LincRNA-p21 inhibits invasion and metastasis of hepatocellular carcinoma through miR-9/E-cadherin cascade signaling pathway molecular mechanism

Figures & data

Figure 1 LincRNA-p21 is downregulated in human HCC and inhibits HCC cell migration and invasion.

Notes: (A) LincRNA-p21 level was significantly reduced in tissues from HCC (tumor) than that from nontumor adjacent normal tissues (normal) (n=12 in each group). (B) The low level of lincRNA-p21 was observed in HCC cell lines (HepG2, SMMC7721, Hep3B, MHCC97H and SK-Hep1). (C) Real-time quantitative polymerase chain reaction analysis was used to detect the transduction efficiency of lentivirus expressing lincRNA-p21 vector in HepG2 and SK-Hep1 cells. (D) LincRNA-p21 overexpression significantly inhibited the migration of HepG2 and SK-Hep1 cells. (E) LincRNA-p21 overexpression markedly reduced invasion of HepG2 and SK-Hep1 cells. A statistically significant difference was indicated as P<0.05. *P<0.05 and **P<0.01 vs the corresponding controls. The magnification in D and E = ×100. Black dots and squares represent human samples.
Abbreviations: lincRNA, long intergenic noncoding RNA; HCC, hepatocellular carcinoma; qRT-PCR, quantitative real-time polymerase chain reaction.

Figure 2 The association between lincRNA-p21 expression and miR-9 level.

Notes: (A) LincRNA-p21 overexpression significantly inhibited the expression level of miR-9 in HepG2 and SK-Hep1 cells. (B) LincRNA-p21 knockdown (anti-lincRNA-p21) significantly enhanced the expression level of miR-9 in HepG2 and SK-Hep1 cells. (C) MiR-9 level was significantly induced in tissues from HCC (tumor) than that from nontumor adjacent normal tissues (normal). (D) The Spearman rank correlation analysis showed the negative relationship between lincRNA-p21 expression and miR-9 level. *P<0.05 and **P<0.01 vs the corresponding controls. Black dots and squares represent human samples.
Abbreviations: lincRNA, long intergenic noncoding RNA; HCC, hepatocellular carcinoma.

Figure 3 MiR-9 knockdown inhibits HCC cell migration and invasion.

Notes: (A) The expression level of miR-9 in HepG2, SMMC7721, Hep3B, MHCC97H and SK-Hep1 cells. (B) qRT-PCR analysis was used to detect the transfection efficiency of miR-9 inhibitor in HepG2 and SK-Hep1 cells. (C) MiR-9 knockdown inhibited the migration of HepG2 and SK-Hep1 cells. (D) MiR-9 knockdown also reduced the invasion of HepG2 and SK-Hep1 cells. A statistically significant difference was indicated as P<0.05. *P<0.05 and **P<0.01 vs the corresponding controls. The magnification in C and D = ×100.
Abbreviations: HCC, hepatocellular carcinoma; qRT-PCR, quantitative real-time polymerase chain reaction.

Figure 4 E-cadherin is a target of miR-9.

Notes: (A) MiR-9 target sequence was at nt1327–1333 of the CDH1-3′-UTR. (B) Fluorescence activity was significantly decreased after cells were co-transfected with the miR-9 mimic and 3′-UTR of CDH1 mRNA luciferase reporter vector as compared to cells transfected with 3′-UTR of CDH1 luciferase reporter vector and miR-NC. (C) Fluorescence activity was significantly increased after cells were co-transfected with the miR-9 inhibitor and 3′-UTR of CDH1 mRNA luciferase reporter vector as compared to cells transfected with 3′-UTR of CDH1 luciferase reporter vector and miR-NC. (D) MiR-9 knockdown increased CDH1 expression in HepG2 and SK-Hep1 cells. (E) LincRNA-p21 overexpression also increased CDH1 expression in HepG2 and SK-Hep1 cells. A statistically significant difference was indicated as P<0.05. *P<0.05 vs the corresponding controls.
Abbreviations: lincRNA, long intergenic noncoding RNA; mRNA, messenger RNA; WT, wild type.