MicroRNA-155-5p Contributes to 5-Fluorouracil Resistance Through Down-Regulating TP53INP1 in Oral Squamous Cell Carcinoma

Bowen Liu; Jingchao Hu; Han Zhao; Li Zhao; Shiyuan Pan

doi:10.3389/fonc.2021.706095

MicroRNA-155-5p Contributes to 5-Fluorouracil Resistance Through Down-Regulating TP53INP1 in Oral Squamous Cell Carcinoma

Front Oncol. 2022 Jan 6:11:706095. doi: 10.3389/fonc.2021.706095. eCollection 2021.

Authors

Bowen Liu¹, Jingchao Hu², Han Zhao³, Li Zhao^{4

5

6}, Shiyuan Pan⁷

Affiliations

¹ Outpatient Department of Oral and Maxillofacial Surgery, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China.
² Department of Periodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China.
³ Multi-disciplinary Treatment Center, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China.
⁴ Department of Prosthodontics, Stomatological Hospital of Chongqing Medical University, Chongqing, China.
⁵ Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China.
⁶ Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China.
⁷ Department of Dentistry, Chongqing Huamei Plastic Surgery Hospital, Chongqing, China.

Abstract

The anticancer drug 5-fluorouracil (5-FU) resistance is a major obstacle to reducing the effectiveness of cancer treatment, and its detailed mechanism has not been fully elucidated. Here, in 5-FU-resistant human oral squamous cell carcinoma (OSCC) HSC3 cells (HSC3/5-FU), the levels of 21 miRNA candidates were detected using RT-PCR and miR-155-5p level increased strikingly in HSC3/5-FU cells compared to HSC3 cells. Compared with HSC3 cells, the CCK-8 assay showed that the HSC3/5-FU cells transfected with miR-155-5p inhibitors decreased 5-FU IC50. Ectopic expression of miR-155-5p in HSC3 and HSC4 cells increased 5-FU IC50 (CCK-8 assay), migration (wound-healing and transwell assays) and invasion (transwell assay) abilities. Seven miR-155-5p target candidates were discovered by miRNA prediction algorithms (miRDB, Targetscan, and miRWalk), and the RT-PCR results showed that in HSC3/5-FU cells TP53INP1 was of the lowest mRNA expression level compared with HSC3 cells. The RT-PCR and Western blotting assays showed that ectopic expression of miR-155-5p in HSC3 and HSC4 cells decreased TP53INP1 expression level. Furthermore, the luciferase reporter and RNA pull-down assays determined the interference effect of miR-155-5p on TP53INP1 expression. The enhancement of cell viability (CCK-8 assay), migration (wound-healing and transwell assays) and invasion (transwell assay) by miR-155-5p after 5-FU treatment was reversed by TP53INP1 overexpression. After treatment with 5-FU, HSC3-miR-155-5p tumor-bearing nude mice presented growing tumors, while HSC3-TP53INP1 group possessed shrinking tumors. In conclusion, these results lead to the proposal that miR-155-5p enhances 5-FU resistance by decreasing TP53INP1 expression in OSCC.

Keywords: 5-fluorouracil; TP53INP1; microRNA-155-5p; oral squamous cell carcinoma; resistance.