AIM: To study the expression and cancer-promoting mechanism of miR-130b in human retinoblastoma(RB).

METHODS: Detected the expression levels of miR-130b in human RB carcinoma tissues, adjacent tissues and human RB cell lines(HXO-Rb44 and Y79)by qRT-PCR; detected the expression levels of PTEN in HXO-Rb44 and Y79 cells by qRT-PCR, Western Blot and immunofluorescence; verified the target relationship between miR-130b and PTEN by dual-luciferase reporter gene test; the co-transfection test was used to investigate the relationship between PTEN and miR-130b on the expression of PI3K/Akt signaling pathway in RB cell line.

RESULTS: The expression level of miR-130b in cancer tissue of RB was significantly higher than that of paracancerous tissue(P<0.05). Compared with axben-181 cells, the expression level of miR-130b in HXO-Rb44 and Y79 cells was significantly increased(P<0.05). Compared with RB cancer tissue, the expression level of PTEN in its paracancerous tissue was significantly increased(P<0.05). The expression level of miR-130b was negatively correlated with the expression level of PTEN(P<0.001). The mRNA and protein expression levels of PTEN in HXO-Rb44 cells overexpressing miR-130b were significantly reduced, while the mRNA and protein expression levels of PTEN in Y79 cells after miR-130b interference were significantly increased(P<0.05). Compared with miR-130b mimics+PTEN-NC group, the luciferase activity of miR-130b mimics+wt-PTEN group was significantly reduced(P<0.05).In the HXO-Rb44 cells co-transfected with miR-130b mimics+PTEN-NC, the expression levels of p-Akt 308 and p-Akt 473 protein were significantly increased(P<0.05), while the expression levels of PTEN protein were significantly decreased(P<0.05). In the HXO-Rb44 cells co-transfected with miR-130b mimics+PTEN, no significant changes were observed in the above three proteins.

CONCLUSION: miR-130b is highly expressed in RB tissues and cell lines. PTEN is the target gene of miR-130b, and miR-130b may negatively regulate PTEN to affect the expression of PI3K/Akt signaling pathway and ultimately play a role in promoting cancer.