to mast cells and anti-CD31 and anti-CD34 for blood vessels and we count the number of mast cells and determine the percentage of CD31 and CD34 antibody staining (vascular density).

Results:

The mast cells had lower density in OSCC compared to control and dysplasia (p = 0.009). In angiogenesis, the expression of CD31 showed a higher percentage of blood vessels in OSCC (p < 0.001), however, CD34 showed no difference between groups (p=0.092). The CD31 antibody presented as a high immunostaining in oral mucosa than CD34.

Conclusions:

The increased vascularity in squamous cell carcinoma suggests that angiogenesis begins when malignant transformation starts that seems to be inversely associated with the number of mast cells.

Isoform-Specific Role of Akt in Oral Squamous Cell Carcinoma

Protein kinase B (Akt) plays a very significant role in various cancers including oral cancer. However, it has three isoforms (Akt1, Akt2, and Akt3) and they perform distinct functions and even play contrasting roles in different cancers. Therefore, it becomes essential to evaluate the isoform-specific role of Akt in oral cancer. In the present study, an attempt has been made to elucidate the isoform-specific role of Akt in oral cancer. The immunohistochemical analysis of oral cancer tissues showed an overexpression of Akt1 and 2 isoforms but not Akt3. Moreover, the dataset of "The Cancer Genome Atlas" for head and neck cancer has suggested the genetic alterations of Akt1 and 2 tend to be associated with the utmost poor clinical outcome in oral cancer. Further, treatment of oral cancer cells with tobacco and its components such as benzo(a)pyrene and nicotine caused increased mRNA levels of Akt1 and 2 isoforms and also enhanced the aggressiveness of oral cancer cells in terms of proliferation, and clonogenic and migration potential. Finally, silencing of Akt1 and 2 isoforms caused decreased cell survival and induced cell cycle arrest at the G2/M phase. Akt1/2 silencing also reduced tobacco-induced aggressiveness by decreasing the clonogenic and migration potential of oral cancer cells. Moreover, silencing of Akt1 and 2 isoforms was found to decrease the expression of proteins regulating cancer cell survival and proliferation such as cyclooxygenase-2, B-cell lymphoma 2 (Bcl-2), cyclin D1, and survivin. Thus, the important role of Akt1 and 2 isoforms have been elucidated in oral cancer with in-depth mechanistic analysis.

Epidermal growth factor receptor expression in different subtypes of oral lichenoid disease

The oral lichenoid disease (OLD) includes different chronic inflammatory processes such as oral lichen planus (OLP) and oral lichenoid lesions (OLL), both entities with controversial diagnosis and malignant potential. Epidermal growth factor receptor (EFGR) is an important oral carcinogenesis biomarker and overexpressed in several oral potentially malignant disorders. Objectives: To analyze the EGFR expression in the OLD to find differences between OLP and OLL, and to correlate it with the main clinical and pathological features. Material and Methods: Forty-four OLD cases were studied and classified according to their clinical (Group C1: only papular lesions / Group C2: papular and other lesions) and histopathological features (Group HT: OLP-typical / Group HC: OLP-compatible) based in previous published criteria. Standard immunohistochemical identification of EGFR protein was performed. Comparative and descriptive statistical analyses were performed. Results: Thirty-five cases (79.5%) showed EGFR overexpression without significant differences between clinical and histopathological groups (p<0.05). Histological groups showed significant differences in the EGFR expression pattern (p=0.016). Conlusions: All OLD samples showed high EGFR expression. The type of clinical lesion was not related with EGFR expression; however, there are differences in the EGFR expression pattern between histological groups that may be related with a different biological profile and malignant risk.

Key words:Oral lichenoid disease, oral lichen planus, oral lichenoid lesion, oral carcinogenesis, EGFR.

Optical molecular imaging of multiple biomarkers of epithelial neoplasia: epidermal growth factor receptor expression and metabolic activity in oral mucosa

Biomarkers of cancer can indicate the presence of disease and serve as therapeutic targets. Our goal is to develop an optical imaging approach using molecularly targeted contrast agents to assess several centimeters of mucosal surface for mapping expression of multiple biomarkers simultaneously with high spatial resolution. The ability to image biomarker expression level and heterogeneity in vivo would be extremely useful for clinical cancer research, patient selection of personalized medicine, and monitoring therapy. In this proof-of-concept ex vivo study, we examined correlation of neoplasia with two clinically relevant biomarkers: epidermal growth factor receptor (EGFR) and metabolic activity. Two hundred eighty-six unique locations in nine samples of freshly resected oral mucosa were imaged after topically applying optical imaging agents EGF-Alexa 647 (to target EGFR) and 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (to target metabolic activity). Quantitative features were calculated from resulting fluorescence images and compared with tissue histopathology maps. The EGF-Alexa 647 signal correlated well with EGFR expression as indicated by immunohistochemistry. A classification algorithm for presence of neoplasia based on the signal from both contrast agents resulted in an area under the curve of 0.83. Regions with a posterior probability from 0.80 to 1.00 contained more than 50% neoplasia 99% (84/85) of the time. This study demonstrates a proof-of-concept of how noninvasive optical imaging can be used as a tool to study expression levels of multiple biomarkers and their heterogeneity across a large mucosal surface and how biomarker characteristics correlate with presence of neoplasia. Applications of this approach include predicting regions with the highest likelihood of disease, elucidating the role of biomarker heterogeneity in cancer biology, and identifying patients who will respond to targeted therapy.

Biomarkers of oral premalignant epithelial lesions for clinical application

Oral cancer is the sixth most common form of cancer worldwide, and the majority of cases occur in India and Southeast Asia. Its major risk factors in the western world include smoking and drinking alcohol, whereas in Asia, it is primarily caused by tobacco/areca nut/betel leaf chewing and/or human papillomavirus (HPV) infections. Little is known about this type of cancer despite recent advances in cancer biology. The generally asymptomatic nature of the early oral lesions causes them to remain undetected in many cases. Thus, the disease progresses substantially before the patients seek treatment and is a major contributing factor to the severity of this disease. Therefore, there is a great need to create awareness for its prevention and early diagnosis. The application of advanced molecular biological and biochemical methodologies to elucidate its biomarkers may aid in early detection; however, much more work must be done for this information to be effectively applied in the clinical setting. This review focuses on the need for systematic diagnoses in the early detection of oral cancer using molecular and biochemical approaches, thereby reducing the number of advanced cases in the chewing tobacco-dominated oral cancer population.

The Role of p53 and MDM2 in Head and Neck Cancer

Head and neck cancer is a complex disorder that includes mostly squamous cell carcinomas that can develop in the throat, larynx, nose, sinuses, and mouth. Etiopathogenesis is due to tobacco and alcohol consumption and to infection by human papillomavirus (HPV) type 16/18. Tumors often develop within preneoplastic fields of genetically altered cells. Most head and neck cancers result from multistep accumulation of genetic alterationsm resulting in clonal outgrowth of transformed cells. These DNA changes are caused by a variety of mechanisms like endogenous mutations and exogenous mutations. Dysregulated molecular pathway includes alterations of critical inhibitor of cyclin CDK complexes, inactivating mutations of p53 gene, and activation of oncogenes and growth factors. This paper attempts to review the role of p53 and MDM2 genetic aberrations and pathways in head and neck cancer.