Genomic Signature of Mismatch Repair Deficiency in Areca Nut-Related Oral Cancer

Global, regional, and national cancer burdens of respiratory and digestive tracts in 1990-2044: A cross-sectional and age-period-cohort forecast study

BACKGROUND

Understanding the current status and future trends of cancer burdens by systems provides important information for specialists, policymakers, and specific risk populations.

METHODS

The aim of this study was to compare the current and future cancer burdens of the gastrointestinal (GI) and respiratory tracts in terms of their magnitude and distribution. Data from a total of eight cancers of the digestive and respiratory tracts in the Global Burden of Disease (GBD) database were collected. The age-standardized incidence/death rates (ASIR/ASDRs), disability-adjusted life years (DALYs), and estimated annual percentage changes (EAPCs) were analyzed. Future trends were predicted with Bayesian age-period-cohort (BAPC) and NORDPRED models.

RESULTS

In 2019, there was a significant increase in DALY for both digestive and respiratory tract cancers compared to 1990. Meanwhile, ASIR increased slightly and ASDR decreased notably. In 2019, the global cancer burdens of respiratory and digestive tracts were 38568363.53 and 66912328.72 in DALY, 34.28 and 55.32 in ASIR, and 656.82 and 808.22 in ASDR per 100,000 population with changes of +54.63% and +43.93%, +2.92% and +5.65%, and -17.39% and -26.83% compared to those in 1990, respectively. Significant cross-regional differences in the cancer burdens were observed among the regions. Compared to four representative chronic diseases, the burden of cancers showed less remission and greater global inequalities. The burdens of both digestive and respiratory tract cancers were higher in males than in females in terms of the ASIR, ASDR, and DALY. The incidence and mortality rates of respiratory tract cancers were up to 3-4 times higher in males than in females, whereas the difference between male and female rates of digestive tract cancers was relatively smaller. The main risk factor associated with all kinds of digestive and respiratory tract cancers is tobacco, leading to 18.5 in ASDR and 3.38×107 in DALY for respiratory tract cancers; 8.29 in ASDR and 1.60×107 in DALY for digestive tract cancers, in 2019. Additionally, alcohol use contributes to most digestive and respiratory tract cancers (1.23/1.03 in ASDR and 1.60×106/2.57×106 in DALY for respiratory tract cancers; 4.19/3.82 in ASDR and 4.49×106/8.06×106 in DALY for digestive tract cancers), except for stomach cancer and tracheal, bronchus, and lung cancer. The cancer burdens of respiratory and digestive tracts are likely to decrease substantially between 2020 and 2044. For most metrics, except for the ASIR and male-to-female ratios of ASDR and ASDALY in digestive tract cancers, the worldwide variances of burden metrics have been decreasing in the past decades and will possibly maintain stable trends in the future.

CONCLUSIONS

The epidemiology of respiratory and GI tract cancers has common features and individual characteristics that are reflected in geography, age characteristics, and risk factors. Current epidemiological status, future trends, and the globalization of these disease burdens are important factors for making scientific planning of resources to minimize the cancer burden metrics and their cross-regional inequalities.

Betel-nut chewing does not influence PD-L1 expression rates in recurrent/metastatic head and neck squamous cell carcinoma (HNSCC): A prospective biomarker prevalence study

This study explored the relationship between betel-nut chewing and programmed death-ligand 1 (PD-L1) expression in recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) patients in Taiwan. A total 280 R/M HNSCC patients, predominantly male, were evaluated; 75.4 % of whom chewed betel-nut. The prevalence of PD-L1 expression (combined positive score ≥1) was 94.3 % with similar PD-L1 expression rates between betel-nut-exposed and non-exposed groups. PD-L1 prevalence did not differ in those who received prior first-or second-line systemic therapy. In summary, betel-nut exposure did not notably affect PD-L1 expression rates in R/M HNSCC patients in Taiwan.

Arecoline promotes proliferation and migration of human HepG2 cells through activation of the PI3K/AKT/mTOR pathway

Background

Arecoline is a well-known risk factor for oral submucosal fibrosis and cancer. However, the mechanistic correlation between arecoline and hepatocellular cancer remains elusive. Here, we investigated the effect of arecoline on the proliferation and migration of human HepG2 hepatoma cells and its potential oncogenic mechanisms.

Methods

Bioinformatic technologies were used to identify the deferentially expressed miRNAs (DE-miRNAs) and hub target genes of arecoline-induced cancers. These DE-miRNAs, hub genes and pathway were proved in arecoline-treated HepG2 cells.

Results

A total of 86 DE-miRNAs and 460 target genes were identified. These target genes are associated with DNA-templated regulation of transcription and other biological processes. Significant molecular functions were protein binding, calcium ion binding, and enrichment in the nucleus and cytoplasm. These genes are involved in the PI3K-AKT pathway. CDK1, CCND1, RAF1, CDKN1B and BTRC were defined as the top 5 hub target genes, and patients with high expression of CDK1 showed poor prognosis. Compared with control group, 2.5 µM arecoline treatment increased the proliferation and migration ability of the HepG2 cells. Treatment with 2.5 µM arecoline increased the levels of miR-21-3p, miR-21-5p and miR-1267, upregulated the expression of PI3K-AKT pathway factors, CDK1, CCND1 but decreased RAF1 expression.

Conclusion

A low concentration arecoline can induce the proliferation and migration of HepG2 cells, with the potential mechanism of action linked to high levels of exosomal miR-21 and miR-1267, activation of the PI3K-AKT pathway, upregulation of CDK1 and CCND1, and downregulation of RAF1.

Molecular Research on Oral Diseases and Related Biomaterials: A Journey from Oral Cell Models to Advanced Regenerative Perspectives

Oral diseases such as gingivitis, periodontitis, and oral cancer affect millions of people worldwide. Much research has been conducted to understand the pathogenetic mechanisms of these diseases and translate this knowledge into therapeutics. This review aims to take the reader on a journey from the initial molecular discoveries to complex regenerative issues in oral medicine. For this, a semi-systematic literature search was carried out in Medline and Web of Science databases to retrieve the primary literature describing oral cell models and biomaterial applications in oral regenerative medicine. First, an in vitro cell model of gingival keratinocytes is discussed, which illustrates patho- and physiologic principles in the context of oral epithelial homeostasis and carcinogenesis and represents a cellular tool to understand biomaterial-based approaches for periodontal tissue regeneration. Consequently, a layered gradient nonwoven (LGN) is described, which demonstrates that the key features of biomaterials serve as candidates for oral tissue regeneration. LGN supports proper tissue formation and obeys the important principles for molecular mechanotransduction. Furthermore, current biomaterial-based tissue regeneration trends, including polymer modifications, cell-based treatments, antimicrobial peptides and optogenetics, are introduced to represent the full spectrum of current approaches to oral disease mitigation and prevention. Altogether, this review is a foray through established and new concepts in oral regenerative medicine and illustrates the process of knowledge translation from basic molecular and cell biological research to future clinical applications.

Co-upregulation of miR-31 and its host gene lncRNA MIR31HG in oral squamous cell carcinoma

Background/purpose

Several long non-coding RNAs (lncRNAs) harbor miRNA in their genome. MIR31HG harbors miR-31 in its intron and it is speculated that they are co-expressed in tumors. This study addressed whether frequent miR-31 and MIR31HG co-upregulation occurred in oral squamous cell carcinoma (OSCC) and its clinical implications.

Materials and methods

Microarray was performed to retrieve dis-regulated lncRNAs from tissue sample. The ectopic gene expression was carried out to specify the phenotypic influences of selected lncRNA screened from bioinformatic algorithms. The expression of miR-31 and MIR31HG in tissues or scrapped samples was analyzed using qRT-PCR. The implications of gene expression as related to metastasis or survival were further dissected.

Results

Microarray identified disrupted transcripts including MIR31HG and other 152 lncRNAs aberrantly expressed in OSCC tissues. In silico algorithms annotated an eminent involvement of aberrant transcripts in the regulation of cell cycle, extracellular modulation, adhesion, and wound healing. The enhancement of proliferation, wound healing, invasion and anchorage-independent colony formation mediated by MIR31HG was ascertained by ectopic expression in OECM1 cells. Besides, co-upregulation of miR-31 and MIR31HG was conspicuous in OSCC tissues. High expression of miR-31 and MIR31HG designated a trend of worse OSCC prognosis. Interestingly, high MIR31HG expression defined a very poor survival in stage IV diseases. By contrast, high miR-31 expression predicted nodal metastasis in stage I–III diseases.

Conclusion

Assessment of miR-31 and MIR31HG expression in OSCC may enable the prognostic prediction. The candidate lncRNAs isolated from this work can be further validated as crucial factors contributing to OSCC pathogenesis.

Comprehensive analysis of circRNA expression pattern and circRNA-miRNA-mRNA network in oral squamous cell carcinoma

OBJECTIVE

CircRNAs are critical gene modulators in tumor initiation and progression. However, the expression pattern and molecular pathogenesis of circRNAs in oral squamous cell carcinoma (OSCC) are still poorly characterized.

METHODS

RNA sequencing with CIRCexplorer2 pipeline was performed to identify circRNAs in 46 tumor-normal paired tissues from OSCC patients. Another set of 48 head and neck squamous cell carcinoma samples from the MiOncoCirc database were utilized as an independent validation.

RESULTS

Of the 1276 identified high-confidence circRNAs, 154 were differentially expressed between tumor and normal tissues (log₂|Fold Change|≥1 and false discovery rate < 0.05). CircRNAs expression was globally down-regulated in tumors compared to normal tissues (P = 9.44 × 10^-14). Correlation analysis demonstrated that the global expression of circRNAs was positively related to tumor infiltrating lymphocyte (P = 1.10 × 10^-4) and stromal signature (P = 2.70 × 10^-3) whereas negatively associated with cell proliferation markers (P = 4.32 × 10^-2). CircRNAs-miRNAs-mRNAs regulatory network revealed 6574 interactions, and the target genes were enriched in extracellular matrix and immune-related pathways. Survival analysis were performed on target genes in immune-related pathways, and 20 genes were significantly associated with the prognostic status of OSCC in The Cancer Genome Atlas cohort. The risk model constructed with above 20 genes was associated with the prognosis status of OSCC (HR = 3.28, P = 5.06 × 10^-11), and the result was validated in an independent study (GSE41613) (HR = 2.06, P = 1.73 × 10^-2).

CONCLUSION

CircRNAs showed a global down-regulation pattern in OSCC tissues, and genes regulated by circRNAs primarily involved in immune and extracellular matrix pathways, which could also affect the OSCC prognosis, indicating that they may serve as potential prognostic biomarkers.

Molecular landscape of head and neck cancer and implications for therapy

Head and neck squamous cell carcinomas (HNSCC) arising from the oral cavity, pharynx, and larynx constitute the 6^th most common human cancer. Human papillomavirus (HPV)-positive tumours are distinct from HPV-negative counterparts, with HPV status affording clear clinical utility, prognostic benefit and better treatment outcomes. In contrast to their HPV-positive counterparts, HPV-negative tumours are characterized by high mutational load and chromosomal aberrations, with varying copy number alteration (CNA) profiles. HNSCC are distinct tumours at the chromosomal, gene and expression levels, with additional insight gained from immune profiling. Based on mutational analyses, HNSCC are categorized as HPV-positive, HPV-negative CNA-silent, and HPV-negative CNA-high tumours. Furthermore, gene expression profiling segregates these tumours into atypical, classical, basal, and mesenchymal, with clear differences observed between tumours of the oral cavity, oropharynx, hypopharynx and larynx. Additional immune profiling further classifies tumours as either immune-active or immune-exhausted. The clinical utility and impact of these tumour molecular subtypes however remains to be determined. HNSCC harbor high levels of somatic mutations. They display loss at 3p and 18q and gain at 3q and 8q, with mutations in CDKN2A, TP53, CCND1, EGFR, PIK3CA, PTEN, NOTCH1, NSD1, FAT1, AJUBA and KMT2D. Important pathways include the p53 and RB pathways which are involved in cell cycle control and are frequently lost in HPV-negative tumours, the WNT-β-catenin pathway related to the mesenchymal subtype and smoking etiology, and the PI3K pathway which includes the most common genetic alteration in HPV-positive HNSCC. Understanding the mutational, genomic and transcriptomic landscape of HNSCC has leveraged better therapeutic approaches to manage this group of diseases, and it is hoped that additional insight into the molecular subtypes of HNSCC and its specific subsites will further drive improved strategies to stratify and treat patients with this debilitating disease.

Predictive factors in the treatment of oral squamous cell carcinoma using PD-1/PD-L1 inhibitors

Due to immune impairment and lymphocyte enrichment of oral squamous cell carcinoma (OSCC), anti-PD-1/PD-L1 therapy is regarded as a potential treatment option. However, tumor heterogeneity, differences in the immune conditions of patients, and the interrelation between tumor cells and stromal cells within the tumor microenvironment (TME) could affect the therapeutic efficacy of immune checkpoint blockades. Therefore, to maximize the benefit of blockade PD-1/PD-L1 axis, to find an efficient predictor (the possible clinical parameters or biological factors) before treatment are of great importance. In this review, we discuss the advantages of anti-PD-1/PD-L1 therapy for OSCC patients and find three respects that are currently available in predicting curative effect. Firstly, OSCC with high PD-L1 expression evaluating by immunohistochemistry (high tumor proportion score (TPS) and combined positive score (CPS)) are considered to be suitable for anti-PD-1/PD-L1 therapy. Secondly, gene-level predictive biomarkers including high metastatic mismatch repair deficiency (dMMR) signature or enrichment of interferon-γ and PD1 signaling pathway is expected to be favorable factors. Besides, PET/CT parameters (SUV_max, MTV, TLG) are proved to be correlated with PD-L1 expression, and some newly developed immunoPET probes are enlarging the application of PET/CT in predicting therapeutic efficacy of PD-1/PD-L1 inhibitors.