LDOC1 Suppresses Microbe-Induced Production of IL-1β in Human Normal and Cancerous Oral Cells through the PI3K/Akt/GSK-3β Axis

Inflammasomes in epithelial innate immunity: front line warriors

Our epithelium represents a battle ground against a variety of insults including pathogens and danger signals. It encodes multiple sensors that detect and respond to such insults, playing an essential role in maintaining and defending tissue homeostasis. One key set of defense mechanisms is our inflammasomes which drive innate immune responses including, sensing and responding to pathogen attack, through the secretion of pro-inflammatory cytokines and cell death. Identification of physiologically relevant triggers for inflammasomes has greatly influenced our ability to decipher the mechanisms behind inflammasome activation. Furthermore, identification of patient mutations within inflammasome components implicates their involvement in a range of epithelial diseases. This review will focus on exploring the roles of inflammasomes in epithelial immunity and cover: the diversity and differential expression of inflammasome sensors amongst our epithelial barriers, their ability to sense local infection and damage and the contribution of the inflammasomes to epithelial homeostasis and disease.

The evil companion of OSCC: Candida albicans

OBJECTIVE

Microbial dysbiosis and microbiome-induced inflammation may play a role in the etiopathogenesis of oral squamous cell carcinoma (OSCC). Candida albicans (C. albicans) is the most prevalent opportunistic pathogenic fungus in the oral cavity, and Candida infection is considered as one of its high-risk factors. Although oral microbiota-host interactions are closely associated with the development of OSCC, the interrelationship between fungi and OSCC is poorly understood compared to that between bacteria and viruses.

RESULTS

We accumulated knowledge of the evidence, pathogenic factors, and possible multiple mechanisms by which C. albicans promotes malignant transformation of OSCC, focusing on the induction of epithelial damage, production of carcinogens, and regulation of the tumor microenvironment. In addition, we highlight the latest treatment strategies for Candida infection.

CONCLUSION

This review provides a new perspective on the interrelationship between C. albicans and OSCC and contributes to the establishment of a systematic and reliable clinical treatment system for OSCC patients with C. albicans infection.

Tumor-suppressive action of miR-30a-5p in lung adenocarcinoma correlates with ABL2 inhibition and PI3K/AKT pathway inactivation

INTRODUCTION

ABL2 contributes to the oncogenic potential of cancers, pointing to its inhibition as a possible strategy against malignant diseases. Bioinformatics prediction of upstream effector miR-30a-5p for ABL2 allowed us to hypothesize and then validate mechanistic actions of miR-30a-5p in lung adenocarcinoma (LUAD).

MATERIALS AND METHODS

The ABL2 expression in LUAD was analyzed in the TCGA data, clinical samples, and cell lines. The shRNA-mediated silencing of ABL2 was introduced to illustrate its effect on malignant phenotypes of LUAD cells. The binding affinity between ABL2 and miR-30a-5p was verified by luciferase activity and RNA pull-down assay. Ectopic expression, knockdown methods, and PI3K inhibitor LY294002 were used to investigate their effects on in vitro biological characteristics and in vivo tumor growth of LUAD cells. Using nude mouse lung adenocarcinoma in situ and brain metastasis models to validate the inhibitory effect of miR-30a-5p on LUAD by regulating the ABL2/PI3K/AKT signaling axis.

RESULTS

High expression of ABL2 and poor expression of miR-30a-5p were noticed in LUAD tissues and cell lines. Importantly, miR-30a-5p was demonstrated to target and downregulate ABL2, subsequently inactivating the PI3K/AKT pathway. miR-30a-5p inhibited the malignant phenotypes of LUAD cells by inhibiting ABL2 expression and inactivating the PI3K/AKT pathway. For in vivo experiments, miR-30a-5p was substantiated to thwart tumor tumorigenesis by regulating the ABL2/PI3K/AKT axis. In addition, miR-30a-5p suppresses the occurrence and development of in situ lung cancer and brain metastasis via the ABL2/PI3K/AKT signaling pathway.

CONCLUSION

This study underscores the inhibitory role of miR-30a-5p in LUAD through the ABL2/PI3K/AKT axis, which may be a viable target for LUAD treatment.

Therapeutic Effects of Perilla Phenols in Oral Squamous Cell Carcinoma

The herbal medicine perilla leaf extract (PLE) exhibits various pharmacological properties. We showed that PLE inhibits the viability of oral squamous cell carcinoma (OSCC) cells. HPLC analysis revealed that caffeic acid (CA) and rosmarinic acid (RA) are the two main phenols in PLE, and reduced OSCC cell viability in a dose-dependent manner. The optimal CA/RA combination ratio was 1:2 at concentrations of 300-500 μM but had no synergistic inhibitory effect on the viability of OSCC cells. CA, RA, or their combination effectively suppressed interleukin (IL)-1β secretion by OSCC OC3 cells. Long-term treatment with CA and CA/RA mixtures, respectively, induced EGFR activation, which might cause OC3 cells to become EGFR-dependent and consequently increased the sensitivity of OC3 cells to a low dose (5 μM) of the EGFR tyrosine kinase inhibitor gefitinib. Chronic treatment with CA, RA, or their combination exhibited an inhibitory effect more potent than that of low-dose (1 μM) cisplatin on the colony formation ability of OSCC cells; this may be attributed to the induction of apoptosis by these treatments. These findings suggest that perilla phenols, particularly CA and RA, can be used as adjuvant therapies to improve the efficacy of chemotherapy and EGFR-targeted therapy in OSCC.

Candida albicans Promotes Oral Cancer via IL-17A/IL-17RA-Macrophage Axis

The association between Candida albicans (C. albicans) and oral cancer (OC) has been noticed for a long time, but the mechanisms for C. albicans promoting OC are rarely explored. In this study, we determined that C. albicans infection promoted OC incidence in a 4-nitroquinoline 1-oxide (4NQO)-induced mouse tongue carcinogenesis model as well as promoted OC progression in a tongue tumor-bearing mouse model (C3H/HeN-SCC VII). We then demonstrated that tumor-associated macrophage (TAMs) infiltration was elevated during C. albicans infection. Meanwhile, the attracted TAMs polarized into M2-like macrophages with high expression of programmed death ligand 1 (PD-L1) and galectin-9 (GAL-9). Further analysis suggested that the interleukin (IL)-17A/IL-17RA pathway activated in OC cells was a contributor to the excessive TAMs infiltration in C. albicans-infected mice. Thus, we constructed IL-17A neutralization and macrophage depletion experiments in C3H/HeN-SCC VII mice to explore the role of IL-17A/IL-17RA and TAMs in OC development caused by C. albicans infection. The results showed that both IL-17A neutralization and macrophage depletion tended to reduce the TAMs number and tumor size in mice with C. albicans infection. Collectively, our finding revealed that C. albicans promoted OC development via the IL-17A/IL-17RA-macrophage axis, opening perspectives for revealing C. albicans-tumor immune microenvironment links. IMPORTANCE The relationship between fungi and cancer is gradually receiving attention. Among them, some clinical evidence has shown that Candida may be a contributor to gastrointestinal cancers, especially oral cancer. However, the underlying mechanisms for Candida promoting oral cancer need to be explored. For this reason, this study demonstrated the role of C. albicans in oral cancer development. Moreover, this study revealed the underlying mechanisms for C. albicans promoting oral cancer from the perspective of the tumor immune microenvironment.

Is Candida albicans a contributor to cancer? A critical review based on the current evidence

The association between Candida albicans (C. albicans) and cancer has been noticed for decades. Whether C. albicans infection is a complication of cancer status or as a contributor to cancer development remains to be discussed. This review systematically summarized the up-to-date knowledge about associations between C. albicans and various types of cancer, and discussed the role of C. albicans in cancer development. Most of the current clinical and animal evidence support the relationship between C. albicans and oral cancer development. However, there is insufficient evidence to demonstrate the role of C. albicans in other types of cancer. Moreover, this review explored the underlying mechanisms for C. albicans promoting cancer. It was hypothesized that C. albicans may promote cancer progression by producing carcinogenic metabolites, inducing chronic inflammation, remodeling immune microenvironment, activating pro-cancer signals, and synergizing with bacteria.

Malignant Transformation and Treatment Recommendations of Chronic Hyperplastic Candidiasis-A Six-year Retrospective Cohort Study

BACKGROUND

Oral chronic hyperplastic candidiasis (CHC) is the most uncommon type of oral candidiasis with diverse manifestations. Up to date the diagnosis, long-term management and prognosis of this oral potentially malignant disorder remain obscure.

OBJECTIVES

The aim of this study was to provide the recommendations guiding the diagnostic procedure, clinical management and prognosis assessment of CHC.

METHODS

A retrospective cohort study was performed during January 2015 to April 2021 involving patients with a definite diagnosis of CHC in the Department of Oral Medicine of Peking University School and Hospital of Stomatology. Demographic features, clinical and histopathological features, treatment protocols and follow-ups including malignancy transformation were analysed.

RESULTS

Fourty eight CHC patients were collected and reviewed, with a male-to-female ratio of 2.69:1. The average age at diagnosis was 54.92 ± 9.79 (36-80) years old. Clinically, the multiform oral lesions were diverse and frequently presented as white plaque and erythematous lesions. As a result, the initial diagnostic accordance rate was only 54.17%, and the most common presumptive initial diagnoses were oral lichen planus (22.92%), oral leukoplakia (20.83%) and traumatic lesion (2.08%). Histopathologically, ten (20.83%) patients had varying degrees of epithelial dysplasia, and two (4.17%) patients had malignant transformation with a mean transformation time of 6.5 ± 6.36 months. Among the 28 patients who underwent fungal culture, 24 patients were exclusively infected by Candida albicans, with two patients each mixed infected by C glabrata and C tropicalis, respectively. Notably, treatment with fluconazole had the lower recurrence rate compared with topical nystatin.

CONCLUSIONS

The diagnosis and management of CHC remain a challenge due to its polymorphic clinical presentations, chronic progression and potential of malignant transformation.