AUTHOR=Ostrowska Kamila , Rawłuszko-Wieczorek Agnieszka A. , Ostapowicz Julia , Suchorska Wiktoria M. , Golusiński Wojciech 

TITLE=The two-faced role of RNA methyltransferase METTL3 on cellular response to cisplatin in head and neck squamous cell carcinoma in vitro model

JOURNAL=Frontiers in Oncology

VOLUME=14

YEAR=2024

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2024.1402126

DOI=10.3389/fonc.2024.1402126

ISSN=2234-943X

ABSTRACT=<sec><title>Background</title><p>RNA methyltransferase-like 3 (METTL3) is responsible for methyl group transfer in the progression of <italic>N</italic><sup>6</sup>-methyladenosine (m<sup>6</sup>A) modification. This epigenetic feature contributes to the structural and functional regulation of RNA and consequently may promote tumorigenesis, tumor progression, and cellular response to anticancer treatment (chemo-, radio-, and immunotherapy). In head and neck squamous cell carcinoma (HNSCC), the commonly used chemotherapy is cisplatin. Unfortunately, cisplatin resistance is still a major cause of tumor relapse and patients’ death. Thus, this study aimed to investigate the role of METTL3 on cellular response to cisplatin in HNSCC <italic>in vitro</italic> models.</p></sec><sec><title>Materials and methods</title><p>HNSCC cell lines (H103, FaDu, and Detroit-562) with stable METTL3 knockdown (sgMETTL3) established with CRISPR-Cas9 system were treated with 0.5 tolerable plasma level (TPL) and 1 TPL of cisplatin. Further, cell cycle distribution, apoptosis, CD44/CD133 surface marker expression, and cell’s ability to colony formation were analyzed in comparison to controls (cells transduced with control sgRNA).</p></sec><sec><title>Results</title><p>The analyses of cell cycle distribution and apoptosis indicated a significantly higher percentage of cells with METTL3 knockdown 1) arrested in the G2/S phase and 2) characterized as a late apoptotic or death in comparison to control. The colony formation assay showed intensified inhibition of a single cell’s ability to grow into a colony in FaDu and Detroit-562 METTL3-deficient cells, while a higher colony number was observed in H103 METTL3 knockdown cells after cisplatin treatment. Also, METTL3 deficiency significantly increased cancer stem cell markers’ surface expression in all studied cell lines.</p></sec><sec><title>Conclusion</title><p>Our findings highlight the significant influence of METTL3 on the cellular response to cisplatin, suggesting its potential as a promising therapeutic target for addressing cisplatin resistance in certain cases of HNSCC.</p></sec>