Identification of multidrug chemoresistant genes in head and neck squamous cell carcinoma cells

Multidrug resistance renders treatment failure in a large proportion of head and neck squamous cell carcinoma (HNSCC) patients that require multimodal therapy involving chemotherapy in conjunction with surgery and/or radiotherapy. Molecular events conferring chemoresistance remain unclear. Through transcriptome datamining, 28 genes were subjected to pharmacological and siRNA rescue functional assays on 12 strains of chemoresistant cell lines each against cisplatin, 5-fluorouracil (5FU), paclitaxel (PTX) and docetaxel (DTX). Ten multidrug chemoresistance genes (TOP2A, DNMT1, INHBA, CXCL8, NEK2, FOXO6, VIM, FOXM1B, NR3C1 and BIRC5) were identified. Of these, four genes (TOP2A, DNMT1, INHBA and NEK2) were upregulated in an HNSCC patient cohort (n = 221). Silencing NEK2 abrogated chemoresistance in all drug-resistant cell strains. INHBA and TOP2A were found to confer chemoresistance in majority of the drug-resistant cell strains whereas DNMT1 showed heterogeneous results. Pan-cancer Kaplan-Meier survival analysis on 21 human cancer types revealed significant prognostic values for INHBA and NEK2 in at least 16 cancer types. Drug library screens identified two compounds (Sirodesmin A and Carfilzomib) targeting both INHBA and NEK2 and re-sensitised cisplatin-resistant cells. We have provided the first evidence for NEK2 and INHBA in conferring chemoresistance in HNSCC cells and siRNA gene silencing of either gene abrogated multidrug chemoresistance. The two existing compounds could be repurposed to counteract cisplatin chemoresistance in HNSCC. This finding may lead to novel personalised biomarker-linked therapeutics that can prevent and/or abrogate chemoresistance in HNSCC and other tumour types with elevated NEK2 and INHBA expression. Further investigation is necessary to delineate their signalling mechanisms in tumour chemoresistance.

Critical Evaluation of Global Infection Prevention and Control Guidelines for Dentistry Published during the First 2 Years of the COVID-19 Pandemic

Objectives

The outbreak of the coronavirus disease (COVID-19) encouraged immediate actions by governments and healthcare associations across the world to flatten the curve and prevent health systems from being overburdened. As dentistry comprises aerosol-generating procedures (AGPs), which could increase the risk of infection, various guidelines were issued for dental services which focused on infection prevention and control (IPC) measures for COVID-19. This systematic review focuses on dental IPC guidelines, with the aim of comparing these guidelines against a gold standard.

Method

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 checklist was employed. Predefined inclusion and exclusion criteria were constructed. Information sources comprised Google Scholar, PubMed, and a manual search from December 2019 to December 2021. The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument was used. Consensus scoring was applied for all guidelines.

Results

A total 61 guidelines were included in the review. The UK national guideline was used as a gold standard as it ranked the highest AGREE score (75 out of 84) and thus was established for comparison with each of the included guidelines. Overall, 40% of the included guidelines had a high consensus score in relation to the UK national guideline.

Conclusion

This systematic review highlighted the variability in content and quality of advice given by different organizations in response to the COVID-19 pandemic in their efforts to reduce SARS-CoV-2 transmission in dentistry. Establishing a single worldwide fast-acting dental organization would ensure that high-quality standardized guidance is available, to enhance health equality and worldwide dental clinical standards.