N6-methyladenosine-modified long non-coding RNA KIF9-AS1 promotes stemness and sorafenib resistance in hepatocellular carcinoma by upregulating SHOX2 expression

Figure 4 The long noncoding RNA KIF9-AS1 increases the stability and expression of short stature homeobox 2 through ubiquitin-specific peptidase 1-mediated short stature homeobox 2 deubiquitination. A: The expression of ubiquitin-specific peptidase 1 (USP1) and short stature homeobox 2 (SHOX2) in hepatocellular carcinoma tissues and para-cancerous tissues was evaluated via quantitative reverse transcription polymerase chain reaction (n = 20); B: Image of immunohistochemical staining of SHOX2 in tumor tissues and para-cancerous tissues; C: Correlation analysis between KIF9-AS1 and USP1 and between USP1 and SHOX2; D: The protein levels of USP1 and SHOX2 in Huh-7 and Huh-7/R cells were assessed via western blotting; E: The interaction between KIF9-AS1 and USP1 was verified via an RNA immunoprecipitation assay; F: The interaction between USP1 and SHOX2 was confirmed via a coimmunoprecipitation assay; G: The ubiquitination levels of SHOX2 in Huh-7 and Huh-7/R cells were determined via immunoprecipitation and western blotting; H: After cycloheximide treatment for 0, 3, 6, or 12 hours, the protein level of SHOX2 was evaluated via western blotting. ^aP < 0.05, ^bP < 0.01, ^cP < 0.001. Each experiment was repeated three times. USP1: Ubiquitin-specific peptidase 1; SHOX2: Short stature homeobox 2; HCC: Hepatocellular carcinoma; IgG: Immunoglobulin G.