Differential expression of cyclooxygenase-2 and cyclin D1 in salivary gland tumors

The Impact of Inflammation on the Etiopathogenesis of Benign Salivary Gland Tumors: A Scoping Review

Salivary gland tumors are rare head and neck tumors constituting up to 6% of all head and neck neoplasms; despite being mostly benign, these tumors present in diverse histological subtypes, making them challenging to diagnose and treat. Our research aims to investigate the link between inflammation and tumorigenesis within the salivary glands based on the literature regarding the etiopathogenesis of benign salivary gland tumors. This scoping review was conducted following the PRISMA extension for scoping reviews and reporting guidelines. The search was conducted using the Pubmed and Embase databases. Articles published between 2004 and May 2024 were included in the review. A total of 1097 papers were collected and identified. After 271 duplicates were removed, 826 titles and abstracts were independently reviewed by two researchers. Based on the title and abstract, 735 citations were excluded, and 91 articles were assessed for eligibility. Data were extracted from 46 articles that met the inclusion criteria. The review highlights the significance of inflammation-related factors and its relations with benign salivary gland tumors (SGTs). Knowledge of the etiopathogenesis of these tumors remains insufficient, and their rich immunological background poses challenges in diagnosis. The findings also point to directions for further clinical research, which will be necessary to implement these molecules in clinical practice.

Salivary gland cancer organoids are valid for preclinical genotype-oriented medical precision trials

Salivary gland cancers (SGCs) are heterogeneous tumors, and precision oncology represents a promising therapeutic approach; however, its impact on SGCs remains obscure. This study aimed to establish a translational model for testing molecular-targeted therapies by combining patient-derived organoids and genomic analyses of SGCs. We enrolled 29 patients, including 24 with SGCs and 5 with benign tumors. Resected tumors were subjected to organoid and monolayer cultures, as well as whole-exome sequencing. Organoid and monolayer cultures of SGCs were successfully established in 70.8% and 62.5% of cases, respectively. Organoids retained most histopathological and genetic profiles of their original tumors. In contrast, 40% of the monolayer-cultured cells did not harbor somatic mutations of their original tumors. The efficacy of molecular-targeted drugs tested on organoids depended on their oncogenic features. Organoids recapitulated the primary tumors and were useful for testing genotype-oriented molecular targeted therapy, which is valuable for precision medicine in patients with SGCs.

Expression of Syndecan-1 and Cyclin D1 in Salivary Gland Tumors in Relation to Clinicopathological Parameters

Background

Salivary tumors have various morphological features and might share some histopathological findings. They are considered a problematic area in diagnosis due to complex clinicopathological features and different biological behavior.

Objective

To identify the pathological behavior of salivary tumors immunohistochemically.

Methodology

This retrospective study involved thirty formalin-fixed paraffin-embedded blocks of salivary gland tumors. These tumors were stained immunohistochemically with syndecan-1 and cyclin D1. Chi-Square test was used to relate immunoscoring, intracellular localization, intensity, and invasion to different salivary tumors. The correlation of these two markers was done by spearman's rho test. P-value <0.05 was considered statistically significant.

Results

The mean age of the patients was 48.69 ± 17.7. The parotid gland was the most commonly reported site in benign tumors, and regarding malignant tumors, maxilla was the most prevalent site. Syndecan-1 in benign tumors showed a predominate score 3, most widely detected in pleomorphic adenoma. Malignant salivary tumors showed 89.4% positive expression with a more frequent score 3, most commonly found in adenocystic carcinoma. Cyclin D1 expressed in all benign salivary tumors, with prominent diffuse mixed intracellular localization in pleomorphic adenoma. Malignant tumors revealed an expression of 94.7%. Moderate scoring with mixed intracellular localization was recorded in adenocystic carcinoma, followed by mucoepidermoid carcinoma. There was a significant correlation between the two markers in response to the distribution of immunostaining in different cell compartments.

Conclusion

Syndecan-1 and cyclin D1 showed a significant combined role in salivary tumor progression. Interestingly notable ductal-myoepithelial cells affect epithelial morphogenesis, and growth of pleomorphic adenoma was observed. Furthermore, basophilic cells of cribriform adenocystic carcinomas might control the aggressiveness and proliferation rate of these tumors.

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.