TGF-β1 induces amoeboid-to-mesenchymal transition of CD44high oral squamous cell carcinoma cells via miR-422a downregulation through ERK activation and Cofilin-1 phosphorylation

Sho Yokoyama; Hideo Shigeishi; Hiroshi Murodumi; Miyuki Sakuma; Hiroki Kato; Koichiro Higashikawa; Kouji Ohta; Masaru Sugiyama; Masaaki Takechi

doi:10.1111/jop.13113

TGF-β1 induces amoeboid-to-mesenchymal transition of CD44^high oral squamous cell carcinoma cells via miR-422a downregulation through ERK activation and Cofilin-1 phosphorylation

J Oral Pathol Med. 2021 Feb;50(2):155-164. doi: 10.1111/jop.13113. Epub 2020 Oct 29.

Authors

Sho Yokoyama¹, Hideo Shigeishi², Hiroshi Murodumi¹, Miyuki Sakuma¹, Hiroki Kato¹, Koichiro Higashikawa¹, Kouji Ohta², Masaru Sugiyama², Masaaki Takechi¹

Affiliations

¹ Department of Oral and Maxillofacial Surgery, Program of Dentistry, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
² Department of Public Oral Health, Program of Oral Health Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.

PMID: 33107637
DOI: 10.1111/jop.13113

Abstract

Background: The objective of this study was to clarify the molecular mechanism of amoeboid-to-mesenchymal transition (AMT) of CD44^high oral squamous cell carcinoma (OSCC) cells.

Methods: Morphology and expression of mesenchymal genes were investigated in CD44^high OSCC cells (CD44^high OM-1 cells) cultured on laminin-coated soft silicone gel. Additionally, microarray analysis was performed to investigate microRNA (miRNA) expression inhibited by transforming growth factor-β1 (TGF-β1) in CD44^high OM-1 cells.

Results: When CD44^high OM-1 cells were cultured on 2.0-kPa laminin-coated silicone gel, the cells exhibited an amoeboid-like round morphology. Cofilin-1 expression was found in the nucleus and cytoplasm of amoeboid-like CD44^high OM-1 cells. The invasive capacity was significantly reduced after Cofilin-1 knockdown. Additionally, Cofilin-1 knockdown cells had an irregularly extended shape. Phosphorylated Cofilin-1 was significantly upregulated by TGF-β1. Additionally, TGF-β1 enhanced N-cadherin and Snail mRNA expression and induced a spindle-shaped morphology. ERK1/2 phosphorylation was induced by TGF-β1. Microarray analysis revealed that miR-422a exhibited the greatest downregulation (fold change: 0.22) in the presence of TGF-β1. Importantly, TGF-β1-inhibited miR-422a expression was recovered by the ERK inhibitor or ERK1/2 knockdown. Additionally, miR-422a inhibitor-transfected CD44^high OM-1 cells exhibited high N-cadherin and Snail mRNA expression. Furthermore, Cofilin-1 knockdown and miR-422a inhibition induced a spindle cell morphology.

Conclusion: Cofilin-1 is involved in the invasive ability of CD44^high OSCC cells. TGF-β1 contributes to AMT by downregulation of miR-422a via ERK activation and Cofilin-1 phosphorylation. Our findings suggest that miR-422a and Cofilin-1 play major roles in the maintenance of amoeboid-like CD44^high cells.

Keywords: CD44; TGF-β1; amoeboid-to-mesenchymal transition; miR-422a; oral squamous cell carcinoma.

MeSH terms

Carcinoma, Squamous Cell* / genetics
Cell Line, Tumor
Cofilin 1 / genetics
Down-Regulation
Epithelial-Mesenchymal Transition
Head and Neck Neoplasms*
Humans
Hyaluronan Receptors / genetics
MicroRNAs* / genetics
MicroRNAs* / metabolism
Mouth Neoplasms* / genetics
Phosphorylation
Squamous Cell Carcinoma of Head and Neck
Transforming Growth Factor beta1 / metabolism

Substances

CD44 protein, human
Cofilin 1
Hyaluronan Receptors
MicroRNAs
Transforming Growth Factor beta1

Grants and funding

20K10138/Japanese Ministry of Education, Culture, Sports, Science and Technology