AIM: To investigate the expression of high mobility group A1(HMGA1)protein in uveal melanoma(UM)tissues, and the effect of inhibiting the expression of HMGA1 on cell proliferation and invasion.

METHODS: A total of 53 cases(53 eyes)of UM patients who underwent surgical treatment in our hospital from February 2014 to August 2019 were selected. In the same period, 34 cases(34 eyes)of normal uveal tissues removed from the eye due to trauma were selected. The expression of HMGA1 protein in tissues was detected by immunohistochemistry. The human UM cell line M23 was cultured and divided into HMGA1 downregulation group, negative control group and blank group, respectively, transfected with HMGA1 interference sequence, negative control sequence and without any treatment. The expression of HMGA1 was detected by real-time quantitative PCR. The cell proliferation ability was detected by CCK-8 method, and the cell migration and invasion abilities were detected by Transwell method.

RESULTS: The positive expression rate of HMGA1 protein in UM tissue was 77%, which was higher than that in the normal uveal tissue, which was 29%(P<0.001). Compared with the no scleral occurring infiltration, no ciliary body involving, and no extraocular growth, the positive expression rates of HMGA1 proteins in the scleral infiltration, ciliary body involving, and extraocular growth occurring tissues were increased(all P<0.05). The relative expression level of HMGA1 mRNA in cells in the HMGA1 downregulation group was lower than that in the negative control group and the blank group. Compared with the negative control group and the blank group, the absorbance OD values of cells in the HMGA1 downregulation group at 24, 48, 72 and 96h were decreased(P<0.05). The number of migrating cells and the number of invading cells in the HMGA1 downregulation group was significantly less than those in the negative control group and the blank group(P<0.05).

CONCLUSION: The positive expression rate of HMGA1 protein in UM tissue is increased. Down regulation the expression of HMGA1 in M23 cells can reduce cell proliferation and inhibit cell migration and invasion.