NF-κB subunit RELA suppression of mucosa-associated lymphoid tissue lymphoma translocation protein 1 expression in oral carcinoma cells

• Published in: Biochemical and biophysical research communications 2021-02, Vol.542, p.24-28
• Main Authors: Nozawa, Takaomi, Mihara-Tomiyama, Nozomi, Chiba, Tadashige, Imai, Kazushi
• Format: Article
• Language: English
• Subjects: Mucosa-associated lymphoid tissue lymphoma translocation protein 1; NF-κB; Oral carcinoma; Repressor proteins
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2021.01.025

Loss of mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) expression closely associates with increased aggressive behaviors of oral carcinoma cells. It emphasizes that a mechanism to suppress the expression is an important subject for understanding carcinoma progression pathway. However, nothing is known at present. This study conducted on transcriptional regulation of the gene down-regulation. Reporter assays showed the presence of the silencer region between +402 and +501 region of MALT1 gene in oral carcinoma cells. It encoded a binding site of nuclear factor-κB subunit, RELA. RELA binding to the site was confirmed by the chromatin immunoprecipitation analyses, and deletion and mutations of the site significantly decreased the RELA binding. Short interfering RNAs for RELA up-regulated reporter gene and endogenous MALT1 protein expressions, and deletion and mutations of RELA binding site increased reporter gene expression. These results demonstrated RELA-binding to the site suppresses MALT1 expression that may facilitate oral carcinoma progression. •Suppressive mechanism of MALT1 expression in oral carcinoma cells is unknown.•A 100 bp region of MALT1 gene encoding κB site suppressed the expression.•Inhibition of NF-κB subunit RELA by siRNAs increased MALT1 expression.•RELA-binding to silencer down-regulates MALT1 in oral carcinoma cells.