Long non-coding RNA SLC7A11 antisense RNA1 promotes oral squamous cell carcinoma progression by regulating ubiquitination of K-homology type splicing regulatory protein.

OBJECTIVES

This article aims to elucidate the role of Long non-coding RNA SLC7A11 antisense RNA1 (SLC7A11-AS1) in oral squamous cell carcinoma, which are expected to be useful for the oral squamous cell carcinoma diagnosis and treatment.

DESIGN

SLC7A11-AS1 expression was detected by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) in oral squamous cell carcinoma cell lines. Cellular localization of SLC7A11-AS1C was detected by fluorescence in situ hybridization (FISH) assays and subcellular fractionation assay. Biological functions of SLC7A11-AS1 were explored by 3-(4,5-dimethyl-2-thiazolyl)- 2,5-diphenyl-2-H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), wounding healing, and transwell invasion assays in vitro, as well as mice xenograft experiments and metastasis assays in vivo. RNA pull-down, RNA immunoprecipitation, co-immunoprecipitation, ubiquitination assays, and rescue experiments were performed to determine the molecular mechanism of SLC7A11-AS1 in oral squamous cell carcinoma.

RESULTS

SLC7A11-AS1 is overexpressed in oral cancer tissues and cell lines. Functionally, knockdown of SLC7A11-AS1 reduced the proliferation, migration, and invasion of oral squamous cell carcinoma cells in vitro and inhibited tumor growth as well as metastasis in vivo. Mechanistically, SLC7A11-AS1 impeded the interaction between K-homology type splicing regulatory protein (KHSRP) and kelch-like 12 (KLHL12), maintaining the stability of KHSRP by restraining KHSRP degradation through the ubiquitination-proteasome pathway. Furthermore, KHSRP overexpression recovered the malignant behaviors inhibited by SLC7A11-AS1 knockdown in oral cancer cells.

CONCLUSION

SLC7A11-AS1 promoted oral squamous cell carcinoma development by interacting with KHSRP and maintaining KHSRP stability by preventing its degradation via the ubiquitination-proteasome pathway. Thus, SLC7A11-AS1 is a potential therapeutic target for oral cancer.