Tripartite Motif Containing 71 Suppresses Tumor Growth by Down-Regulating eIF5A2 Expression in Laryngeal Squamous Cell Carcinoma.

Abstract

The incidence of laryngeal squamous cell carcinoma (LSCC) has been rising recently. LSCC is one of the most prevalent malignant tumors of the head and neck. In this study, we aimed to investigate whether tripartite motif containing 71 (TRIM71) could serve as a molecular target for the treatment of LSCC. The mRNA and protein levels were examined by using real-time qPCR and Western blot, respectively. Cell proliferation was determined by cell-counting kit 8 assay. To further confirm the function of TRIM71 in LSCC, an in vivo cell line-derived xenograft study was conducted. The half-life of eukaryotic translation initiation factor 5A2 (eIF5A2) protein was measured by cycloheximide chase assay. Our results showed that TRIM71 was significantly downregulated in LSCC tumor tissues. TRIM71 overexpression significantly inhibited LSCC cell growth and suppressed tumor volume and weight in the xenograft models. The interaction between TRIM71 and eIF5A2 was verified by co-immunoprecipitation assay. Moreover, overexpression of TRIM71 in LSCC cells significantly inhibited the protein expression of eIF5A2 by down-regulating its stability, while it did not affect its mRNA level. In contrast, overexpression of eIF5A2 abolished the anti-tumor effects of TRIM71. In summary, TRIM71 may exert its anti-tumor effects through regulating eIF5A2, highlighting the potential of TRIM71 as an effective therapeutic target for the treatment of LSCC.