Inhibitory Effect of 1,8-Cineol on β-Catenin Regulation, WNT11 Expression, and Cellular Progression in HNSCC

Modes of Action of 1,8-Cineol in Infections and Inflammation

The monoterpene 1,8-Cineol is a natural plant-based therapeutic agent that is commonly applied to treat different inflammatory diseases due to its mucolytic, anti-microbial and anti-inflammatory properties. It has become increasingly clear in the recent years that 1,8-Cineol spreads almost everywhere in the human body after its oral administration, from the gut to the blood to the brain. Its anti-microbial potential and even its anti-viral effects have been observed to include numerous bacteria and fungi species. Many recent studies help to better understand the cellular and molecular immunological consequences of 1,8-Cineol treatment in inflammatory diseases and further provide information concerning the mechanistic modes of action in the regulation of distinct inflammatory biosynthetic pathways. This review aims to present a holistic and understandable overview of the different aspects of 1,8-Cineol in infections and inflammation.

Determination of orally administered 1,8-Cineol in nasal polyp tissues from chronic rhinosinusitis patients using gas chromatography: mass spectrometry

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common inflammatory disease causing considerable disease burden. The anti-inflammatory monoterpene 1,8-Cineol is a natural plant-based therapeutic agent that is well established to treat chronic and acute airway diseases. Aim of this study was to investigate whether the herbal drug 1,8-Cineol reaches the nasal tissue via the gut and the blood stream upon its oral administration. A highly sensitive gas chromatography mass spectrometry-based method with stir bar sorptive extraction (SBSE) for sample preparation has been developed and validated for the extraction, detection and quantification of 1,8-Cineol in tissue samples of nasal polyps from 30 CRSwNP patients. Data revealed a highly sensitive detection of 1,8-Cineol in nasal tissue samples after 14 days of oral administration of 1,8-Cineol prior to surgical treatment. There was no significant correlation between the measured 1,8-Cineol concentrations and bodyweight or BMI values of the analyzed patients, respectively. Our data indicate a systemic distribution of 1,8-Cineol in the human body after its oral administration. Individual differences in terms of metabolic characteristics and have to be further investigated. The study increases our understanding of the systemic effects of 1,8-Cineol upon its therapeutic application and benefit in patients with CRSwNP.

Terpenes and terpenoids as main bioactive compounds of essential oils, their roles in human health and potential application as natural food preservatives

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Terpenes and terpenoids are the main bioactive compounds of essential oils (EOs).

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EOs and their major constituents confer several biological activities.

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EOs are potential as natural food preservatives.

Essential oils (EOs) are volatile and concentrated liquids extracted from different parts of plants. Bioactive compounds found in EOs, especially terpenes and terpenoids possess a wide range of biological activities including anticancer, antimicrobial, anti-inflammatory, antioxidant, and antiallergic. Available literature confirms that EOs exhibit antimicrobial and food preservative properties that are considered as a real potential application in food industry. Hence, the purpose of this review is to present an overview of current knowledge of EOs for application in pharmaceutical and medical industries as well as their potential as food preservatives in food industry.

The let-7 family of microRNAs suppresses immune evasion in head and neck squamous cell carcinoma by promoting PD-L1 degradation

Background

Accumulation of immunosuppressive protein programmed death-ligand 1 (PD-L1) has been documented in several cancers and contributes to the evasion of the host immune system. However, cancer cell-intrinsic signaling-dependent control of PD-L1 expression remains to be elucidated. Herein, we aimed to identify the let-7 family of microRNAs as candidates that up-regulate tumor cell PD-L1 expression and mediates immune evasion of head and neck squamous cell carcinoma (HNSCC).

Methods

The expression of let-7 family and PD-L1 was quantified in HNSCC tissues and adjacent normal tissues. PD-L1 degradation was evaluated in HNSCC cells in response to elevated expressions of let-7a or let-7b. The regulation of let-7 family on PD-L1 degradation through a mechanism involving T-cell factor-4 (TCF-4) control of β-catenin/STT3 pathway was evaluated. Immune recognition of HNSCC in vivo was examined in subcutaneous tumor-bearing C3H mice in the presence of let-7a/b and/or CTLA-4 antibody.

Results

The let-7 family were significantly down-regulated in the context of HNSCC, sharing a negative correlation with PD-L1 expression. Glycosylated PD-L1 was detected in HNSCC cells, which was reduced by let-7a/b over-expression. TCF-4, the target of let-7a/b, activated the β-catenin/STT3 pathway and promoted PD-L1 degradation. In vivo analysis demonstrated that let-7a/b over-expression potentiated anticancer immunotherapy by CTLA-4 blockade.

Conclusions

Taken together, our findings highlight targeting let-7 family as a potential strategy to enhance immune checkpoint therapy for HNSCC.

Wnt Signaling: A Potential Therapeutic Target in Head and Neck Squamous Cell Carcinoma

Cellular maintenance and development are two fundamental mechanisms regulated by the canonical Wnt signaling pathway. Wnt/beta-catenin signaling pathway controls a myriad of cellular processes that are essential for normal cell functioning. Cell cycle progression, differentiation, fate determination, and migration are generally orchestrated by canonical Wnt signaling. Altered Wnt/beta-catenin signaling has been considered a promoting event for different types of cancers and the oncogenic potential of Wnt signaling have been discussed in many cancer types, including breast, colon, pancreatic as well as head and neck. Furthermore, Wnt signaling is critical for the maintenance and stemness of both the normal as well as cancer stem cells. This review sheds new light on Wnt signaling and explains how it can regulate normal physiological processes and curtail the development of cancer. It depicts the vital functions of Wnt signaling in the stem cell growth and differentiation by focusing on current druggable targets that have been ascribed by recent studies. Thus, Wnt signaling pathway retains a tremendous potential in eradicating head and neck squamous cell carcinoma.